func: 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;
  
  }