FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
vocdec.c
Go to the documentation of this file.
1 /*
2  * Creative Voice File demuxer.
3  * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 #include "libavutil/intreadwrite.h"
23 #include "voc.h"
24 #include "internal.h"
25 
26 
27 static int voc_probe(AVProbeData *p)
28 {
29  int version, check;
30 
31  if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
32  return 0;
33  version = AV_RL16(p->buf + 22);
34  check = AV_RL16(p->buf + 24);
35  if (~version + 0x1234 != check)
36  return 10;
37 
38  return AVPROBE_SCORE_MAX;
39 }
40 
42 {
43  VocDecContext *voc = s->priv_data;
44  AVIOContext *pb = s->pb;
45  int header_size;
46  AVStream *st;
47 
48  avio_skip(pb, 20);
49  header_size = avio_rl16(pb) - 22;
50  if (header_size != 4) {
51  av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
52  return AVERROR(ENOSYS);
53  }
54  avio_skip(pb, header_size);
55  st = avformat_new_stream(s, NULL);
56  if (!st)
57  return AVERROR(ENOMEM);
59 
60  voc->remaining_size = 0;
61  return 0;
62 }
63 
64 int
66 {
67  VocDecContext *voc = s->priv_data;
68  AVCodecContext *dec = st->codec;
69  AVIOContext *pb = s->pb;
70  VocType type;
71  int size, tmp_codec=-1;
72  int sample_rate = 0;
73  int channels = 1;
74  int64_t duration;
75  int ret;
76 
78  avio_tell(pb),
79  voc->pts,
80  voc->remaining_size,
81  0,
83 
84  while (!voc->remaining_size) {
85  type = avio_r8(pb);
86  if (type == VOC_TYPE_EOF)
87  return AVERROR_EOF;
88  voc->remaining_size = avio_rl24(pb);
89  if (!voc->remaining_size) {
90  if (!s->pb->seekable)
91  return AVERROR(EIO);
92  voc->remaining_size = avio_size(pb) - avio_tell(pb);
93  }
94  max_size -= 4;
95 
96  switch (type) {
98  if (!dec->sample_rate) {
99  dec->sample_rate = 1000000 / (256 - avio_r8(pb));
100  if (sample_rate)
101  dec->sample_rate = sample_rate;
102  avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
103  dec->channels = channels;
105  } else
106  avio_skip(pb, 1);
107  tmp_codec = avio_r8(pb);
108  voc->remaining_size -= 2;
109  max_size -= 2;
110  channels = 1;
111  break;
112 
114  break;
115 
116  case VOC_TYPE_EXTENDED:
117  sample_rate = avio_rl16(pb);
118  avio_r8(pb);
119  channels = avio_r8(pb) + 1;
120  sample_rate = 256000000 / (channels * (65536 - sample_rate));
121  voc->remaining_size = 0;
122  max_size -= 4;
123  break;
124 
126  if (!dec->sample_rate) {
127  dec->sample_rate = avio_rl32(pb);
128  avpriv_set_pts_info(st, 64, 1, dec->sample_rate);
129  dec->bits_per_coded_sample = avio_r8(pb);
130  dec->channels = avio_r8(pb);
131  } else
132  avio_skip(pb, 6);
133  tmp_codec = avio_rl16(pb);
134  avio_skip(pb, 4);
135  voc->remaining_size -= 12;
136  max_size -= 12;
137  break;
138 
139  default:
140  avio_skip(pb, voc->remaining_size);
141  max_size -= voc->remaining_size;
142  voc->remaining_size = 0;
143  break;
144  }
145  }
146 
147  if (tmp_codec >= 0) {
148  tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
149  if (dec->codec_id == AV_CODEC_ID_NONE)
150  dec->codec_id = tmp_codec;
151  else if (dec->codec_id != tmp_codec)
152  av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
153  if (dec->codec_id == AV_CODEC_ID_NONE) {
154  if (s->audio_codec_id == AV_CODEC_ID_NONE) {
155  av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
156  return AVERROR(EINVAL);
157  }
158  av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
159  }
160  }
161 
162  dec->bit_rate = dec->sample_rate * dec->channels * dec->bits_per_coded_sample;
163 
164  if (max_size <= 0)
165  max_size = 2048;
166  size = FFMIN(voc->remaining_size, max_size);
167  voc->remaining_size -= size;
168 
169  ret = av_get_packet(pb, pkt, size);
170  pkt->dts = pkt->pts = voc->pts;
171 
172  duration = av_get_audio_frame_duration(st->codec, size);
173  if (duration > 0 && voc->pts != AV_NOPTS_VALUE)
174  voc->pts += duration;
175  else
176  voc->pts = AV_NOPTS_VALUE;
177 
178  return ret;
179 }
180 
182 {
183  return ff_voc_get_packet(s, pkt, s->streams[0], 0);
184 }
185 
186 static int voc_read_seek(AVFormatContext *s, int stream_index,
187  int64_t timestamp, int flags)
188 {
189  VocDecContext *voc = s->priv_data;
190  AVStream *st = s->streams[stream_index];
191  int index = av_index_search_timestamp(st, timestamp, flags);
192 
193  if (index >= 0 && index < st->nb_index_entries - 1) {
194  AVIndexEntry *e = &st->index_entries[index];
195  avio_seek(s->pb, e->pos, SEEK_SET);
196  voc->pts = e->timestamp;
197  voc->remaining_size = e->size;
198  return 0;
199  } else if (st->nb_index_entries && st->index_entries[0].timestamp <= timestamp) {
