我正在使用AudioTrack播放一些浮点值。
代码:
float[] audio_payload = getFloatValues();
final int length = audio_payload.length;
int PLAYER_MODE = AudioTrack.MODE_STREAM;
int PLAYER_STREAM_TYPE = AudioManager.STREAM_MUSIC;
int PLAYER_FORMAT = AudioFormat.ENCODING_PCM_FLOAT;
int PLAYER_CONF = AudioFormat.CHANNEL_OUT_MONO;
int PLAYER_SR = 44100;
AudioTrack track = new AudioTrack(PLAYER_STREAM_TYPE, PLAYER_SR, PLAYER_CONF, PLAYER_FORMAT, audio_payload.length*4, PLAYER_MODE);
track.write(audio_payload, 0, length, AudioTrack.WRITE_NON_BLOCKING);
track.play();
我的问题是在android 20或更低版本的函数中,不支持track.write(float[], offset, lenghtInBytes, writeMode);
。Android Developer Docs
如何将浮点值转换为short或bytes数组以进行播放,因为Android API 3级或更高级别支持它们?
我尝试将float数组转换为short数组,但是没有用,转换后,我的原始音频被更改了。当我尝试将float转换为字节数组时,也发生了同样的情况。
我正在研究的项目具有本机库,因此在C或Java中,将float转换为short或将float转换为字节将很有帮助。
我使用的浮动代码的缩写:
public static short floatToShort(float x) {
if (x < Short.MIN_VALUE) {
return Short.MIN_VALUE;
}
if (x > Short.MAX_VALUE) {
return Short.MAX_VALUE;
}
return (short) Math.round(x);
}
浮到字节:
public static byte[] convertToByteArray(float value) {
byte[] bytes = new byte[4];
ByteBuffer buffer = ByteBuffer.allocate(bytes.length);
buffer.putFloat(value);
return buffer.array();
}
转换后的音频记录器未播放音频,也看不到任何错误
更新也尝试过
private short [] floatArrayToShortArray(float [] array) {
short [] payload = new short[array.length];
for (int i=0; i<array.length; i++) {
payload[i] = (short) ((short) array[i] * 32767);
}
return payload;
}
但是audioTrack无法播放。
我能够通过这种方法将Float
转换为PCM16 short:
/**
* Used to convert Float to PCM16 short byte array.
*/
private val convertBuffer = ByteBuffer.allocate(2).apply {
order(ByteOrder.LITTLE_ENDIAN)
}
/**
* Converts Float to PCM16 short byte buffer.
* @param value Float value to convert
* @return PCM16 short byte array from Float value
*/
private fun floatToPcm16(value: Float): ByteArray {
convertBuffer.clear()
convertBuffer.putShort((value * 32768F).toShort())
return convertBuffer.array()
}