如何获取过滤后的音频并将其输出为wav文件？
我已经使用IIR带通滤波器过滤了音频，当我点击＆＃34; Play＆＃34;按钮，我听到音频被过滤但是当我去.wav文件时它是原始音频而不是过滤后的音频。
当前代码实现
package com.example.audio;
import ddf.minim.effects.*;
import ddf.minim.*;
import ddf.minim.analysis.*;
import ddf.minim.javasound.*;
import ddf.minim.javax.sound.sampled.*;
import ddf.minim.javax.sound.sampled.spi.*;
import ddf.minim.signals.*;
import ddf.minim.spi.*;
import ddf.minim.ugens.*;
import java.io.BufferedInputStream;
import java.io.BufferedOutputStream;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import com.varma.samples.audiorecorder.R;
import android.app.Activity;
import android.content.Context;
import android.media.AudioFormat;
import android.media.AudioManager;
import android.media.AudioRecord;
import android.media.AudioTrack;
import android.media.MediaRecorder;
import android.media.MediaScannerConnection;
import android.os.Bundle;
import android.os.Environment;
import android.os.Handler;
import android.os.Message;
import android.text.SpannableStringBuilder;
import android.text.style.RelativeSizeSpan;
import android.util.Log;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
import android.widget.LinearLayout;
import android.widget.TextView;
import android.widget.Toast;
public class RecorderActivity extends Activity {
private static final int RECORDER_BPP = 16;
private static final String AUDIO_RECORDER_FILE_EXT_WAV = ".wav";
private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
private static final String AUDIO_RECORDER_TEMP_FILE = "record_temp.raw";
private static final int RECORDER_SAMPLERATE = 44100;// 44100; //18000
private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_STEREO; //AudioFormat.CHANNEL_IN_STEREO;
private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
private static final int PLAY_CHANNELS = AudioFormat.CHANNEL_OUT_STEREO; //AudioFormat.CHANNEL_OUT_STEREO;
private static final int FREQUENCY_LEFT = 2000; //Original:18000 (16 Dec)
private static final int FREQUENCY_RIGHT = 2000; //Original:18000 (16 Dec)
private static final int AMPLITUDE_LEFT = 1;
private static final int AMPLITUDE_RIGHT = 1;
private static final int DURATION_SECOND = 10;
private static final int SAMPLE_RATE = 44100;
private static final float SWEEP_RANGE = 1000.0f;
private static final int WRITE_NON_BLOCKING = 0;
String store;
private AudioRecord recorder = null;
private int bufferSize = 0;
private Thread recordingThread = null;
private boolean isRecording = false;
double time;
float[] buffer1;
float[] buffer2;
byte[] byteBuffer1;
byte[] byteBuffer2;
byte[] byteBufferFinal;
int bufferIndex;
short x;
short y;
AudioTrack audioTrack;
Button btnPlay, btnStart, btnStop;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
setButtonHandlers();
enableButtons(false);
btnPlay = (Button) findViewById(R.id.btnPlay);
btnStop = (Button) findViewById(R.id.btnStop);
btnStart = (Button) findViewById(R.id.btnStart);
bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE, RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING);
buffer1 = new float[(int) (DURATION_SECOND * SAMPLE_RATE)];
buffer2 = new float[(int) (DURATION_SECOND * SAMPLE_RATE)];
float f1 = 0.0f, f2 = 0.0f;
for (int sample = 0, step = 0; sample < buffer1.length; sample++) {
time = sample / (SAMPLE_RATE * 1.0);
//f1 = (float)(FREQUENCY_LEFT + ((sample / (buffer1.length * 1.0)) * SWEEP_RANGE)); // frequency sweep
//f2 = (float)(FREQUENCY_RIGHT + ((sample / (buffer1.length * 1.0)) * SWEEP_RANGE)); // frequency sweep
f1 = FREQUENCY_LEFT; // static frequency
f2 = FREQUENCY_RIGHT; // static frequency
buffer1[sample] = (float) (AMPLITUDE_LEFT * Math.sin(2 * Math.PI * f1 * time));
buffer2[sample] = (float) (AMPLITUDE_RIGHT * Math.sin(2 * Math.PI * f2 * time));
}
byteBuffer1 = new byte[buffer1.length * 2]; // two bytes per audio
// frame, 16 bits
for (int i = 0, bufferIndex = 0; i < byteBuffer1.length; i++) {
x = (short) (buffer1[bufferIndex++] * 32767.0); // [2^16 - 1]/2 =
// 32767.0
byteBuffer1[i] = (byte) x; // low byte
byteBuffer1[++i] = (byte) (x >>> 8); // high byte
}
byteBuffer2 = new byte[buffer2.length * 2];
