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
|
#include "avformat.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;
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, AVFormatParameters *ap)
{
AVStream* st;
ByteIOContext *pb = s->pb;
st=av_new_stream(s, 0);
if (!st)
return AVERROR(ENOMEM);
st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
st->codec->codec_id=CODEC_ID_G729;
st->codec->sample_rate=8000;
st->codec->block_align = 16;
st->codec->channels=1;
av_set_pts_info(st, 64, 1, 100);
return 0;
}
static int read_packet(AVFormatContext *s,
AVPacket *pkt)
{
ByteIOContext *pb = s->pb;
PutBitContext pbo;
uint16_t buf[8 * MAX_FRAME_SIZE + 2];
int packet_size;
int sync;
uint16_t* src=buf;
int i, j, ret;
if(url_feof(pb))
return AVERROR_EOF;
sync = get_le16(pb); // sync word
packet_size = get_le16(pb) / 8;
if(packet_size > MAX_FRAME_SIZE)
return AVERROR(EIO);
ret = get_buffer(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);
av_new_packet(pkt, packet_size);
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;
return 0;
}
AVInputFormat ff_bit_demuxer = {
"bit",
"G.729 BIT file format",
0,
probe,
read_header,
read_packet,
.extensions = "bit"
};
#ifdef CONFIG_MUXERS
static int write_header(AVFormatContext *s)
{
AVCodecContext *enc = s->streams[0]->codec;
enc->codec_id = CODEC_ID_G729;
enc->channels = 1;
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)
{
ByteIOContext *pb = s->pb;
GetBitContext gb;
int i;
uint16_t b;
put_le16(pb, SYNC_WORD);
put_le16(pb, 8 * 10);
init_get_bits(&gb, pkt->data, 8*10);
for(i=0; i< 8 * 10; i++)
put_le16(pb, get_bits1(&gb) ? BIT_1 : BIT_0);
put_flush_packet(pb);
return 0;
}
AVOutputFormat ff_bit_muxer = {
"bit",
"G.729 BIT file format",
"audio/bit",
"bit",
0,
CODEC_ID_G729,
CODEC_ID_NONE,
write_header,
write_packet,
.extensions = "bit"
};
#endif
|
