FFmpeg: libavformat/aixdec.c Source File

FFmpeg
aixdec.c
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1 /*
2  * AIX demuxer
3  * Copyright (c) 2016 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 aix_probe(const AVProbeData *p)
28 {
29  if (AV_RL32(p->buf) != MKTAG('A','I','X','F') ||
30  AV_RB32(p->buf + 8) != 0x01000014 ||
31  AV_RB32(p->buf + 12) != 0x00000800)
32  return 0;
33 
34  return AVPROBE_SCORE_MAX;
35 }
36 
37  static int aix_read_header(AVFormatContext *s)
38 {
39  unsigned nb_streams, first_offset, nb_segments;
40  unsigned stream_list_offset;
41  unsigned segment_list_offset = 0x20;
42  unsigned segment_list_entry_size = 0x10;
43  unsigned size;
44  int i;
45 
46  avio_skip(s->pb, 4);
47  first_offset = avio_rb32(s->pb) + 8;
48  avio_skip(s->pb, 16);
49  nb_segments = avio_rb16(s->pb);
50  if (nb_segments == 0)
51  return AVERROR_INVALIDDATA;
52  stream_list_offset = segment_list_offset + segment_list_entry_size * nb_segments + 0x10;
53  if (stream_list_offset >= first_offset)
54  return AVERROR_INVALIDDATA;
55  avio_seek(s->pb, stream_list_offset, SEEK_SET);
56  nb_streams = avio_r8(s->pb);
57  if (nb_streams == 0)
58  return AVERROR_INVALIDDATA;
59  avio_skip(s->pb, 7);
60  for (i = 0; i < nb_streams; i++) {
61  AVStream *st = avformat_new_stream(s, NULL);
62 
63  if (!st)
64  return AVERROR(ENOMEM);
65  st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
66  st->codecpar->codec_id = AV_CODEC_ID_ADPCM_ADX;
67  st->codecpar->sample_rate = avio_rb32(s->pb);
68  st->codecpar->ch_layout.nb_channels = avio_r8(s->pb);
69  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
70  avio_skip(s->pb, 3);
71  }
72 
73  avio_seek(s->pb, first_offset, SEEK_SET);
74  for (i = 0; i < nb_streams; i++) {
75  if (avio_rl32(s->pb) != MKTAG('A','I','X','P'))
76  return AVERROR_INVALIDDATA;
77  size = avio_rb32(s->pb);
78  if (size <= 8)
79  return AVERROR_INVALIDDATA;
80  avio_skip(s->pb, 8);
81  ff_get_extradata(s, s->streams[i]->codecpar, s->pb, size - 8);
82  }
83 
84  return 0;
85 }
86 
87  static int aix_read_packet(AVFormatContext *s, AVPacket *pkt)
88 {
89  unsigned size, index, duration, chunk;
90  int64_t pos;
91  int sequence, ret, i;
92 
93  pos = avio_tell(s->pb);
94  if (avio_feof(s->pb))
95  return AVERROR_EOF;
96  chunk = avio_rl32(s->pb);
97  size = avio_rb32(s->pb);
98  if (chunk == MKTAG('A','I','X','E')) {
99  avio_skip(s->pb, size);
100  for (i = 0; i < s->nb_streams; i++) {
101  if (avio_feof(s->pb))
102  return AVERROR_EOF;
103  chunk = avio_rl32(s->pb);
104  size = avio_rb32(s->pb);
105  avio_skip(s->pb, size);
106  }
107  pos = avio_tell(s->pb);
108  chunk = avio_rl32(s->pb);
109  size = avio_rb32(s->pb);
110  }
111 
112  if (chunk != MKTAG('A','I','X','P'))
113  return AVERROR_INVALIDDATA;
114  if (size <= 8)
115  return AVERROR_INVALIDDATA;
116  index = avio_r8(s->pb);
117  if (avio_r8(s->pb) != s->nb_streams || index >= s->nb_streams)
118  return AVERROR_INVALIDDATA;
119  duration = avio_rb16(s->pb);
120  sequence = avio_rb32(s->pb);
121  if (sequence < 0) {
122  avio_skip(s->pb, size - 8);
123  return 0;
124  }
125 
126  ret = av_get_packet(s->pb, pkt, size - 8);
127  pkt->stream_index = index;
128  pkt->duration = duration;
129  pkt->pos = pos;
130  return ret;
131 }
132 
133  const AVInputFormat ff_aix_demuxer = {
134  .name = "aix",
135  .long_name = NULL_IF_CONFIG_SMALL("CRI AIX"),
136  .read_probe = aix_probe,
137  .read_header = aix_read_header,
138  .read_packet = aix_read_packet,
139  .extensions = "aix",
140  .flags = AVFMT_GENERIC_INDEX,
141 };
aix_probe
static int aix_probe(const AVProbeData *p)
Definition: aixdec.c:27
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
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: options.c:243
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:58
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:392
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:311
ff_get_extradata
int ff_get_extradata(void *logctx, AVCodecParameters *par, AVIOContext *pb, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0 and f...
Definition: demux_utils.c:355
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:771
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:500
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:480
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:782
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:546
duration
int64_t duration
Definition: movenc.c:64
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:551
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
nb_streams
static int nb_streams
Definition: ffprobe.c:309
AVFormatContext
Format I/O context.
Definition: avformat.h:1104
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:861
NULL
#define NULL
Definition: coverity.c:32
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:213
index
int index
Definition: gxfenc.c:89
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:178
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:751
AV_CODEC_ID_ADPCM_ADX
@ AV_CODEC_ID_ADPCM_ADX
Definition: codec_id.h:374
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:115
aix_read_header
static int aix_read_header(AVFormatContext *s)
Definition: aixdec.c:37
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
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:624
aix_read_packet
static int aix_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: aixdec.c:87
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
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:102
ff_aix_demuxer
const AVInputFormat ff_aix_demuxer
Definition: aixdec.c:133
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:838
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:252
avio_rb16
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:767
pos
unsigned int pos
Definition: spdifenc.c:413
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:376
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:339
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:62
AVPacket
This structure stores compressed data.
Definition: packet.h:351
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:394
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:367
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