for (int j = 0, bufferIndex = 0; j < byteBuffer2.length; j++) {
y = (short) (buffer2[bufferIndex++] * 32767.0);
byteBuffer2[j] = (byte) y; // low byte
byteBuffer2[++j] = (byte) (y >>> 8); // high byte
}
byteBufferFinal = new byte[byteBuffer1.length * 2];
// LL RR LL RR LL RR
for (int k = 0, index = 0; index < byteBufferFinal.length - 4; k = k + 2) {
byteBufferFinal[index] = byteBuffer1[k]; // LEFT
// {0,1/4,5/8,9/12,13;...}
byteBufferFinal[index + 1] = byteBuffer1[k + 1];
index = index + 2;
byteBufferFinal[index] = byteBuffer2[k]; // RIGHT
// {2,3/6,7/10,11;...}
byteBufferFinal[index + 1] = byteBuffer2[k + 1];
index = index + 2;
}
try {
FileOutputStream ss = new FileOutputStream(Environment.getExternalStorageDirectory().getPath() + "/" + AUDIO_RECORDER_FOLDER + "/source.txt");
ss.write(byteBufferFinal);
ss.flush();
ss.close();
}
catch (IOException ioe){
Log.e("IO Error","Write source error.");
}
}
private void setButtonHandlers() {
((Button) findViewById(R.id.btnStart)).setOnClickListener(startClick);
((Button) findViewById(R.id.btnStop)).setOnClickListener(stopClick);
((Button) findViewById(R.id.btnPlay)).setOnClickListener(playClick);
}
private void enableButton(int id, boolean isEnable) {
((Button) findViewById(id)).setEnabled(isEnable);
}
private void enableButtons(boolean isRecording) {
enableButton(R.id.btnStart, !isRecording);
enableButton(R.id.btnStop, isRecording);
enableButton(R.id.btnPlay, isRecording);
}
private String getFilename() {
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath, AUDIO_RECORDER_FOLDER);
if (!file.exists()) {
file.mkdirs();
}
MediaScannerConnection.scanFile(this, new String[]{filepath}, null, null);
store = file.getAbsolutePath() + "/" + "AudioOriginal"
+ AUDIO_RECORDER_FILE_EXT_WAV;
return store;
}
private String getTempFilename() {
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath, AUDIO_RECORDER_FOLDER);
if (!file.exists()) {
file.mkdirs();
}
File tempFile = new File(filepath, AUDIO_RECORDER_TEMP_FILE);
if (tempFile.exists())
tempFile.delete();
return (file.getAbsolutePath() + "/" + AUDIO_RECORDER_TEMP_FILE);
}
private void startRecording() {
recorder = new AudioRecord(MediaRecorder.AudioSource.CAMCORDER,
RECORDER_SAMPLERATE, RECORDER_CHANNELS,
RECORDER_AUDIO_ENCODING, bufferSize);
AudioManager am = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
am.setStreamVolume(AudioManager.STREAM_MUSIC, am.getStreamMaxVolume(AudioManager.STREAM_MUSIC), 0);
audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
(int) SAMPLE_RATE, PLAY_CHANNELS,
AudioFormat.ENCODING_PCM_16BIT, byteBufferFinal.length,
AudioTrack.MODE_STATIC);
audioTrack.write(byteBufferFinal, 0, byteBufferFinal.length);
audioTrack.play();
audioTrack.setPlaybackRate(RECORDER_SAMPLERATE);
recorder.startRecording();
isRecording = true;
recordingThread = new Thread(new Runnable() {
@Override
public void run() {
try {
writeAudioDataToFile();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}, "AudioRecorder Thread");
recordingThread.start();
}
float[][] deinterleaveData(float[] samples, int numChannels) {
// assert(samples.length() % numChannels == 0);
int numFrames = samples.length / numChannels;
float[][] result = new float[numChannels][];
for (int ch = 0; ch < numChannels; ch++) {
result[ch] = new float[numFrames];
for (int i = 0; i < numFrames; i++) {
result[ch][i] = samples[numChannels * i + ch];
}
}
return result;
}
float[] interleaveData(float[][] data) {
int numChannels = data.length;
int numFrames = data[0].length;
float[] result = new float[numFrames];
for (int i = 0; i < numFrames; i++) {
for (int ch = 0; ch < numChannels; ch++) {
result[numChannels * i + ch] = data[ch][i];
}
}
return result;
}
private int[] byteToShort(byte[] rawdata) {
int[] converted = new int[rawdata.length / 2];
for (int i = 0; i < converted.length; i++) {
// Wave file data are stored in little-endian order
int lo = rawdata[2*i];
int hi = rawdata[2*i+1];
converted[i] = ((hi&0xFF)<<8) | (lo&0xFF);
}
return converted;
}
private float[] byteToFloat(byte[] audio) {
return shortToFloat(byteToShort(audio));
}
/**
* Convert int[] audio to 32 bit float format.
