/* * 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, };