FFmpeg
3dostr.c
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1 /*
2  * 3DO 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 threedostr_probe(const AVProbeData *p)
26 {
27  if (memcmp(p->buf, "CTRL", 4) &&
28  memcmp(p->buf, "SHDR", 4) &&
29  memcmp(p->buf, "SNDS", 4))
30  return 0;
31 
32  return AVPROBE_SCORE_MAX / 3 * 2;
33 }
34 
36 {
37  unsigned chunk, codec = 0, size, ctrl_size = -1, found_shdr = 0;
38  AVStream *st;
39 
40  while (!avio_feof(s->pb) && !found_shdr) {
41  chunk = avio_rl32(s->pb);
42  size = avio_rb32(s->pb);
43 
44  if (size < 8)
45  return AVERROR_INVALIDDATA;
46  size -= 8;
47 
48  switch (chunk) {
49  case MKTAG('C','T','R','L'):
50  ctrl_size = size;
51  break;
52  case MKTAG('S','N','D','S'):
53  if (size < 56)
54  return AVERROR_INVALIDDATA;
55  avio_skip(s->pb, 8);
56  if (avio_rl32(s->pb) != MKTAG('S','H','D','R'))
57  return AVERROR_INVALIDDATA;
58  avio_skip(s->pb, 24);
59 
60  st = avformat_new_stream(s, NULL);
61  if (!st)
62  return AVERROR(ENOMEM);
63 
65  st->codecpar->sample_rate = avio_rb32(s->pb);
66  st->codecpar->channels = avio_rb32(s->pb);
67  if (st->codecpar->channels <= 0)
68  return AVERROR_INVALIDDATA;
69  codec = avio_rl32(s->pb);
70  avio_skip(s->pb, 4);
71  if (ctrl_size == 20 || ctrl_size == 3 || ctrl_size == -1)
72  st->duration = (avio_rb32(s->pb) - 1) / st->codecpar->channels;
73  else
74  st->duration = avio_rb32(s->pb) * 16 / st->codecpar->channels;
75  size -= 56;
76  found_shdr = 1;
77  break;
78  case MKTAG('S','H','D','R'):
79  if (size > 0x78) {
80  avio_skip(s->pb, 0x74);
81  size -= 0x78;
82  if (avio_rl32(s->pb) == MKTAG('C','T','R','L') && size > 4) {
83  ctrl_size = avio_rb32(s->pb);
84  size -= 4;
85  }
86  }
87  break;
88  default:
89  av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
90  break;
91  }
92 
93  avio_skip(s->pb, size);
94  }
95 
96  switch (codec) {
97  case MKTAG('S','D','X','2'):
99  st->codecpar->block_align = 1 * st->codecpar->channels;
100  break;
101  default:
102  avpriv_request_sample(s, "codec %X", codec);
103  return AVERROR_PATCHWELCOME;
104  }
105 
106  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
107 
108  return 0;
109 }
110 
112 {
113  unsigned chunk, size, found_ssmp = 0;
114  AVStream *st = s->streams[0];
115  int64_t pos;
116  int ret = 0;
117 
118  while (!found_ssmp) {
119  if (avio_feof(s->pb))
120  return AVERROR_EOF;
121 
122  pos = avio_tell(s->pb);
123  chunk = avio_rl32(s->pb);
124  size = avio_rb32(s->pb);
125 
126  if (!size)
127  continue;
128 
129  if (size < 8)
130  return AVERROR_INVALIDDATA;
131  size -= 8;
132 
133  switch (chunk) {
134  case MKTAG('S','N','D','S'):
135  if (size <= 16)
136  return AVERROR_INVALIDDATA;
137  avio_skip(s->pb, 8);
138  if (avio_rl32(s->pb) != MKTAG('S','S','M','P'))
139  return AVERROR_INVALIDDATA;
140  avio_skip(s->pb, 4);
141  size -= 16;
142  ret = av_get_packet(s->pb, pkt, size);
143  pkt->pos = pos;
144  pkt->stream_index = 0;
145  pkt->duration = size / st->codecpar->channels;
146  size = 0;
147  found_ssmp = 1;
148  break;
149  default:
150  av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
151  break;
152  }
153 
154  avio_skip(s->pb, size);
155  }
156 
157  return ret;
158 }
159 
161  .name = "3dostr",
162  .long_name = NULL_IF_CONFIG_SMALL("3DO STR"),
163  .read_probe = threedostr_probe,
164  .read_header = threedostr_read_header,
165  .read_packet = threedostr_read_packet,
166  .extensions = "str",
167  .flags = AVFMT_GENERIC_INDEX,
168 };
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1497
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:4882
#define avpriv_request_sample(...)
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3953
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
static AVPacket pkt
Format I/O context.
Definition: avformat.h:1358
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:801
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1495
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4455
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
#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:310
ptrdiff_t size
Definition: opengl_enc.c:100
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
#define av_log(a,...)
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:770
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:197
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3949
AVInputFormat ff_threedostr_demuxer
Definition: 3dostr.c:160
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:4070
#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
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
#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:4063
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
static int threedostr_probe(const AVProbeData *p)
Definition: 3dostr.c:25
Main libavformat public API header.
int channels
Audio only.
Definition: avcodec.h:4059
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
static int threedostr_read_header(AVFormatContext *s)
Definition: 3dostr.c:35
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:358
int stream_index
Definition: avcodec.h:1479
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
#define MKTAG(a, b, c, d)
Definition: common.h:366
static int threedostr_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: 3dostr.c:111
This structure stores compressed data.
Definition: avcodec.h:1454