utils.c

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/*
 * various utility functions for use within FFmpeg
 * Copyright (c) 2000, 2001, 2002 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#undef NDEBUG
#include <assert.h>
#include <stdarg.h>
#include <stdint.h>

#include "config.h"

#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/dict.h"
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/parseutils.h"
#include "libavutil/pixdesc.h"
#include "libavutil/time.h"
#include "libavutil/timestamp.h"

#include "libavcodec/bytestream.h"
#include "libavcodec/internal.h"
#include "libavcodec/raw.h"

#include "audiointerleave.h"
#include "avformat.h"
#include "avio_internal.h"
#include "id3v2.h"
#include "internal.h"
#include "metadata.h"
#if CONFIG_NETWORK
#include "network.h"
#endif
#include "riff.h"
#include "url.h"

/**
 * @file
 * various utility functions for use within FFmpeg
 */

unsigned avformat_version(void)
{
    av_assert0(LIBAVFORMAT_VERSION_MICRO >= 100);
    return LIBAVFORMAT_VERSION_INT;
}

const char *avformat_configuration(void)
{
    return FFMPEG_CONFIGURATION;
}

const char *avformat_license(void)
{
#define LICENSE_PREFIX "libavformat license: "
    return LICENSE_PREFIX FFMPEG_LICENSE + sizeof(LICENSE_PREFIX) - 1;
}

#define RELATIVE_TS_BASE (INT64_MAX - (1LL<<48))

static int is_relative(int64_t ts) {
    return ts > (RELATIVE_TS_BASE - (1LL<<48));
}

/**
 * Wrap a given time stamp, if there is an indication for an overflow
 *
 * @param st stream
 * @param timestamp the time stamp to wrap
 * @return resulting time stamp
 */
static int64_t wrap_timestamp(AVStream *st, int64_t timestamp)
{
    if (st->pts_wrap_behavior != AV_PTS_WRAP_IGNORE &&
        st->pts_wrap_reference != AV_NOPTS_VALUE && timestamp != AV_NOPTS_VALUE) {
        if (st->pts_wrap_behavior == AV_PTS_WRAP_ADD_OFFSET &&
            timestamp < st->pts_wrap_reference)
            return timestamp + (1ULL << st->pts_wrap_bits);
        else if (st->pts_wrap_behavior == AV_PTS_WRAP_SUB_OFFSET &&
            timestamp >= st->pts_wrap_reference)
            return timestamp - (1ULL << st->pts_wrap_bits);
    }
    return timestamp;
}

MAKE_ACCESSORS(AVStream, stream, AVRational, r_frame_rate)
MAKE_ACCESSORS(AVStream, stream, char *, recommended_encoder_configuration)
MAKE_ACCESSORS(AVFormatContext, format, AVCodec *, video_codec)
MAKE_ACCESSORS(AVFormatContext, format, AVCodec *, audio_codec)
MAKE_ACCESSORS(AVFormatContext, format, AVCodec *, subtitle_codec)
MAKE_ACCESSORS(AVFormatContext, format, int, metadata_header_padding)
MAKE_ACCESSORS(AVFormatContext, format, void *, opaque)
MAKE_ACCESSORS(AVFormatContext, format, av_format_control_message, control_message_cb)

int64_t av_stream_get_end_pts(const AVStream *st)
{
    return st->pts.val;
}

struct AVCodecParserContext *av_stream_get_parser(const AVStream *st)
{
    return st->parser;
}

void av_format_inject_global_side_data(AVFormatContext *s)
{
    int i;
    s->internal->inject_global_side_data = 1;
    for (i = 0; i < s->nb_streams; i++) {
        AVStream *st = s->streams[i];
        st->inject_global_side_data = 1;
    }
}

int ff_copy_whitelists(AVFormatContext *dst, AVFormatContext *src)
{
    av_assert0(!dst->codec_whitelist && !dst->format_whitelist);
    dst-> codec_whitelist = av_strdup(src->codec_whitelist);
    dst->format_whitelist = av_strdup(src->format_whitelist);
    if (   (src-> codec_whitelist && !dst-> codec_whitelist)
        || (src->format_whitelist && !dst->format_whitelist)) {
        av_log(dst, AV_LOG_ERROR, "Failed to duplicate whitelist\n");
        return AVERROR(ENOMEM);
    }
    return 0;
}

static const AVCodec *find_decoder(AVFormatContext *s, AVStream *st, enum AVCodecID codec_id)
{
    if (st->codec->codec)
        return st->codec->codec;

    switch (st->codec->codec_type) {
    case AVMEDIA_TYPE_VIDEO:
        if (s->video_codec)    return s->video_codec;
        break;
    case AVMEDIA_TYPE_AUDIO:
        if (s->audio_codec)    return s->audio_codec;
        break;
    case AVMEDIA_TYPE_SUBTITLE:
        if (s->subtitle_codec) return s->subtitle_codec;
        break;
    }

    return avcodec_find_decoder(codec_id);
}

int av_format_get_probe_score(const AVFormatContext *s)
{
    return s->probe_score;
}

/* an arbitrarily chosen "sane" max packet size -- 50M */
#define SANE_CHUNK_SIZE (50000000)

int ffio_limit(AVIOContext *s, int size)
{
    if (s->maxsize>= 0) {
        int64_t remaining= s->maxsize - avio_tell(s);
        if (remaining < size) {
            int64_t newsize = avio_size(s);
            if (!s->maxsize || s->maxsize<newsize)
                s->maxsize = newsize - !newsize;
            remaining= s->maxsize - avio_tell(s);
            remaining= FFMAX(remaining, 0);
        }

        if (s->maxsize>= 0 && remaining+1 < size) {
            av_log(NULL, remaining ? AV_LOG_ERROR : AV_LOG_DEBUG, "Truncating packet of size %d to %"PRId64"\n", size, remaining+1);
            size = remaining+1;
        }
    }
    return size;
}

/* Read the data in sane-sized chunks and append to pkt.
 * Return the number of bytes read or an error. */
static int append_packet_chunked(AVIOContext *s, AVPacket *pkt, int size)
{
    int64_t orig_pos   = pkt->pos; // av_grow_packet might reset pos
    int orig_size      = pkt->size;
    int ret;

    do {
        int prev_size = pkt->size;
        int read_size;

        /* When the caller requests a lot of data, limit it to the amount
         * left in file or SANE_CHUNK_SIZE when it is not known. */
        read_size = size;
        if (read_size > SANE_CHUNK_SIZE/10) {
            read_size = ffio_limit(s, read_size);
            // If filesize/maxsize is unknown, limit to SANE_CHUNK_SIZE
            if (s->maxsize < 0)
                read_size = FFMIN(read_size, SANE_CHUNK_SIZE);
        }

        ret = av_grow_packet(pkt, read_size);
        if (ret < 0)
            break;

        ret = avio_read(s, pkt->data + prev_size, read_size);
        if (ret != read_size) {
            av_shrink_packet(pkt, prev_size + FFMAX(ret, 0));
            break;
        }

        size -= read_size;
    } while (size > 0);
    if (size > 0)
        pkt->flags |= AV_PKT_FLAG_CORRUPT;

    pkt->pos = orig_pos;
    if (!pkt->size)
        av_free_packet(pkt);
    return pkt->size > orig_size ? pkt->size - orig_size : ret;
}

int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
{
    av_init_packet(pkt);
    pkt->data = NULL;
    pkt->size = 0;
    pkt->pos  = avio_tell(s);

    return append_packet_chunked(s, pkt, size);
}

int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
{
    if (!pkt->size)
        return av_get_packet(s, pkt, size);
    return append_packet_chunked(s, pkt, size);
}

int av_filename_number_test(const char *filename)
{
    char buf[1024];
    return filename &&
           (av_get_frame_filename(buf, sizeof(buf), filename, 1) >= 0);
}

static int set_codec_from_probe_data(AVFormatContext *s, AVStream *st,
                                     AVProbeData *pd)
{
    static const struct {
        const char *name;
        enum AVCodecID id;
        enum AVMediaType type;
    } fmt_id_type[] = {
        { "aac",       AV_CODEC_ID_AAC,        AVMEDIA_TYPE_AUDIO },
        { "ac3",       AV_CODEC_ID_AC3,        AVMEDIA_TYPE_AUDIO },
        { "dts",       AV_CODEC_ID_DTS,        AVMEDIA_TYPE_AUDIO },
        { "eac3",      AV_CODEC_ID_EAC3,       AVMEDIA_TYPE_AUDIO },
        { "h264",      AV_CODEC_ID_H264,       AVMEDIA_TYPE_VIDEO },
        { "hevc",      AV_CODEC_ID_HEVC,       AVMEDIA_TYPE_VIDEO },
        { "loas",      AV_CODEC_ID_AAC_LATM,   AVMEDIA_TYPE_AUDIO },
        { "m4v",       AV_CODEC_ID_MPEG4,      AVMEDIA_TYPE_VIDEO },
        { "mp3",       AV_CODEC_ID_MP3,        AVMEDIA_TYPE_AUDIO },
        { "mpegvideo", AV_CODEC_ID_MPEG2VIDEO, AVMEDIA_TYPE_VIDEO },
        { 0 }
    };
    int score;
    AVInputFormat *fmt = av_probe_input_format3(pd, 1, &score);

    if (fmt && st->request_probe <= score) {
        int i;
        av_log(s, AV_LOG_DEBUG,
               "Probe with size=%d, packets=%d detected %s with score=%d\n",
               pd->buf_size, MAX_PROBE_PACKETS - st->probe_packets,
               fmt->name, score);
        for (i = 0; fmt_id_type[i].name; i++) {
            if (!strcmp(fmt->name, fmt_id_type[i].name)) {
                st->codec->codec_id   = fmt_id_type[i].id;
                st->codec->codec_type = fmt_id_type[i].type;
                return score;
            }
        }
    }
    return 0;
}

/************************************************************/
/* input media file */

int av_demuxer_open(AVFormatContext *ic) {
    int err;

    if (ic->format_whitelist && av_match_list(ic->iformat->name, ic->format_whitelist, ',') <= 0) {
        av_log(ic, AV_LOG_ERROR, "Format not on whitelist\n");
        return AVERROR(EINVAL);
    }

    if (ic->iformat->read_header) {
        err = ic->iformat->read_header(ic);
        if (err < 0)
            return err;
    }

    if (ic->pb && !ic->data_offset)
        ic->data_offset = avio_tell(ic->pb);

    return 0;
}

/* Open input file and probe the format if necessary. */
static int init_input(AVFormatContext *s, const char *filename,
                      AVDictionary **options)
{
    int ret;
    AVProbeData pd = { filename, NULL, 0 };
    int score = AVPROBE_SCORE_RETRY;

    if (s->pb) {
        s->flags |= AVFMT_FLAG_CUSTOM_IO;
        if (!s->iformat)
            return av_probe_input_buffer2(s->pb, &s->iformat, filename,
                                         s, 0, s->format_probesize);
        else if (s->iformat->flags & AVFMT_NOFILE)
            av_log(s, AV_LOG_WARNING, "Custom AVIOContext makes no sense and "
                                      "will be ignored with AVFMT_NOFILE format.\n");
        return 0;
    }

    if ((s->iformat && s->iformat->flags & AVFMT_NOFILE) ||
        (!s->iformat && (s->iformat = av_probe_input_format2(&pd, 0, &score))))
        return score;

    if ((ret = avio_open2(&s->pb, filename, AVIO_FLAG_READ | s->avio_flags,
                          &s->interrupt_callback, options)) < 0)
        return ret;
    if (s->iformat)
        return 0;
    return av_probe_input_buffer2(s->pb, &s->iformat, filename,
                                 s, 0, s->format_probesize);
}

static AVPacket *add_to_pktbuf(AVPacketList **packet_buffer, AVPacket *pkt,
                               AVPacketList **plast_pktl)
{
    AVPacketList *pktl = av_mallocz(sizeof(AVPacketList));
    if (!pktl)
        return NULL;

    if (*packet_buffer)
        (*plast_pktl)->next = pktl;
    else
        *packet_buffer = pktl;

    /* Add the packet in the buffered packet list. */
    *plast_pktl = pktl;
    pktl->pkt   = *pkt;
    return &pktl->pkt;
}

int avformat_queue_attached_pictures(AVFormatContext *s)
{
    int i;
    for (i = 0; i < s->nb_streams; i++)
        if (s->streams[i]->disposition & AV_DISPOSITION_ATTACHED_PIC &&
            s->streams[i]->discard < AVDISCARD_ALL) {
            AVPacket copy = s->streams[i]->attached_pic;
            if (copy.size <= 0) {
                av_log(s, AV_LOG_WARNING,
                    "Attached picture on stream %d has invalid size, "
                    "ignoring\n", i);
                continue;
            }
            copy.buf = av_buffer_ref(copy.buf);
            if (!copy.buf)
                return AVERROR(ENOMEM);

            add_to_pktbuf(&s->raw_packet_buffer, &copy,
                          &s->raw_packet_buffer_end);
        }
    return 0;
}

int avformat_open_input(AVFormatContext **ps, const char *filename,
                        AVInputFormat *fmt, AVDictionary **options)
{
    AVFormatContext *s = *ps;
    int ret = 0;
    AVDictionary *tmp = NULL;
    ID3v2ExtraMeta *id3v2_extra_meta = NULL;

    if (!s && !(s = avformat_alloc_context()))
        return AVERROR(ENOMEM);
    if (!s->av_class) {
        av_log(NULL, AV_LOG_ERROR, "Input context has not been properly allocated by avformat_alloc_context() and is not NULL either\n");
        return AVERROR(EINVAL);
    }
    if (fmt)
        s->iformat = fmt;

    if (options)
        av_dict_copy(&tmp, *options, 0);

    if ((ret = av_opt_set_dict(s, &tmp)) < 0)
        goto fail;

    if ((ret = init_input(s, filename, &tmp)) < 0)
        goto fail;
    s->probe_score = ret;

    if (s->format_whitelist && av_match_list(s->iformat->name, s->format_whitelist, ',') <= 0) {
        av_log(s, AV_LOG_ERROR, "Format not on whitelist\n");
        ret = AVERROR(EINVAL);
        goto fail;
    }

    avio_skip(s->pb, s->skip_initial_bytes);

    /* Check filename in case an image number is expected. */
    if (s->iformat->flags & AVFMT_NEEDNUMBER) {
        if (!av_filename_number_test(filename)) {
            ret = AVERROR(EINVAL);
            goto fail;
        }
    }

    s->duration = s->start_time = AV_NOPTS_VALUE;
    av_strlcpy(s->filename, filename ? filename : "", sizeof(s->filename));

    /* Allocate private data. */
    if (s->iformat->priv_data_size > 0) {
        if (!(s->priv_data = av_mallocz(s->iformat->priv_data_size))) {
            ret = AVERROR(ENOMEM);
            goto fail;
        }
        if (s->iformat->priv_class) {
            *(const AVClass **) s->priv_data = s->iformat->priv_class;
            av_opt_set_defaults(s->priv_data);
            if ((ret = av_opt_set_dict(s->priv_data, &tmp)) < 0)
                goto fail;
        }
    }

    /* e.g. AVFMT_NOFILE formats will not have a AVIOContext */
    if (s->pb)
        ff_id3v2_read(s, ID3v2_DEFAULT_MAGIC, &id3v2_extra_meta, 0);

    if (!(s->flags&AVFMT_FLAG_PRIV_OPT) && s->iformat->read_header)
        if ((ret = s->iformat->read_header(s)) < 0)
            goto fail;

    if (id3v2_extra_meta) {
        if (!strcmp(s->iformat->name, "mp3") || !strcmp(s->iformat->name, "aac") ||
            !strcmp(s->iformat->name, "tta")) {
            if ((ret = ff_id3v2_parse_apic(s, &id3v2_extra_meta)) < 0)
                goto fail;
        } else
            av_log(s, AV_LOG_DEBUG, "demuxer does not support additional id3 data, skipping\n");
    }
    ff_id3v2_free_extra_meta(&id3v2_extra_meta);

    if ((ret = avformat_queue_attached_pictures(s)) < 0)
        goto fail;

    if (!(s->flags&AVFMT_FLAG_PRIV_OPT) && s->pb && !s->data_offset)
        s->data_offset = avio_tell(s->pb);

    s->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;

    if (options) {
        av_dict_free(options);
        *options = tmp;
    }
    *ps = s;
    return 0;

fail:
    ff_id3v2_free_extra_meta(&id3v2_extra_meta);
    av_dict_free(&tmp);
    if (s->pb && !(s->flags & AVFMT_FLAG_CUSTOM_IO))
        avio_close(s->pb);
    avformat_free_context(s);
    *ps = NULL;
    return ret;
}

/*******************************************************/

static void force_codec_ids(AVFormatContext *s, AVStream *st)
{
    switch (st->codec->codec_type) {
    case AVMEDIA_TYPE_VIDEO:
        if (s->video_codec_id)
            st->codec->codec_id = s->video_codec_id;
        break;
    case AVMEDIA_TYPE_AUDIO:
        if (s->audio_codec_id)
            st->codec->codec_id = s->audio_codec_id;
        break;
    case AVMEDIA_TYPE_SUBTITLE:
        if (s->subtitle_codec_id)
            st->codec->codec_id = s->subtitle_codec_id;
        break;
    }
}

static int probe_codec(AVFormatContext *s, AVStream *st, const AVPacket *pkt)
{
    if (st->request_probe>0) {
        AVProbeData *pd = &st->probe_data;
        int end;
        av_log(s, AV_LOG_DEBUG, "probing stream %d pp:%d\n", st->index, st->probe_packets);
        --st->probe_packets;

        if (pkt) {
            uint8_t *new_buf = av_realloc(pd->buf, pd->buf_size+pkt->size+AVPROBE_PADDING_SIZE);
            if (!new_buf) {
                av_log(s, AV_LOG_WARNING,
                       "Failed to reallocate probe buffer for stream %d\n",
                       st->index);
                goto no_packet;
            }
            pd->buf = new_buf;
            memcpy(pd->buf + pd->buf_size, pkt->data, pkt->size);
            pd->buf_size += pkt->size;
            memset(pd->buf + pd->buf_size, 0, AVPROBE_PADDING_SIZE);
        } else {
no_packet:
            st->probe_packets = 0;
            if (!pd->buf_size) {
                av_log(s, AV_LOG_WARNING,
                       "nothing to probe for stream %d\n", st->index);
            }
        }

        end=    s->raw_packet_buffer_remaining_size <= 0
                || st->probe_packets<= 0;

        if (end || av_log2(pd->buf_size) != av_log2(pd->buf_size - pkt->size)) {
            int score = set_codec_from_probe_data(s, st, pd);
            if (    (st->codec->codec_id != AV_CODEC_ID_NONE && score > AVPROBE_SCORE_STREAM_RETRY)
                || end) {
                pd->buf_size = 0;
                av_freep(&pd->buf);
                st->request_probe = -1;
                if (st->codec->codec_id != AV_CODEC_ID_NONE) {
                    av_log(s, AV_LOG_DEBUG, "probed stream %d\n", st->index);
                } else
                    av_log(s, AV_LOG_WARNING, "probed stream %d failed\n", st->index);
            }
            force_codec_ids(s, st);
        }
    }
    return 0;
}

static int update_wrap_reference(AVFormatContext *s, AVStream *st, int stream_index, AVPacket *pkt)
{
    int64_t ref = pkt->dts;
    int i, pts_wrap_behavior;
    int64_t pts_wrap_reference;
    AVProgram *first_program;

    if (ref == AV_NOPTS_VALUE)
        ref = pkt->pts;
    if (st->pts_wrap_reference != AV_NOPTS_VALUE || st->pts_wrap_bits >= 63 || ref == AV_NOPTS_VALUE || !s->correct_ts_overflow)
        return 0;
    ref &= (1LL << st->pts_wrap_bits)-1;

