func: static av_cold void set_bandwidth(AC3EncodeContext *s, int cutoff)
  
  {
  
      int ch, bw_code;
  
  
  
      if (cutoff) {
  
          /* calculate bandwidth based on user-specified cutoff frequency */
  
          int fbw_coeffs;
  
          cutoff         = av_clip(cutoff, 1, s->sample_rate >> 1);
  
          fbw_coeffs     = cutoff * 2 * AC3_MAX_COEFS / s->sample_rate;
  
          bw_code        = av_clip((fbw_coeffs - 73) / 3, 0, 60);
  
      } else {
  
          /* use default bandwidth setting */
  
          /* XXX: should compute the bandwidth according to the frame
  
             size, so that we avoid annoying high frequency artifacts */
  
          bw_code = 50;
  
      }
  
  
  
      /* set number of coefficients for each channel */
  
      for (ch = 0; ch < s->fbw_channels; ch++) {
  
          s->bandwidth_code[ch] = bw_code;
  
          s->nb_coefs[ch]       = bw_code * 3 + 73;
  
      }
  
      if (s->lfe_on)
  
          s->nb_coefs[s->lfe_channel] = 7; /* LFE channel always has 7 coefs */
  
  }
  