android.media.AudioFormat#CHANNEL_CONFIGURATION_MONO源码实例Demo

private int getMinBufferSize(int sampleRate, int channelConfig, int audioFormat) {
    minBufferSize = AudioTrack.getMinBufferSize(sampleRate, channelConfig, audioFormat);
    // 解决异常IllegalArgumentException: Invalid audio buffer size
    int channelCount = 1;
    switch (channelConfig) {
        // AudioFormat.CHANNEL_CONFIGURATION_DEFAULT
        case AudioFormat.CHANNEL_OUT_DEFAULT:
        case AudioFormat.CHANNEL_OUT_MONO:
        case AudioFormat.CHANNEL_CONFIGURATION_MONO:
            channelCount = 1;
            break;
        case AudioFormat.CHANNEL_OUT_STEREO:
        case AudioFormat.CHANNEL_CONFIGURATION_STEREO:
            channelCount = 2;
            break;
        default:
            channelCount = Integer.bitCount(channelConfig);
    }
    // 判断minBufferSize是否在范围内，如果不在设定默认值为1152
    int frameSizeInBytes = channelCount * (audioFormat == AudioFormat.ENCODING_PCM_8BIT ? 1 : 2);
    if ((minBufferSize % frameSizeInBytes != 0) || (minBufferSize < 1)) {
        minBufferSize = 1152;
    }
    return minBufferSize;
}
 

public AudioThread(int sampleRateInHz, int channel, long streamId, long decoderId, Media media)
{
	if (channel == 1)
	{
		channel_configuration = AudioFormat.CHANNEL_CONFIGURATION_MONO;
	} else
	{
		channel_configuration = AudioFormat.CHANNEL_CONFIGURATION_STEREO;
	}
	this.mediaStreamId = streamId;
	this.decoderId = decoderId;
	this.media = media;
	int minBufferSize = AudioTrack.getMinBufferSize(sampleRateInHz, channel_configuration, AudioFormat.ENCODING_PCM_16BIT);
	if (minBufferSize > audioLength)
	{
		audioLength = minBufferSize;
	}
	mAudioBuffer = new byte[audioLength];
	mAudio = new AudioTrack(AudioManager.STREAM_MUSIC, sampleRateInHz, channel_configuration, AudioFormat.ENCODING_PCM_16BIT, audioLength, AudioTrack.MODE_STREAM);
}
 

private void startRecord(){
	File file = new File(Environment.getExternalStorageDirectory(), "record.pcm");
	int sampleFreq = (Integer)spFrequency.getSelectedItem();
	
	try{
		file.createNewFile();
		
		OutputStream outputStream = new FileOutputStream(file);
		BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
		DataOutputStream dataOutputStream = new DataOutputStream(bufferedOutputStream);
		
		int minBufferedSize = AudioRecord.getMinBufferSize(sampleFreq, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);
		
		short[] audioData = new short[minBufferedSize];
		
		AudioRecord audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC, sampleFreq, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, minBufferedSize);
		audioRecord.startRecording();
		
		while (recording) {
			int numberOfShort = audioRecord.read(audioData, 0, minBufferedSize);
			for(int i = 0; i < numberOfShort; i++){
				dataOutputStream.writeShort(audioData[i]);
			}
		}
		
		audioRecord.stop();
		dataOutputStream.close();
		
	} catch(Exception ex){
		ex.printStackTrace();
	}
}
 

/**
 * Constructor.
 * 
 * @param sampleRate
 *            The sample rate (e.g. 44100 Hz).
 */
public AudioRecorder(int sampleRate) {
	int bufferSize = AudioRecord.getMinBufferSize(sampleRate,
			AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);
	
	audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC,
			sampleRate, AudioFormat.CHANNEL_CONFIGURATION_MONO,
			AudioFormat.ENCODING_PCM_16BIT, bufferSize);
	swtWindowing = false;
}