2 * AMR Audio encoder stub
3 * Copyright (c) 2003 the ffmpeg project
5 * This file is part of FFmpeg.
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.
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.
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
22 #include <vo-amrwbenc/enc_if.h>
25 #include "libavutil/avstring.h"
26 #include "libavutil/opt.h"
28 typedef struct AMRWBContext {
36 static const AVOption options[] = {
37 { "dtx", "Allow DTX (generate comfort noise)", offsetof(AMRWBContext, allow_dtx), AV_OPT_TYPE_INT, { 0 }, 0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },
41 static const AVClass class = {
42 "libvo_amrwbenc", av_default_item_name, options, LIBAVUTIL_VERSION_INT
45 static int get_wb_bitrate_mode(int bitrate, void *log_ctx)
47 /* make the correspondance between bitrate and mode */
48 static const int rates[] = { 6600, 8850, 12650, 14250, 15850, 18250,
49 19850, 23050, 23850 };
50 int i, best = -1, min_diff = 0;
53 for (i = 0; i < 9; i++) {
54 if (rates[i] == bitrate)
56 if (best < 0 || abs(rates[i] - bitrate) < min_diff) {
58 min_diff = abs(rates[i] - bitrate);
61 /* no bitrate matching exactly, log a warning */
62 snprintf(log_buf, sizeof(log_buf), "bitrate not supported: use one of ");
63 for (i = 0; i < 9; i++)
64 av_strlcatf(log_buf, sizeof(log_buf), "%.2fk, ", rates[i] / 1000.f);
65 av_strlcatf(log_buf, sizeof(log_buf), "using %.2fk", rates[best] / 1000.f);
66 av_log(log_ctx, AV_LOG_WARNING, "%s\n", log_buf);
71 static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
73 AMRWBContext *s = avctx->priv_data;
75 if (avctx->sample_rate != 16000) {
76 av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");
77 return AVERROR(ENOSYS);
80 if (avctx->channels != 1) {
81 av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
82 return AVERROR(ENOSYS);
85 s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx);
86 s->last_bitrate = avctx->bit_rate;
88 avctx->frame_size = 320;
89 avctx->coded_frame = avcodec_alloc_frame();
91 s->state = E_IF_init();
96 static int amr_wb_encode_close(AVCodecContext *avctx)
98 AMRWBContext *s = avctx->priv_data;
101 av_freep(&avctx->coded_frame);
105 static int amr_wb_encode_frame(AVCodecContext *avctx,
106 unsigned char *frame/*out*/,
107 int buf_size, void *data/*in*/)
109 AMRWBContext *s = avctx->priv_data;
112 if (s->last_bitrate != avctx->bit_rate) {
113 s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx);
114 s->last_bitrate = avctx->bit_rate;
116 size = E_IF_encode(s->state, s->mode, data, frame, s->allow_dtx);
120 AVCodec ff_libvo_amrwbenc_encoder = {
121 .name = "libvo_amrwbenc",
122 .type = AVMEDIA_TYPE_AUDIO,
123 .id = CODEC_ID_AMR_WB,
124 .priv_data_size = sizeof(AMRWBContext),
125 .init = amr_wb_encode_init,
126 .encode = amr_wb_encode_frame,
127 .close = amr_wb_encode_close,
128 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE},
129 .long_name = NULL_IF_CONFIG_SMALL("Android VisualOn Adaptive Multi-Rate "
131 .priv_class = &class,