FFmpeg
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(const 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  int mult;
37  AVStream *st;
38 
39  st = avformat_new_stream(s, NULL);
40  if (!st)
41  return AVERROR(ENOMEM);
42 
44  st->codecpar->channels = avio_rl32(s->pb);
45  st->codecpar->sample_rate = avio_rl32(s->pb);
46  codec = avio_rl32(s->pb);
47  align = avio_rl32(s->pb);
48  avio_skip(s->pb, 4);
49  st->duration = avio_rl32(s->pb);
50  mult = avio_rl32(s->pb);
51  if (st->codecpar->channels <= 0 || mult <= 0 || mult > INT_MAX / st->codecpar->channels) {
52  av_log(s, AV_LOG_ERROR, "invalid number of channels %d x %d\n", st->codecpar->channels, mult);
53  return AVERROR_INVALIDDATA;
54  }
55  st->codecpar->channels *= mult;
56  if (!align || align > INT_MAX / st->codecpar->channels)
57  return AVERROR_INVALIDDATA;
58  st->codecpar->block_align = align * st->codecpar->channels;
59 
60  switch (codec) {
61  case 4: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_AICA; break;
62  case 16: st->codecpar->codec_id = AV_CODEC_ID_PCM_S16LE_PLANAR; break;
63  default: avpriv_request_sample(s, "codec %X", codec);
64  return AVERROR_PATCHWELCOME;
65  }
66 
67  avio_skip(s->pb, 0x800 - avio_tell(s->pb));
68  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
69 
70  return 0;
71 }
72 
74 {
75  AVCodecParameters *par = s->streams[0]->codecpar;
76  return av_get_packet(s->pb, pkt, par->block_align);
77 }
78 
80  .name = "dcstr",
81  .long_name = NULL_IF_CONFIG_SMALL("Sega DC STR"),
82  .read_probe = dcstr_probe,
83  .read_header = dcstr_read_header,
84  .read_packet = dcstr_read_packet,
85  .extensions = "str",
87 };
#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:473
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
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:4897
#define avpriv_request_sample(...)
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3958
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
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:3950
Format I/O context.
Definition: avformat.h:1358
static int dcstr_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: dcstr.c:73
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4470
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
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:310
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:772
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3954
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
int block_align
Audio only.
Definition: avcodec.h:4075
static int16_t mult(Float11 *f1, Float11 *f2)
Definition: g726.c:55
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:881
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
const AVS_VideoInfo int align
Definition: avisynth_c.h:887
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
AVInputFormat ff_dcstr_demuxer
Definition: dcstr.c:79
static int dcstr_probe(const AVProbeData *p)
Definition: dcstr.c:25
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:468
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4068
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
#define AVFMT_NO_BYTE_SEEK
Format does not allow seeking by bytes.
Definition: avformat.h:475
int channels
Audio only.
Definition: avcodec.h:4064
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
This structure stores compressed data.
Definition: avcodec.h:1455