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
|
/*
* AMR Audio encoder stub
* Copyright (c) 2003 the ffmpeg project
*
* 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 <vo-amrwbenc/enc_if.h>
#include "avcodec.h"
#include "libavutil/avstring.h"
#include "libavutil/opt.h"
typedef struct AMRWBContext {
AVClass *av_class;
void *state;
int mode;
int last_bitrate;
int allow_dtx;
} AMRWBContext;
static const AVOption options[] = {
{ "dtx", "Allow DTX (generate comfort noise)", offsetof(AMRWBContext, allow_dtx), FF_OPT_TYPE_INT, 0, 0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },
{ NULL }
};
static const AVClass class = {
"libvo_amrwbenc", av_default_item_name, options, LIBAVUTIL_VERSION_INT
};
static int get_wb_bitrate_mode(int bitrate, void *log_ctx)
{
/* make the correspondance between bitrate and mode */
static const int rates[] = { 6600, 8850, 12650, 14250, 15850, 18250,
19850, 23050, 23850 };
int i, best = -1, min_diff = 0;
char log_buf[200];
for (i = 0; i < 9; i++) {
if (rates[i] == bitrate)
return i;
if (best < 0 || abs(rates[i] - bitrate) < min_diff) {
best = i;
min_diff = abs(rates[i] - bitrate);
}
}
/* no bitrate matching exactly, log a warning */
snprintf(log_buf, sizeof(log_buf), "bitrate not supported: use one of ");
for (i = 0; i < 9; i++)
av_strlcatf(log_buf, sizeof(log_buf), "%.2fk, ", rates[i] / 1000.f);
av_strlcatf(log_buf, sizeof(log_buf), "using %.2fk", rates[best] / 1000.f);
av_log(log_ctx, AV_LOG_WARNING, "%s\n", log_buf);
return best;
}
static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
{
AMRWBContext *s = avctx->priv_data;
if (avctx->sample_rate != 16000) {
av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");
return AVERROR(ENOSYS);
}
if (avctx->channels != 1) {
av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
return AVERROR(ENOSYS);
}
s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx);
s->last_bitrate = avctx->bit_rate;
avctx->frame_size = 320;
avctx->coded_frame = avcodec_alloc_frame();
s->state = E_IF_init();
return 0;
}
static int amr_wb_encode_close(AVCodecContext *avctx)
{
AMRWBContext *s = avctx->priv_data;
E_IF_exit(s->state);
av_freep(&avctx->coded_frame);
return 0;
}
static int amr_wb_encode_frame(AVCodecContext *avctx,
unsigned char *frame/*out*/,
int buf_size, void *data/*in*/)
{
AMRWBContext *s = avctx->priv_data;
int size;
if (s->last_bitrate != avctx->bit_rate) {
s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx);
s->last_bitrate = avctx->bit_rate;
}
size = E_IF_encode(s->state, s->mode, data, frame, s->allow_dtx);
return size;
}
AVCodec ff_libvo_amrwbenc_encoder = {
"libvo_amrwbenc",
CODEC_TYPE_AUDIO,
CODEC_ID_AMR_WB,
sizeof(AMRWBContext),
amr_wb_encode_init,
amr_wb_encode_frame,
amr_wb_encode_close,
NULL,
.sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
.long_name = NULL_IF_CONFIG_SMALL("Android VisualOn Adaptive Multi-Rate "
"(AMR) Wide-Band"),
.priv_class = &class,
};
|