    // reference time stamp should be 60 s before first time stamp
    pts_wrap_reference = ref - av_rescale(60, st->time_base.den, st->time_base.num);
    // if first time stamp is not more than 1/8 and 60s before the wrap point, subtract rather than add wrap offset
    pts_wrap_behavior = (ref < (1LL << st->pts_wrap_bits) - (1LL << st->pts_wrap_bits-3)) ||
        (ref < (1LL << st->pts_wrap_bits) - av_rescale(60, st->time_base.den, st->time_base.num)) ?
        AV_PTS_WRAP_ADD_OFFSET : AV_PTS_WRAP_SUB_OFFSET;

    first_program = av_find_program_from_stream(s, NULL, stream_index);

    if (!first_program) {
        int default_stream_index = av_find_default_stream_index(s);
        if (s->streams[default_stream_index]->pts_wrap_reference == AV_NOPTS_VALUE) {
            for (i = 0; i < s->nb_streams; i++) {
                s->streams[i]->pts_wrap_reference = pts_wrap_reference;
                s->streams[i]->pts_wrap_behavior = pts_wrap_behavior;
            }
        }
        else {
            st->pts_wrap_reference = s->streams[default_stream_index]->pts_wrap_reference;
            st->pts_wrap_behavior = s->streams[default_stream_index]->pts_wrap_behavior;
        }
    }
    else {
        AVProgram *program = first_program;
        while (program) {
            if (program->pts_wrap_reference != AV_NOPTS_VALUE) {
                pts_wrap_reference = program->pts_wrap_reference;
                pts_wrap_behavior = program->pts_wrap_behavior;
                break;
            }
            program = av_find_program_from_stream(s, program, stream_index);
        }

        // update every program with differing pts_wrap_reference
        program = first_program;
        while (program) {
            if (program->pts_wrap_reference != pts_wrap_reference) {
                for (i = 0; i<program->nb_stream_indexes; i++) {
                    s->streams[program->stream_index[i]]->pts_wrap_reference = pts_wrap_reference;
                    s->streams[program->stream_index[i]]->pts_wrap_behavior = pts_wrap_behavior;
                }

                program->pts_wrap_reference = pts_wrap_reference;
                program->pts_wrap_behavior = pts_wrap_behavior;
            }
            program = av_find_program_from_stream(s, program, stream_index);
        }
    }
    return 1;
}

int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    int ret, i, err;
    AVStream *st;

    for (;;) {
        AVPacketList *pktl = s->raw_packet_buffer;

        if (pktl) {
            *pkt = pktl->pkt;
            st   = s->streams[pkt->stream_index];
            if (s->raw_packet_buffer_remaining_size <= 0)
                if ((err = probe_codec(s, st, NULL)) < 0)
                    return err;
            if (st->request_probe <= 0) {
                s->raw_packet_buffer                 = pktl->next;
                s->raw_packet_buffer_remaining_size += pkt->size;
                av_free(pktl);
                return 0;
            }
        }

        pkt->data = NULL;
        pkt->size = 0;
        av_init_packet(pkt);
        ret = s->iformat->read_packet(s, pkt);
        if (ret < 0) {
            if (!pktl || ret == AVERROR(EAGAIN))
                return ret;
            for (i = 0; i < s->nb_streams; i++) {
                st = s->streams[i];
                if (st->probe_packets)
                    if ((err = probe_codec(s, st, NULL)) < 0)
                        return err;
                av_assert0(st->request_probe <= 0);
            }
            continue;
        }

        if ((s->flags & AVFMT_FLAG_DISCARD_CORRUPT) &&
            (pkt->flags & AV_PKT_FLAG_CORRUPT)) {
            av_log(s, AV_LOG_WARNING,
                   "Dropped corrupted packet (stream = %d)\n",
                   pkt->stream_index);
            av_free_packet(pkt);
            continue;
        }

        if (pkt->stream_index >= (unsigned)s->nb_streams) {
            av_log(s, AV_LOG_ERROR, "Invalid stream index %d\n", pkt->stream_index);
            continue;
        }

        st = s->streams[pkt->stream_index];

        if (update_wrap_reference(s, st, pkt->stream_index, pkt) && st->pts_wrap_behavior == AV_PTS_WRAP_SUB_OFFSET) {
            // correct first time stamps to negative values
            if (!is_relative(st->first_dts))
                st->first_dts = wrap_timestamp(st, st->first_dts);
            if (!is_relative(st->start_time))
                st->start_time = wrap_timestamp(st, st->start_time);
            if (!is_relative(st->cur_dts))
                st->cur_dts = wrap_timestamp(st, st->cur_dts);
        }

        pkt->dts = wrap_timestamp(st, pkt->dts);
        pkt->pts = wrap_timestamp(st, pkt->pts);

        force_codec_ids(s, st);

        /* TODO: audio: time filter; video: frame reordering (pts != dts) */
        if (s->use_wallclock_as_timestamps)
            pkt->dts = pkt->pts = av_rescale_q(av_gettime(), AV_TIME_BASE_Q, st->time_base);

        if (!pktl && st->request_probe <= 0)
            return ret;

        add_to_pktbuf(&s->raw_packet_buffer, pkt, &s->raw_packet_buffer_end);
        s->raw_packet_buffer_remaining_size -= pkt->size;

        if ((err = probe_codec(s, st, pkt)) < 0)
            return err;
    }
}


/**********************************************************/

static int determinable_frame_size(AVCodecContext *avctx)
{
    if (/*avctx->codec_id == AV_CODEC_ID_AAC ||*/
        avctx->codec_id == AV_CODEC_ID_MP1 ||
        avctx->codec_id == AV_CODEC_ID_MP2 ||
        avctx->codec_id == AV_CODEC_ID_MP3/* ||
        avctx->codec_id == AV_CODEC_ID_CELT*/)
        return 1;
    return 0;
}

/**
 * Return the frame duration in seconds. Return 0 if not available.
 */
void ff_compute_frame_duration(AVFormatContext *s, int *pnum, int *pden, AVStream *st,
                               AVCodecParserContext *pc, AVPacket *pkt)
{
    AVRational codec_framerate = s->iformat ? st->codec->framerate :
                                              av_mul_q(av_inv_q(st->codec->time_base), (AVRational){1, st->codec->ticks_per_frame});
    int frame_size;

    *pnum = 0;
    *pden = 0;
    switch (st->codec->codec_type) {
    case AVMEDIA_TYPE_VIDEO:
        if (st->r_frame_rate.num && !pc) {
            *pnum = st->r_frame_rate.den;
            *pden = st->r_frame_rate.num;
        } else if (st->time_base.num * 1000LL > st->time_base.den) {
            *pnum = st->time_base.num;
            *pden = st->time_base.den;
        } else if (codec_framerate.den * 1000LL > codec_framerate.num) {
            av_assert0(st->codec->ticks_per_frame);
            av_reduce(pnum, pden,
                      codec_framerate.den,
                      codec_framerate.num * (int64_t)st->codec->ticks_per_frame,
                      INT_MAX);

            if (pc && pc->repeat_pict) {
                av_assert0(s->iformat); // this may be wrong for interlaced encoding but its not used for that case
                av_reduce(pnum, pden,
                          (*pnum) * (1LL + pc->repeat_pict),
                          (*pden),
                          INT_MAX);
            }
            /* If this codec can be interlaced or progressive then we need
             * a parser to compute duration of a packet. Thus if we have
             * no parser in such case leave duration undefined. */
            if (st->codec->ticks_per_frame > 1 && !pc)
                *pnum = *pden = 0;
        }
        break;
    case AVMEDIA_TYPE_AUDIO:
        frame_size = av_get_audio_frame_duration(st->codec, pkt->size);
        if (frame_size <= 0 || st->codec->sample_rate <= 0)
            break;
        *pnum = frame_size;
        *pden = st->codec->sample_rate;
        break;
    default:
        break;
    }
}

static int is_intra_only(AVCodecContext *enc) {
    const AVCodecDescriptor *desc;

    if (enc->codec_type != AVMEDIA_TYPE_VIDEO)
        return 1;

    desc = av_codec_get_codec_descriptor(enc);
    if (!desc) {
        desc = avcodec_descriptor_get(enc->codec_id);
        av_codec_set_codec_descriptor(enc, desc);
    }
    if (desc)
        return !!(desc->props & AV_CODEC_PROP_INTRA_ONLY);
    return 0;
}

static int has_decode_delay_been_guessed(AVStream *st)
{
    if (st->codec->codec_id != AV_CODEC_ID_H264) return 1;
    if (!st->info) // if we have left find_stream_info then nb_decoded_frames won't increase anymore for stream copy
        return 1;
#if CONFIG_H264_DECODER
    if (st->codec->has_b_frames &&
       avpriv_h264_has_num_reorder_frames(st->codec) == st->codec->has_b_frames)
        return 1;
#endif
    if (st->codec->has_b_frames<3)
        return st->nb_decoded_frames >= 7;
    else if (st->codec->has_b_frames<4)
        return st->nb_decoded_frames >= 18;
    else
        return st->nb_decoded_frames >= 20;
}

static AVPacketList *get_next_pkt(AVFormatContext *s, AVStream *st, AVPacketList *pktl)
{
    if (pktl->next)
        return pktl->next;
    if (pktl == s->packet_buffer_end)
        return s->parse_queue;
    return NULL;
}

static int64_t select_from_pts_buffer(AVStream *st, int64_t *pts_buffer, int64_t dts) {
    int onein_oneout = st->codec->codec_id != AV_CODEC_ID_H264 &&
                       st->codec->codec_id != AV_CODEC_ID_HEVC;

    if(!onein_oneout) {
        int delay = st->codec->has_b_frames;
        int i;

        if (dts == AV_NOPTS_VALUE) {
            int64_t best_score = INT64_MAX;
            for (i = 0; i<delay; i++) {
                if (st->pts_reorder_error_count[i]) {
                    int64_t score = st->pts_reorder_error[i] / st->pts_reorder_error_count[i];
                    if (score < best_score) {
                        best_score = score;
                        dts = pts_buffer[i];
                    }
                }
            }
        } else {
            for (i = 0; i<delay; i++) {
                if (pts_buffer[i] != AV_NOPTS_VALUE) {
                    int64_t diff =  FFABS(pts_buffer[i] - dts)
                                    + (uint64_t)st->pts_reorder_error[i];
                    diff = FFMAX(diff, st->pts_reorder_error[i]);
                    st->pts_reorder_error[i] = diff;
                    st->pts_reorder_error_count[i]++;
                    if (st->pts_reorder_error_count[i] > 250) {
                        st->pts_reorder_error[i] >>= 1;
                        st->pts_reorder_error_count[i] >>= 1;
                    }
                }
            }
        }
    }

    if (dts == AV_NOPTS_VALUE)
        dts = pts_buffer[0];

    return dts;
}

static void update_initial_timestamps(AVFormatContext *s, int stream_index,
                                      int64_t dts, int64_t pts, AVPacket *pkt)
{
    AVStream *st       = s->streams[stream_index];
    AVPacketList *pktl = s->packet_buffer ? s->packet_buffer : s->parse_queue;
    int64_t pts_buffer[MAX_REORDER_DELAY+1];
    int64_t shift;
    int i, delay;

    if (st->first_dts != AV_NOPTS_VALUE ||
        dts           == AV_NOPTS_VALUE ||
        st->cur_dts   == AV_NOPTS_VALUE ||
        is_relative(dts))
        return;

    delay         = st->codec->has_b_frames;
    st->first_dts = dts - (st->cur_dts - RELATIVE_TS_BASE);
    st->cur_dts   = dts;
    shift         = st->first_dts - RELATIVE_TS_BASE;

    for (i = 0; i<MAX_REORDER_DELAY+1; i++)
        pts_buffer[i] = AV_NOPTS_VALUE;

    if (is_relative(pts))
        pts += shift;

    for (; pktl; pktl = get_next_pkt(s, st, pktl)) {
        if (pktl->pkt.stream_index != stream_index)
            continue;
        if (is_relative(pktl->pkt.pts))
            pktl->pkt.pts += shift;

        if (is_relative(pktl->pkt.dts))
            pktl->pkt.dts += shift;

        if (st->start_time == AV_NOPTS_VALUE && pktl->pkt.pts != AV_NOPTS_VALUE)
            st->start_time = pktl->pkt.pts;

        if (pktl->pkt.pts != AV_NOPTS_VALUE && delay <= MAX_REORDER_DELAY && has_decode_delay_been_guessed(st)) {
            pts_buffer[0] = pktl->pkt.pts;
            for (i = 0; i<delay && pts_buffer[i] > pts_buffer[i + 1]; i++)
                FFSWAP(int64_t, pts_buffer[i], pts_buffer[i + 1]);

            pktl->pkt.dts = select_from_pts_buffer(st, pts_buffer, pktl->pkt.dts);
        }
    }

    if (st->start_time == AV_NOPTS_VALUE)
        st->start_time = pts;
}

static void update_initial_durations(AVFormatContext *s, AVStream *st,
                                     int stream_index, int duration)
{
    AVPacketList *pktl = s->packet_buffer ? s->packet_buffer : s->parse_queue;
    int64_t cur_dts    = RELATIVE_TS_BASE;

    if (st->first_dts != AV_NOPTS_VALUE) {
        if (st->update_initial_durations_done)
            return;
        st->update_initial_durations_done = 1;
        cur_dts = st->first_dts;
        for (; pktl; pktl = get_next_pkt(s, st, pktl)) {
            if (pktl->pkt.stream_index == stream_index) {
                if (pktl->pkt.pts != pktl->pkt.dts  ||
                    pktl->pkt.dts != AV_NOPTS_VALUE ||
                    pktl->pkt.duration)
                    break;
                cur_dts -= duration;
            }
        }
        if (pktl && pktl->pkt.dts != st->first_dts) {
            av_log(s, AV_LOG_DEBUG, "first_dts %s not matching first dts %s (pts %s, duration %d) in the queue\n",
                   av_ts2str(st->first_dts), av_ts2str(pktl->pkt.dts), av_ts2str(pktl->pkt.pts), pktl->pkt.duration);
            return;
        }
        if (!pktl) {
            av_log(s, AV_LOG_DEBUG, "first_dts %s but no packet with dts in the queue\n", av_ts2str(st->first_dts));
            return;
        }
        pktl          = s->packet_buffer ? s->packet_buffer : s->parse_queue;
        st->first_dts = cur_dts;
    } else if (st->cur_dts != RELATIVE_TS_BASE)
        return;

    for (; pktl; pktl = get_next_pkt(s, st, pktl)) {
        if (pktl->pkt.stream_index != stream_index)
            continue;
        if (pktl->pkt.pts == pktl->pkt.dts  &&
            (pktl->pkt.dts == AV_NOPTS_VALUE || pktl->pkt.dts == st->first_dts) &&
            !pktl->pkt.duration) {
            pktl->pkt.dts = cur_dts;
            if (!st->codec->has_b_frames)
                pktl->pkt.pts = cur_dts;
//            if (st->codec->codec_type != AVMEDIA_TYPE_AUDIO)
                pktl->pkt.duration = duration;
        } else
            break;
        cur_dts = pktl->pkt.dts + pktl->pkt.duration;
    }
    if (!pktl)
        st->cur_dts = cur_dts;
}

static void compute_pkt_fields(AVFormatContext *s, AVStream *st,
                               AVCodecParserContext *pc, AVPacket *pkt)
{
    int num, den, presentation_delayed, delay, i;
    int64_t offset;
    AVRational duration;
    int onein_oneout = st->codec->codec_id != AV_CODEC_ID_H264 &&
                       st->codec->codec_id != AV_CODEC_ID_HEVC;

    if (s->flags & AVFMT_FLAG_NOFILLIN)
        return;

    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && pkt->dts != AV_NOPTS_VALUE) {
        if (pkt->dts == pkt->pts && st->last_dts_for_order_check != AV_NOPTS_VALUE) {
            if (st->last_dts_for_order_check <= pkt->dts) {
                st->dts_ordered++;
            } else {
                av_log(s, st->dts_misordered ? AV_LOG_DEBUG : AV_LOG_WARNING,
                       "DTS %"PRIi64" < %"PRIi64" out of order\n",
                       pkt->dts,
                       st->last_dts_for_order_check);
                st->dts_misordered++;
            }
            if (st->dts_ordered + st->dts_misordered > 250) {
                st->dts_ordered    >>= 1;
                st->dts_misordered >>= 1;
            }
        }

        st->last_dts_for_order_check = pkt->dts;
        if (st->dts_ordered < 8*st->dts_misordered && pkt->dts == pkt->pts)
            pkt->dts = AV_NOPTS_VALUE;
    }

    if ((s->flags & AVFMT_FLAG_IGNDTS) && pkt->pts != AV_NOPTS_VALUE)
        pkt->dts = AV_NOPTS_VALUE;

    if (pc && pc->pict_type == AV_PICTURE_TYPE_B
        && !st->codec->has_b_frames)
        //FIXME Set low_delay = 0 when has_b_frames = 1
        st->codec->has_b_frames = 1;

    /* do we have a video B-frame ? */
    delay = st->codec->has_b_frames;
    presentation_delayed = 0;

    /* XXX: need has_b_frame, but cannot get it if the codec is
     *  not initialized */
    if (delay &&
        pc && pc->pict_type != AV_PICTURE_TYPE_B)
        presentation_delayed = 1;

    if (pkt->pts != AV_NOPTS_VALUE && pkt->dts != AV_NOPTS_VALUE &&
        st->pts_wrap_bits < 63 &&
        pkt->dts - (1LL << (st->pts_wrap_bits - 1)) > pkt->pts) {
        if (is_relative(st->cur_dts) || pkt->dts - (1LL<<(st->pts_wrap_bits - 1)) > st->cur_dts) {
            pkt->dts -= 1LL << st->pts_wrap_bits;
        } else
            pkt->pts += 1LL << st->pts_wrap_bits;
    }

