我一直试图在Android上合并两个WAVE文件很长一段时间，但实际上似乎无法让它正常工作。
一切看起来都很好，文件被读取，并写入输出文件，该文件在稍后阶段也是可读的，并且具有我希望看到的文件大小。
问题在应用程序完成合并后立即发生。此消息将显示在日志中： updateListener中出现错误，录制已中止这是来自extAudioRecorder的消息，并在OnRecordPositionUpdateListener到达catch子句时出现（Exception已以下detailMessage：写入失败：EBADF（错误的文件编号））。这似乎没有打破任何东西，所以我不太担心这个。
当我尝试创建MediaPlayer并在MediaPlayer实例上调用setDataSource(String path)时，会出现真正的问题。每当我使用合并文件执行此操作时，日志中将显示以下错误消息：无法创建媒体播放器（抛出的IOException包含以下detailMessage： setDataSourceFD失败：状态= 0x80000000 ）。请注意，第一次文件播放完全正常（第一个文件不是由combineWaveFiles()方法创建的）。该错误消息似乎表示音频文件的格式不正确和/或MediaPlayer无法读取。
我的问题是，如果有人发现下面的代码有任何实际问题（我知道它在很多方面都是次优的，但我更喜欢让它先工作然后担心性能）。
public static String MergeRecordings(String cumulativeFile, String recordFile, int sampleRate, int bpp, int bufferSize, int channels) {
if (cumulativeFile == null) {
return recordFile;
} else if (recordFile == null) {
return cumulativeFile;
}
String outputFile = FileUtils.getFilePath(null, MDSettings.shared().getMainActivity());
FileUtils.combineWaveFiles(cumulativeFile, recordFile, outputFile, sampleRate, bpp, bufferSize, channels);
//FileUtils.removeFile(cumulativeFile);
//FileUtils.removeFile(recordFile);
return outputFile;
}
//creates a new file containing file1 + file2 stuck together as such.
private static void combineWaveFiles(String file1, String file2, String outputFile, int sampleRate, int bpp, int bufferSize, int channels) {
FileInputStream in1 = null, in2 = null;
FileOutputStream out = null;
long longSampleRate = sampleRate;
long byteRate = sampleRate * channels * bpp / 8;
byte[] data;
try {
try {
in1 = new FileInputStream(file1);
} catch (Exception e) { }
try {
in2 = new FileInputStream(file2);
} catch (FileNotFoundException e) { }
out = new FileOutputStream(outputFile);
long file1Size = 0;
long file2Size = 0;
if (in1 != null) { file1Size = in1.getChannel().size() - 44; }
if (in2 != null) { file2Size = in2.getChannel().size() - 44; }
long totalAudioLen = file1Size + file2Size;
long totalDataLen = totalAudioLen + 36;
FileUtils.writeWaveFileHeader(out, totalAudioLen, totalDataLen, longSampleRate, channels, byteRate, bpp);
if (in1 != null) {
in1.skip(44);
data = new byte[bufferSize];
if (file1Size < bufferSize) {
data = new byte[(int)file1Size];
}
while (in1.read(data) != -1) {
out.write(data);
file1Size -= bufferSize;
if (file1Size <= 0) {
break;
} else if (file1Size < bufferSize) {
data = new byte[(int)file1Size];
}
}
}
if (in2 != null) {
in2.skip(44);
data = new byte[bufferSize];
if (file2Size < bufferSize) {
data = new byte[(int)file2Size];
}
while (in2.read(data) != -1) {
out.write(data);
file2Size -= bufferSize;
if (file2Size <= 0) {
break;
} else if (file2Size < bufferSize) {
data = new byte[(int)file2Size];
}
}
}
out.close();
if (in1 != null) { in1.close(); }
if (in2 != null) { in2.close(); }
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
}
private static void writeWaveFileHeader(FileOutputStream out, long totalAudioLen, long totalDataLen, long longSampleRate, int channels, long byteRate, int bpp)
throws IOException {
byte[] header = new byte[44];
header[0] = 'R';
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';
header[13] = 'm';
header[14] = 't';
header[15] = ' ';
header[16] = 16;
header[17] = 0;
header[18] = 0;
header[19] = 0;
header[20] = 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)(channels * bpp); //(2 * 16 / 8);
header[33] = 0;
header[34] = (byte)bpp;
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);
}
此代码的大部分内容取自this answer。
答案 0 :(得分：5)
我在我的Android应用程序中完全这样做。而不是两个，我根据用户选择合并多个文件。我使用AsyncTask在后台合并样本。看看这里。只需过滤您需要的部分。如果您对我的应用程序感到好奇，它的名为Sound Recorder + Pro，在合并之后我会混合，添加回声并放大样本：
@Override
protected Void doInBackground(Void... params) {
isProcessingOn=true;
try {
DataOutputStream amplifyOutputStream = new DataOutputStream(new BufferedOutputStream(new FileOutputStream(Environment.getExternalStorageDirectory() + "/Soundrecpluspro/" + year +"-"+ month +"-"+ date +"-"+ hour+"-" + min +"-"+ sec+"ME.wav")));
DataInputStream[] mergeFilesStream = new DataInputStream[selection.size()];
long[] sizes=new long[selection.size()];
for(int i=0; i<selection.size(); i++) {
