/*
  * 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), AV_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 = {

     .name           = "libvo_amrwbenc",
     .type           = AVMEDIA_TYPE_AUDIO,
     .id             = CODEC_ID_AMR_WB,
     .priv_data_size = sizeof(AMRWBContext),
     .init           = amr_wb_encode_init,
     .encode         = amr_wb_encode_frame,
     .close          = amr_wb_encode_close,

     .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,

 };