    /* Some MPEG-2 in MPEG-PS lack dts (issue #171 / input_file.mpg).
     * We take the conservative approach and discard both.
     * Note: If this is misbehaving for an H.264 file, then possibly
     * presentation_delayed is not set correctly. */
    if (delay == 1 && pkt->dts == pkt->pts &&
        pkt->dts != AV_NOPTS_VALUE && presentation_delayed) {
        av_log(s, AV_LOG_DEBUG, "invalid dts/pts combination %"PRIi64"\n", pkt->dts);
        if (    strcmp(s->iformat->name, "mov,mp4,m4a,3gp,3g2,mj2")
             && strcmp(s->iformat->name, "flv")) // otherwise we discard correct timestamps for vc1-wmapro.ism
            pkt->dts = AV_NOPTS_VALUE;
    }

    duration = av_mul_q((AVRational) {pkt->duration, 1}, st->time_base);
    if (pkt->duration == 0) {
        ff_compute_frame_duration(s, &num, &den, st, pc, pkt);
        if (den && num) {
            duration = (AVRational) {num, den};
            pkt->duration = av_rescale_rnd(1,
                                           num * (int64_t) st->time_base.den,
                                           den * (int64_t) st->time_base.num,
                                           AV_ROUND_DOWN);
        }
    }

    if (pkt->duration != 0 && (s->packet_buffer || s->parse_queue))
        update_initial_durations(s, st, pkt->stream_index, pkt->duration);

    /* Correct timestamps with byte offset if demuxers only have timestamps
     * on packet boundaries */
    if (pc && st->need_parsing == AVSTREAM_PARSE_TIMESTAMPS && pkt->size) {
        /* this will estimate bitrate based on this frame's duration and size */
        offset = av_rescale(pc->offset, pkt->duration, pkt->size);
        if (pkt->pts != AV_NOPTS_VALUE)
            pkt->pts += offset;
        if (pkt->dts != AV_NOPTS_VALUE)
            pkt->dts += offset;
    }

    /* This may be redundant, but it should not hurt. */
    if (pkt->dts != AV_NOPTS_VALUE &&
        pkt->pts != AV_NOPTS_VALUE &&
        pkt->pts > pkt->dts)
        presentation_delayed = 1;

    av_dlog(NULL,
            "IN delayed:%d pts:%s, dts:%s cur_dts:%s st:%d pc:%p duration:%d delay:%d onein_oneout:%d\n",
            presentation_delayed, av_ts2str(pkt->pts), av_ts2str(pkt->dts), av_ts2str(st->cur_dts),
            pkt->stream_index, pc, pkt->duration, delay, onein_oneout);
    /* Interpolate PTS and DTS if they are not present. We skip H264
     * currently because delay and has_b_frames are not reliably set. */
    if ((delay == 0 || (delay == 1 && pc)) &&
        onein_oneout) {
        if (presentation_delayed) {
            /* DTS = decompression timestamp */
            /* PTS = presentation timestamp */
            if (pkt->dts == AV_NOPTS_VALUE)
                pkt->dts = st->last_IP_pts;
            update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts, pkt);
            if (pkt->dts == AV_NOPTS_VALUE)
                pkt->dts = st->cur_dts;

            /* This is tricky: the dts must be incremented by the duration
             * of the frame we are displaying, i.e. the last I- or P-frame. */
            if (st->last_IP_duration == 0)
                st->last_IP_duration = pkt->duration;
            if (pkt->dts != AV_NOPTS_VALUE)
                st->cur_dts = pkt->dts + st->last_IP_duration;
            st->last_IP_duration = pkt->duration;
            st->last_IP_pts      = pkt->pts;
            /* Cannot compute PTS if not present (we can compute it only
             * by knowing the future. */
        } else if (pkt->pts != AV_NOPTS_VALUE ||
                   pkt->dts != AV_NOPTS_VALUE ||
                   pkt->duration                ) {

            /* presentation is not delayed : PTS and DTS are the same */
            if (pkt->pts == AV_NOPTS_VALUE)
                pkt->pts = pkt->dts;
            update_initial_timestamps(s, pkt->stream_index, pkt->pts,
                                      pkt->pts, pkt);
            if (pkt->pts == AV_NOPTS_VALUE)
                pkt->pts = st->cur_dts;
            pkt->dts = pkt->pts;
            if (pkt->pts != AV_NOPTS_VALUE)
                st->cur_dts = av_add_stable(st->time_base, pkt->pts, duration, 1);
        }
    }

    if (pkt->pts != AV_NOPTS_VALUE && delay <= MAX_REORDER_DELAY && has_decode_delay_been_guessed(st)) {
        st->pts_buffer[0] = pkt->pts;
        for (i = 0; i<delay && st->pts_buffer[i] > st->pts_buffer[i + 1]; i++)
            FFSWAP(int64_t, st->pts_buffer[i], st->pts_buffer[i + 1]);

        pkt->dts = select_from_pts_buffer(st, st->pts_buffer, pkt->dts);
    }
    // We skipped it above so we try here.
    if (!onein_oneout)
        // This should happen on the first packet
        update_initial_timestamps(s, pkt->stream_index, pkt->dts, pkt->pts, pkt);
    if (pkt->dts > st->cur_dts)
        st->cur_dts = pkt->dts;

    av_dlog(NULL, "OUTdelayed:%d/%d pts:%s, dts:%s cur_dts:%s\n",
            presentation_delayed, delay, av_ts2str(pkt->pts), av_ts2str(pkt->dts), av_ts2str(st->cur_dts));

    /* update flags */
    if (is_intra_only(st->codec))
        pkt->flags |= AV_PKT_FLAG_KEY;
    if (pc)
        pkt->convergence_duration = pc->convergence_duration;
}

static void free_packet_buffer(AVPacketList **pkt_buf, AVPacketList **pkt_buf_end)
{
    while (*pkt_buf) {
        AVPacketList *pktl = *pkt_buf;
        *pkt_buf = pktl->next;
        av_free_packet(&pktl->pkt);
        av_freep(&pktl);
    }
    *pkt_buf_end = NULL;
}

/**
 * Parse a packet, add all split parts to parse_queue.
 *
 * @param pkt Packet to parse, NULL when flushing the parser at end of stream.
 */
static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
{
    AVPacket out_pkt = { 0 }, flush_pkt = { 0 };
    AVStream *st = s->streams[stream_index];
    uint8_t *data = pkt ? pkt->data : NULL;
    int size      = pkt ? pkt->size : 0;
    int ret = 0, got_output = 0;

    if (!pkt) {
        av_init_packet(&flush_pkt);
        pkt        = &flush_pkt;
        got_output = 1;
    } else if (!size && st->parser->flags & PARSER_FLAG_COMPLETE_FRAMES) {
        // preserve 0-size sync packets
        compute_pkt_fields(s, st, st->parser, pkt);
    }

    while (size > 0 || (pkt == &flush_pkt && got_output)) {
        int len;

        av_init_packet(&out_pkt);
        len = av_parser_parse2(st->parser, st->codec,
                               &out_pkt.data, &out_pkt.size, data, size,
                               pkt->pts, pkt->dts, pkt->pos);

        pkt->pts = pkt->dts = AV_NOPTS_VALUE;
        pkt->pos = -1;
        /* increment read pointer */
        data += len;
        size -= len;

        got_output = !!out_pkt.size;

        if (!out_pkt.size)
            continue;

        if (pkt->side_data) {
            out_pkt.side_data       = pkt->side_data;
            out_pkt.side_data_elems = pkt->side_data_elems;
            pkt->side_data          = NULL;
            pkt->side_data_elems    = 0;
        }

        /* set the duration */
        out_pkt.duration = 0;
        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
            if (st->codec->sample_rate > 0) {
                out_pkt.duration =
                    av_rescale_q_rnd(st->parser->duration,
                                     (AVRational) { 1, st->codec->sample_rate },
                                     st->time_base,
                                     AV_ROUND_DOWN);
            }
        }

        out_pkt.stream_index = st->index;
        out_pkt.pts          = st->parser->pts;
        out_pkt.dts          = st->parser->dts;
        out_pkt.pos          = st->parser->pos;

        if (st->need_parsing == AVSTREAM_PARSE_FULL_RAW)
            out_pkt.pos = st->parser->frame_offset;

        if (st->parser->key_frame == 1 ||
            (st->parser->key_frame == -1 &&
             st->parser->pict_type == AV_PICTURE_TYPE_I))
            out_pkt.flags |= AV_PKT_FLAG_KEY;

        if (st->parser->key_frame == -1 && st->parser->pict_type ==AV_PICTURE_TYPE_NONE && (pkt->flags&AV_PKT_FLAG_KEY))
            out_pkt.flags |= AV_PKT_FLAG_KEY;

        compute_pkt_fields(s, st, st->parser, &out_pkt);

        if (out_pkt.data == pkt->data && out_pkt.size == pkt->size) {
            out_pkt.buf = pkt->buf;
            pkt->buf    = NULL;
#if FF_API_DESTRUCT_PACKET
FF_DISABLE_DEPRECATION_WARNINGS
            out_pkt.destruct = pkt->destruct;
            pkt->destruct = NULL;
FF_ENABLE_DEPRECATION_WARNINGS
#endif
        }
        if ((ret = av_dup_packet(&out_pkt)) < 0)
            goto fail;

        if (!add_to_pktbuf(&s->parse_queue, &out_pkt, &s->parse_queue_end)) {
            av_free_packet(&out_pkt);
            ret = AVERROR(ENOMEM);
            goto fail;
        }
    }

    /* end of the stream => close and free the parser */
    if (pkt == &flush_pkt) {
        av_parser_close(st->parser);
        st->parser = NULL;
    }

fail:
    av_free_packet(pkt);
    return ret;
}

static int read_from_packet_buffer(AVPacketList **pkt_buffer,
                                   AVPacketList **pkt_buffer_end,
                                   AVPacket      *pkt)
{
    AVPacketList *pktl;
    av_assert0(*pkt_buffer);
    pktl        = *pkt_buffer;
    *pkt        = pktl->pkt;
    *pkt_buffer = pktl->next;
    if (!pktl->next)
        *pkt_buffer_end = NULL;
    av_freep(&pktl);
    return 0;
}

static int64_t ts_to_samples(AVStream *st, int64_t ts)
{
    return av_rescale(ts, st->time_base.num * st->codec->sample_rate, st->time_base.den);
}

static int read_frame_internal(AVFormatContext *s, AVPacket *pkt)
{
    int ret = 0, i, got_packet = 0;
    AVDictionary *metadata = NULL;

    av_init_packet(pkt);

    while (!got_packet && !s->parse_queue) {
        AVStream *st;
        AVPacket cur_pkt;

        /* read next packet */
        ret = ff_read_packet(s, &cur_pkt);
        if (ret < 0) {
            if (ret == AVERROR(EAGAIN))
                return ret;
            /* flush the parsers */
            for (i = 0; i < s->nb_streams; i++) {
                st = s->streams[i];
                if (st->parser && st->need_parsing)
                    parse_packet(s, NULL, st->index);
            }
            /* all remaining packets are now in parse_queue =>
             * really terminate parsing */
            break;
        }
        ret = 0;
        st  = s->streams[cur_pkt.stream_index];

        if (cur_pkt.pts != AV_NOPTS_VALUE &&
            cur_pkt.dts != AV_NOPTS_VALUE &&
            cur_pkt.pts < cur_pkt.dts) {
            av_log(s, AV_LOG_WARNING,
                   "Invalid timestamps stream=%d, pts=%s, dts=%s, size=%d\n",
                   cur_pkt.stream_index,
                   av_ts2str(cur_pkt.pts),
                   av_ts2str(cur_pkt.dts),
                   cur_pkt.size);
        }
        if (s->debug & FF_FDEBUG_TS)
            av_log(s, AV_LOG_DEBUG,
                   "ff_read_packet stream=%d, pts=%s, dts=%s, size=%d, duration=%d, flags=%d\n",
                   cur_pkt.stream_index,
                   av_ts2str(cur_pkt.pts),
                   av_ts2str(cur_pkt.dts),
                   cur_pkt.size, cur_pkt.duration, cur_pkt.flags);

        if (st->need_parsing && !st->parser && !(s->flags & AVFMT_FLAG_NOPARSE)) {
            st->parser = av_parser_init(st->codec->codec_id);
            if (!st->parser) {
                av_log(s, AV_LOG_VERBOSE, "parser not found for codec "
                       "%s, packets or times may be invalid.\n",
                       avcodec_get_name(st->codec->codec_id));
                /* no parser available: just output the raw packets */
                st->need_parsing = AVSTREAM_PARSE_NONE;
            } else if (st->need_parsing == AVSTREAM_PARSE_HEADERS)
                st->parser->flags |= PARSER_FLAG_COMPLETE_FRAMES;
            else if (st->need_parsing == AVSTREAM_PARSE_FULL_ONCE)
                st->parser->flags |= PARSER_FLAG_ONCE;
            else if (st->need_parsing == AVSTREAM_PARSE_FULL_RAW)
                st->parser->flags |= PARSER_FLAG_USE_CODEC_TS;
        }

        if (!st->need_parsing || !st->parser) {
            /* no parsing needed: we just output the packet as is */
            *pkt = cur_pkt;
            compute_pkt_fields(s, st, NULL, pkt);
            if ((s->iformat->flags & AVFMT_GENERIC_INDEX) &&
                (pkt->flags & AV_PKT_FLAG_KEY) && pkt->dts != AV_NOPTS_VALUE) {
                ff_reduce_index(s, st->index);
                av_add_index_entry(st, pkt->pos, pkt->dts,
                                   0, 0, AVINDEX_KEYFRAME);
            }
            got_packet = 1;
        } else if (st->discard < AVDISCARD_ALL) {
            if ((ret = parse_packet(s, &cur_pkt, cur_pkt.stream_index)) < 0)
                return ret;
        } else {
            /* free packet */
            av_free_packet(&cur_pkt);
        }
        if (pkt->flags & AV_PKT_FLAG_KEY)
            st->skip_to_keyframe = 0;
        if (st->skip_to_keyframe) {
            av_free_packet(&cur_pkt);
            if (got_packet) {
                *pkt = cur_pkt;
            }
            got_packet = 0;
        }
    }

    if (!got_packet && s->parse_queue)
        ret = read_from_packet_buffer(&s->parse_queue, &s->parse_queue_end, pkt);

    if (ret >= 0) {
        AVStream *st = s->streams[pkt->stream_index];
        int discard_padding = 0;
        if (st->first_discard_sample && pkt->pts != AV_NOPTS_VALUE) {
            int64_t pts = pkt->pts - (is_relative(pkt->pts) ? RELATIVE_TS_BASE : 0);
            int64_t sample = ts_to_samples(st, pts);
            int duration = ts_to_samples(st, pkt->duration);
            int64_t end_sample = sample + duration;
            if (duration > 0 && end_sample >= st->first_discard_sample &&
                sample < st->last_discard_sample)
                discard_padding = FFMIN(end_sample - st->first_discard_sample, duration);
        }
        if (st->skip_samples || discard_padding) {
            uint8_t *p = av_packet_new_side_data(pkt, AV_PKT_DATA_SKIP_SAMPLES, 10);
            if (p) {
                AV_WL32(p, st->skip_samples);
                AV_WL32(p + 4, discard_padding);
                av_log(s, AV_LOG_DEBUG, "demuxer injecting skip %d\n", st->skip_samples);
            }
            st->skip_samples = 0;
        }

        if (st->inject_global_side_data) {
            for (i = 0; i < st->nb_side_data; i++) {
                AVPacketSideData *src_sd = &st->side_data[i];
                uint8_t *dst_data;

                if (av_packet_get_side_data(pkt, src_sd->type, NULL))
                    continue;

                dst_data = av_packet_new_side_data(pkt, src_sd->type, src_sd->size);
                if (!dst_data) {
                    av_log(s, AV_LOG_WARNING, "Could not inject global side data\n");
                    continue;
                }

                memcpy(dst_data, src_sd->data, src_sd->size);
            }
            st->inject_global_side_data = 0;
        }

        if (!(s->flags & AVFMT_FLAG_KEEP_SIDE_DATA))
            av_packet_merge_side_data(pkt);
    }

    av_opt_get_dict_val(s, "metadata", AV_OPT_SEARCH_CHILDREN, &metadata);
    if (metadata) {
        s->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
        av_dict_copy(&s->metadata, metadata, 0);
        av_dict_free(&metadata);
        av_opt_set_dict_val(s, "metadata", NULL, AV_OPT_SEARCH_CHILDREN);
    }

    if (s->debug & FF_FDEBUG_TS)
        av_log(s, AV_LOG_DEBUG,
               "read_frame_internal stream=%d, pts=%s, dts=%s, "
               "size=%d, duration=%d, flags=%d\n",
               pkt->stream_index,
               av_ts2str(pkt->pts),
               av_ts2str(pkt->dts),
               pkt->size, pkt->duration, pkt->flags);

    return ret;
}

int av_read_frame(AVFormatContext *s, AVPacket *pkt)
{
    const int genpts = s->flags & AVFMT_FLAG_GENPTS;
    int eof = 0;
    int ret;
    AVStream *st;

    if (!genpts) {
        ret = s->packet_buffer
              ? read_from_packet_buffer(&s->packet_buffer,
                                        &s->packet_buffer_end, pkt)
              : read_frame_internal(s, pkt);
        if (ret < 0)
            return ret;
        goto return_packet;
    }

    for (;;) {
        AVPacketList *pktl = s->packet_buffer;

        if (pktl) {
            AVPacket *next_pkt = &pktl->pkt;

            if (next_pkt->dts != AV_NOPTS_VALUE) {
                int wrap_bits = s->streams[next_pkt->stream_index]->pts_wrap_bits;
                // last dts seen for this stream. if any of packets following
                // current one had no dts, we will set this to AV_NOPTS_VALUE.
                int64_t last_dts = next_pkt->dts;
                while (pktl && next_pkt->pts == AV_NOPTS_VALUE) {
                    if (pktl->pkt.stream_index == next_pkt->stream_index &&
                        (av_compare_mod(next_pkt->dts, pktl->pkt.dts, 2LL << (wrap_bits - 1)) < 0)) {
                        if (av_compare_mod(pktl->pkt.pts, pktl->pkt.dts, 2LL << (wrap_bits - 1))) {
                            // not B-frame
                            next_pkt->pts = pktl->pkt.dts;
                        }
                        if (last_dts != AV_NOPTS_VALUE) {
                            // Once last dts was set to AV_NOPTS_VALUE, we don't change it.
                            last_dts = pktl->pkt.dts;
                        }
                    }
                    pktl = pktl->next;
                }
                if (eof && next_pkt->pts == AV_NOPTS_VALUE && last_dts != AV_NOPTS_VALUE) {
                    // Fixing the last reference frame had none pts issue (For MXF etc).
                    // We only do this when
                    // 1. eof.
                    // 2. we are not able to resolve a pts value for current packet.
                    // 3. the packets for this stream at the end of the files had valid dts.
                    next_pkt->pts = last_dts + next_pkt->duration;
                }
                pktl = s->packet_buffer;
            }

