Libav 0.7.1
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00001 /* 00002 * AMR Audio encoder stub 00003 * Copyright (c) 2003 the ffmpeg project 00004 * 00005 * This file is part of Libav. 00006 * 00007 * Libav is free software; you can redistribute it and/or 00008 * modify it under the terms of the GNU Lesser General Public 00009 * License as published by the Free Software Foundation; either 00010 * version 2.1 of the License, or (at your option) any later version. 00011 * 00012 * Libav is distributed in the hope that it will be useful, 00013 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00014 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00015 * Lesser General Public License for more details. 00016 * 00017 * You should have received a copy of the GNU Lesser General Public 00018 * License along with Libav; if not, write to the Free Software 00019 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00020 */ 00021 00022 #include <vo-amrwbenc/enc_if.h> 00023 00024 #include "avcodec.h" 00025 #include "libavutil/avstring.h" 00026 #include "libavutil/opt.h" 00027 00028 typedef struct AMRWBContext { 00029 AVClass *av_class; 00030 void *state; 00031 int mode; 00032 int last_bitrate; 00033 int allow_dtx; 00034 } AMRWBContext; 00035 00036 static const AVOption options[] = { 00037 { "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 }, 00038 { NULL } 00039 }; 00040 00041 static const AVClass class = { 00042 "libvo_amrwbenc", av_default_item_name, options, LIBAVUTIL_VERSION_INT 00043 }; 00044 00045 static int get_wb_bitrate_mode(int bitrate, void *log_ctx) 00046 { 00047 /* make the correspondance between bitrate and mode */ 00048 static const int rates[] = { 6600, 8850, 12650, 14250, 15850, 18250, 00049 19850, 23050, 23850 }; 00050 int i, best = -1, min_diff = 0; 00051 char log_buf[200]; 00052 00053 for (i = 0; i < 9; i++) { 00054 if (rates[i] == bitrate) 00055 return i; 00056 if (best < 0 || abs(rates[i] - bitrate) < min_diff) { 00057 best = i; 00058 min_diff = abs(rates[i] - bitrate); 00059 } 00060 } 00061 /* no bitrate matching exactly, log a warning */ 00062 snprintf(log_buf, sizeof(log_buf), "bitrate not supported: use one of "); 00063 for (i = 0; i < 9; i++) 00064 av_strlcatf(log_buf, sizeof(log_buf), "%.2fk, ", rates[i] / 1000.f); 00065 av_strlcatf(log_buf, sizeof(log_buf), "using %.2fk", rates[best] / 1000.f); 00066 av_log(log_ctx, AV_LOG_WARNING, "%s\n", log_buf); 00067 00068 return best; 00069 } 00070 00071 static av_cold int amr_wb_encode_init(AVCodecContext *avctx) 00072 { 00073 AMRWBContext *s = avctx->priv_data; 00074 00075 if (avctx->sample_rate != 16000) { 00076 av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n"); 00077 return AVERROR(ENOSYS); 00078 } 00079 00080 if (avctx->channels != 1) { 00081 av_log(avctx, AV_LOG_ERROR, "Only mono supported\n"); 00082 return AVERROR(ENOSYS); 00083 } 00084 00085 s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx); 00086 s->last_bitrate = avctx->bit_rate; 00087 00088 avctx->frame_size = 320; 00089 avctx->coded_frame = avcodec_alloc_frame(); 00090 00091 s->state = E_IF_init(); 00092 00093 return 0; 00094 } 00095 00096 static int amr_wb_encode_close(AVCodecContext *avctx) 00097 { 00098 AMRWBContext *s = avctx->priv_data; 00099 00100 E_IF_exit(s->state); 00101 av_freep(&avctx->coded_frame); 00102 return 0; 00103 } 00104 00105 static int amr_wb_encode_frame(AVCodecContext *avctx, 00106 unsigned char *frame/*out*/, 00107 int buf_size, void *data/*in*/) 00108 { 00109 AMRWBContext *s = avctx->priv_data; 00110 int size; 00111 00112 if (s->last_bitrate != avctx->bit_rate) { 00113 s->mode = get_wb_bitrate_mode(avctx->bit_rate, avctx); 00114 s->last_bitrate = avctx->bit_rate; 00115 } 00116 size = E_IF_encode(s->state, s->mode, data, frame, s->allow_dtx); 00117 return size; 00118 } 00119 00120 AVCodec ff_libvo_amrwbenc_encoder = { 00121 "libvo_amrwbenc", 00122 AVMEDIA_TYPE_AUDIO, 00123 CODEC_ID_AMR_WB, 00124 sizeof(AMRWBContext), 00125 amr_wb_encode_init, 00126 amr_wb_encode_frame, 00127 amr_wb_encode_close, 00128 NULL, 00129 .sample_fmts = (const enum AVSampleFormat[]){AV_SAMPLE_FMT_S16,AV_SAMPLE_FMT_NONE}, 00130 .long_name = NULL_IF_CONFIG_SMALL("Android VisualOn Adaptive Multi-Rate " 00131 "(AMR) Wide-Band"), 00132 .priv_class = &class, 00133 }; 00134