* From [-32768,32768] to [-1,1]
* @param audio
*/
private float[] shortToFloat(int[] audio) {
Log.d("SHORTTOFLOAT","INSIDE SHORTTOFLOAT");
float[] converted = new float[audio.length];
for (int i = 0; i < converted.length; i++) {
// [-32768,32768] -> [-1,1]
converted[i] = audio[i] / 32768f; /* default range for Android PCM audio buffers) */
System.out.println("Converted is " + converted[i]);
}
return converted;
}
private void writeAudioDataToFile() throws IOException {
int read = 0;
byte data[] = new byte[bufferSize];
String filename = getTempFilename();
FileOutputStream os = null;
FileOutputStream rs = null;
try {
os = new FileOutputStream(filename);
rs = new FileOutputStream(getFilename().split(".wav")[0] + ".txt");
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
if (null != os) {
//BandPass bandpass = new BandPass(19000,2000,44100);
while (isRecording) {
// decode and deinterleave stereo 16-bit per sample data
// float[][] signals = deinterleaveData(byteToFloat(data), 2);
// filter data samples, updating the buffers with the filtered samples.
// bandpass.process(signals[0], signals[1]);
read = recorder.read(data, 0, bufferSize);
if (AudioRecord.ERROR_INVALID_OPERATION != read) {
try {
os.write(data);
rs.write(data);
} catch (IOException e) {
e.printStackTrace();
}
}
}
try {
os.close();
rs.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void stopRecording() {
if (null != recorder) {
isRecording = false;
audioTrack.flush();
audioTrack.stop();
audioTrack.release();
recorder.stop();
recorder.release();
recorder = null;
recordingThread = null;
}
copyWaveFile(getTempFilename(), getFilename());
deleteTempFile();
MediaScannerConnection.scanFile(this, new String[]{getFilename()}, null, null);
AudioManager am = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
am.setStreamVolume(AudioManager.STREAM_MUSIC, 0, 0);
}
private void deleteTempFile() {
File file = new File(getTempFilename());
file.delete();
}
private void copyWaveFile(String inFilename, String outFilename) {
FileInputStream in = null;
FileOutputStream out = null;
long totalAudioLen = 0;
long totalDataLen = totalAudioLen + 36;
long longSampleRate = RECORDER_SAMPLERATE;
int channels = 2;
long byteRate = RECORDER_BPP * RECORDER_SAMPLERATE * channels / 8;
byte[] data = new byte[bufferSize];
try {
in = new FileInputStream(inFilename);
out = new FileOutputStream(outFilename);
totalAudioLen = in.getChannel().size();
totalDataLen = totalAudioLen + 36;
WriteWaveFileHeader(out, totalAudioLen, totalDataLen,
longSampleRate, channels, byteRate);
while (in.read(data) != -1) {
out.write(data);
}
in.close();
out.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private void playWaveFile() {
String filepath = store;
// define the buffer size for audio track
int minBufferSize = AudioTrack.getMinBufferSize(8000,
AudioFormat.CHANNEL_OUT_STEREO, AudioFormat.ENCODING_PCM_16BIT);
int bufferSize = 512;
audioTrack = new AudioTrack(AudioManager.STREAM_MUSIC,
(int) RECORDER_SAMPLERATE, AudioFormat.CHANNEL_OUT_STEREO,
AudioFormat.ENCODING_PCM_16BIT, minBufferSize,
AudioTrack.MODE_STREAM);
int count = 0;
byte[] data = new byte[bufferSize];
try {
FileInputStream fileInputStream = new FileInputStream(filepath);
DataInputStream dataInputStream = new DataInputStream(
fileInputStream);
audioTrack.play();
//BandPass bandpass = new BandPass(19000,2000,44100);
BandPass bandpass = new BandPass(550,20,44100);
while ((count = dataInputStream.read(data, 0, bufferSize)) > -1)
{
// decode and deinterleave stereo 16-bit per sample data
// float[][] signals = deinterleaveData(byteToFloat(data), 2);
// filter data samples, updating the buffers with the filtered samples.