            /* read packet from packet buffer, if there is data */
            st = s->streams[next_pkt->stream_index];
            if (!(next_pkt->pts == AV_NOPTS_VALUE && st->discard < AVDISCARD_ALL &&
                  next_pkt->dts != AV_NOPTS_VALUE && !eof)) {
                ret = read_from_packet_buffer(&s->packet_buffer,
                                               &s->packet_buffer_end, pkt);
                goto return_packet;
            }
        }

        ret = read_frame_internal(s, pkt);
        if (ret < 0) {
            if (pktl && ret != AVERROR(EAGAIN)) {
                eof = 1;
                continue;
            } else
                return ret;
        }

        if (av_dup_packet(add_to_pktbuf(&s->packet_buffer, pkt,
                                        &s->packet_buffer_end)) < 0)
            return AVERROR(ENOMEM);
    }

return_packet:

    st = s->streams[pkt->stream_index];
    if ((s->iformat->flags & AVFMT_GENERIC_INDEX) && pkt->flags & AV_PKT_FLAG_KEY) {
        ff_reduce_index(s, st->index);
        av_add_index_entry(st, pkt->pos, pkt->dts, 0, 0, AVINDEX_KEYFRAME);
    }

    if (is_relative(pkt->dts))
        pkt->dts -= RELATIVE_TS_BASE;
    if (is_relative(pkt->pts))
        pkt->pts -= RELATIVE_TS_BASE;

    return ret;
}

/* XXX: suppress the packet queue */
static void flush_packet_queue(AVFormatContext *s)
{
    free_packet_buffer(&s->parse_queue,       &s->parse_queue_end);
    free_packet_buffer(&s->packet_buffer,     &s->packet_buffer_end);
    free_packet_buffer(&s->raw_packet_buffer, &s->raw_packet_buffer_end);

    s->raw_packet_buffer_remaining_size = RAW_PACKET_BUFFER_SIZE;
}

/*******************************************************/
/* seek support */

int av_find_default_stream_index(AVFormatContext *s)
{
    int i;
    AVStream *st;
    int best_stream = 0;
    int best_score = -1;

    if (s->nb_streams <= 0)
        return -1;
    for (i = 0; i < s->nb_streams; i++) {
        int score = 0;
        st = s->streams[i];
        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
            !(st->disposition & AV_DISPOSITION_ATTACHED_PIC)) {
            if (!st->codec->width && !st->codec->height && !st->codec_info_nb_frames)
                score += 25;
            else
                score += 100;
        }
        if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
            if (!st->codec->sample_rate && !st->codec_info_nb_frames)
                score += 12;
            else
                score += 50;
        }

        if (score > best_score) {
            best_score = score;
            best_stream = i;
        }
    }
    return best_stream;
}

/** Flush the frame reader. */
void ff_read_frame_flush(AVFormatContext *s)
{
    AVStream *st;
    int i, j;

    flush_packet_queue(s);

    /* Reset read state for each stream. */
    for (i = 0; i < s->nb_streams; i++) {
        st = s->streams[i];

        if (st->parser) {
            av_parser_close(st->parser);
            st->parser = NULL;
        }
        st->last_IP_pts = AV_NOPTS_VALUE;
        st->last_dts_for_order_check = AV_NOPTS_VALUE;
        if (st->first_dts == AV_NOPTS_VALUE)
            st->cur_dts = RELATIVE_TS_BASE;
        else
            /* We set the current DTS to an unspecified origin. */
            st->cur_dts = AV_NOPTS_VALUE;

        st->probe_packets = MAX_PROBE_PACKETS;

        for (j = 0; j < MAX_REORDER_DELAY + 1; j++)
            st->pts_buffer[j] = AV_NOPTS_VALUE;

        if (s->internal->inject_global_side_data)
            st->inject_global_side_data = 1;
    }
}

void ff_update_cur_dts(AVFormatContext *s, AVStream *ref_st, int64_t timestamp)
{
    int i;

    for (i = 0; i < s->nb_streams; i++) {
        AVStream *st = s->streams[i];

        st->cur_dts =
            av_rescale(timestamp,
                       st->time_base.den * (int64_t) ref_st->time_base.num,
                       st->time_base.num * (int64_t) ref_st->time_base.den);
    }
}

void ff_reduce_index(AVFormatContext *s, int stream_index)
{
    AVStream *st             = s->streams[stream_index];
    unsigned int max_entries = s->max_index_size / sizeof(AVIndexEntry);

    if ((unsigned) st->nb_index_entries >= max_entries) {
        int i;
        for (i = 0; 2 * i < st->nb_index_entries; i++)
            st->index_entries[i] = st->index_entries[2 * i];
        st->nb_index_entries = i;
    }
}

int ff_add_index_entry(AVIndexEntry **index_entries,
                       int *nb_index_entries,
                       unsigned int *index_entries_allocated_size,
                       int64_t pos, int64_t timestamp,
                       int size, int distance, int flags)
{
    AVIndexEntry *entries, *ie;
    int index;

    if ((unsigned) *nb_index_entries + 1 >= UINT_MAX / sizeof(AVIndexEntry))
        return -1;

    if (timestamp == AV_NOPTS_VALUE)
        return AVERROR(EINVAL);

    if (size < 0 || size > 0x3FFFFFFF)
        return AVERROR(EINVAL);

    if (is_relative(timestamp)) //FIXME this maintains previous behavior but we should shift by the correct offset once known
        timestamp -= RELATIVE_TS_BASE;

    entries = av_fast_realloc(*index_entries,
                              index_entries_allocated_size,
                              (*nb_index_entries + 1) *
                              sizeof(AVIndexEntry));
    if (!entries)
        return -1;

    *index_entries = entries;

    index = ff_index_search_timestamp(*index_entries, *nb_index_entries,
                                      timestamp, AVSEEK_FLAG_ANY);

    if (index < 0) {
        index = (*nb_index_entries)++;
        ie    = &entries[index];
        av_assert0(index == 0 || ie[-1].timestamp < timestamp);
    } else {
        ie = &entries[index];
        if (ie->timestamp != timestamp) {
            if (ie->timestamp <= timestamp)
                return -1;
            memmove(entries + index + 1, entries + index,
                    sizeof(AVIndexEntry) * (*nb_index_entries - index));
            (*nb_index_entries)++;
        } else if (ie->pos == pos && distance < ie->min_distance)
            // do not reduce the distance
            distance = ie->min_distance;
    }

    ie->pos          = pos;
    ie->timestamp    = timestamp;
    ie->min_distance = distance;
    ie->size         = size;
    ie->flags        = flags;

    return index;
}

int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp,
                       int size, int distance, int flags)
{
    timestamp = wrap_timestamp(st, timestamp);
    return ff_add_index_entry(&st->index_entries, &st->nb_index_entries,
                              &st->index_entries_allocated_size, pos,
                              timestamp, size, distance, flags);
}

int ff_index_search_timestamp(const AVIndexEntry *entries, int nb_entries,
                              int64_t wanted_timestamp, int flags)
{
    int a, b, m;
    int64_t timestamp;

    a = -1;
    b = nb_entries;

    // Optimize appending index entries at the end.
    if (b && entries[b - 1].timestamp < wanted_timestamp)
        a = b - 1;

    while (b - a > 1) {
        m         = (a + b) >> 1;
        timestamp = entries[m].timestamp;
        if (timestamp >= wanted_timestamp)
            b = m;
        if (timestamp <= wanted_timestamp)
            a = m;
    }
    m = (flags & AVSEEK_FLAG_BACKWARD) ? a : b;

    if (!(flags & AVSEEK_FLAG_ANY))
        while (m >= 0 && m < nb_entries &&
               !(entries[m].flags & AVINDEX_KEYFRAME))
            m += (flags & AVSEEK_FLAG_BACKWARD) ? -1 : 1;

    if (m == nb_entries)
        return -1;
    return m;
}

int av_index_search_timestamp(AVStream *st, int64_t wanted_timestamp, int flags)
{
    return ff_index_search_timestamp(st->index_entries, st->nb_index_entries,
                                     wanted_timestamp, flags);
}

static int64_t ff_read_timestamp(AVFormatContext *s, int stream_index, int64_t *ppos, int64_t pos_limit,
                                 int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ))
{
    int64_t ts = read_timestamp(s, stream_index, ppos, pos_limit);
    if (stream_index >= 0)
        ts = wrap_timestamp(s->streams[stream_index], ts);
    return ts;
}

int ff_seek_frame_binary(AVFormatContext *s, int stream_index,
                         int64_t target_ts, int flags)
{
    AVInputFormat *avif = s->iformat;
    int64_t av_uninit(pos_min), av_uninit(pos_max), pos, pos_limit;
    int64_t ts_min, ts_max, ts;
    int index;
    int64_t ret;
    AVStream *st;

    if (stream_index < 0)
        return -1;

    av_dlog(s, "read_seek: %d %s\n", stream_index, av_ts2str(target_ts));

    ts_max =
    ts_min = AV_NOPTS_VALUE;
    pos_limit = -1; // GCC falsely says it may be uninitialized.

    st = s->streams[stream_index];
    if (st->index_entries) {
        AVIndexEntry *e;

        /* FIXME: Whole function must be checked for non-keyframe entries in
         * index case, especially read_timestamp(). */
        index = av_index_search_timestamp(st, target_ts,
                                          flags | AVSEEK_FLAG_BACKWARD);
        index = FFMAX(index, 0);
        e     = &st->index_entries[index];

        if (e->timestamp <= target_ts || e->pos == e->min_distance) {
            pos_min = e->pos;
            ts_min  = e->timestamp;
            av_dlog(s, "using cached pos_min=0x%"PRIx64" dts_min=%s\n",
                    pos_min, av_ts2str(ts_min));
        } else {
            av_assert1(index == 0);
        }

        index = av_index_search_timestamp(st, target_ts,
                                          flags & ~AVSEEK_FLAG_BACKWARD);
        av_assert0(index < st->nb_index_entries);
        if (index >= 0) {
            e = &st->index_entries[index];
            av_assert1(e->timestamp >= target_ts);
            pos_max   = e->pos;
            ts_max    = e->timestamp;
            pos_limit = pos_max - e->min_distance;
            av_dlog(s, "using cached pos_max=0x%"PRIx64" pos_limit=0x%"PRIx64
                    " dts_max=%s\n", pos_max, pos_limit, av_ts2str(ts_max));
        }
    }

    pos = ff_gen_search(s, stream_index, target_ts, pos_min, pos_max, pos_limit,
                        ts_min, ts_max, flags, &ts, avif->read_timestamp);
    if (pos < 0)
        return -1;

    /* do the seek */
    if ((ret = avio_seek(s->pb, pos, SEEK_SET)) < 0)
        return ret;

    ff_read_frame_flush(s);
    ff_update_cur_dts(s, st, ts);

    return 0;
}

int ff_find_last_ts(AVFormatContext *s, int stream_index, int64_t *ts, int64_t *pos,
                    int64_t (*read_timestamp)(struct AVFormatContext *, int , int64_t *, int64_t ))
{
    int64_t step = 1024;
    int64_t limit, ts_max;
    int64_t filesize = avio_size(s->pb);
    int64_t pos_max  = filesize - 1;
    do {
        limit = pos_max;
        pos_max = FFMAX(0, (pos_max) - step);
        ts_max  = ff_read_timestamp(s, stream_index,
                                    &pos_max, limit, read_timestamp);
        step   += step;
    } while (ts_max == AV_NOPTS_VALUE && 2*limit > step);
    if (ts_max == AV_NOPTS_VALUE)
        return -1;

    for (;;) {
        int64_t tmp_pos = pos_max + 1;
        int64_t tmp_ts  = ff_read_timestamp(s, stream_index,
                                            &tmp_pos, INT64_MAX, read_timestamp);
        if (tmp_ts == AV_NOPTS_VALUE)
            break;
        av_assert0(tmp_pos > pos_max);
        ts_max  = tmp_ts;
        pos_max = tmp_pos;
        if (tmp_pos >= filesize)
            break;
    }

    if (ts)
        *ts = ts_max;
    if (pos)
        *pos = pos_max;

    return 0;
}

int64_t ff_gen_search(AVFormatContext *s, int stream_index, int64_t target_ts,
                      int64_t pos_min, int64_t pos_max, int64_t pos_limit,
                      int64_t ts_min, int64_t ts_max,
                      int flags, int64_t *ts_ret,
                      int64_t (*read_timestamp)(struct AVFormatContext *, int,
                                                int64_t *, int64_t))
{
    int64_t pos, ts;
    int64_t start_pos;
    int no_change;
    int ret;

    av_dlog(s, "gen_seek: %d %s\n", stream_index, av_ts2str(target_ts));

    if (ts_min == AV_NOPTS_VALUE) {
        pos_min = s->data_offset;
        ts_min  = ff_read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp);
        if (ts_min == AV_NOPTS_VALUE)
            return -1;
    }

    if (ts_min >= target_ts) {
        *ts_ret = ts_min;
        return pos_min;
    }

    if (ts_max == AV_NOPTS_VALUE) {
        if ((ret = ff_find_last_ts(s, stream_index, &ts_max, &pos_max, read_timestamp)) < 0)
            return ret;
        pos_limit = pos_max;
    }

    if (ts_max <= target_ts) {
        *ts_ret = ts_max;
        return pos_max;
    }

    if (ts_min > ts_max)
        return -1;
    else if (ts_min == ts_max)
        pos_limit = pos_min;

    no_change = 0;
    while (pos_min < pos_limit) {
        av_dlog(s,
                "pos_min=0x%"PRIx64" pos_max=0x%"PRIx64" dts_min=%s dts_max=%s\n",
                pos_min, pos_max, av_ts2str(ts_min), av_ts2str(ts_max));
        assert(pos_limit <= pos_max);

        if (no_change == 0) {
            int64_t approximate_keyframe_distance = pos_max - pos_limit;
            // interpolate position (better than dichotomy)
            pos = av_rescale(target_ts - ts_min, pos_max - pos_min,
                             ts_max - ts_min) +
                  pos_min - approximate_keyframe_distance;
        } else if (no_change == 1) {
            // bisection if interpolation did not change min / max pos last time
            pos = (pos_min + pos_limit) >> 1;
        } else {
            /* linear search if bisection failed, can only happen if there
             * are very few or no keyframes between min/max */
            pos = pos_min;
        }
        if (pos <= pos_min)
            pos = pos_min + 1;
        else if (pos > pos_limit)
            pos = pos_limit;
        start_pos = pos;

        // May pass pos_limit instead of -1.
        ts = ff_read_timestamp(s, stream_index, &pos, INT64_MAX, read_timestamp);
        if (pos == pos_max)
            no_change++;
        else
            no_change = 0;
        av_dlog(s, "%"PRId64" %"PRId64" %"PRId64" / %s %s %s"
                " target:%s limit:%"PRId64" start:%"PRId64" noc:%d\n",
                pos_min, pos, pos_max,
                av_ts2str(ts_min), av_ts2str(ts), av_ts2str(ts_max), av_ts2str(target_ts),
                pos_limit, start_pos, no_change);
        if (ts == AV_NOPTS_VALUE) {
            av_log(s, AV_LOG_ERROR, "read_timestamp() failed in the middle\n");
            return -1;
        }
        if (target_ts <= ts) {
            pos_limit = start_pos - 1;
            pos_max   = pos;
            ts_max    = ts;
        }
        if (target_ts >= ts) {
            pos_min = pos;
            ts_min  = ts;
        }
    }

    pos     = (flags & AVSEEK_FLAG_BACKWARD) ? pos_min : pos_max;
    ts      = (flags & AVSEEK_FLAG_BACKWARD) ? ts_min  : ts_max;
#if 0
    pos_min = pos;
    ts_min  = ff_read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp);
    pos_min++;
    ts_max = ff_read_timestamp(s, stream_index, &pos_min, INT64_MAX, read_timestamp);
    av_dlog(s, "pos=0x%"PRIx64" %s<=%s<=%s\n",
            pos, av_ts2str(ts_min), av_ts2str(target_ts), av_ts2str(ts_max));
#endif
    *ts_ret = ts;
    return pos;
}

static int seek_frame_byte(AVFormatContext *s, int stream_index,
                           int64_t pos, int flags)
{
    int64_t pos_min, pos_max;

    pos_min = s->data_offset;
    pos_max = avio_size(s->pb) - 1;

    if (pos < pos_min)
        pos = pos_min;
    else if (pos > pos_max)
        pos = pos_max;

    avio_seek(s->pb, pos, SEEK_SET);

    s->io_repositioned = 1;

    return 0;
}

static int seek_frame_generic(AVFormatContext *s, int stream_index,
                              int64_t timestamp, int flags)
{
    int index;
    int64_t ret;
    AVStream *st;
    AVIndexEntry *ie;

    st = s->streams[stream_index];

    index = av_index_search_timestamp(st, timestamp, flags);

    if (index < 0 && st->nb_index_entries &&
        timestamp < st->index_entries[0].timestamp)
        return -1;

    if (index < 0 || index == st->nb_index_entries - 1) {
        AVPacket pkt;
        int nonkey = 0;

        if (st->nb_index_entries) {
            av_assert0(st->index_entries);
            ie = &st->index_entries[st->nb_index_entries - 1];
            if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0)
                return ret;
            ff_update_cur_dts(s, st, ie->timestamp);
        } else {
            if ((ret = avio_seek(s->pb, s->data_offset, SEEK_SET)) < 0)
                return ret;
        }
        for (;;) {
            int read_status;
            do {
                read_status = av_read_frame(s, &pkt);
            } while (read_status == AVERROR(EAGAIN));
            if (read_status < 0)
                break;
            av_free_packet(&pkt);
            if (stream_index == pkt.stream_index && pkt.dts > timestamp) {
                if (pkt.flags & AV_PKT_FLAG_KEY)
                    break;
                if (nonkey++ > 1000 && st->codec->codec_id != AV_CODEC_ID_CDGRAPHICS) {
                    av_log(s, AV_LOG_ERROR,"seek_frame_generic failed as this stream seems to contain no keyframes after the target timestamp, %d non keyframes found\n", nonkey);
                    break;
                }
            }
        }
        index = av_index_search_timestamp(st, timestamp, flags);
    }
    if (index < 0)
        return -1;

    ff_read_frame_flush(s);
    if (s->iformat->read_seek)
        if (s->iformat->read_seek(s, stream_index, timestamp, flags) >= 0)
            return 0;
    ie = &st->index_entries[index];
    if ((ret = avio_seek(s->pb, ie->pos, SEEK_SET)) < 0)
        return ret;
    ff_update_cur_dts(s, st, ie->timestamp);

    return 0;
}

static int seek_frame_internal(AVFormatContext *s, int stream_index,
                               int64_t timestamp, int flags)
{
    int ret;
    AVStream *st;

    if (flags & AVSEEK_FLAG_BYTE) {
        if (s->iformat->flags & AVFMT_NO_BYTE_SEEK)
            return -1;
        ff_read_frame_flush(s);
        return seek_frame_byte(s, stream_index, timestamp, flags);
    }

    if (stream_index < 0) {
        stream_index = av_find_default_stream_index(s);
        if (stream_index < 0)
            return -1;

        st = s->streams[stream_index];
        /* timestamp for default must be expressed in AV_TIME_BASE units */
        timestamp = av_rescale(timestamp, st->time_base.den,
                               AV_TIME_BASE * (int64_t) st->time_base.num);
    }

