android.media.AudioTrack#MODE_STATIC源码实例Demo

public AndroidAudioPlayer(final AudioConfig audioConfig) {
    AudioAttributes audioAttributes = new AudioAttributes.Builder()
            .setLegacyStreamType(AudioManager.STREAM_MUSIC)
            .setUsage(AudioAttributes.USAGE_MEDIA)
            .setContentType(AudioAttributes.CONTENT_TYPE_MUSIC)
            .build();

    AudioFormat audioFormat = new AudioFormat.Builder()
            .setChannelMask(audioConfig.getOutputChannel())
            .setEncoding(audioConfig.getOutputFormat())
            .setSampleRate(audioConfig.getSampleRate())
            .build();

    audioTrack = new AudioTrack(audioAttributes,
            audioFormat,
            audioConfig.getOutputBufferSize(),
            AudioTrack.MODE_STATIC,
            AudioManager.AUDIO_SESSION_ID_GENERATE);

    outputByteCount = audioConfig.getOutputFormatByteCount();
}
 

/**
 * Create a sin wave of certain frequency and duration.
 *
 * @param freqHz     The frequency in Hertz
 * @param durationMs The duration in milliseconds
 * @return An AudioTrack with the corresponding sine wave.
 */
public static AudioTrack generateToneSine(final double freqHz, final int durationMs) {
	int count = (int) (BITRATE * 2.0 * (durationMs / MILLIS_IN_SECOND)) & ~1;
	short[] samples = new short[count];
	for (int i = 0; i < count; i += 2) {
		short sample = (short) (Math.sin(2 * Math.PI * i / (BITRATE / freqHz)) * 0x7FFF); // MAGIC_NUMBER
		samples[i] = sample;
		samples[i + 1] = sample;
	}
	@SuppressWarnings("deprecation")
	AudioTrack track = new AudioTrack(AudioManager.STREAM_MUSIC, (int) BITRATE,
			AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT,
			count * (Short.SIZE / 8), AudioTrack.MODE_STATIC); // MAGIC_NUMBER
	track.write(samples, 0, count);
	return track;
}
 

/**
 * Create a sin wave of certain frequency and duration.
 *
 * @param freqHz     The frequency in Hertz
 * @param durationMs The duration in milliseconds
 * @return An AudioTrack with the corresponding sine wave.
 */
public static AudioTrack generateTonePulse(final double freqHz, final int durationMs) {
	int count = (int) (BITRATE * 2.0 * (durationMs / MILLIS_IN_SECOND)) & ~1;
	short[] samples = new short[count];
	for (int i = 0; i < count; i += 2) {
		short sample = TONE_MAP_2[(int) (2 * i / (BITRATE / freqHz)) % 2];
		samples[i] = sample;
		samples[i + 1] = sample;
	}
	@SuppressWarnings("deprecation")
	AudioTrack track = new AudioTrack(AudioManager.STREAM_MUSIC, (int) BITRATE,
			AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT,
			count * (Short.SIZE / 8), AudioTrack.MODE_STATIC); // MAGIC_NUMBER
	track.write(samples, 0, count);
	return track;
}
 

/**
 * Create a tone of highest possible frequency.
 *
 * @param durationMs The duration in milliseconds
 * @return An AudioTrack with the corresponding sine wave.
 */
public static AudioTrack generateHighFreqTone(final int durationMs) {
	int count = (int) (BITRATE * 2.0 * (durationMs / MILLIS_IN_SECOND)) & ~1;
	short[] samples = new short[count];
	for (int i = 0; i < count; i += 2) { // MAGIC_NUMBER
		short sample = TONE_MAP[(i / 4) % 4]; // MAGIC_NUMBER
		samples[i] = sample;
		samples[i + 1] = sample;
	}
	@SuppressWarnings("deprecation")
	AudioTrack track = new AudioTrack(AudioManager.STREAM_MUSIC, (int) BITRATE,
			AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT,
			count * (Short.SIZE / 8), AudioTrack.MODE_STATIC); // MAGIC_NUMBER
	track.write(samples, 0, count);
	return track;
}
 

FrequencyPlayer(double frequency) {
    numSamples = sampleRate * duration / MILLIS_PER_SECOND;
    generatedSound = new byte[2 * numSamples];
    sample = new double[numSamples];

    audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, sampleRate, AudioFormat.CHANNEL_OUT_MONO,
            AudioFormat.ENCODING_PCM_16BIT, generatedSound.length, AudioTrack.MODE_STATIC);

    setFrequency(frequency);
}
 

public void setSource(short[] src)
{
	mSource = src;
	mAudioTrack = new AudioTrack(AudioManager.STREAM_MUSIC, 44100, AudioFormat.CHANNEL_OUT_MONO, AudioFormat.ENCODING_PCM_16BIT, src.length*2, AudioTrack.MODE_STATIC);
}