FFmpeg: libavformat/g723_1.c Source File

FFmpeg
g723_1.c
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1 /*
2  * G.723.1 demuxer
3  * Copyright (c) 2010 Mohamed Naufal Basheer
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 /**
23  * @file
24  * G.723.1 demuxer
25  */
26 
27 #include "libavutil/attributes.h"
28 #include "libavutil/channel_layout.h"
29 #include "avformat.h"
30 #include "internal.h"
31 
32  static const uint8_t frame_size[4] = { 24, 20, 4, 1 };
33 
34  static av_cold int g723_1_init(AVFormatContext *s)
35 {
36  AVStream *st;
37 
38  st = avformat_new_stream(s, NULL);
39  if (!st)
40  return AVERROR(ENOMEM);
41 
42  st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
43  st->codecpar->codec_id = AV_CODEC_ID_G723_1;
44  st->codecpar->channel_layout = AV_CH_LAYOUT_MONO;
45  st->codecpar->channels = 1;
46  st->codecpar->sample_rate = 8000;
47 
48  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
49  st->start_time = 0;
50 
51  return 0;
52 }
53 
54  static int g723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
55 {
56  int size, byte, ret;
57 
58  pkt->pos = avio_tell(s->pb);
59  byte = avio_r8(s->pb);
60  size = frame_size[byte & 3];
61 
62  ret = av_new_packet(pkt, size);
63  if (ret < 0)
64  return ret;
65 
66  pkt->data[0] = byte;
67  pkt->duration = 240;
68  pkt->stream_index = 0;
69 
70  ret = avio_read(s->pb, pkt->data + 1, size - 1);
71  if (ret < size - 1) {
72  av_packet_unref(pkt);
73  return ret < 0 ? ret : AVERROR_EOF;
74  }
75 
76  return pkt->size;
77 }
78 
79  AVInputFormat ff_g723_1_demuxer = {
80  .name = "g723_1",
81  .long_name = NULL_IF_CONFIG_SMALL("G.723.1"),
82  .read_header = g723_1_init,
83  .read_packet = g723_1_read_packet,
84  .extensions = "tco,rco,g723_1",
85  .flags = AVFMT_GENERIC_INDEX
86 };
NULL
#define NULL
Definition: coverity.c:32
g723_1_read_packet
static int g723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: g723_1.c:54
s
const char * s
Definition: avisynth_c.h:768
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1450
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:4820
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3884
AVPacket::size
int size
Definition: avcodec.h:1431
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
frame_size
static const uint8_t frame_size[4]
Definition: g723_1.c:32
attributes.h
Macro definitions for various function/variable attributes.
AVFormatContext
Format I/O context.
Definition: avformat.h:1342
uint8_t
uint8_t
Definition: audio_convert.c:194
av_cold
#define av_cold
Definition: attributes.h:82
ff_g723_1_demuxer
AVInputFormat ff_g723_1_demuxer
Definition: g723_1.c:79
AVPacket::duration
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1448
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4450
AVPacket::data
uint8_t * data
Definition: avcodec.h:1430
AV_CODEC_ID_G723_1
Definition: avcodec.h:603
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
size
ptrdiff_t size
Definition: opengl_enc.c:101
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
AVCodecParameters::channel_layout
uint64_t channel_layout
Audio only.
Definition: avcodec.h:3986
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:648
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
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:186
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3880
AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:639
channel_layout.h
audio channel layout utility functions
AVStream
Stream structure.
Definition: avformat.h:873
byte
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_WB16 unsigned int_TMPL byte
Definition: bytestream.h:87
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1384
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:592
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:470
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: avcodec.h:3994
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:912
g723_1_init
static av_cold int g723_1_init(AVFormatContext *s)
Definition: g723_1.c:34
AVCodecParameters::channels
int channels
Audio only.
Definition: avcodec.h:3990
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:647
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1020
AVPacket::stream_index
int stream_index
Definition: avcodec.h:1432
AV_CH_LAYOUT_MONO
#define AV_CH_LAYOUT_MONO
Definition: channel_layout.h:85
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1407
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