FFmpeg: libavformat/ilbc.c Source File

FFmpeg
ilbc.c
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1 /*
2  * iLBC storage file format
3  * Copyright (c) 2012 Martin Storsjo
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 const char mode20_header[] = "#!iLBC20\n";
26  static const char mode30_header[] = "#!iLBC30\n";
27 
28  static int ilbc_write_header(AVFormatContext *s)
29 {
30  AVIOContext *pb = s->pb;
31  AVCodecContext *enc;
32 
33  if (s->nb_streams != 1) {
34  av_log(s, AV_LOG_ERROR, "Unsupported number of streams\n");
35  return AVERROR(EINVAL);
36  }
37  enc = s->streams[0]->codec;
38 
39  if (enc->codec_id != AV_CODEC_ID_ILBC) {
40  av_log(s, AV_LOG_ERROR, "Unsupported codec\n");
41  return AVERROR(EINVAL);
42  }
43 
44  if (enc->block_align == 50) {
45  avio_write(pb, mode30_header, sizeof(mode30_header) - 1);
46  } else if (enc->block_align == 38) {
47  avio_write(pb, mode20_header, sizeof(mode20_header) - 1);
48  } else {
49  av_log(s, AV_LOG_ERROR, "Unsupported mode\n");
50  return AVERROR(EINVAL);
51  }
52  avio_flush(pb);
53  return 0;
54 }
55 
56  static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
57 {
58  avio_write(s->pb, pkt->data, pkt->size);
59  return 0;
60 }
61 
62  static int ilbc_probe(AVProbeData *p)
63 {
64  // Only check for "#!iLBC" which matches both formats
65  if (!memcmp(p->buf, mode20_header, 6))
66  return AVPROBE_SCORE_MAX;
67  else
68  return 0;
69 }
70 
71  static int ilbc_read_header(AVFormatContext *s)
72 {
73  AVIOContext *pb = s->pb;
74  AVStream *st;
75  uint8_t header[9];
76 
77  avio_read(pb, header, 9);
78 
79  st = avformat_new_stream(s, NULL);
80  if (!st)
81  return AVERROR(ENOMEM);
82  st->codec->codec_id = AV_CODEC_ID_ILBC;
83  st->codec->sample_rate = 8000;
84  st->codec->channels = 1;
85  st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
86  st->start_time = 0;
87  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
88  if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
89  st->codec->block_align = 38;
90  st->codec->bit_rate = 15200;
91  } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
92  st->codec->block_align = 50;
93  st->codec->bit_rate = 13333;
94  } else {
95  av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n");
96  return AVERROR_INVALIDDATA;
97  }
98 
99  return 0;
100 }
101 
102  static int ilbc_read_packet(AVFormatContext *s,
103  AVPacket *pkt)
104 {
105  AVCodecContext *enc = s->streams[0]->codec;
106  int ret;
107 
108  if ((ret = av_new_packet(pkt, enc->block_align)) < 0)
109  return ret;
110 
111  pkt->stream_index = 0;
112  pkt->pos = avio_tell(s->pb);
113  pkt->duration = enc->block_align == 38 ? 160 : 240;
114  if ((ret = avio_read(s->pb, pkt->data, enc->block_align)) != enc->block_align) {
115  av_packet_unref(pkt);
116  return ret < 0 ? ret : AVERROR(EIO);
117  }
118 
119  return 0;
120 }
121 
122  AVInputFormat ff_ilbc_demuxer = {
123  .name = "ilbc",
124  .long_name = NULL_IF_CONFIG_SMALL("iLBC storage"),
125  .read_probe = ilbc_probe,
126  .read_header = ilbc_read_header,
127  .read_packet = ilbc_read_packet,
128  .flags = AVFMT_GENERIC_INDEX,
129 };
130 
131  AVOutputFormat ff_ilbc_muxer = {
132  .name = "ilbc",
133  .long_name = NULL_IF_CONFIG_SMALL("iLBC storage"),
134  .mime_type = "audio/iLBC",
135  .extensions = "lbc",
136  .audio_codec = AV_CODEC_ID_ILBC,
137  .write_header = ilbc_write_header,
138  .write_packet = ilbc_write_packet,
139  .flags = AVFMT_NOTIMESTAMPS,
140 };
NULL
#define NULL
Definition: coverity.c:32
mode30_header
static const char mode30_header[]
Definition: ilbc.c:26
s
const char * s
Definition: avisynth_c.h:631
AVIOContext
Bytestream IO Context.
Definition: avio.h:111
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
AVCodecContext::bit_rate
int64_t bit_rate
the average bitrate
Definition: avcodec.h:1597
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1487
avpriv_set_pts_info
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:4149
ilbc_read_header
static int ilbc_read_header(AVFormatContext *s)
Definition: ilbc.c:71
AVPacket::size
int size
Definition: avcodec.h:1468
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
AVCodecContext::block_align
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2324
AVFormatContext
Format I/O context.
Definition: avformat.h:1314
ilbc_probe
static int ilbc_probe(AVProbeData *p)
Definition: ilbc.c:62
uint8_t
uint8_t
Definition: audio_convert.c:194
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1485
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3805
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1382
AVPacket::data
uint8_t * data
Definition: avcodec.h:1467
ff_ilbc_demuxer
AVInputFormat ff_ilbc_demuxer
Definition: ilbc.c:122
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:442
header
static const uint8_t header[24]
Definition: sdr2.c:67
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:182
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:545
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVERROR
#define AVERROR(e)
Definition: error.h:43
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:176
ilbc_write_header
static int ilbc_write_header(AVFormatContext *s)
Definition: ilbc.c:28
AVMEDIA_TYPE_AUDIO
Definition: avutil.h:194
ff_ilbc_muxer
AVOutputFormat ff_ilbc_muxer
Definition: ilbc.c:131
ilbc_read_packet
static int ilbc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:102
AVStream::codec
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:896
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:462
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1370
ilbc_write_packet
static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:56
avio_flush
int void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:202
AVOutputFormat::name
const char * name
Definition: avformat.h:523
AVStream
Stream structure.
Definition: avformat.h:877
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:485
AVCodecContext::codec_type
enum AVMediaType codec_type
Definition: avcodec.h:1540
AVCodecContext::codec_id
enum AVCodecID codec_id
Definition: avcodec.h:1549
AVCodecContext::sample_rate
int sample_rate
samples per second
Definition: avcodec.h:2287
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1356
AVCodecContext
main external API structure.
Definition: avcodec.h:1532
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:545
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:486
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:460
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:472
avformat.h
Main libavformat public API header.
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:929
mode20_header
static const char mode20_header[]
Definition: ilbc.c:25
AVCodecContext::channels
int channels
number of audio channels
Definition: avcodec.h:2288
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:661
AVPacket::stream_index
int stream_index
Definition: avcodec.h:1469
AV_CODEC_ID_ILBC
Definition: avcodec.h:481
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1444
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