title: Lame - increase bitrate to 320
body: <p>First I want to show my method for converting source .wav files to .mp3 by Lame library:</p>
  
  <pre><code>- (void)convertFromWav:(NSString *)sourceFilePath ToMp3:(NSString *)resultName {
    NSString *mp3FileName = [resultName stringByAppendingString:@".mp3"];
    NSString *mp3FilePath = [NSTemporaryDirectory() stringByAppendingPathComponent:mp3FileName];
  
    @try {
      int read, write;
      FILE *pcm = fopen([sourceFilePath UTF8String], "rb");  //source
      if (pcm == NULL) {
        perror("fopen");
        return;
      }
      fseek(pcm, 4*1024, SEEK_CUR);                                   //skip file header
      FILE *mp3 = fopen([mp3FilePath cStringUsingEncoding:1], "wb");  //output
  
      const int sampleRate = 44100;
      const int bitsPerSample = 16;
      const int numberOfChannels = 2;
  
      const int PCM_SIZE = 8192*2;
      const int MP3_SIZE = 8192*2;
      short int pcm_buffer[PCM_SIZE*2];
      unsigned char mp3_buffer[MP3_SIZE];
  
      lame_t lame = lame_init();
      lame_set_in_samplerate(lame, sampleRate);
      lame_set_VBR(lame, vbr_default);
      lame_init_params(lame);
  
      lame_get_num_samples(lame);
  
      long long fileSize = [[[[NSFileManager defaultManager] attributesOfItemAtPath:sourceFilePath error:nil] objectForKey:NSFileSize] longLongValue];
      long duration = fileSize / (sampleRate * numberOfChannels * bitsPerSample / 8);//(fileSize * 8.0f) / (sampleRate * 2);
  
      lame_set_num_samples(lame, (duration * sampleRate));
      lame_get_num_samples(lame);
  
      float percent     = 0.0;
      int totalframes = lame_get_totalframes(lame);
  
      do {
        read = fread(pcm_buffer, 2*sizeof(short int), PCM_SIZE, pcm);
        if (read == 0)
          write = lame_encode_flush(lame, mp3_buffer, MP3_SIZE);
        else
          write = lame_encode_buffer_interleaved(lame, pcm_buffer, read, mp3_buffer, MP3_SIZE);
  
        fwrite(mp3_buffer, write, 1, mp3);
  
        int frameNum    = lame_get_frameNum(lame);
        if (frameNum &lt; totalframes)
          percent = (100. * frameNum / totalframes + 0.5);
        else
          percent = 100;
  
        if ([_delegate respondsToSelector:@selector(convertingProgressChangedWithPercent:)])
        {
          [_delegate convertingProgressChangedWithPercent:percent];
        }
  
      } while (read != 0);
  
      lame_close(lame);
      fclose(mp3);
      fclose(pcm);
    }
    @catch (NSException *exception) {
      NSLog(@"%@",[exception description]);
    }
    @finally {
      if ([_delegate respondsToSelector:@selector(convertingDidFinish:)])
      {
        [_delegate convertingDidFinish:mp3FilePath];
      }
    }
  }
  </code></pre>
  
  <p>It's okay and it's working. As a result I have .mp3 which has 152000 bits per second. But I want to make it 320000 bits per second. How can I change it? I am not good in theory about this stuff so I don't know which values change to what. Thanks.</p>