    /* first, we try the format specific seek */
    if (s->iformat->read_seek) {
        ff_read_frame_flush(s);
        ret = s->iformat->read_seek(s, stream_index, timestamp, flags);
    } else
        ret = -1;
    if (ret >= 0)
        return 0;

    if (s->iformat->read_timestamp &&
        !(s->iformat->flags & AVFMT_NOBINSEARCH)) {
        ff_read_frame_flush(s);
        return ff_seek_frame_binary(s, stream_index, timestamp, flags);
    } else if (!(s->iformat->flags & AVFMT_NOGENSEARCH)) {
        ff_read_frame_flush(s);
        return seek_frame_generic(s, stream_index, timestamp, flags);
    } else
        return -1;
}

int av_seek_frame(AVFormatContext *s, int stream_index,
                  int64_t timestamp, int flags)
{
    int ret;

    if (s->iformat->read_seek2 && !s->iformat->read_seek) {
        int64_t min_ts = INT64_MIN, max_ts = INT64_MAX;
        if ((flags & AVSEEK_FLAG_BACKWARD))
            max_ts = timestamp;
        else
            min_ts = timestamp;
        return avformat_seek_file(s, stream_index, min_ts, timestamp, max_ts,
                                  flags & ~AVSEEK_FLAG_BACKWARD);
    }

    ret = seek_frame_internal(s, stream_index, timestamp, flags);

    if (ret >= 0)
        ret = avformat_queue_attached_pictures(s);

    return ret;
}

int avformat_seek_file(AVFormatContext *s, int stream_index, int64_t min_ts,
                       int64_t ts, int64_t max_ts, int flags)
{
    if (min_ts > ts || max_ts < ts)
        return -1;
    if (stream_index < -1 || stream_index >= (int)s->nb_streams)
        return AVERROR(EINVAL);

    if (s->seek2any>0)
        flags |= AVSEEK_FLAG_ANY;
    flags &= ~AVSEEK_FLAG_BACKWARD;

    if (s->iformat->read_seek2) {
        int ret;
        ff_read_frame_flush(s);

        if (stream_index == -1 && s->nb_streams == 1) {
            AVRational time_base = s->streams[0]->time_base;
            ts = av_rescale_q(ts, AV_TIME_BASE_Q, time_base);
            min_ts = av_rescale_rnd(min_ts, time_base.den,
                                    time_base.num * (int64_t)AV_TIME_BASE,
                                    AV_ROUND_UP   | AV_ROUND_PASS_MINMAX);
            max_ts = av_rescale_rnd(max_ts, time_base.den,
                                    time_base.num * (int64_t)AV_TIME_BASE,
                                    AV_ROUND_DOWN | AV_ROUND_PASS_MINMAX);
        }

        ret = s->iformat->read_seek2(s, stream_index, min_ts,
                                     ts, max_ts, flags);

        if (ret >= 0)
            ret = avformat_queue_attached_pictures(s);
        return ret;
    }

    if (s->iformat->read_timestamp) {
        // try to seek via read_timestamp()
    }

    // Fall back on old API if new is not implemented but old is.
    // Note the old API has somewhat different semantics.
    if (s->iformat->read_seek || 1) {
        int dir = (ts - (uint64_t)min_ts > (uint64_t)max_ts - ts ? AVSEEK_FLAG_BACKWARD : 0);
        int ret = av_seek_frame(s, stream_index, ts, flags | dir);
        if (ret<0 && ts != min_ts && max_ts != ts) {
            ret = av_seek_frame(s, stream_index, dir ? max_ts : min_ts, flags | dir);
            if (ret >= 0)
                ret = av_seek_frame(s, stream_index, ts, flags | (dir^AVSEEK_FLAG_BACKWARD));
        }
        return ret;
    }

    // try some generic seek like seek_frame_generic() but with new ts semantics
    return -1; //unreachable
}

/*******************************************************/

/**
 * Return TRUE if the stream has accurate duration in any stream.
 *
 * @return TRUE if the stream has accurate duration for at least one component.
 */
static int has_duration(AVFormatContext *ic)
{
    int i;
    AVStream *st;

    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        if (st->duration != AV_NOPTS_VALUE)
            return 1;
    }
    if (ic->duration != AV_NOPTS_VALUE)
        return 1;
    return 0;
}

/**
 * Estimate the stream timings from the one of each components.
 *
 * Also computes the global bitrate if possible.
 */
static void update_stream_timings(AVFormatContext *ic)
{
    int64_t start_time, start_time1, start_time_text, end_time, end_time1;
    int64_t duration, duration1, filesize;
    int i;
    AVStream *st;
    AVProgram *p;

    start_time = INT64_MAX;
    start_time_text = INT64_MAX;
    end_time   = INT64_MIN;
    duration   = INT64_MIN;
    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        if (st->start_time != AV_NOPTS_VALUE && st->time_base.den) {
            start_time1 = av_rescale_q(st->start_time, st->time_base,
                                       AV_TIME_BASE_Q);
            if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE || st->codec->codec_type == AVMEDIA_TYPE_DATA) {
                if (start_time1 < start_time_text)
                    start_time_text = start_time1;
            } else
                start_time = FFMIN(start_time, start_time1);
            end_time1   = AV_NOPTS_VALUE;
            if (st->duration != AV_NOPTS_VALUE) {
                end_time1 = start_time1 +
                            av_rescale_q(st->duration, st->time_base,
                                         AV_TIME_BASE_Q);
                end_time = FFMAX(end_time, end_time1);
            }
            for (p = NULL; (p = av_find_program_from_stream(ic, p, i)); ) {
                if (p->start_time == AV_NOPTS_VALUE || p->start_time > start_time1)
                    p->start_time = start_time1;
                if (p->end_time < end_time1)
                    p->end_time = end_time1;
            }
        }
        if (st->duration != AV_NOPTS_VALUE) {
            duration1 = av_rescale_q(st->duration, st->time_base,
                                     AV_TIME_BASE_Q);
            duration  = FFMAX(duration, duration1);
        }
    }
    if (start_time == INT64_MAX || (start_time > start_time_text && start_time - start_time_text < AV_TIME_BASE))
        start_time = start_time_text;
    else if (start_time > start_time_text)
        av_log(ic, AV_LOG_VERBOSE, "Ignoring outlier non primary stream starttime %f\n", start_time_text / (float)AV_TIME_BASE);

    if (start_time != INT64_MAX) {
        ic->start_time = start_time;
        if (end_time != INT64_MIN) {
            if (ic->nb_programs) {
                for (i = 0; i < ic->nb_programs; i++) {
                    p = ic->programs[i];
                    if (p->start_time != AV_NOPTS_VALUE && p->end_time > p->start_time)
                        duration = FFMAX(duration, p->end_time - p->start_time);
                }
            } else
                duration = FFMAX(duration, end_time - start_time);
        }
    }
    if (duration != INT64_MIN && duration > 0 && ic->duration == AV_NOPTS_VALUE) {
        ic->duration = duration;
    }
    if (ic->pb && (filesize = avio_size(ic->pb)) > 0 && ic->duration != AV_NOPTS_VALUE) {
        /* compute the bitrate */
        double bitrate = (double) filesize * 8.0 * AV_TIME_BASE /
                         (double) ic->duration;
        if (bitrate >= 0 && bitrate <= INT_MAX)
            ic->bit_rate = bitrate;
    }
}

static void fill_all_stream_timings(AVFormatContext *ic)
{
    int i;
    AVStream *st;

    update_stream_timings(ic);
    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        if (st->start_time == AV_NOPTS_VALUE) {
            if (ic->start_time != AV_NOPTS_VALUE)
                st->start_time = av_rescale_q(ic->start_time, AV_TIME_BASE_Q,
                                              st->time_base);
            if (ic->duration != AV_NOPTS_VALUE)
                st->duration = av_rescale_q(ic->duration, AV_TIME_BASE_Q,
                                            st->time_base);
        }
    }
}

static void estimate_timings_from_bit_rate(AVFormatContext *ic)
{
    int64_t filesize, duration;
    int i, show_warning = 0;
    AVStream *st;

    /* if bit_rate is already set, we believe it */
    if (ic->bit_rate <= 0) {
        int bit_rate = 0;
        for (i = 0; i < ic->nb_streams; i++) {
            st = ic->streams[i];
            if (st->codec->bit_rate > 0) {
                if (INT_MAX - st->codec->bit_rate < bit_rate) {
                    bit_rate = 0;
                    break;
                }
                bit_rate += st->codec->bit_rate;
            }
        }
        ic->bit_rate = bit_rate;
    }

    /* if duration is already set, we believe it */
    if (ic->duration == AV_NOPTS_VALUE &&
        ic->bit_rate != 0) {
        filesize = ic->pb ? avio_size(ic->pb) : 0;
        if (filesize > ic->data_offset) {
            filesize -= ic->data_offset;
            for (i = 0; i < ic->nb_streams; i++) {
                st      = ic->streams[i];
                if (   st->time_base.num <= INT64_MAX / ic->bit_rate
                    && st->duration == AV_NOPTS_VALUE) {
                    duration = av_rescale(8 * filesize, st->time_base.den,
                                          ic->bit_rate *
                                          (int64_t) st->time_base.num);
                    st->duration = duration;
                    show_warning = 1;
                }
            }
        }
    }
    if (show_warning)
        av_log(ic, AV_LOG_WARNING,
               "Estimating duration from bitrate, this may be inaccurate\n");
}

#define DURATION_MAX_READ_SIZE 250000LL
#define DURATION_MAX_RETRY 4

/* only usable for MPEG-PS streams */
static void estimate_timings_from_pts(AVFormatContext *ic, int64_t old_offset)
{
    AVPacket pkt1, *pkt = &pkt1;
    AVStream *st;
    int num, den, read_size, i, ret;
    int found_duration = 0;
    int is_end;
    int64_t filesize, offset, duration;
    int retry = 0;

    /* flush packet queue */
    flush_packet_queue(ic);

    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        if (st->start_time == AV_NOPTS_VALUE &&
            st->first_dts == AV_NOPTS_VALUE &&
            st->codec->codec_type != AVMEDIA_TYPE_UNKNOWN)
            av_log(st->codec, AV_LOG_WARNING,
                   "start time for stream %d is not set in estimate_timings_from_pts\n", i);

        if (st->parser) {
            av_parser_close(st->parser);
            st->parser = NULL;
        }
    }

    av_opt_set(ic, "skip_changes", "1", AV_OPT_SEARCH_CHILDREN);
    /* estimate the end time (duration) */
    /* XXX: may need to support wrapping */
    filesize = ic->pb ? avio_size(ic->pb) : 0;
    do {
        is_end = found_duration;
        offset = filesize - (DURATION_MAX_READ_SIZE << retry);
        if (offset < 0)
            offset = 0;

        avio_seek(ic->pb, offset, SEEK_SET);
        read_size = 0;
        for (;;) {
            if (read_size >= DURATION_MAX_READ_SIZE << (FFMAX(retry - 1, 0)))
                break;

            do {
                ret = ff_read_packet(ic, pkt);
            } while (ret == AVERROR(EAGAIN));
            if (ret != 0)
                break;
            read_size += pkt->size;
            st         = ic->streams[pkt->stream_index];
            if (pkt->pts != AV_NOPTS_VALUE &&
                (st->start_time != AV_NOPTS_VALUE ||
                 st->first_dts  != AV_NOPTS_VALUE)) {
                if (pkt->duration == 0) {
                    ff_compute_frame_duration(ic, &num, &den, st, st->parser, pkt);
                    if (den && num) {
                        pkt->duration = av_rescale_rnd(1,
                                           num * (int64_t) st->time_base.den,
                                           den * (int64_t) st->time_base.num,
                                           AV_ROUND_DOWN);
                    }
                }
                duration = pkt->pts + pkt->duration;
                found_duration = 1;
                if (st->start_time != AV_NOPTS_VALUE)
                    duration -= st->start_time;
                else
                    duration -= st->first_dts;
                if (duration > 0) {
                    if (st->duration == AV_NOPTS_VALUE || st->info->last_duration<= 0 ||
                        (st->duration < duration && FFABS(duration - st->info->last_duration) < 60LL*st->time_base.den / st->time_base.num))
                        st->duration = duration;
                    st->info->last_duration = duration;
                }
            }
            av_free_packet(pkt);
        }

        /* check if all audio/video streams have valid duration */
        if (!is_end) {
            is_end = 1;
            for (i = 0; i < ic->nb_streams; i++) {
                st = ic->streams[i];
                switch (st->codec->codec_type) {
                    case AVMEDIA_TYPE_VIDEO:
                    case AVMEDIA_TYPE_AUDIO:
                        if (st->duration == AV_NOPTS_VALUE)
                            is_end = 0;
                }
            }
        }
    } while (!is_end &&
             offset &&
             ++retry <= DURATION_MAX_RETRY);

    av_opt_set(ic, "skip_changes", "0", AV_OPT_SEARCH_CHILDREN);

    /* warn about audio/video streams which duration could not be estimated */
    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        if (st->duration == AV_NOPTS_VALUE) {
            switch (st->codec->codec_type) {
            case AVMEDIA_TYPE_VIDEO:
            case AVMEDIA_TYPE_AUDIO:
                if (st->start_time != AV_NOPTS_VALUE || st->first_dts  != AV_NOPTS_VALUE) {
                    av_log(ic, AV_LOG_DEBUG, "stream %d : no PTS found at end of file, duration not set\n", i);
                } else
                    av_log(ic, AV_LOG_DEBUG, "stream %d : no TS found at start of file, duration not set\n", i);
            }
        }
    }
    fill_all_stream_timings(ic);

    avio_seek(ic->pb, old_offset, SEEK_SET);
    for (i = 0; i < ic->nb_streams; i++) {
        int j;

        st              = ic->streams[i];
        st->cur_dts     = st->first_dts;
        st->last_IP_pts = AV_NOPTS_VALUE;
        st->last_dts_for_order_check = AV_NOPTS_VALUE;
        for (j = 0; j < MAX_REORDER_DELAY + 1; j++)
            st->pts_buffer[j] = AV_NOPTS_VALUE;
    }
}

static void estimate_timings(AVFormatContext *ic, int64_t old_offset)
{
    int64_t file_size;

    /* get the file size, if possible */
    if (ic->iformat->flags & AVFMT_NOFILE) {
        file_size = 0;
    } else {
        file_size = avio_size(ic->pb);
        file_size = FFMAX(0, file_size);
    }

    if ((!strcmp(ic->iformat->name, "mpeg") ||
         !strcmp(ic->iformat->name, "mpegts")) &&
        file_size && ic->pb->seekable) {
        /* get accurate estimate from the PTSes */
        estimate_timings_from_pts(ic, old_offset);
        ic->duration_estimation_method = AVFMT_DURATION_FROM_PTS;
    } else if (has_duration(ic)) {
        /* at least one component has timings - we use them for all
         * the components */
        fill_all_stream_timings(ic);
        ic->duration_estimation_method = AVFMT_DURATION_FROM_STREAM;
    } else {
        /* less precise: use bitrate info */
        estimate_timings_from_bit_rate(ic);
        ic->duration_estimation_method = AVFMT_DURATION_FROM_BITRATE;
    }
    update_stream_timings(ic);

    {
        int i;
        AVStream av_unused *st;
        for (i = 0; i < ic->nb_streams; i++) {
            st = ic->streams[i];
            av_dlog(ic, "%d: start_time: %0.3f duration: %0.3f\n", i,
                    (double) st->start_time / AV_TIME_BASE,
                    (double) st->duration   / AV_TIME_BASE);
        }
        av_dlog(ic,
                "stream: start_time: %0.3f duration: %0.3f bitrate=%d kb/s\n",
                (double) ic->start_time / AV_TIME_BASE,
                (double) ic->duration   / AV_TIME_BASE,
                ic->bit_rate / 1000);
    }
}

static int has_codec_parameters(AVStream *st, const char **errmsg_ptr)
{
    AVCodecContext *avctx = st->codec;

#define FAIL(errmsg) do {                                         \
        if (errmsg_ptr)                                           \
            *errmsg_ptr = errmsg;                                 \
        return 0;                                                 \
    } while (0)

    if (   avctx->codec_id == AV_CODEC_ID_NONE
        && avctx->codec_type != AVMEDIA_TYPE_DATA)
        FAIL("unknown codec");
    switch (avctx->codec_type) {
    case AVMEDIA_TYPE_AUDIO:
        if (!avctx->frame_size && determinable_frame_size(avctx))
            FAIL("unspecified frame size");
        if (st->info->found_decoder >= 0 &&
            avctx->sample_fmt == AV_SAMPLE_FMT_NONE)
            FAIL("unspecified sample format");
        if (!avctx->sample_rate)
            FAIL("unspecified sample rate");
        if (!avctx->channels)
            FAIL("unspecified number of channels");
        if (st->info->found_decoder >= 0 && !st->nb_decoded_frames && avctx->codec_id == AV_CODEC_ID_DTS)
            FAIL("no decodable DTS frames");
        break;
    case AVMEDIA_TYPE_VIDEO:
        if (!avctx->width)
            FAIL("unspecified size");
        if (st->info->found_decoder >= 0 && avctx->pix_fmt == AV_PIX_FMT_NONE)
            FAIL("unspecified pixel format");
        if (st->codec->codec_id == AV_CODEC_ID_RV30 || st->codec->codec_id == AV_CODEC_ID_RV40)
            if (!st->sample_aspect_ratio.num && !st->codec->sample_aspect_ratio.num && !st->codec_info_nb_frames)
                FAIL("no frame in rv30/40 and no sar");
        break;
    case AVMEDIA_TYPE_SUBTITLE:
        if (avctx->codec_id == AV_CODEC_ID_HDMV_PGS_SUBTITLE && !avctx->width)
            FAIL("unspecified size");
        break;
    case AVMEDIA_TYPE_DATA:
        if (avctx->codec_id == AV_CODEC_ID_NONE) return 1;
    }

    return 1;
}

/* returns 1 or 0 if or if not decoded data was returned, or a negative error */
static int try_decode_frame(AVFormatContext *s, AVStream *st, AVPacket *avpkt,
                            AVDictionary **options)
{
    const AVCodec *codec;
    int got_picture = 1, ret = 0;
    AVFrame *frame = av_frame_alloc();
    AVSubtitle subtitle;
    AVPacket pkt = *avpkt;

    if (!frame)
        return AVERROR(ENOMEM);

    if (!avcodec_is_open(st->codec) &&
        st->info->found_decoder <= 0 &&
        (st->codec->codec_id != -st->info->found_decoder || !st->codec->codec_id)) {
        AVDictionary *thread_opt = NULL;

        codec = find_decoder(s, st, st->codec->codec_id);

        if (!codec) {
            st->info->found_decoder = -st->codec->codec_id;
            ret                     = -1;
            goto fail;
        }

