dtshddec.c

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/*
 * Raw DTS-HD demuxer
 * Copyright (c) 2012 Paul B Mahol
 *
 * 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
 */
 
#include "libavutil/intreadwrite.h"
#include "libavutil/dict.h"
#include "libavutil/mem.h"
#include "libavcodec/dca.h"
#include "avformat.h"
#include "demux.h"
#include "internal.h"
#include "avio_internal.h"
 
#define AUPR_HDR 0x415550522D484452
#define AUPRINFO 0x41555052494E464F
#define BITSHVTB 0x4249545348565442
#define BLACKOUT 0x424C41434B4F5554
#define BRANCHPT 0x4252414E43485054
#define BUILDVER 0x4255494C44564552
#define CORESSMD 0x434F524553534D44
#define DTSHDHDR 0x4454534844484452
#define EXTSS_MD 0x45585453535f4d44
#define FILEINFO 0x46494C45494E464F
#define NAVI_TBL 0x4E4156492D54424C
#define STRMDATA 0x5354524D44415441
#define TIMECODE 0x54494D45434F4445
 
typedef struct DTSHDDemuxContext {
    uint64_t    data_end;
} DTSHDDemuxContext;
 
static int dtshd_probe(const AVProbeData *p)
{
    if (AV_RB64(p->buf) == DTSHDHDR)
        return AVPROBE_SCORE_MAX;
    return 0;
}
 
static int dtshd_read_header(AVFormatContext *s)
{
    DTSHDDemuxContext *dtshd = s->priv_data;
    AVIOContext *pb = s->pb;
    uint64_t chunk_type, chunk_size;
    int64_t duration, orig_nb_samples, data_start;
    AVStream *st;
    FFStream *sti;
    int ret;
    char *value;
 
    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);
    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
    st->codecpar->codec_id   = AV_CODEC_ID_DTS;
    sti = ffstream(st);
    sti->need_parsing = AVSTREAM_PARSE_FULL_RAW;
 
    for (;;) {
        chunk_type = avio_rb64(pb);
        chunk_size = avio_rb64(pb);
 
        if (avio_feof(pb))
            break;
 
        if (chunk_size < 4) {
            av_log(s, AV_LOG_ERROR, "chunk size too small\n");
            return AVERROR_INVALIDDATA;
        }
        if (chunk_size > ((uint64_t)1 << 61)) {
            av_log(s, AV_LOG_ERROR, "chunk size too big\n");
            return AVERROR_INVALIDDATA;
        }
 
        switch (chunk_type) {
        case STRMDATA:
            data_start = avio_tell(pb);
            dtshd->data_end = data_start + chunk_size;
            if (dtshd->data_end <= chunk_size)
                return AVERROR_INVALIDDATA;
            if (!(pb->seekable & AVIO_SEEKABLE_NORMAL))
                goto break_loop;
            goto skip;
            break;
        case AUPR_HDR:
            if (chunk_size < 21)
                return AVERROR_INVALIDDATA;
            avio_skip(pb, 3);
            st->codecpar->sample_rate = avio_rb24(pb);
            if (!st->codecpar->sample_rate)
                return AVERROR_INVALIDDATA;
            duration  = avio_rb32(pb); // num_frames
            duration *= avio_rb16(pb); // samples_per_frames
            st->duration = duration;
            orig_nb_samples  = avio_rb32(pb);
            orig_nb_samples <<= 8;
            orig_nb_samples |= avio_r8(pb);
            st->codecpar->ch_layout.nb_channels = ff_dca_count_chs_for_mask(avio_rb16(pb));
            st->codecpar->initial_padding = avio_rb16(pb);
            st->codecpar->trailing_padding = FFMAX(st->duration - orig_nb_samples - st->codecpar->initial_padding, 0);
            st->start_time =
            sti->start_skip_samples = st->codecpar->initial_padding;
            sti->first_discard_sample = orig_nb_samples + st->codecpar->initial_padding;
            sti->last_discard_sample = st->duration;
            avio_skip(pb, chunk_size - 21);
            break;
        case FILEINFO:
            if (chunk_size > INT_MAX)
                goto skip;
            value = av_malloc(chunk_size);
            if (!value)
                goto skip;
            ret = ffio_read_size(pb, value, chunk_size);
            if (ret < 0) {
                av_free(value);
                goto skip;
            }
            value[chunk_size - 1] = 0;
            av_dict_set(&s->metadata, "fileinfo", value,
                        AV_DICT_DONT_STRDUP_VAL);
            break;
        default:
skip:
            ret = avio_skip(pb, chunk_size);
            if (ret < 0)
                return ret;
        };
    }
 
    if (!dtshd->data_end)
        return AVERROR_EOF;
 
    avio_seek(pb, data_start, SEEK_SET);
 
break_loop:
    if (st->codecpar->sample_rate)
        avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
 
    return 0;
}
 
static int raw_read_packet(AVFormatContext *s, AVPacket *pkt)
{
    DTSHDDemuxContext *dtshd = s->priv_data;
    int64_t size, left;
    int ret;
 
    left = dtshd->data_end - avio_tell(s->pb);
    size = FFMIN(left, 1024);
    if (size <= 0)
        return AVERROR_EOF;
 
    ret = av_get_packet(s->pb, pkt, size);
    if (ret < 0)
        return ret;
 
    pkt->stream_index = 0;
 
    return ret;
}
 
const FFInputFormat ff_dtshd_demuxer = {
    .p.name         = "dtshd",
    .p.long_name    = NULL_IF_CONFIG_SMALL("raw DTS-HD"),
    .p.flags        = AVFMT_GENERIC_INDEX,
    .p.extensions   = "dtshd",
    .priv_data_size = sizeof(DTSHDDemuxContext),
    .read_probe     = dtshd_probe,
    .read_header    = dtshd_read_header,
    .read_packet    = raw_read_packet,
    .raw_codec_id   = AV_CODEC_ID_DTS,
};