FFmpeg: libavformat/3dostr.c Source File

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 "libavutil/intreadwrite.h"
23 #include "avformat.h"
24 #include "demux.h"
25 #include "internal.h"
26 
27  static int threedostr_probe(const AVProbeData *p)
28 {
29  for (int i = 0; i < p->buf_size;) {
30  unsigned chunk = AV_RL32(p->buf + i);
31  unsigned size = AV_RB32(p->buf + i + 4);
32 
33  if (size < 8 || p->buf_size - i < size)
34  return 0;
35  i += 8;
36  size -= 8;
37  switch (chunk) {
38  case MKTAG('C','T','R','L'):
39  break;
40  case MKTAG('S','N','D','S'):
41  if (size < 56)
42  return 0;
43  i += 8;
44  if (AV_RL32(p->buf + i) != MKTAG('S','H','D','R'))
45  return 0;
46  i += 28;
47 
48  if (AV_RB32(p->buf + i) <= 0)
49  return 0;
50  i += 4;
51  if (AV_RB32(p->buf + i) <= 0)
52  return 0;
53  i += 4;
54  if (AV_RL32(p->buf + i) == MKTAG('S','D','X','2'))
55  return AVPROBE_SCORE_MAX;
56  else
57  return 0;
58  break;
59  case MKTAG('S','H','D','R'):
60  if (size > 0x78) {
61  i += 0x78;
62  size -= 0x78;
63  }
64  break;
65  default:
66  break;
67  }
68 
69  i += size;
70  }
71 
72  return 0;
73 }
74 
75  static int threedostr_read_header(AVFormatContext *s)
76 {
77  unsigned chunk, codec = 0, size, ctrl_size = -1, found_shdr = 0;
78  AVStream *st;
79 
80  while (!avio_feof(s->pb) && !found_shdr) {
81  chunk = avio_rl32(s->pb);
82  size = avio_rb32(s->pb);
83 
84  if (size < 8)
85  return AVERROR_INVALIDDATA;
86  size -= 8;
87 
88  switch (chunk) {
89  case MKTAG('C','T','R','L'):
90  ctrl_size = size;
91  break;
92  case MKTAG('S','N','D','S'):
93  if (size < 56)
94  return AVERROR_INVALIDDATA;
95  avio_skip(s->pb, 8);
96  if (avio_rl32(s->pb) != MKTAG('S','H','D','R'))
97  return AVERROR_INVALIDDATA;
98  avio_skip(s->pb, 24);
99 
100  st = avformat_new_stream(s, NULL);
101  if (!st)
102  return AVERROR(ENOMEM);
103 
104  st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
105  st->codecpar->sample_rate = avio_rb32(s->pb);
106  st->codecpar->ch_layout.nb_channels = avio_rb32(s->pb);
107  if (st->codecpar->ch_layout.nb_channels <= 0 || st->codecpar->sample_rate <= 0)
108  return AVERROR_INVALIDDATA;
109  codec = avio_rl32(s->pb);
110  avio_skip(s->pb, 4);
111  if (ctrl_size == 20 || ctrl_size == 3 || ctrl_size == -1)
112  st->duration = (avio_rb32(s->pb) - 1) / st->codecpar->ch_layout.nb_channels;
113  else
114  st->duration = avio_rb32(s->pb) * 16 / st->codecpar->ch_layout.nb_channels;
115  size -= 56;
116  found_shdr = 1;
117  break;
118  case MKTAG('S','H','D','R'):
119  if (size > 0x78) {
120  avio_skip(s->pb, 0x74);
121  size -= 0x78;
122  if (avio_rl32(s->pb) == MKTAG('C','T','R','L') && size > 4) {
123  ctrl_size = avio_rb32(s->pb);
124  size -= 4;
125  }
126  }
127  break;
128  default:
129  av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
130  break;
131  }
132 
133  avio_skip(s->pb, size);
134  }
135 
136  switch (codec) {
137  case MKTAG('S','D','X','2'):
138  st->codecpar->codec_id = AV_CODEC_ID_SDX2_DPCM;
139  st->codecpar->block_align = 1 * st->codecpar->ch_layout.nb_channels;
140  break;
141  default:
142  avpriv_request_sample(s, "codec %X", codec);
143  return AVERROR_PATCHWELCOME;
144  }
145 
146  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
147 
148  return 0;
149 }
150 
151  static int threedostr_read_packet(AVFormatContext *s, AVPacket *pkt)
152 {
153  unsigned chunk, size;
154  AVStream *st = s->streams[0];
155  int64_t pos;
156  int ret = 0;
157 
158  while (!avio_feof(s->pb)) {
159  pos = avio_tell(s->pb);
160  chunk = avio_rl32(s->pb);
161  size = avio_rb32(s->pb);
162 
163  if (!size)
164  continue;
165 
166  if (size < 8)
167  return AVERROR_INVALIDDATA;
168  size -= 8;
169 
170  switch (chunk) {
171  case MKTAG('S','N','D','S'):
172  if (size <= 16)
173  return AVERROR_INVALIDDATA;
174  avio_skip(s->pb, 8);
175  if (avio_rl32(s->pb) != MKTAG('S','S','M','P'))
176  return AVERROR_INVALIDDATA;
177  avio_skip(s->pb, 4);
178  size -= 16;
179  ret = av_get_packet(s->pb, pkt, size);
180  pkt->pos = pos;
181  pkt->stream_index = 0;
182  pkt->duration = size / st->codecpar->ch_layout.nb_channels;
183  return ret;
184  default:
185  av_log(s, AV_LOG_DEBUG, "skipping unknown chunk: %X\n", chunk);
186  break;
187  }
188 
189  avio_skip(s->pb, size);
190  }
191 
192  return AVERROR_EOF;
193 }
194 
195  const FFInputFormat ff_threedostr_demuxer = {
196  .p.name = "3dostr",
197  .p.long_name = NULL_IF_CONFIG_SMALL("3DO STR"),
198  .p.extensions = "str",
199  .p.flags = AVFMT_GENERIC_INDEX,
200  .read_probe = threedostr_probe,
201  .read_header = threedostr_read_header,
202  .read_packet = threedostr_read_packet,
203 };
AVERROR
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
int64_t
long long int64_t
Definition: coverity.c:34
threedostr_probe
static int threedostr_probe(const AVProbeData *p)
Definition: 3dostr.c:27
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:557
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:454
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:321
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:463
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:860
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:494
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:480
ff_threedostr_demuxer
const FFInputFormat ff_threedostr_demuxer
Definition: 3dostr.c:195
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:807
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:761
pkt
AVPacket * pkt
Definition: movenc.c:60
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:553
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
threedostr_read_header
static int threedostr_read_header(AVFormatContext *s)
Definition: 3dostr.c:75
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
AVFormatContext
Format I/O context.
Definition: avformat.h:1287
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:771
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:180
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:184
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:730
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
size
int size
Definition: twinvq_data.h:10344
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:41
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:191
demux.h
av_get_packet
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:91
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:748
pos
unsigned int pos
Definition: spdifenc.c:414
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
AVPacket::stream_index
int stream_index
Definition: packet.h:541
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:318
AV_CODEC_ID_SDX2_DPCM
@ AV_CODEC_ID_SDX2_DPCM
Definition: codec_id.h:433
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:36
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:516
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:559
FFInputFormat
Definition: demux.h:37
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:346
threedostr_read_packet
static int threedostr_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: 3dostr.c:151
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