200  AVIndexEntry *e = &st->index_entries[st->nb_index_entries - 1];
201  // prepare context for seek_frame_generic()
202  voc->pts = e->timestamp;
203  voc->remaining_size = e->size;
204  }
205  return -1;
206 }
207 
209  .name = "voc",
210  .long_name = NULL_IF_CONFIG_SMALL("Creative Voice"),
211  .priv_data_size = sizeof(VocDecContext),
216  .codec_tag = (const AVCodecTag* const []){ ff_voc_codec_tags, 0 },
217 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:282
static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: vocdec.c:181
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:1745
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:2773
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4083
int64_t pos
Definition: avformat.h:784
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
AVInputFormat ff_voc_demuxer
Definition: vocdec.c:208
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:204
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:1045
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:277
int version
Definition: avisynth_c.h:629
static AVPacket pkt
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:87
Format I/O context.
Definition: avformat.h:1273
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3749
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1341
#define AVERROR_EOF
End of file.
Definition: error.h:55
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:244
ptrdiff_t size
Definition: opengl_enc.c:101
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:390
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2996
static int64_t duration
Definition: ffplay.c:326
#define av_log(a,...)
#define AVINDEX_KEYFRAME
Definition: avformat.h:791
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int av_get_bits_per_sample(enum AVCodecID codec_id)
Return codec bits per sample.
Definition: utils.c:3392
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:1844
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:659
#define AVERROR(e)
Definition: error.h:43
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:785
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
static int voc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: vocdec.c:186
VocType
Definition: voc.h:33
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:529
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:861
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:450
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:160
int bit_rate
the average bitrate
Definition: avcodec.h:1567
#define FFMIN(a, b)
Definition: common.h:81
enum AVCodecID audio_codec_id
Forced audio codec_id.
Definition: avformat.h:1437
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
static int voc_probe(AVProbeData *p)
Definition: vocdec.c:27
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:623
Stream structure.
Definition: avformat.h:842
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
sample_rate
const AVCodecTag ff_voc_codec_tags[]
Definition: voc.c:27
enum AVMediaType codec_type
Definition: avcodec.h:1510
enum AVCodecID codec_id
Definition: avcodec.h:1519
int sample_rate
samples per second
Definition: avcodec.h:2262
AVIOContext * pb
I/O context.
Definition: avformat.h:1315
main external API structure.
Definition: avcodec.h:1502
int64_t pts
Definition: voc.h:30
GLint GLenum type
Definition: opengl_enc.c:105
int nb_index_entries
Definition: avformat.h:1047
int index
Definition: gxfenc.c:89
int ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
Definition: vocdec.c:65
This structure contains the data a format has to probe a file.
Definition: avformat.h:448
int av_get_audio_frame_duration(AVCodecContext *avctx, int frame_bytes)
Return audio frame duration.
Definition: utils.c:3410
const unsigned char ff_voc_magic[21]
Definition: voc.c:25
static int flags
Definition: cpu.c:47
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:460
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:643
int channels
number of audio channels
Definition: avcodec.h:2263
void * priv_data
Format private data.
Definition: avformat.h:1301
int64_t remaining_size
Definition: voc.h:29
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1422
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:628
static int voc_read_header(AVFormatContext *s)
Definition: vocdec.c:41
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:651
This structure stores compressed data.
Definition: avcodec.h:1400
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1416
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:240
#define check(x, y, S, v)