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 Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 
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 
57 {
58  avio_write(s->pb, pkt->data, pkt->size);
59  avio_flush(s->pb);
60  return 0;
61 }
62 
63 static int ilbc_probe(AVProbeData *p)
64 {
65  // Only check for "#!iLBC" which matches both formats
66  if (!memcmp(p->buf, mode20_header, 6))
67  return AVPROBE_SCORE_MAX;
68  else
69  return 0;
70 }
71 
73 {
74  AVIOContext *pb = s->pb;
75  AVStream *st;
76  uint8_t header[9];
77 
78  avio_read(pb, header, 9);
79 
80  st = avformat_new_stream(s, NULL);
81  if (!st)
82  return AVERROR(ENOMEM);
84  st->codec->sample_rate = 8000;
85  st->codec->channels = 1;
87  st->start_time = 0;
88  avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);
89  if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
90  st->codec->block_align = 38;
91  st->codec->bit_rate = 15200;
92  } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
93  st->codec->block_align = 50;
94  st->codec->bit_rate = 13333;
95  } else {
96  av_log(s, AV_LOG_ERROR, "Unrecognized iLBC file header\n");
97  return AVERROR_INVALIDDATA;
98  }
99 
100  return 0;
101 }
102 
104  AVPacket *pkt)
105 {
106  AVCodecContext *enc = s->streams[0]->codec;
107  int ret;
108 
109  if ((ret = av_new_packet(pkt, enc->block_align)) < 0)
110  return ret;
111 
112  pkt->stream_index = 0;
113  pkt->pos = avio_tell(s->pb);
114  pkt->duration = enc->block_align == 38 ? 160 : 240;
115  if ((ret = avio_read(s->pb, pkt->data, enc->block_align)) != enc->block_align) {
116  av_free_packet(pkt);
117  return ret < 0 ? ret : AVERROR(EIO);
118  }
119 
120  return 0;
121 }
122 
124  .name = "ilbc",
125  .long_name = NULL_IF_CONFIG_SMALL("iLBC storage"),
126  .read_probe = ilbc_probe,
127  .read_header = ilbc_read_header,
128  .read_packet = ilbc_read_packet,
129  .flags = AVFMT_GENERIC_INDEX,
130 };
131 
133  .name = "ilbc",
134  .long_name = NULL_IF_CONFIG_SMALL("iLBC storage"),
135  .mime_type = "audio/iLBC",
136  .extensions = "lbc",
137  .audio_codec = AV_CODEC_ID_ILBC,
138  .write_header = ilbc_write_header,
139  .write_packet = ilbc_write_packet,
140  .flags = AVFMT_NOTIMESTAMPS,
141 };
static const char mode30_header[]
Definition: ilbc.c:26
Bytestream IO Context.
Definition: avio.h:68
void av_free_packet(AVPacket *pkt)
Free a packet.
Definition: avpacket.c:153
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:940
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:3283
static int ilbc_read_header(AVFormatContext *s)
Definition: ilbc.c:72
int size
Definition: avcodec.h:916
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:2141
Format I/O context.
Definition: avformat.h:828
static int ilbc_probe(AVProbeData *p)
Definition: ilbc.c:63
uint8_t
AVStream ** streams
Definition: avformat.h:876
uint8_t * data
Definition: avcodec.h:915
AVInputFormat ff_ilbc_demuxer
Definition: ilbc.c:123
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:219
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:165
int duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:937
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:446
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:56
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:88
static int ilbc_write_header(AVFormatContext *s)
Definition: ilbc.c:28
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:146
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2736
AVOutputFormat ff_ilbc_muxer
Definition: ilbc.c:132
static int ilbc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:103
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:641
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:340
unsigned int nb_streams
A list of all streams in the file.
Definition: avformat.h:875
int bit_rate
the average bitrate
Definition: avcodec.h:1404
static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:56
int void avio_flush(AVIOContext *s)
Definition: aviobuf.c:180
const char * name
Definition: avformat.h:376
Stream structure.
Definition: avformat.h:622
NULL
Definition: eval.c:52
enum AVMediaType codec_type
Definition: avcodec.h:1347
enum AVCodecID codec_id
Definition: avcodec.h:1350
int sample_rate
samples per second
Definition: avcodec.h:2104
AVIOContext * pb
I/O context.
Definition: avformat.h:861
main external API structure.
Definition: avcodec.h:1339
This structure contains the data a format has to probe a file.
Definition: avformat.h:338
Main libavformat public API header.
int64_t start_time
Decoding: pts of the first frame of the stream, in stream time base.
Definition: avformat.h:677
static const char mode20_header[]
Definition: ilbc.c:25
int channels
number of audio channels
Definition: avcodec.h:2105
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:455
int stream_index
Definition: avcodec.h:917
This structure stores compressed data.
Definition: avcodec.h:898