FFmpeg
aea.c
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1 /*
2  * MD STUDIO audio demuxer
3  *
4  * Copyright (c) 2009 Benjamin Larsson
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
24 #include "libavutil/intreadwrite.h"
25 #include "avformat.h"
26 #include "pcm.h"
27 
28 #define AT1_SU_SIZE 212
29 
30 static int aea_read_probe(const AVProbeData *p)
31 {
32  if (p->buf_size <= 2048+212)
33  return 0;
34 
35  /* Magic is '00 08 00 00' in little-endian*/
36  if (AV_RL32(p->buf)==0x800) {
37  int ch, i;
38  ch = p->buf[264];
39 
40  if (ch != 1 && ch != 2)
41  return 0;
42 
43  /* Check so that the redundant bsm bytes and info bytes are valid
44  * the block size mode bytes have to be the same
45  * the info bytes have to be the same
46  */
47  for (i = 2048; i + 211 < p->buf_size; i+= 212) {
48  int bsm_s, bsm_e, inb_s, inb_e;
49  bsm_s = p->buf[0];
50  inb_s = p->buf[1];
51  inb_e = p->buf[210];
52  bsm_e = p->buf[211];
53 
54  if (bsm_s != bsm_e || inb_s != inb_e)
55  return 0;
56  }
57  return AVPROBE_SCORE_MAX / 4 + 1;
58  }
59  return 0;
60 }
61 
63 {
65  if (!st)
66  return AVERROR(ENOMEM);
67 
68  /* Parse the amount of channels and skip to pos 2048(0x800) */
69  avio_skip(s->pb, 264);
70  st->codecpar->channels = avio_r8(s->pb);
71  avio_skip(s->pb, 1783);
72 
73 
76  st->codecpar->sample_rate = 44100;
77  st->codecpar->bit_rate = 292000;
78 
79  if (st->codecpar->channels != 1 && st->codecpar->channels != 2) {
80  av_log(s, AV_LOG_ERROR, "Channels %d not supported!\n", st->codecpar->channels);
81  return AVERROR_INVALIDDATA;
82  }
83 
85 
87  return 0;
88 }
89 
91 {
92  int ret = av_get_packet(s->pb, pkt, s->streams[0]->codecpar->block_align);
93 
94  pkt->stream_index = 0;
95  if (ret <= 0)
96  return AVERROR(EIO);
97 
98  return ret;
99 }
100 
102  .name = "aea",
103  .long_name = NULL_IF_CONFIG_SMALL("MD STUDIO audio"),
104  .read_probe = aea_read_probe,
105  .read_header = aea_read_header,
106  .read_packet = aea_read_packet,
107  .read_seek = ff_pcm_read_seek,
108  .flags = AVFMT_GENERIC_INDEX,
109  .extensions = "aea",
110 };
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: utils.c:4372
pcm.h
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AV_CH_LAYOUT_MONO
#define AV_CH_LAYOUT_MONO
Definition: channel_layout.h:90
aea_read_probe
static int aea_read_probe(const AVProbeData *p)
Definition: aea.c:30
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
AT1_SU_SIZE
#define AT1_SU_SIZE
Definition: aea.c:28
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
AVCodecParameters::channels
int channels
Audio only.
Definition: codec_par.h:166
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
AV_CH_LAYOUT_STEREO
#define AV_CH_LAYOUT_STEREO
Definition: channel_layout.h:91
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:181
AVInputFormat
Definition: avformat.h:616
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:621
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVFormatContext
Format I/O context.
Definition: avformat.h:1106
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:979
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
aea_read_packet
static int aea_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: aea.c:90
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:170
aea_read_header
static int aea_read_header(AVFormatContext *s)
Definition: aea.c:62
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:117
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:607
AV_CODEC_ID_ATRAC1
@ AV_CODEC_ID_ATRAC1
Definition: codec_id.h:467
i
int i
Definition: input.c:407
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:177
ff_aea_demuxer
const AVInputFormat ff_aea_demuxer
Definition: aea.c:101
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:280
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:832
ff_pcm_read_seek
int ff_pcm_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: pcm.c:56
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
channel_layout.h
AVPacket::stream_index
int stream_index
Definition: packet.h:367
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:327
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:342
AVCodecParameters::channel_layout
uint64_t channel_layout
Audio only.
Definition: codec_par.h:162
AVCodecParameters::bit_rate
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: codec_par.h:89
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59