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- /*
- * AMR Audio encoder stub
- * Copyright (c) 2003 the ffmpeg project
- *
- * This file is part of Libav.
- *
- * Libav 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.
- *
- * Libav 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 Libav; 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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