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  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  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 
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->codec->sample_rate = 8000;
84  st->codec->channels = 1;
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 
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_free_packet(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 };
static const char mode30_header[]
Definition: ilbc.c:26
const char * s
Definition: avisynth_c.h:668
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
void av_free_packet(AVPacket *pkt)
Definition: avpacket.c:242
int64_t pos
byte position in stream, -1 if unknown
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
static int ilbc_read_header(AVFormatContext *s)
Definition: ilbc.c:71
static int ilbc_probe(AVProbeData *p)
Definition: ilbc.c:62
uint8_t
static AVPacket pkt
Definition: demuxing.c:56
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
AVStream ** streams
Definition: avformat.h:992
uint8_t * data
AVInputFormat ff_ilbc_demuxer
Definition: ilbc.c:122
static av_always_inline int64_t avio_tell(AVIOContext *s)
Definition: avio.h:248
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:173
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Definition: aviobuf.c:478
int av_new_packet(AVPacket *pkt, int size)
Definition: avpacket.c:73
#define NULL_IF_CONFIG_SMALL(x)
static int ilbc_write_header(AVFormatContext *s)
Definition: ilbc.c:28
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:246
AVOutputFormat ff_ilbc_muxer
Definition: ilbc.c:131
static int ilbc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:102
AVCodecContext * codec
Definition: avformat.h:662
unsigned char * buf
Definition: avformat.h:336
unsigned int nb_streams
Definition: avformat.h:991
static int ilbc_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ilbc.c:56
int void avio_flush(AVIOContext *s)
Definition: aviobuf.c:193
ret
Definition: avfilter.c:821
const char * name
Definition: avformat.h:378
#define AVFMT_NOTIMESTAMPS
Definition: avformat.h:352
NULL
Definition: eval.c:55
enum AVMediaType codec_type
enum AVCodecID codec_id
int sample_rate
samples per second
AVIOContext * pb
Definition: avformat.h:977
#define AV_LOG_ERROR
Definition: log.h:148
#define AVFMT_GENERIC_INDEX
Definition: avformat.h:353
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFilterBuffer 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.Buffer references ownership and permissions
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:340
int64_t start_time
Definition: avformat.h:689
static const char mode20_header[]
Definition: ilbc.c:25
int channels
number of audio channels
const char * name
Definition: avformat.h:461