FFmpeg
apc.c
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1 /*
2  * CRYO APC audio format demuxer
3  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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 <string.h>
23 
25 #include "avformat.h"
26 #include "internal.h"
27 
28 static int apc_probe(const AVProbeData *p)
29 {
30  if (!strncmp(p->buf, "CRYO_APC", 8))
31  return AVPROBE_SCORE_MAX;
32 
33  return 0;
34 }
35 
37 {
38  AVIOContext *pb = s->pb;
39  AVStream *st;
40 
41  avio_rl32(pb); /* CRYO */
42  avio_rl32(pb); /* _APC */
43  avio_rl32(pb); /* 1.20 */
44 
45  st = avformat_new_stream(s, NULL);
46  if (!st)
47  return AVERROR(ENOMEM);
48 
51 
52  avio_rl32(pb); /* number of samples */
53  st->codecpar->sample_rate = avio_rl32(pb);
54 
55  /* initial predictor values for adpcm decoder */
56  if (ff_get_extradata(s, st->codecpar, pb, 2 * 4) < 0)
57  return AVERROR(ENOMEM);
58 
59  if (avio_rl32(pb)) {
60  st->codecpar->channels = 2;
62  } else {
63  st->codecpar->channels = 1;
65  }
66 
69  * st->codecpar->sample_rate;
70  st->codecpar->block_align = 1;
71 
72  return 0;
73 }
74 
75 #define MAX_READ_SIZE 4096
76 
78 {
79  if (av_get_packet(s->pb, pkt, MAX_READ_SIZE) <= 0)
80  return AVERROR(EIO);
81  pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
82  pkt->stream_index = 0;
83  return 0;
84 }
85 
87  .name = "apc",
88  .long_name = NULL_IF_CONFIG_SMALL("CRYO APC"),
89  .read_probe = apc_probe,
90  .read_header = apc_read_header,
91  .read_packet = apc_read_packet,
92 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3960
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
Format I/O context.
Definition: avformat.h:1358
static int apc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: apc.c:77
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4469
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
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4062
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3989
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:3956
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1486
AVInputFormat ff_apc_demuxer
Definition: apc.c:86
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
#define MAX_READ_SIZE
Definition: apc.c:75
static int apc_probe(const AVProbeData *p)
Definition: apc.c:28
int block_align
Audio only.
Definition: avcodec.h:4077
audio channel layout utility functions
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:881
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int sample_rate
Audio only.
Definition: avcodec.h:4070
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
static int apc_read_header(AVFormatContext *s)
Definition: apc.c:36
Main libavformat public API header.
int ff_get_extradata(AVFormatContext *s, 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: utils.c:3316
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: avcodec.h:1513
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:4002
int channels
Audio only.
Definition: avcodec.h:4066
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
int stream_index
Definition: avcodec.h:1482
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 AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:1457