1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
|
/*
* G.729 bit format muxer and demuxer
* Copyright (c) 2007-2008 Vladimir Voroshilov
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avformat.h"
#include "internal.h"
#include "libavcodec/get_bits.h"
#include "libavcodec/put_bits.h"
#define MAX_FRAME_SIZE 10
#define SYNC_WORD 0x6b21
#define BIT_0 0x7f
#define BIT_1 0x81
static int probe(AVProbeData *p)
{
int i, j;
if(p->buf_size < 0x40)
return 0;
for(i=0; i+3<p->buf_size && i< 10*0x50; ){
if(AV_RL16(&p->buf[0]) != SYNC_WORD)
return 0;
j=AV_RL16(&p->buf[2]);
if(j!=0x40 && j!=0x50)
return 0;
i+=j;
}
return AVPROBE_SCORE_MAX/2;
}
static int read_header(AVFormatContext *s)
{
AVStream* st;
st=avformat_new_stream(s, NULL);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id=AV_CODEC_ID_G729;
st->codec->sample_rate=8000;
st->codec->block_align = 16;
st->codec->channels=1;
avpriv_set_pts_info(st, 64, 1, 100);
return 0;
}
static int read_packet(AVFormatContext *s,
AVPacket *pkt)
{
AVIOContext *pb = s->pb;
PutBitContext pbo;
uint16_t buf[8 * MAX_FRAME_SIZE + 2];
int packet_size;
uint16_t* src=buf;
int i, j, ret;
int64_t pos= avio_tell(pb);
if(url_feof(pb))
return AVERROR_EOF;
avio_rl16(pb); // sync word
packet_size = avio_rl16(pb) / 8;
if(packet_size > MAX_FRAME_SIZE)
return AVERROR_INVALIDDATA;
ret = avio_read(pb, (uint8_t*)buf, (8 * packet_size) * sizeof(uint16_t));
if(ret<0)
return ret;
if(ret != 8 * packet_size * sizeof(uint16_t))
return AVERROR(EIO);
if (av_new_packet(pkt, packet_size) < 0)
return AVERROR(ENOMEM);
init_put_bits(&pbo, pkt->data, packet_size);
for(j=0; j < packet_size; j++)
for(i=0; i<8;i++)
put_bits(&pbo,1, AV_RL16(src++) == BIT_1 ? 1 : 0);
flush_put_bits(&pbo);
pkt->duration=1;
pkt->pos = pos;
return 0;
}
AVInputFormat ff_bit_demuxer = {
.name = "bit",
.long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
.read_probe = probe,
.read_header = read_header,
.read_packet = read_packet,
.extensions = "bit",
};
#if CONFIG_MUXERS
static int write_header(AVFormatContext *s)
{
AVCodecContext *enc = s->streams[0]->codec;
if ((enc->codec_id != AV_CODEC_ID_G729) || enc->channels != 1) {
av_log(s, AV_LOG_ERROR,
"only codec g729 with 1 channel is supported by this format\n");
return AVERROR(EINVAL);
}
enc->bits_per_coded_sample = 16;
enc->block_align = (enc->bits_per_coded_sample * enc->channels) >> 3;
return 0;
}
static int write_packet(AVFormatContext *s, AVPacket *pkt)
{
AVIOContext *pb = s->pb;
GetBitContext gb;
int i;
if (pkt->size != 10)
return AVERROR(EINVAL);
avio_wl16(pb, SYNC_WORD);
avio_wl16(pb, 8 * 10);
init_get_bits(&gb, pkt->data, 8*10);
for(i=0; i< 8 * 10; i++)
avio_wl16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
avio_flush(pb);
return 0;
}
AVOutputFormat ff_bit_muxer = {
.name = "bit",
.long_name = NULL_IF_CONFIG_SMALL("G.729 BIT file format"),
.mime_type = "audio/bit",
.extensions = "bit",
.audio_codec = AV_CODEC_ID_G729,
.video_codec = AV_CODEC_ID_NONE,
.write_header = write_header,
.write_packet = write_packet,
};
#endif
|
