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dcstr.c
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1 /*
2  * DC STR demuxer
3  * Copyright (c) 2015 Paul B Mahol
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 "avformat.h"
23 #include "internal.h"
24 
25 static int dcstr_probe(AVProbeData *p)
26 {
27  if (p->buf_size < 224 || memcmp(p->buf + 213, "Sega Stream", 11))
28  return 0;
29 
30  return AVPROBE_SCORE_MAX;
31 }
32 
34 {
35  unsigned codec, align;
36  AVStream *st;
37 
38  st = avformat_new_stream(s, NULL);
39  if (!st)
40  return AVERROR(ENOMEM);
41 
43  st->codecpar->channels = avio_rl32(s->pb);
44  st->codecpar->sample_rate = avio_rl32(s->pb);
45  codec = avio_rl32(s->pb);
46  align = avio_rl32(s->pb);
47  avio_skip(s->pb, 4);
48  st->duration = avio_rl32(s->pb);
49  st->codecpar->channels *= avio_rl32(s->pb);
50  if (!align || align > INT_MAX / st->codecpar->channels)
51  return AVERROR_INVALIDDATA;
52  st->codecpar->block_align = align * st->codecpar->channels;
53 
54  switch (codec) {
55  case 4: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_AICA; break;
56  case 16: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
57  default: avpriv_request_sample(s, "codec %X", codec);
58  return AVERROR_PATCHWELCOME;
59  }
60 
61  avio_skip(s->pb, 0x800 - avio_tell(s->pb));
62  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
63 
64  return 0;
65 }
66 
68 {
69  AVCodecParameters *par = s->streams[0]->codecpar;
70  return av_get_packet(s->pb, pkt, par->block_align);
71 }
72 
74  .name = "dcstr",
75  .long_name = NULL_IF_CONFIG_SMALL("Sega DC STR"),
76  .read_probe = dcstr_probe,
77  .read_header = dcstr_read_header,
78  .read_packet = dcstr_read_packet,
79  .extensions = "str",
81 };
#define NULL
Definition: coverity.c:32
#define AVFMT_NOBINSEARCH
Format does not allow to fall back on binary search via read_timestamp.
Definition: avformat.h:490
const char * s
Definition: avisynth_c.h:631
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static int dcstr_probe(AVProbeData *p)
Definition: dcstr.c:25
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:4427
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3922
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:304
static int dcstr_read_header(AVFormatContext *s)
Definition: dcstr.c:33
static AVPacket pkt
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3914
Format I/O context.
Definition: avformat.h:1325
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
static int dcstr_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: dcstr.c:67
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4065
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1393
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:260
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:511
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:720
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3918
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:462
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:461
int block_align
Audio only.
Definition: avcodec.h:4039
Stream structure.
Definition: avformat.h:876
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
const AVS_VideoInfo int align
Definition: avisynth_c.h:658
AVIOContext * pb
I/O context.
Definition: avformat.h:1367
AVInputFormat ff_dcstr_demuxer
Definition: dcstr.c:73
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:485
This structure contains the data a format has to probe a file.
Definition: avformat.h:459
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4032
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:471
Main libavformat public API header.
#define AVFMT_NO_BYTE_SEEK
Format does not allow seeking by bytes.
Definition: avformat.h:492
int channels
Audio only.
Definition: avcodec.h:4028
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:660
AVCodecParameters * codecpar
Definition: avformat.h:1006
This structure stores compressed data.
Definition: avcodec.h:1557