        /* Force thread count to 1 since the H.264 decoder will not extract
         * SPS and PPS to extradata during multi-threaded decoding. */
        av_dict_set(options ? options : &thread_opt, "threads", "1", 0);
        if (s->codec_whitelist)
            av_dict_set(options ? options : &thread_opt, "codec_whitelist", s->codec_whitelist, 0);
        ret = avcodec_open2(st->codec, codec, options ? options : &thread_opt);
        if (!options)
            av_dict_free(&thread_opt);
        if (ret < 0) {
            st->info->found_decoder = -st->codec->codec_id;
            goto fail;
        }
        st->info->found_decoder = 1;
    } else if (!st->info->found_decoder)
        st->info->found_decoder = 1;

    if (st->info->found_decoder < 0) {
        ret = -1;
        goto fail;
    }

    while ((pkt.size > 0 || (!pkt.data && got_picture)) &&
           ret >= 0 &&
           (!has_codec_parameters(st, NULL) || !has_decode_delay_been_guessed(st) ||
            (!st->codec_info_nb_frames &&
             st->codec->codec->capabilities & CODEC_CAP_CHANNEL_CONF))) {
        got_picture = 0;
        switch (st->codec->codec_type) {
        case AVMEDIA_TYPE_VIDEO:
            ret = avcodec_decode_video2(st->codec, frame,
                                        &got_picture, &pkt);
            break;
        case AVMEDIA_TYPE_AUDIO:
            ret = avcodec_decode_audio4(st->codec, frame, &got_picture, &pkt);
            break;
        case AVMEDIA_TYPE_SUBTITLE:
            ret = avcodec_decode_subtitle2(st->codec, &subtitle,
                                           &got_picture, &pkt);
            ret = pkt.size;
            break;
        default:
            break;
        }
        if (ret >= 0) {
            if (got_picture)
                st->nb_decoded_frames++;
            pkt.data += ret;
            pkt.size -= ret;
            ret       = got_picture;
        }
    }

    if (!pkt.data && !got_picture)
        ret = -1;

fail:
    av_frame_free(&frame);
    return ret;
}

unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id)
{
    while (tags->id != AV_CODEC_ID_NONE) {
        if (tags->id == id)
            return tags->tag;
        tags++;
    }
    return 0;
}

enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
{
    int i;
    for (i = 0; tags[i].id != AV_CODEC_ID_NONE; i++)
        if (tag == tags[i].tag)
            return tags[i].id;
    for (i = 0; tags[i].id != AV_CODEC_ID_NONE; i++)
        if (avpriv_toupper4(tag) == avpriv_toupper4(tags[i].tag))
            return tags[i].id;
    return AV_CODEC_ID_NONE;
}

enum AVCodecID ff_get_pcm_codec_id(int bps, int flt, int be, int sflags)
{
    if (flt) {
        switch (bps) {
        case 32:
            return be ? AV_CODEC_ID_PCM_F32BE : AV_CODEC_ID_PCM_F32LE;
        case 64:
            return be ? AV_CODEC_ID_PCM_F64BE : AV_CODEC_ID_PCM_F64LE;
        default:
            return AV_CODEC_ID_NONE;
        }
    } else {
        bps  += 7;
        bps >>= 3;
        if (sflags & (1 << (bps - 1))) {
            switch (bps) {
            case 1:
                return AV_CODEC_ID_PCM_S8;
            case 2:
                return be ? AV_CODEC_ID_PCM_S16BE : AV_CODEC_ID_PCM_S16LE;
            case 3:
                return be ? AV_CODEC_ID_PCM_S24BE : AV_CODEC_ID_PCM_S24LE;
            case 4:
                return be ? AV_CODEC_ID_PCM_S32BE : AV_CODEC_ID_PCM_S32LE;
            default:
                return AV_CODEC_ID_NONE;
            }
        } else {
            switch (bps) {
            case 1:
                return AV_CODEC_ID_PCM_U8;
            case 2:
                return be ? AV_CODEC_ID_PCM_U16BE : AV_CODEC_ID_PCM_U16LE;
            case 3:
                return be ? AV_CODEC_ID_PCM_U24BE : AV_CODEC_ID_PCM_U24LE;
            case 4:
                return be ? AV_CODEC_ID_PCM_U32BE : AV_CODEC_ID_PCM_U32LE;
            default:
                return AV_CODEC_ID_NONE;
            }
        }
    }
}

unsigned int av_codec_get_tag(const AVCodecTag *const *tags, enum AVCodecID id)
{
    unsigned int tag;
    if (!av_codec_get_tag2(tags, id, &tag))
        return 0;
    return tag;
}

int av_codec_get_tag2(const AVCodecTag * const *tags, enum AVCodecID id,
                      unsigned int *tag)
{
    int i;
    for (i = 0; tags && tags[i]; i++) {
        const AVCodecTag *codec_tags = tags[i];
        while (codec_tags->id != AV_CODEC_ID_NONE) {
            if (codec_tags->id == id) {
                *tag = codec_tags->tag;
                return 1;
            }
            codec_tags++;
        }
    }
    return 0;
}

enum AVCodecID av_codec_get_id(const AVCodecTag *const *tags, unsigned int tag)
{
    int i;
    for (i = 0; tags && tags[i]; i++) {
        enum AVCodecID id = ff_codec_get_id(tags[i], tag);
        if (id != AV_CODEC_ID_NONE)
            return id;
    }
    return AV_CODEC_ID_NONE;
}

static void compute_chapters_end(AVFormatContext *s)
{
    unsigned int i, j;
    int64_t max_time = s->duration +
                       ((s->start_time == AV_NOPTS_VALUE) ? 0 : s->start_time);

    for (i = 0; i < s->nb_chapters; i++)
        if (s->chapters[i]->end == AV_NOPTS_VALUE) {
            AVChapter *ch = s->chapters[i];
            int64_t end = max_time ? av_rescale_q(max_time, AV_TIME_BASE_Q,
                                                  ch->time_base)
                                   : INT64_MAX;

            for (j = 0; j < s->nb_chapters; j++) {
                AVChapter *ch1     = s->chapters[j];
                int64_t next_start = av_rescale_q(ch1->start, ch1->time_base,
                                                  ch->time_base);
                if (j != i && next_start > ch->start && next_start < end)
                    end = next_start;
            }
            ch->end = (end == INT64_MAX) ? ch->start : end;
        }
}

static int get_std_framerate(int i)
{
    if (i < 30*12)
        return (i + 1) * 1001;
    i -= 30*12;

    if (i < 7)
        return ((const int[]) { 40, 48, 50, 60, 80, 120, 240})[i] * 1001 * 12;

    i -= 7;

    return ((const int[]) { 24, 30, 60, 12, 15, 48 })[i] * 1000 * 12;
}

/* Is the time base unreliable?
 * This is a heuristic to balance between quick acceptance of the values in
 * the headers vs. some extra checks.
 * Old DivX and Xvid often have nonsense timebases like 1fps or 2fps.
 * MPEG-2 commonly misuses field repeat flags to store different framerates.
 * And there are "variable" fps files this needs to detect as well. */
static int tb_unreliable(AVCodecContext *c)
{
    if (c->time_base.den >= 101L * c->time_base.num ||
        c->time_base.den <    5L * c->time_base.num ||
        // c->codec_tag == AV_RL32("DIVX") ||
        // c->codec_tag == AV_RL32("XVID") ||
        c->codec_tag == AV_RL32("mp4v") ||
        c->codec_id == AV_CODEC_ID_MPEG2VIDEO ||
        c->codec_id == AV_CODEC_ID_GIF ||
        c->codec_id == AV_CODEC_ID_H264)
        return 1;
    return 0;
}

int ff_alloc_extradata(AVCodecContext *avctx, int size)
{
    int ret;

    if (size < 0 || size >= INT32_MAX - FF_INPUT_BUFFER_PADDING_SIZE) {
        avctx->extradata_size = 0;
        return AVERROR(EINVAL);
    }
    avctx->extradata = av_malloc(size + FF_INPUT_BUFFER_PADDING_SIZE);
    if (avctx->extradata) {
        memset(avctx->extradata + size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
        avctx->extradata_size = size;
        ret = 0;
    } else {
        avctx->extradata_size = 0;
        ret = AVERROR(ENOMEM);
    }
    return ret;
}

int ff_get_extradata(AVCodecContext *avctx, AVIOContext *pb, int size)
{
    int ret = ff_alloc_extradata(avctx, size);
    if (ret < 0)
        return ret;
    ret = avio_read(pb, avctx->extradata, size);
    if (ret != size) {
        av_freep(&avctx->extradata);
        avctx->extradata_size = 0;
        av_log(avctx, AV_LOG_ERROR, "Failed to read extradata of size %d\n", size);
        return ret < 0 ? ret : AVERROR_INVALIDDATA;
    }

    return ret;
}

int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t ts)
{
    int i, j;
    int64_t last = st->info->last_dts;

    if (   ts != AV_NOPTS_VALUE && last != AV_NOPTS_VALUE && ts > last
       && ts - (uint64_t)last < INT64_MAX) {
        double dts = (is_relative(ts) ?  ts - RELATIVE_TS_BASE : ts) * av_q2d(st->time_base);
        int64_t duration = ts - last;

        if (!st->info->duration_error)
            st->info->duration_error = av_mallocz(sizeof(st->info->duration_error[0])*2);
        if (!st->info->duration_error)
            return AVERROR(ENOMEM);

//         if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO)
//             av_log(NULL, AV_LOG_ERROR, "%f\n", dts);
        for (i = 0; i<MAX_STD_TIMEBASES; i++) {
            if (st->info->duration_error[0][1][i] < 1e10) {
                int framerate = get_std_framerate(i);
                double sdts = dts*framerate/(1001*12);
                for (j= 0; j<2; j++) {
                    int64_t ticks = llrint(sdts+j*0.5);
                    double error= sdts - ticks + j*0.5;
                    st->info->duration_error[j][0][i] += error;
                    st->info->duration_error[j][1][i] += error*error;
                }
            }
        }
        st->info->duration_count++;
        st->info->rfps_duration_sum += duration;

        if (st->info->duration_count % 10 == 0) {
            int n = st->info->duration_count;
            for (i = 0; i<MAX_STD_TIMEBASES; i++) {
                if (st->info->duration_error[0][1][i] < 1e10) {
                    double a0     = st->info->duration_error[0][0][i] / n;
                    double error0 = st->info->duration_error[0][1][i] / n - a0*a0;
                    double a1     = st->info->duration_error[1][0][i] / n;
                    double error1 = st->info->duration_error[1][1][i] / n - a1*a1;
                    if (error0 > 0.04 && error1 > 0.04) {
                        st->info->duration_error[0][1][i] = 2e10;
                        st->info->duration_error[1][1][i] = 2e10;
                    }
                }
            }
        }

        // ignore the first 4 values, they might have some random jitter
        if (st->info->duration_count > 3 && is_relative(ts) == is_relative(last))
            st->info->duration_gcd = av_gcd(st->info->duration_gcd, duration);
    }
    if (ts != AV_NOPTS_VALUE)
        st->info->last_dts = ts;

    return 0;
}

void ff_rfps_calculate(AVFormatContext *ic)
{
    int i, j;

    for (i = 0; i < ic->nb_streams; i++) {
        AVStream *st = ic->streams[i];

        if (st->codec->codec_type != AVMEDIA_TYPE_VIDEO)
            continue;
        // the check for tb_unreliable() is not completely correct, since this is not about handling
        // a unreliable/inexact time base, but a time base that is finer than necessary, as e.g.
        // ipmovie.c produces.
        if (tb_unreliable(st->codec) && st->info->duration_count > 15 && st->info->duration_gcd > FFMAX(1, st->time_base.den/(500LL*st->time_base.num)) && !st->r_frame_rate.num)
            av_reduce(&st->r_frame_rate.num, &st->r_frame_rate.den, st->time_base.den, st->time_base.num * st->info->duration_gcd, INT_MAX);
        if (st->info->duration_count>1 && !st->r_frame_rate.num
            && tb_unreliable(st->codec)) {
            int num = 0;
            double best_error= 0.01;
            AVRational ref_rate = st->r_frame_rate.num ? st->r_frame_rate : av_inv_q(st->time_base);

            for (j= 0; j<MAX_STD_TIMEBASES; j++) {
                int k;

                if (st->info->codec_info_duration && st->info->codec_info_duration*av_q2d(st->time_base) < (1001*12.0)/get_std_framerate(j))
                    continue;
                if (!st->info->codec_info_duration && 1.0 < (1001*12.0)/get_std_framerate(j))
                    continue;

                if (av_q2d(st->time_base) * st->info->rfps_duration_sum / st->info->duration_count < (1001*12.0 * 0.8)/get_std_framerate(j))
                    continue;

                for (k= 0; k<2; k++) {
                    int n = st->info->duration_count;
                    double a= st->info->duration_error[k][0][j] / n;
                    double error= st->info->duration_error[k][1][j]/n - a*a;

                    if (error < best_error && best_error> 0.000000001) {
                        best_error= error;
                        num = get_std_framerate(j);
                    }
                    if (error < 0.02)
                        av_log(NULL, AV_LOG_DEBUG, "rfps: %f %f\n", get_std_framerate(j) / 12.0/1001, error);
                }
            }
            // do not increase frame rate by more than 1 % in order to match a standard rate.
            if (num && (!ref_rate.num || (double)num/(12*1001) < 1.01 * av_q2d(ref_rate)))
                av_reduce(&st->r_frame_rate.num, &st->r_frame_rate.den, num, 12*1001, INT_MAX);
        }
        if (   !st->avg_frame_rate.num
            && st->r_frame_rate.num && st->info->rfps_duration_sum
            && st->info->codec_info_duration <= 0
            && st->info->duration_count > 2
            && fabs(1.0 / (av_q2d(st->r_frame_rate) * av_q2d(st->time_base)) - st->info->rfps_duration_sum / (double)st->info->duration_count) <= 1.0
            ) {
            av_log(ic, AV_LOG_DEBUG, "Setting avg frame rate based on r frame rate\n");
            st->avg_frame_rate = st->r_frame_rate;
        }

        av_freep(&st->info->duration_error);
        st->info->last_dts = AV_NOPTS_VALUE;
        st->info->duration_count = 0;
        st->info->rfps_duration_sum = 0;
    }
}

int avformat_find_stream_info(AVFormatContext *ic, AVDictionary **options)
{
    int i, count, ret = 0, j;
    int64_t read_size;
    AVStream *st;
    AVPacket pkt1, *pkt;
    int64_t old_offset  = avio_tell(ic->pb);
    // new streams might appear, no options for those
    int orig_nb_streams = ic->nb_streams;
    int flush_codecs;
    int64_t max_analyze_duration = ic->max_analyze_duration2;
    int64_t max_stream_analyze_duration;
    int64_t probesize = ic->probesize2;

    if (!max_analyze_duration)
        max_analyze_duration = ic->max_analyze_duration;
    if (ic->probesize)
        probesize = ic->probesize;
    flush_codecs = probesize > 0;

    av_opt_set(ic, "skip_clear", "1", AV_OPT_SEARCH_CHILDREN);

    max_stream_analyze_duration = max_analyze_duration;
    if (!max_analyze_duration) {
        max_stream_analyze_duration =
        max_analyze_duration        = 5*AV_TIME_BASE;
        if (!strcmp(ic->iformat->name, "flv"))
            max_stream_analyze_duration = 30*AV_TIME_BASE;
    }

    if (ic->pb)
        av_log(ic, AV_LOG_DEBUG, "Before avformat_find_stream_info() pos: %"PRId64" bytes read:%"PRId64" seeks:%d\n",
               avio_tell(ic->pb), ic->pb->bytes_read, ic->pb->seek_count);

    for (i = 0; i < ic->nb_streams; i++) {
        const AVCodec *codec;
        AVDictionary *thread_opt = NULL;
        st = ic->streams[i];

        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO ||
            st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE) {
/*            if (!st->time_base.num)
                st->time_base = */
            if (!st->codec->time_base.num)
                st->codec->time_base = st->time_base;
        }
        // only for the split stuff
        if (!st->parser && !(ic->flags & AVFMT_FLAG_NOPARSE)) {
            st->parser = av_parser_init(st->codec->codec_id);
            if (st->parser) {
                if (st->need_parsing == AVSTREAM_PARSE_HEADERS) {
                    st->parser->flags |= PARSER_FLAG_COMPLETE_FRAMES;
                } else if (st->need_parsing == AVSTREAM_PARSE_FULL_RAW) {
                    st->parser->flags |= PARSER_FLAG_USE_CODEC_TS;
                }
            } else if (st->need_parsing) {
                av_log(ic, AV_LOG_VERBOSE, "parser not found for codec "
                       "%s, packets or times may be invalid.\n",
                       avcodec_get_name(st->codec->codec_id));
            }
        }
        codec = find_decoder(ic, st, st->codec->codec_id);

        /* Force thread count to 1 since the H.264 decoder will not extract
         * SPS and PPS to extradata during multi-threaded decoding. */
        av_dict_set(options ? &options[i] : &thread_opt, "threads", "1", 0);

        if (ic->codec_whitelist)
            av_dict_set(options ? &options[i] : &thread_opt, "codec_whitelist", ic->codec_whitelist, 0);

        /* Ensure that subtitle_header is properly set. */
        if (st->codec->codec_type == AVMEDIA_TYPE_SUBTITLE
            && codec && !st->codec->codec) {
            if (avcodec_open2(st->codec, codec, options ? &options[i] : &thread_opt) < 0)
                av_log(ic, AV_LOG_WARNING,
                       "Failed to open codec in av_find_stream_info\n");
        }

        // Try to just open decoders, in case this is enough to get parameters.
        if (!has_codec_parameters(st, NULL) && st->request_probe <= 0) {
            if (codec && !st->codec->codec)
                if (avcodec_open2(st->codec, codec, options ? &options[i] : &thread_opt) < 0)
                    av_log(ic, AV_LOG_WARNING,
                           "Failed to open codec in av_find_stream_info\n");
        }
        if (!options)
            av_dict_free(&thread_opt);
    }

    for (i = 0; i < ic->nb_streams; i++) {
#if FF_API_R_FRAME_RATE
        ic->streams[i]->info->last_dts = AV_NOPTS_VALUE;
#endif
        ic->streams[i]->info->fps_first_dts = AV_NOPTS_VALUE;
        ic->streams[i]->info->fps_last_dts  = AV_NOPTS_VALUE;
    }

    count     = 0;
    read_size = 0;
    for (;;) {
        int analyzed_all_streams;
        if (ff_check_interrupt(&ic->interrupt_callback)) {
            ret = AVERROR_EXIT;
            av_log(ic, AV_LOG_DEBUG, "interrupted\n");
            break;
        }

