Statistics
| Branch: | Revision:

ffmpeg / libavcodec / libvo-amrwbenc.c @ f502ff3f

History | View | Annotate | Download (3.55 KB)

1
/*
2
 * AMR Audio encoder stub
3
 * Copyright (c) 2003 the ffmpeg project
4
 *
5
 * This file is part of Libav.
6
 *
7
 * Libav 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
 * Libav 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 Libav; if not, write to the Free Software
19
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20
 */
21

    
22
#include <vo-amrwbenc/enc_if.h>
23

    
24
#include "avcodec.h"
25

    
26
static const char wb_bitrate_unsupported[] =
27
    "bitrate not supported: use one of 6.6k, 8.85k, 12.65k, 14.25k, 15.85k, "
28
    "18.25k, 19.85k, 23.05k, or 23.85k\n";
29

    
30
typedef struct AMRWB_bitrates {
31
    int rate;
32
    int mode;
33
} AMRWB_bitrates;
34

    
35
typedef struct AMRWBContext {
36
    void  *state;
37
    int    mode;
38
    int    allow_dtx;
39
} AMRWBContext;
40

    
41
static int getWBBitrateMode(int bitrate)
42
{
43
    /* make the correspondance between bitrate and mode */
44
    AMRWB_bitrates rates[] = { { 6600, 0},
45
                               { 8850, 1},
46
                               {12650, 2},
47
                               {14250, 3},
48
                               {15850, 4},
49
                               {18250, 5},
50
                               {19850, 6},
51
                               {23050, 7},
52
                               {23850, 8}, };
53
    int i;
54

    
55
    for (i = 0; i < 9; i++)
56
        if (rates[i].rate == bitrate)
57
            return rates[i].mode;
58
    /* no bitrate matching, return an error */
59
    return -1;
60
}
61

    
62
static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
63
{
64
    AMRWBContext *s = avctx->priv_data;
65

    
66
    if (avctx->sample_rate != 16000) {
67
        av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");
68
        return -1;
69
    }
70

    
71
    if (avctx->channels != 1) {
72
        av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
73
        return -1;
74
    }
75

    
76
    if ((s->mode = getWBBitrateMode(avctx->bit_rate)) < 0) {
77
        av_log(avctx, AV_LOG_ERROR, wb_bitrate_unsupported);
78
        return -1;
79
    }
80

    
81
    avctx->frame_size  = 320;
82
    avctx->coded_frame = avcodec_alloc_frame();
83

    
84
    s->state     = E_IF_init();
85
    s->allow_dtx = 0;
86

    
87
    return 0;
88
}
89

    
90
static int amr_wb_encode_close(AVCodecContext *avctx)
91
{
92
    AMRWBContext *s = avctx->priv_data;
93

    
94
    E_IF_exit(s->state);
95
    av_freep(&avctx->coded_frame);
96
    return 0;
97
}
98

    
99
static int amr_wb_encode_frame(AVCodecContext *avctx,
100
                               unsigned char *frame/*out*/,
101
                               int buf_size, void *data/*in*/)
102
{
103
    AMRWBContext *s = avctx->priv_data;
104
    int size;
105

    
106
    if ((s->mode = getWBBitrateMode(avctx->bit_rate)) < 0) {
107
        av_log(avctx, AV_LOG_ERROR, wb_bitrate_unsupported);
108
        return -1;
109
    }
110
    size = E_IF_encode(s->state, s->mode, data, frame, s->allow_dtx);
111
    return size;
112
}
113

    
114
AVCodec ff_libvo_amrwbenc_encoder = {
115
    "libvo_amrwbenc",
116
    CODEC_TYPE_AUDIO,
117
    CODEC_ID_AMR_WB,
118
    sizeof(AMRWBContext),
119
    amr_wb_encode_init,
120
    amr_wb_encode_frame,
121
    amr_wb_encode_close,
122
    NULL,
123
    .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
124
    .long_name = NULL_IF_CONFIG_SMALL("libvo-amrwbenc Adaptive Multi-Rate "
125
                                      "(AMR) Wide-Band"),
126
};
127