// bandpass.process(signals[0], signals[1]);
// recombine signals for playback
//audioTrack.write(interleaveData(signals), 0, count, WRITE_NON_BLOCKING);
// audioTrack.write(data, 0, count);
}
audioTrack.stop();
audioTrack.release();
dataInputStream.close();
fileInputStream.close();
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private void WriteWaveFileHeader(FileOutputStream out, long totalAudioLen,
long totalDataLen, long longSampleRate, int channels, long byteRate)
throws IOException {
byte[] header = new byte[44];
header[0] = 'R'; // RIFF/WAVE header
header[1] = 'I';
header[2] = 'F';
header[3] = 'F';
header[4] = (byte) (totalDataLen & 0xff);
header[5] = (byte) ((totalDataLen >> 8) & 0xff);
header[6] = (byte) ((totalDataLen >> 16) & 0xff);
header[7] = (byte) ((totalDataLen >> 24) & 0xff);
header[8] = 'W';
header[9] = 'A';
header[10] = 'V';
header[11] = 'E';
header[12] = 'f'; // 'fmt ' chunk
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
header[16] = 16; // 4 bytes: size of 'fmt ' chunk
header[17] = 0;
header[18] = 0;
header[19] = 0;
header[20] = 1; // format = 1
header[21] = 0;
header[22] = (byte) channels;
header[23] = 0;
header[24] = (byte) (longSampleRate & 0xff);
header[25] = (byte) ((longSampleRate >> 8) & 0xff);
header[26] = (byte) ((longSampleRate >> 16) & 0xff);
header[27] = (byte) ((longSampleRate >> 24) & 0xff);
header[28] = (byte) (byteRate & 0xff);
header[29] = (byte) ((byteRate >> 8) & 0xff);
header[30] = (byte) ((byteRate >> 16) & 0xff);
header[31] = (byte) ((byteRate >> 24) & 0xff);
header[32] = (byte) (2 * 16 / 8); // block align
header[33] = 0;
header[34] = RECORDER_BPP; // bits per sample
header[35] = 0;
header[36] = 'd';
header[37] = 'a';
header[38] = 't';
header[39] = 'a';
header[40] = (byte) (totalAudioLen & 0xff);
header[41] = (byte) ((totalAudioLen >> 8) & 0xff);
header[42] = (byte) ((totalAudioLen >> 16) & 0xff);
header[43] = (byte) ((totalAudioLen >> 24) & 0xff);
out.write(header, 0, 44);
}
private View.OnClickListener startClick = new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
Thread recordThread = new Thread(new Runnable() {
@Override
public void run() {
isRecording = true;
startRecording();
}
});
recordThread.start();
btnStart.setEnabled(false);
btnStop.setEnabled(true);
btnPlay.setEnabled(false);
}
};
private View.OnClickListener stopClick = new View.OnClickListener() {
@Override
public void onClick(View v) {
new Handler().postDelayed(new Runnable() {
@Override
public void run() {
// TODO Auto-generated method stub
stopRecording();
enableButtons(false);
btnPlay.setEnabled(true);
// stop();
}
}, 100);
}
};
private View.OnClickListener playClick = new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
playWaveFile();
btnPlay.setEnabled(true);
String filepath = store;
final String promptPlayRecord = "PlayWaveFile()\n" + filepath;
SpannableStringBuilder biggerText = new SpannableStringBuilder(promptPlayRecord);
biggerText.setSpan(new RelativeSizeSpan(2.05f), 0, promptPlayRecord.length(), 0);
Toast.makeText(RecorderActivity.this, biggerText, Toast.LENGTH_LONG).show();
}
};
}
我尝试将过滤器置于方法＆＃34; writeAudioDataToFile＆＃34;下，虽然它生成了过滤后的音频wav文件，但它是一个快速转发的版本。例如：我录制约5秒，但.wav文件只播放1秒。为什么会这样？
我是否正确地将过滤器置于方法＆＃34; writeAudioDataToFile＆＃34;？否则，应采取哪些步骤来确保过滤后的音频可以作为.wav文件输出。
感谢你们的建议!!赞赏它
使用的库
https://github.com/ddf/Minim/blob/master/src/ddf/minim/effects/BandPass.java https://github.com/DASAR/Minim-Android/blob/master/src/ddf/minim/effects/IIRFilter.java