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vocdec.c
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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 static int voc_probe(AVProbeData *p)
27 {
28  int version, check;
29 
30  if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
31  return 0;
32  version = AV_RL16(p->buf + 22);
33  check = AV_RL16(p->buf + 24);
34  if (~version + 0x1234 != check)
35  return 10;
36 
37  return AVPROBE_SCORE_MAX;
38 }
39 
41 {
42  VocDecContext *voc = s->priv_data;
43  AVIOContext *pb = s->pb;
44  int header_size;
45 
46  avio_skip(pb, 20);
47  header_size = avio_rl16(pb) - 22;
48  if (header_size != 4) {
49  av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
50  return AVERROR(ENOSYS);
51  }
52  avio_skip(pb, header_size);
53 
55 
56  voc->remaining_size = 0;
57  return 0;
58 }
59 
61 {
62  if (!s->nb_streams) {
64  if (!st)
65  return AVERROR(ENOMEM);
67  }
68  return ff_voc_get_packet(s, pkt, s->streams[0], 0);
69 }
70 
71 static int voc_read_seek(AVFormatContext *s, int stream_index,
72  int64_t timestamp, int flags)
73 {
74  VocDecContext *voc = s->priv_data;
75  AVStream *st;
76  int index;
77 
78  if (s->nb_streams < 1) {
79  av_log(s, AV_LOG_ERROR, "cannot seek while no stream was found yet\n");
80  return AVERROR(EINVAL);
81  }
82 
83  st = s->streams[stream_index];
84  index = av_index_search_timestamp(st, timestamp, flags);
85 
86  if (index >= 0 && index < st->nb_index_entries - 1) {
87  AVIndexEntry *e = &st->index_entries[index];
88  avio_seek(s->pb, e->pos, SEEK_SET);
89  voc->pts = e->timestamp;
90  voc->remaining_size = e->size;
91  return 0;
92  } else if (st->nb_index_entries && st->index_entries[0].timestamp <= timestamp) {
93  AVIndexEntry *e = &st->index_entries[st->nb_index_entries - 1];
94  // prepare context for seek_frame_generic()
95  voc->pts = e->timestamp;
96  voc->remaining_size = e->size;
97  }
98  return -1;
99 }
100 
102  .name = "voc",
103  .long_name = NULL_IF_CONFIG_SMALL("Creative Voice"),
104  .priv_data_size = sizeof(VocDecContext),
109  .codec_tag = (const AVCodecTag* const []){ ff_voc_codec_tags, 0 },
110 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:631
Bytestream IO Context.
Definition: avio.h:111
int ff_voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
Definition: voc_packet.c:27
static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: vocdec.c:60
int64_t pos
Definition: avformat.h:816
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:101
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:213
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:1085
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:287
int version
Definition: avisynth_c.h:629
static AVPacket pkt
int ctx_flags
Flags signalling stream properties.
Definition: avformat.h:1368
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:1319
#define AVFMTCTX_NOHEADER
signal that no header is present (streams are added dynamically)
Definition: avformat.h:1278
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4043
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1387
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:1999
#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:817
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
static int voc_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: vocdec.c:71
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3911
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1375
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
static int voc_probe(AVProbeData *p)
Definition: vocdec.c:26
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:638
Stream structure.
Definition: avformat.h:876
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
const AVCodecTag ff_voc_codec_tags[]
Definition: voc.c:27
AVIOContext * pb
I/O context.
Definition: avformat.h:1361
int64_t pts
Definition: voc.h:30
int nb_index_entries
Definition: avformat.h:1087
int index
Definition: gxfenc.c:89
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
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:471
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:656
void * priv_data
Format private data.
Definition: avformat.h:1347
int64_t remaining_size
Definition: voc.h:29
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
AVCodecParameters * codecpar
Definition: avformat.h:1006
static int voc_read_header(AVFormatContext *s)
Definition: vocdec.c:40
This structure stores compressed data.
Definition: avcodec.h:1554
#define check(x, y, S, v)