我想从.wav文件中获取频率和时间并保存到2D数组中。我已经将声音录制到.wav文件中，但我不知道如何在android中获取频率值。但是使用MatLab我已经打印了频率值。
package com.example.soundrecordingexample2;
import android.os.Bundle;
import android.app.Activity;
import android.util.Log;
import android.view.Menu;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Environment;
import android.view.View;
import android.widget.Button;
public class MainActivity 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 final int RECORDER_SAMPLERATE = 44100;
private final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_STEREO;
private final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
private AudioRecord recorder = null;
private int bufferSize = 0;
private Thread recordingThread = null;
private boolean isRecording = false;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
setButtonHandlers();
enableButtons(false);
bufferSize = AudioRecord.getMinBufferSize(44100,
AudioFormat.CHANNEL_IN_STEREO,
AudioFormat.ENCODING_PCM_16BIT);
Log.d( String.valueOf(bufferSize), "nadeeBufferaaaaaaaaaaaaaaaa");
}
private void setButtonHandlers() {
((Button)findViewById(R.id.btnStart)).setOnClickListener(btnClick);
((Button)findViewById(R.id.btnStop)).setOnClickListener(btnClick);
}
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);
}
private String getFilename(){
String filepath = Environment.getExternalStorageDirectory().getPath();
File file = new File(filepath,AUDIO_RECORDER_FOLDER);
if(!file.exists()){
file.mkdirs();
}
return (file.getAbsolutePath() + "/" + System.currentTimeMillis() + AUDIO_RECORDER_FILE_EXT_WAV);
}
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.MIC,
RECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING, bufferSize);
int i = recorder.getState();
Log.e(String.valueOf(i), "recorder");
if(i==1)
{
recorder.startRecording();
Log.d("aaa"," equal 1");
}
else
{
Log.d("hhhh","not equal 1");
}
isRecording = true;
recordingThread = new Thread(new Runnable() {
@Override
public void run() {
writeAudioDataToFile();
}
},"AudioRecorder Thread");
recordingThread.start();
}
private void writeAudioDataToFile(){
byte data[] = new byte[bufferSize];
String filename = getTempFilename();
FileOutputStream os = null;
try {
os = new FileOutputStream(filename);
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
int read = 0;
if(null != os){
while(isRecording){
read = recorder.read(data, 0, bufferSize);
if(AudioRecord.ERROR_INVALID_OPERATION != read){
try {
os.write(data);
} catch (IOException e) {
e.printStackTrace();
}
}
}
try {
os.close();
} catch (IOException e) {
e.printStackTrace();
}
}
}
private void stopRecording(){
if(null != recorder){
isRecording = false;
int i = recorder.getState();
if(i==1)
recorder.stop();
recorder.release();
recorder = null;
recordingThread = null;
}
copyWaveFile(getTempFilename(),getFilename());
deleteTempFile();
}
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;
AppLog.logString("File size: " + totalDataLen);
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 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 btnClick = new View.OnClickListener() {
@Override
public void onClick(View v) {
switch(v.getId()){
case R.id.btnStart:{
AppLog.logString("Start Recording");
enableButtons(true);
startRecording();
break;
}
case R.id.btnStop:{
AppLog.logString("Start Recording");
enableButtons(false);
stopRecording();
break;
}
}
}
};
@Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
}
答案 0 :(得分：0)
你可以通过将文件大小除以音频的长度（以秒为单位）来实现，例如，从我的库中的随机AAC编码的M4A开始：
文件大小5MB
长度183秒
给出：40000000（5MB）/ 183 = 218579.234973位/秒或~218kbps
Actual Bitrate: 200kbps
由于大多数音频文件都有一组已知的有效比特率级别，因此可以使用该比特率将比特率调整到适当的级别进行显示。