        /* check if one codec still needs to be handled */
        for (i = 0; i < ic->nb_streams; i++) {
            int fps_analyze_framecount = 20;

            st = ic->streams[i];
            if (!has_codec_parameters(st, NULL))
                break;
            /* If the timebase is coarse (like the usual millisecond precision
             * of mkv), we need to analyze more frames to reliably arrive at
             * the correct fps. */
            if (av_q2d(st->time_base) > 0.0005)
                fps_analyze_framecount *= 2;
            if (!tb_unreliable(st->codec))
                fps_analyze_framecount = 0;
            if (ic->fps_probe_size >= 0)
                fps_analyze_framecount = ic->fps_probe_size;
            if (st->disposition & AV_DISPOSITION_ATTACHED_PIC)
                fps_analyze_framecount = 0;
            /* variable fps and no guess at the real fps */
            if (!(st->r_frame_rate.num && st->avg_frame_rate.num) &&
                st->info->duration_count < fps_analyze_framecount &&
                st->codec->codec_type == AVMEDIA_TYPE_VIDEO)
                break;
            if (st->parser && st->parser->parser->split &&
                !st->codec->extradata)
                break;
            if (st->first_dts == AV_NOPTS_VALUE &&
                !(ic->iformat->flags & AVFMT_NOTIMESTAMPS) &&
                st->codec_info_nb_frames < ic->max_ts_probe &&
                (st->codec->codec_type == AVMEDIA_TYPE_VIDEO ||
                 st->codec->codec_type == AVMEDIA_TYPE_AUDIO))
                break;
        }
        analyzed_all_streams = 0;
        if (i == ic->nb_streams) {
            analyzed_all_streams = 1;
            /* NOTE: If the format has no header, then we need to read some
             * packets to get most of the streams, so we cannot stop here. */
            if (!(ic->ctx_flags & AVFMTCTX_NOHEADER)) {
                /* If we found the info for all the codecs, we can stop. */
                ret = count;
                av_log(ic, AV_LOG_DEBUG, "All info found\n");
                flush_codecs = 0;
                break;
            }
        }
        /* We did not get all the codec info, but we read too much data. */
        if (read_size >= probesize) {
            ret = count;
            av_log(ic, AV_LOG_DEBUG,
                   "Probe buffer size limit of %"PRId64" bytes reached\n", probesize);
            for (i = 0; i < ic->nb_streams; i++)
                if (!ic->streams[i]->r_frame_rate.num &&
                    ic->streams[i]->info->duration_count <= 1 &&
                    ic->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO &&
                    strcmp(ic->iformat->name, "image2"))
                    av_log(ic, AV_LOG_WARNING,
                           "Stream #%d: not enough frames to estimate rate; "
                           "consider increasing probesize\n", i);
            break;
        }

        /* NOTE: A new stream can be added there if no header in file
         * (AVFMTCTX_NOHEADER). */
        ret = read_frame_internal(ic, &pkt1);
        if (ret == AVERROR(EAGAIN))
            continue;

        if (ret < 0) {
            /* EOF or error*/
            break;
        }

        if (ic->flags & AVFMT_FLAG_NOBUFFER)
            free_packet_buffer(&ic->packet_buffer, &ic->packet_buffer_end);
        {
            pkt = add_to_pktbuf(&ic->packet_buffer, &pkt1,
                                &ic->packet_buffer_end);
            if (!pkt) {
                ret = AVERROR(ENOMEM);
                goto find_stream_info_err;
            }
            if ((ret = av_dup_packet(pkt)) < 0)
                goto find_stream_info_err;
        }

        st = ic->streams[pkt->stream_index];
        if (!(st->disposition & AV_DISPOSITION_ATTACHED_PIC))
            read_size += pkt->size;

        if (pkt->dts != AV_NOPTS_VALUE && st->codec_info_nb_frames > 1) {
            /* check for non-increasing dts */
            if (st->info->fps_last_dts != AV_NOPTS_VALUE &&
                st->info->fps_last_dts >= pkt->dts) {
                av_log(ic, AV_LOG_DEBUG,
                       "Non-increasing DTS in stream %d: packet %d with DTS "
                       "%"PRId64", packet %d with DTS %"PRId64"\n",
                       st->index, st->info->fps_last_dts_idx,
                       st->info->fps_last_dts, st->codec_info_nb_frames,
                       pkt->dts);
                st->info->fps_first_dts =
                st->info->fps_last_dts  = AV_NOPTS_VALUE;
            }
            /* Check for a discontinuity in dts. If the difference in dts
             * is more than 1000 times the average packet duration in the
             * sequence, we treat it as a discontinuity. */
            if (st->info->fps_last_dts != AV_NOPTS_VALUE &&
                st->info->fps_last_dts_idx > st->info->fps_first_dts_idx &&
                (pkt->dts - st->info->fps_last_dts) / 1000 >
                (st->info->fps_last_dts     - st->info->fps_first_dts) /
                (st->info->fps_last_dts_idx - st->info->fps_first_dts_idx)) {
                av_log(ic, AV_LOG_WARNING,
                       "DTS discontinuity in stream %d: packet %d with DTS "
                       "%"PRId64", packet %d with DTS %"PRId64"\n",
                       st->index, st->info->fps_last_dts_idx,
                       st->info->fps_last_dts, st->codec_info_nb_frames,
                       pkt->dts);
                st->info->fps_first_dts =
                st->info->fps_last_dts  = AV_NOPTS_VALUE;
            }

            /* update stored dts values */
            if (st->info->fps_first_dts == AV_NOPTS_VALUE) {
                st->info->fps_first_dts     = pkt->dts;
                st->info->fps_first_dts_idx = st->codec_info_nb_frames;
            }
            st->info->fps_last_dts     = pkt->dts;
            st->info->fps_last_dts_idx = st->codec_info_nb_frames;
        }
        if (st->codec_info_nb_frames>1) {
            int64_t t = 0;

            if (st->time_base.den > 0)
                t = av_rescale_q(st->info->codec_info_duration, st->time_base, AV_TIME_BASE_Q);
            if (st->avg_frame_rate.num > 0)
                t = FFMAX(t, av_rescale_q(st->codec_info_nb_frames, av_inv_q(st->avg_frame_rate), AV_TIME_BASE_Q));

            if (   t == 0
                && st->codec_info_nb_frames>30
                && st->info->fps_first_dts != AV_NOPTS_VALUE
                && st->info->fps_last_dts  != AV_NOPTS_VALUE)
                t = FFMAX(t, av_rescale_q(st->info->fps_last_dts - st->info->fps_first_dts, st->time_base, AV_TIME_BASE_Q));

            if (t >= (analyzed_all_streams ? max_analyze_duration : max_stream_analyze_duration)) {
                av_log(ic, AV_LOG_VERBOSE, "max_analyze_duration %"PRId64" reached at %"PRId64" microseconds\n",
                       max_analyze_duration,
                       t);
                if (ic->flags & AVFMT_FLAG_NOBUFFER)
                    av_packet_unref(pkt);
                break;
            }
            if (pkt->duration) {
                st->info->codec_info_duration        += pkt->duration;
                st->info->codec_info_duration_fields += st->parser && st->need_parsing && st->codec->ticks_per_frame ==2 ? st->parser->repeat_pict + 1 : 2;
            }
        }
#if FF_API_R_FRAME_RATE
        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO)
            ff_rfps_add_frame(ic, st, pkt->dts);
#endif
        if (st->parser && st->parser->parser->split && !st->codec->extradata) {
            int i = st->parser->parser->split(st->codec, pkt->data, pkt->size);
            if (i > 0 && i < FF_MAX_EXTRADATA_SIZE) {
                if (ff_alloc_extradata(st->codec, i))
                    return AVERROR(ENOMEM);
                memcpy(st->codec->extradata, pkt->data,
                       st->codec->extradata_size);
            }
        }

        /* If still no information, we try to open the codec and to
         * decompress the frame. We try to avoid that in most cases as
         * it takes longer and uses more memory. For MPEG-4, we need to
         * decompress for QuickTime.
         *
         * If CODEC_CAP_CHANNEL_CONF is set this will force decoding of at
         * least one frame of codec data, this makes sure the codec initializes
         * the channel configuration and does not only trust the values from
         * the container. */
        try_decode_frame(ic, st, pkt,
                         (options && i < orig_nb_streams) ? &options[i] : NULL);

        if (ic->flags & AVFMT_FLAG_NOBUFFER)
            av_packet_unref(pkt);

        st->codec_info_nb_frames++;
        count++;
    }

    if (flush_codecs) {
        AVPacket empty_pkt = { 0 };
        int err = 0;
        av_init_packet(&empty_pkt);

        for (i = 0; i < ic->nb_streams; i++) {

            st = ic->streams[i];

            /* flush the decoders */
            if (st->info->found_decoder == 1) {
                do {
                    err = try_decode_frame(ic, st, &empty_pkt,
                                            (options && i < orig_nb_streams)
                                            ? &options[i] : NULL);
                } while (err > 0 && !has_codec_parameters(st, NULL));

                if (err < 0) {
                    av_log(ic, AV_LOG_INFO,
                        "decoding for stream %d failed\n", st->index);
                }
            }
        }
    }

    // close codecs which were opened in try_decode_frame()
    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        avcodec_close(st->codec);
    }

    ff_rfps_calculate(ic);

    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO) {
            if (st->codec->codec_id == AV_CODEC_ID_RAWVIDEO && !st->codec->codec_tag && !st->codec->bits_per_coded_sample) {
                uint32_t tag= avcodec_pix_fmt_to_codec_tag(st->codec->pix_fmt);
                if (avpriv_find_pix_fmt(avpriv_get_raw_pix_fmt_tags(), tag) == st->codec->pix_fmt)
                    st->codec->codec_tag= tag;
            }

            /* estimate average framerate if not set by demuxer */
            if (st->info->codec_info_duration_fields &&
                !st->avg_frame_rate.num &&
                st->info->codec_info_duration) {
                int best_fps      = 0;
                double best_error = 0.01;

                if (st->info->codec_info_duration        >= INT64_MAX / st->time_base.num / 2||
                    st->info->codec_info_duration_fields >= INT64_MAX / st->time_base.den ||
                    st->info->codec_info_duration        < 0)
                    continue;
                av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
                          st->info->codec_info_duration_fields * (int64_t) st->time_base.den,
                          st->info->codec_info_duration * 2 * (int64_t) st->time_base.num, 60000);

                /* Round guessed framerate to a "standard" framerate if it's
                 * within 1% of the original estimate. */
                for (j = 0; j < MAX_STD_TIMEBASES; j++) {
                    AVRational std_fps = { get_std_framerate(j), 12 * 1001 };
                    double error       = fabs(av_q2d(st->avg_frame_rate) /
                                              av_q2d(std_fps) - 1);

                    if (error < best_error) {
                        best_error = error;
                        best_fps   = std_fps.num;
                    }
                }
                if (best_fps)
                    av_reduce(&st->avg_frame_rate.num, &st->avg_frame_rate.den,
                              best_fps, 12 * 1001, INT_MAX);
            }

            if (!st->r_frame_rate.num) {
                if (    st->codec->time_base.den * (int64_t) st->time_base.num
                    <= st->codec->time_base.num * st->codec->ticks_per_frame * (int64_t) st->time_base.den) {
                    st->r_frame_rate.num = st->codec->time_base.den;
                    st->r_frame_rate.den = st->codec->time_base.num * st->codec->ticks_per_frame;
                } else {
                    st->r_frame_rate.num = st->time_base.den;
                    st->r_frame_rate.den = st->time_base.num;
                }
            }
            if (st->display_aspect_ratio.num && st->display_aspect_ratio.den) {
                AVRational hw_ratio = { st->codec->height, st->codec->width };
                st->sample_aspect_ratio = av_mul_q(st->display_aspect_ratio,
                                                   hw_ratio);
            }
        } else if (st->codec->codec_type == AVMEDIA_TYPE_AUDIO) {
            if (!st->codec->bits_per_coded_sample)
                st->codec->bits_per_coded_sample =
                    av_get_bits_per_sample(st->codec->codec_id);
            // set stream disposition based on audio service type
            switch (st->codec->audio_service_type) {
            case AV_AUDIO_SERVICE_TYPE_EFFECTS:
                st->disposition = AV_DISPOSITION_CLEAN_EFFECTS;
                break;
            case AV_AUDIO_SERVICE_TYPE_VISUALLY_IMPAIRED:
                st->disposition = AV_DISPOSITION_VISUAL_IMPAIRED;
                break;
            case AV_AUDIO_SERVICE_TYPE_HEARING_IMPAIRED:
                st->disposition = AV_DISPOSITION_HEARING_IMPAIRED;
                break;
            case AV_AUDIO_SERVICE_TYPE_COMMENTARY:
                st->disposition = AV_DISPOSITION_COMMENT;
                break;
            case AV_AUDIO_SERVICE_TYPE_KARAOKE:
                st->disposition = AV_DISPOSITION_KARAOKE;
                break;
            }
        }
    }

    if (probesize)
    estimate_timings(ic, old_offset);

    av_opt_set(ic, "skip_clear", "0", AV_OPT_SEARCH_CHILDREN);

    if (ret >= 0 && ic->nb_streams)
        /* We could not have all the codec parameters before EOF. */
        ret = -1;
    for (i = 0; i < ic->nb_streams; i++) {
        const char *errmsg;
        st = ic->streams[i];
        if (!has_codec_parameters(st, &errmsg)) {
            char buf[256];
            avcodec_string(buf, sizeof(buf), st->codec, 0);
            av_log(ic, AV_LOG_WARNING,
                   "Could not find codec parameters for stream %d (%s): %s\n"
                   "Consider increasing the value for the 'analyzeduration' and 'probesize' options\n",
                   i, buf, errmsg);
        } else {
            ret = 0;
        }
    }

    compute_chapters_end(ic);

find_stream_info_err:
    for (i = 0; i < ic->nb_streams; i++) {
        st = ic->streams[i];
        if (ic->streams[i]->codec->codec_type != AVMEDIA_TYPE_AUDIO)
            ic->streams[i]->codec->thread_count = 0;
        if (st->info)
            av_freep(&st->info->duration_error);
        av_freep(&ic->streams[i]->info);
    }
    if (ic->pb)
        av_log(ic, AV_LOG_DEBUG, "After avformat_find_stream_info() pos: %"PRId64" bytes read:%"PRId64" seeks:%d frames:%d\n",
               avio_tell(ic->pb), ic->pb->bytes_read, ic->pb->seek_count, count);
    return ret;
}

AVProgram *av_find_program_from_stream(AVFormatContext *ic, AVProgram *last, int s)
{
    int i, j;

    for (i = 0; i < ic->nb_programs; i++) {
        if (ic->programs[i] == last) {
            last = NULL;
        } else {
            if (!last)
                for (j = 0; j < ic->programs[i]->nb_stream_indexes; j++)
                    if (ic->programs[i]->stream_index[j] == s)
                        return ic->programs[i];
        }
    }
    return NULL;
}

int av_find_best_stream(AVFormatContext *ic, enum AVMediaType type,
                        int wanted_stream_nb, int related_stream,
                        AVCodec **decoder_ret, int flags)
{
    int i, nb_streams = ic->nb_streams;
    int ret = AVERROR_STREAM_NOT_FOUND, best_count = -1, best_bitrate = -1, best_multiframe = -1, count, bitrate, multiframe;
    unsigned *program = NULL;
    const AVCodec *decoder = NULL, *best_decoder = NULL;

    if (related_stream >= 0 && wanted_stream_nb < 0) {
        AVProgram *p = av_find_program_from_stream(ic, NULL, related_stream);
        if (p) {
            program    = p->stream_index;
            nb_streams = p->nb_stream_indexes;
        }
    }
    for (i = 0; i < nb_streams; i++) {
        int real_stream_index = program ? program[i] : i;
        AVStream *st          = ic->streams[real_stream_index];
        AVCodecContext *avctx = st->codec;
        if (avctx->codec_type != type)
            continue;
        if (wanted_stream_nb >= 0 && real_stream_index != wanted_stream_nb)
            continue;
        if (wanted_stream_nb != real_stream_index &&
            st->disposition & (AV_DISPOSITION_HEARING_IMPAIRED |
                               AV_DISPOSITION_VISUAL_IMPAIRED))
            continue;
        if (type == AVMEDIA_TYPE_AUDIO && !avctx->channels)
            continue;
        if (decoder_ret) {
            decoder = find_decoder(ic, st, st->codec->codec_id);
            if (!decoder) {
                if (ret < 0)
                    ret = AVERROR_DECODER_NOT_FOUND;
                continue;
            }
        }
        count = st->codec_info_nb_frames;
        bitrate = avctx->bit_rate;
        if (!bitrate)
            bitrate = avctx->rc_max_rate;
        multiframe = FFMIN(5, count);
        if ((best_multiframe >  multiframe) ||
            (best_multiframe == multiframe && best_bitrate >  bitrate) ||
            (best_multiframe == multiframe && best_bitrate == bitrate && best_count >= count))
            continue;
        best_count   = count;
        best_bitrate = bitrate;
        best_multiframe = multiframe;
        ret          = real_stream_index;
        best_decoder = decoder;
        if (program && i == nb_streams - 1 && ret < 0) {
            program    = NULL;
            nb_streams = ic->nb_streams;
            /* no related stream found, try again with everything */
            i = 0;
        }
    }
    if (decoder_ret)
        *decoder_ret = (AVCodec*)best_decoder;
    return ret;
}

/*******************************************************/

int av_read_play(AVFormatContext *s)
{
    if (s->iformat->read_play)
        return s->iformat->read_play(s);
    if (s->pb)
        return avio_pause(s->pb, 0);
    return AVERROR(ENOSYS);
}

int av_read_pause(AVFormatContext *s)
{
    if (s->iformat->read_pause)
        return s->iformat->read_pause(s);
    if (s->pb)
        return avio_pause(s->pb, 1);
    return AVERROR(ENOSYS);
}

void ff_free_stream(AVFormatContext *s, AVStream *st) {
    int j;
    av_assert0(s->nb_streams>0);
    av_assert0(s->streams[ s->nb_streams - 1 ] == st);

    for (j = 0; j < st->nb_side_data; j++)
        av_freep(&st->side_data[j].data);
    av_freep(&st->side_data);
    st->nb_side_data = 0;

    if (st->parser) {
        av_parser_close(st->parser);
    }
    if (st->attached_pic.data)
        av_free_packet(&st->attached_pic);
    av_dict_free(&st->metadata);
    av_freep(&st->probe_data.buf);
    av_freep(&st->index_entries);
    av_freep(&st->codec->extradata);
    av_freep(&st->codec->subtitle_header);
    av_freep(&st->codec);
    av_freep(&st->priv_data);
    if (st->info)
        av_freep(&st->info->duration_error);
    av_freep(&st->info);
    av_freep(&st->recommended_encoder_configuration);
    av_freep(&s->streams[ --s->nb_streams ]);
}

void avformat_free_context(AVFormatContext *s)
{
    int i;

    if (!s)
        return;

    av_opt_free(s);
    if (s->iformat && s->iformat->priv_class && s->priv_data)
        av_opt_free(s->priv_data);
    if (s->oformat && s->oformat->priv_class && s->priv_data)
        av_opt_free(s->priv_data);

    for (i = s->nb_streams - 1; i >= 0; i--) {
        ff_free_stream(s, s->streams[i]);
    }
    for (i = s->nb_programs - 1; i >= 0; i--) {
        av_dict_free(&s->programs[i]->metadata);
        av_freep(&s->programs[i]->stream_index);
        av_freep(&s->programs[i]);
    }
    av_freep(&s->programs);
    av_freep(&s->priv_data);
    while (s->nb_chapters--) {
        av_dict_free(&s->chapters[s->nb_chapters]->metadata);
        av_freep(&s->chapters[s->nb_chapters]);
    }
    av_freep(&s->chapters);
    av_dict_free(&s->metadata);
    av_freep(&s->streams);
    av_freep(&s->internal);
    flush_packet_queue(s);
    av_free(s);
}

void avformat_close_input(AVFormatContext **ps)
{
    AVFormatContext *s;
    AVIOContext *pb;

    if (!ps || !*ps)
        return;

    s  = *ps;
    pb = s->pb;

    if ((s->iformat && strcmp(s->iformat->name, "image2") && s->iformat->flags & AVFMT_NOFILE) ||
        (s->flags & AVFMT_FLAG_CUSTOM_IO))
        pb = NULL;

    flush_packet_queue(s);

    if (s->iformat)
        if (s->iformat->read_close)
            s->iformat->read_close(s);

    avformat_free_context(s);

