func: static int64_t get_bit_rate(AVCodecContext *ctx)
  
  {
  
      int64_t bit_rate;
  
      int bits_per_sample;
  
  
  
      switch (ctx->codec_type) {
  
      case AVMEDIA_TYPE_VIDEO:
  
      case AVMEDIA_TYPE_DATA:
  
      case AVMEDIA_TYPE_SUBTITLE:
  
      case AVMEDIA_TYPE_ATTACHMENT:
  
          bit_rate = ctx->bit_rate;
  
          break;
  
      case AVMEDIA_TYPE_AUDIO:
  
          bits_per_sample = av_get_bits_per_sample(ctx->codec_id);
  
          bit_rate = bits_per_sample ? ctx->sample_rate * ctx->channels * bits_per_sample : ctx->bit_rate;
  
          break;
  
      default:
  
          bit_rate = 0;
  
          break;
  
      }
  
      return bit_rate;
  
  }
  