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 
29 {
30  AVIOContext *pb = s->pb;
31  AVCodecParameters *par;
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  par = s->streams[0]->codecpar;
38 
39  if (par->codec_id != AV_CODEC_ID_ILBC) {
40  av_log(s, AV_LOG_ERROR, "Unsupported codec\n");
41  return AVERROR(EINVAL);
42  }
43 
44  if (par->block_align == 50) {
45  avio_write(pb, mode30_header, sizeof(mode30_header) - 1);
46  } else if (par->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  return 0;
60 }
61 
62 static int ilbc_probe(const 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 
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);
83  st->codecpar->sample_rate = 8000;
84  st->codecpar->channels = 1;
86  st->start_time = 0;
87  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
88  if (!memcmp(header, mode20_header, sizeof(mode20_header) - 1)) {
89  st->codecpar->block_align = 38;
90  st->codecpar->bit_rate = 15200;
91  } else if (!memcmp(header, mode30_header, sizeof(mode30_header) - 1)) {
92  st->codecpar->block_align = 50;
93  st->codecpar->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 
103  AVPacket *pkt)
104 {
105  AVCodecParameters *par = s->streams[0]->codecpar;
106  int ret;
107 
108  if ((ret = av_new_packet(pkt, par->block_align)) < 0)
109  return ret;
110 
111  pkt->stream_index = 0;
112  pkt->pos = avio_tell(s->pb);
113  pkt->duration = par->block_align == 38 ? 160 : 240;
114  if ((ret = avio_read(s->pb, pkt->data, par->block_align)) != par->block_align) {
115  av_packet_unref(pkt);
116  return ret < 0 ? ret : AVERROR(EIO);
117  }
118 
119  return 0;
120 }
121 
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 
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 };
#define NULL
Definition: coverity.c:32
static const char mode30_header[]
Definition: ilbc.c:26
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1500
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:4926
static int ilbc_read_header(AVFormatContext *s)
Definition: ilbc.c:71
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
int size
Definition: avcodec.h:1481
static AVPacket pkt
This struct describes the properties of an encoded stream.
Definition: avcodec.h:3960
Format I/O context.
Definition: avformat.h:1358
uint8_t
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1498
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4499
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
uint8_t * data
Definition: avcodec.h:1480
AVInputFormat ff_ilbc_demuxer
Definition: ilbc.c:122
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
static const uint8_t header[24]
Definition: sdr2.c:67
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:650
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3997
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
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
static int ilbc_write_header(AVFormatContext *s)
Definition: ilbc.c:28
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
AVOutputFormat ff_ilbc_muxer
Definition: ilbc.c:131
static int ilbc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:102
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1414
int block_align
Audio only.
Definition: avcodec.h:4085
static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:56
const char * name
Definition: avformat.h:505
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:881
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:467
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:599
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:468
void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:238
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
int sample_rate
Audio only.
Definition: avcodec.h:4078
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:920
static int ilbc_probe(const AVProbeData *p)
Definition: ilbc.c:62
static const char mode20_header[]
Definition: ilbc.c:25
int channels
Audio only.
Definition: avcodec.h:4074
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
This structure stores compressed data.
Definition: avcodec.h:1457