    *ps = NULL;

    avio_close(pb);
}

AVStream *avformat_new_stream(AVFormatContext *s, const AVCodec *c)
{
    AVStream *st;
    int i;
    AVStream **streams;

    if (s->nb_streams >= INT_MAX/sizeof(*streams))
        return NULL;
    streams = av_realloc_array(s->streams, s->nb_streams + 1, sizeof(*streams));
    if (!streams)
        return NULL;
    s->streams = streams;

    st = av_mallocz(sizeof(AVStream));
    if (!st)
        return NULL;
    if (!(st->info = av_mallocz(sizeof(*st->info)))) {
        av_free(st);
        return NULL;
    }
    st->info->last_dts = AV_NOPTS_VALUE;

    st->codec = avcodec_alloc_context3(c);
    if (s->iformat) {
        /* no default bitrate if decoding */
        st->codec->bit_rate = 0;

        /* default pts setting is MPEG-like */
        avpriv_set_pts_info(st, 33, 1, 90000);
    }

    st->index      = s->nb_streams;
    st->start_time = AV_NOPTS_VALUE;
    st->duration   = AV_NOPTS_VALUE;
    /* we set the current DTS to 0 so that formats without any timestamps
     * but durations get some timestamps, formats with some unknown
     * timestamps have their first few packets buffered and the
     * timestamps corrected before they are returned to the user */
    st->cur_dts       = s->iformat ? RELATIVE_TS_BASE : 0;
    st->first_dts     = AV_NOPTS_VALUE;
    st->probe_packets = MAX_PROBE_PACKETS;
    st->pts_wrap_reference = AV_NOPTS_VALUE;
    st->pts_wrap_behavior = AV_PTS_WRAP_IGNORE;

    st->last_IP_pts = AV_NOPTS_VALUE;
    st->last_dts_for_order_check = AV_NOPTS_VALUE;
    for (i = 0; i < MAX_REORDER_DELAY + 1; i++)
        st->pts_buffer[i] = AV_NOPTS_VALUE;

    st->sample_aspect_ratio = (AVRational) { 0, 1 };

#if FF_API_R_FRAME_RATE
    st->info->last_dts      = AV_NOPTS_VALUE;
#endif
    st->info->fps_first_dts = AV_NOPTS_VALUE;
    st->info->fps_last_dts  = AV_NOPTS_VALUE;

    st->inject_global_side_data = s->internal->inject_global_side_data;

    s->streams[s->nb_streams++] = st;
    return st;
}

AVProgram *av_new_program(AVFormatContext *ac, int id)
{
    AVProgram *program = NULL;
    int i;

    av_dlog(ac, "new_program: id=0x%04x\n", id);

    for (i = 0; i < ac->nb_programs; i++)
        if (ac->programs[i]->id == id)
            program = ac->programs[i];

    if (!program) {
        program = av_mallocz(sizeof(AVProgram));
        if (!program)
            return NULL;
        dynarray_add(&ac->programs, &ac->nb_programs, program);
        program->discard = AVDISCARD_NONE;
    }
    program->id = id;
    program->pts_wrap_reference = AV_NOPTS_VALUE;
    program->pts_wrap_behavior = AV_PTS_WRAP_IGNORE;

    program->start_time =
    program->end_time   = AV_NOPTS_VALUE;

    return program;
}

AVChapter *avpriv_new_chapter(AVFormatContext *s, int id, AVRational time_base,
                              int64_t start, int64_t end, const char *title)
{
    AVChapter *chapter = NULL;
    int i;

    if (end != AV_NOPTS_VALUE && start > end) {
        av_log(s, AV_LOG_ERROR, "Chapter end time %"PRId64" before start %"PRId64"\n", end, start);
        return NULL;
    }

    for (i = 0; i < s->nb_chapters; i++)
        if (s->chapters[i]->id == id)
            chapter = s->chapters[i];

    if (!chapter) {
        chapter = av_mallocz(sizeof(AVChapter));
        if (!chapter)
            return NULL;
        dynarray_add(&s->chapters, &s->nb_chapters, chapter);
    }
    av_dict_set(&chapter->metadata, "title", title, 0);
    chapter->id        = id;
    chapter->time_base = time_base;
    chapter->start     = start;
    chapter->end       = end;

    return chapter;
}

void ff_program_add_stream_index(AVFormatContext *ac, int progid, unsigned idx)
{
    int i, j;
    AVProgram *program = NULL;
    void *tmp;

    if (idx >= ac->nb_streams) {
        av_log(ac, AV_LOG_ERROR, "stream index %d is not valid\n", idx);
        return;
    }

    for (i = 0; i < ac->nb_programs; i++) {
        if (ac->programs[i]->id != progid)
            continue;
        program = ac->programs[i];
        for (j = 0; j < program->nb_stream_indexes; j++)
            if (program->stream_index[j] == idx)
                return;

        tmp = av_realloc_array(program->stream_index, program->nb_stream_indexes+1, sizeof(unsigned int));
        if (!tmp)
            return;
        program->stream_index = tmp;
        program->stream_index[program->nb_stream_indexes++] = idx;
        return;
    }
}

uint64_t ff_ntp_time(void)
{
    return (av_gettime() / 1000) * 1000 + NTP_OFFSET_US;
}

int av_get_frame_filename(char *buf, int buf_size, const char *path, int number)
{
    const char *p;
    char *q, buf1[20], c;
    int nd, len, percentd_found;

    q = buf;
    p = path;
    percentd_found = 0;
    for (;;) {
        c = *p++;
        if (c == '\0')
            break;
        if (c == '%') {
            do {
                nd = 0;
                while (av_isdigit(*p))
                    nd = nd * 10 + *p++ - '0';
                c = *p++;
            } while (av_isdigit(c));

            switch (c) {
            case '%':
                goto addchar;
            case 'd':
                if (percentd_found)
                    goto fail;
                percentd_found = 1;
                snprintf(buf1, sizeof(buf1), "%0*d", nd, number);
                len = strlen(buf1);
                if ((q - buf + len) > buf_size - 1)
                    goto fail;
                memcpy(q, buf1, len);
                q += len;
                break;
            default:
                goto fail;
            }
        } else {
addchar:
            if ((q - buf) < buf_size - 1)
                *q++ = c;
        }
    }
    if (!percentd_found)
        goto fail;
    *q = '\0';
    return 0;
fail:
    *q = '\0';
    return -1;
}

void av_url_split(char *proto, int proto_size,
                  char *authorization, int authorization_size,
                  char *hostname, int hostname_size,
                  int *port_ptr, char *path, int path_size, const char *url)
{
    const char *p, *ls, *ls2, *at, *at2, *col, *brk;

    if (port_ptr)
        *port_ptr = -1;
    if (proto_size > 0)
        proto[0] = 0;
    if (authorization_size > 0)
        authorization[0] = 0;
    if (hostname_size > 0)
        hostname[0] = 0;
    if (path_size > 0)
        path[0] = 0;

    /* parse protocol */
    if ((p = strchr(url, ':'))) {
        av_strlcpy(proto, url, FFMIN(proto_size, p + 1 - url));
        p++; /* skip ':' */
        if (*p == '/')
            p++;
        if (*p == '/')
            p++;
    } else {
        /* no protocol means plain filename */
        av_strlcpy(path, url, path_size);
        return;
    }

    /* separate path from hostname */
    ls = strchr(p, '/');
    ls2 = strchr(p, '?');
    if (!ls)
        ls = ls2;
    else if (ls && ls2)
        ls = FFMIN(ls, ls2);
    if (ls)
        av_strlcpy(path, ls, path_size);
    else
        ls = &p[strlen(p)];  // XXX

    /* the rest is hostname, use that to parse auth/port */
    if (ls != p) {
        /* authorization (user[:pass]@hostname) */
        at2 = p;
        while ((at = strchr(p, '@')) && at < ls) {
            av_strlcpy(authorization, at2,
                       FFMIN(authorization_size, at + 1 - at2));
            p = at + 1; /* skip '@' */
        }

        if (*p == '[' && (brk = strchr(p, ']')) && brk < ls) {
            /* [host]:port */
            av_strlcpy(hostname, p + 1,
                       FFMIN(hostname_size, brk - p));
            if (brk[1] == ':' && port_ptr)
                *port_ptr = atoi(brk + 2);
        } else if ((col = strchr(p, ':')) && col < ls) {
            av_strlcpy(hostname, p,
                       FFMIN(col + 1 - p, hostname_size));
            if (port_ptr)
                *port_ptr = atoi(col + 1);
        } else
            av_strlcpy(hostname, p,
                       FFMIN(ls + 1 - p, hostname_size));
    }
}

char *ff_data_to_hex(char *buff, const uint8_t *src, int s, int lowercase)
{
    int i;
    static const char hex_table_uc[16] = { '0', '1', '2', '3',
                                           '4', '5', '6', '7',
                                           '8', '9', 'A', 'B',
                                           'C', 'D', 'E', 'F' };
    static const char hex_table_lc[16] = { '0', '1', '2', '3',
                                           '4', '5', '6', '7',
                                           '8', '9', 'a', 'b',
                                           'c', 'd', 'e', 'f' };
    const char *hex_table = lowercase ? hex_table_lc : hex_table_uc;

    for (i = 0; i < s; i++) {
        buff[i * 2]     = hex_table[src[i] >> 4];
        buff[i * 2 + 1] = hex_table[src[i] & 0xF];
    }

    return buff;
}

int ff_hex_to_data(uint8_t *data, const char *p)
{
    int c, len, v;

    len = 0;
    v   = 1;
    for (;;) {
        p += strspn(p, SPACE_CHARS);
        if (*p == '\0')
            break;
        c = av_toupper((unsigned char) *p++);
        if (c >= '0' && c <= '9')
            c = c - '0';
        else if (c >= 'A' && c <= 'F')
            c = c - 'A' + 10;
        else
            break;
        v = (v << 4) | c;
        if (v & 0x100) {
            if (data)
                data[len] = v;
            len++;
            v = 1;
        }
    }
    return len;
}

void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits,
                         unsigned int pts_num, unsigned int pts_den)
{
    AVRational new_tb;
    if (av_reduce(&new_tb.num, &new_tb.den, pts_num, pts_den, INT_MAX)) {
        if (new_tb.num != pts_num)
            av_log(NULL, AV_LOG_DEBUG,
                   "st:%d removing common factor %d from timebase\n",
                   s->index, pts_num / new_tb.num);
    } else
        av_log(NULL, AV_LOG_WARNING,
               "st:%d has too large timebase, reducing\n", s->index);

    if (new_tb.num <= 0 || new_tb.den <= 0) {
        av_log(NULL, AV_LOG_ERROR,
               "Ignoring attempt to set invalid timebase %d/%d for st:%d\n",
               new_tb.num, new_tb.den,
               s->index);
        return;
    }
    s->time_base     = new_tb;
    av_codec_set_pkt_timebase(s->codec, new_tb);
    s->pts_wrap_bits = pts_wrap_bits;
}

void ff_parse_key_value(const char *str, ff_parse_key_val_cb callback_get_buf,
                        void *context)
{
    const char *ptr = str;

    /* Parse key=value pairs. */
    for (;;) {
        const char *key;
        char *dest = NULL, *dest_end;
        int key_len, dest_len = 0;

        /* Skip whitespace and potential commas. */
        while (*ptr && (av_isspace(*ptr) || *ptr == ','))
            ptr++;
        if (!*ptr)
            break;

        key = ptr;

        if (!(ptr = strchr(key, '=')))
            break;
        ptr++;
        key_len = ptr - key;

        callback_get_buf(context, key, key_len, &dest, &dest_len);
        dest_end = dest + dest_len - 1;

        if (*ptr == '\"') {
            ptr++;
            while (*ptr && *ptr != '\"') {
                if (*ptr == '\\') {
                    if (!ptr[1])
                        break;
                    if (dest && dest < dest_end)
                        *dest++ = ptr[1];
                    ptr += 2;
                } else {
                    if (dest && dest < dest_end)
                        *dest++ = *ptr;
                    ptr++;
                }
            }
            if (*ptr == '\"')
                ptr++;
        } else {
            for (; *ptr && !(av_isspace(*ptr) || *ptr == ','); ptr++)
                if (dest && dest < dest_end)
                    *dest++ = *ptr;
        }
        if (dest)
            *dest = 0;
    }
}

int ff_find_stream_index(AVFormatContext *s, int id)
{
    int i;
    for (i = 0; i < s->nb_streams; i++)
        if (s->streams[i]->id == id)
            return i;
    return -1;
}

int64_t ff_iso8601_to_unix_time(const char *datestr)
{
    struct tm time1 = { 0 }, time2 = { 0 };
    char *ret1, *ret2;
    ret1 = av_small_strptime(datestr, "%Y - %m - %d %H:%M:%S", &time1);
    ret2 = av_small_strptime(datestr, "%Y - %m - %dT%H:%M:%S", &time2);
    if (ret2 && !ret1)
        return av_timegm(&time2);
    else
        return av_timegm(&time1);
}

int avformat_query_codec(const AVOutputFormat *ofmt, enum AVCodecID codec_id,
                         int std_compliance)
{
    if (ofmt) {
        if (ofmt->query_codec)
            return ofmt->query_codec(codec_id, std_compliance);
        else if (ofmt->codec_tag)
            return !!av_codec_get_tag(ofmt->codec_tag, codec_id);
        else if (codec_id == ofmt->video_codec ||
                 codec_id == ofmt->audio_codec ||
                 codec_id == ofmt->subtitle_codec)
            return 1;
    }
    return AVERROR_PATCHWELCOME;
}

int avformat_network_init(void)
{
#if CONFIG_NETWORK
    int ret;
    ff_network_inited_globally = 1;
    if ((ret = ff_network_init()) < 0)
        return ret;
    ff_tls_init();
#endif
    return 0;
}

int avformat_network_deinit(void)
{
#if CONFIG_NETWORK
    ff_network_close();
    ff_tls_deinit();
#endif
    return 0;
}

int ff_add_param_change(AVPacket *pkt, int32_t channels,
                        uint64_t channel_layout, int32_t sample_rate,
                        int32_t width, int32_t height)
{
    uint32_t flags = 0;
    int size = 4;
    uint8_t *data;
    if (!pkt)
        return AVERROR(EINVAL);
    if (channels) {
        size  += 4;
        flags |= AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT;
    }
    if (channel_layout) {
        size  += 8;
        flags |= AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT;
    }
    if (sample_rate) {
        size  += 4;
        flags |= AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE;
    }
    if (width || height) {
        size  += 8;
        flags |= AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS;
    }
    data = av_packet_new_side_data(pkt, AV_PKT_DATA_PARAM_CHANGE, size);
    if (!data)
        return AVERROR(ENOMEM);
    bytestream_put_le32(&data, flags);
    if (channels)
        bytestream_put_le32(&data, channels);
    if (channel_layout)
        bytestream_put_le64(&data, channel_layout);
    if (sample_rate)
        bytestream_put_le32(&data, sample_rate);
    if (width || height) {
        bytestream_put_le32(&data, width);
        bytestream_put_le32(&data, height);
    }
    return 0;
}

AVRational av_guess_sample_aspect_ratio(AVFormatContext *format, AVStream *stream, AVFrame *frame)
{
    AVRational undef = {0, 1};
    AVRational stream_sample_aspect_ratio = stream ? stream->sample_aspect_ratio : undef;
    AVRational codec_sample_aspect_ratio  = stream && stream->codec ? stream->codec->sample_aspect_ratio : undef;
    AVRational frame_sample_aspect_ratio  = frame  ? frame->sample_aspect_ratio  : codec_sample_aspect_ratio;

    av_reduce(&stream_sample_aspect_ratio.num, &stream_sample_aspect_ratio.den,
               stream_sample_aspect_ratio.num,  stream_sample_aspect_ratio.den, INT_MAX);
    if (stream_sample_aspect_ratio.num <= 0 || stream_sample_aspect_ratio.den <= 0)
        stream_sample_aspect_ratio = undef;

    av_reduce(&frame_sample_aspect_ratio.num, &frame_sample_aspect_ratio.den,
               frame_sample_aspect_ratio.num,  frame_sample_aspect_ratio.den, INT_MAX);
    if (frame_sample_aspect_ratio.num <= 0 || frame_sample_aspect_ratio.den <= 0)
        frame_sample_aspect_ratio = undef;

    if (stream_sample_aspect_ratio.num)
        return stream_sample_aspect_ratio;
    else
        return frame_sample_aspect_ratio;
}

AVRational av_guess_frame_rate(AVFormatContext *format, AVStream *st, AVFrame *frame)
{
    AVRational fr = st->r_frame_rate;
    AVRational codec_fr = st->codec->framerate;
    AVRational   avg_fr = st->avg_frame_rate;

    if (avg_fr.num > 0 && avg_fr.den > 0 && fr.num > 0 && fr.den > 0 &&
        av_q2d(avg_fr) < 70 && av_q2d(fr) > 210) {
        fr = avg_fr;
    }


    if (st->codec->ticks_per_frame > 1) {
        if (   codec_fr.num > 0 && codec_fr.den > 0 && av_q2d(codec_fr) < av_q2d(fr)*0.7
            && fabs(1.0 - av_q2d(av_div_q(avg_fr, fr))) > 0.1)
            fr = codec_fr;
    }

    return fr;
}

int avformat_match_stream_specifier(AVFormatContext *s, AVStream *st,
                                    const char *spec)
{
    if (*spec <= '9' && *spec >= '0') /* opt:index */
        return strtol(spec,