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/*
* 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",
AVMEDIA_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,
};
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