File file = new File(Environment.getExternalStorageDirectory() + "/Soundrecpluspro/" +selection.get(i));
sizes[i] = (file.length()-44)/2;
}
for(int i =0; i<selection.size(); i++) {
mergeFilesStream[i] =new DataInputStream(new BufferedInputStream(new FileInputStream(Environment.getExternalStorageDirectory() + "/Soundrecpluspro/" +selection.get(i))));
if(i == selection.size()-1) {
mergeFilesStream[i].skip(24);
byte[] sampleRt = new byte[4];
mergeFilesStream[i].read(sampleRt);
ByteBuffer bbInt = ByteBuffer.wrap(sampleRt).order(ByteOrder.LITTLE_ENDIAN);
RECORDER_SAMPLERATE = bbInt.getInt();
mergeFilesStream[i].skip(16);
}
else {
mergeFilesStream[i].skip(44);
}
}
for(int b=0; b<selection.size(); b++) {
for(int i=0; i<(int)sizes[b]; i++) {
byte[] dataBytes = new byte[2];
try {
dataBytes[0] = mergeFilesStream[b].readByte();
dataBytes[1] = mergeFilesStream[b].readByte();
}
catch (EOFException e) {
amplifyOutputStream.close();
}
short dataInShort = ByteBuffer.wrap(dataBytes).order(ByteOrder.LITTLE_ENDIAN).getShort();
float dataInFloat= (float) dataInShort/37268.0f;
short outputSample = (short)(dataInFloat * 37268.0f);
byte[] dataFin = new byte[2];
dataFin[0] = (byte) (outputSample & 0xff);
dataFin[1] = (byte)((outputSample >> 8) & 0xff);
amplifyOutputStream.write(dataFin, 0 , 2);
}
}
amplifyOutputStream.close();
for(int i=0; i<selection.size(); i++) {
mergeFilesStream[i].close();
}
} catch (FileNotFoundException e) {
e.printStackTrace();
} catch (IOException e) {
e.printStackTrace();
}
long size =0;
try {
FileInputStream fileSize = new FileInputStream(Environment.getExternalStorageDirectory() + "/Soundrecpluspro/"+year +"-"+ month +"-"+ date +"-"+ hour+"-" + min +"-"+ sec+"ME.wav");
size = fileSize.getChannel().size();
fileSize.close();
} catch (FileNotFoundException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
final int RECORDER_BPP = 16;
long datasize=size+36;
long byteRate = (RECORDER_BPP * RECORDER_SAMPLERATE)/8;
long longSampleRate = RECORDER_SAMPLERATE;
byte[] header = new byte[44];
header[0] = 'R'; // RIFF/WAVE header
header[1] = 'I';
header[2] = 'F';
header[3] = 'F';
header[4] = (byte) (datasize & 0xff);
header[5] = (byte) ((datasize >> 8) & 0xff);
header[6] = (byte) ((datasize >> 16) & 0xff);
header[7] = (byte) ((datasize >> 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) 1;
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) ((RECORDER_BPP) / 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) (size & 0xff);
header[41] = (byte) ((size >> 8) & 0xff);
header[42] = (byte) ((size >> 16) & 0xff);
header[43] = (byte) ((size >> 24) & 0xff);
// out.write(header, 0, 44);
try {
RandomAccessFile rFile = new RandomAccessFile(Environment.getExternalStorageDirectory() + "/Soundrecpluspro/" +year +"-"+ month +"-"+ date +"-"+ hour+"-" + min +"-"+ sec+ "ME.wav", "rw");
rFile.seek(0);
rFile.write(header);
rFile.close();
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return null;
}
答案 1 :(得分：2)
尝试使用此代码连接wav文件：
public class ConcateSongActivity extends Activity {
Button mbutt;
/** Called when the activity is first created. */
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
mbutt = (Button)findViewById(R.id.button_clickme);
mbutt.setOnClickListener(new OnClickListener() {
@Override
public void onClick(View arg0) {
try {
FileInputStream fis1 = new FileInputStream("/sdcard/MJdangerous.wav");
FileInputStream fis2 = new FileInputStream("/sdcard/MJBad.wav");
SequenceInputStream sis = new SequenceInputStream(fis1,fis2);
FileOutputStream fos = new FileOutputStream(new File("/sdcard/MJdangerousMJBad.wav"));
int temp;
try {
while ((temp = sis.read())!= -1){
fos.write(temp);
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
} catch (FileNotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
});
} }
注意：不要忘记授予此权限WRITE_EXTERNAL_STORAGE
其他技巧： 这是用于将3种声音混合在一起的方法：
private void mixFiles(){
try {
InputStream is1 = getResources().openRawResource(R.raw.test1);
List<Short> music1 = createMusicArray(is1);
InputStream is2 = getResources().openRawResource(R.raw.test2);
List<Short> music2 = createMusicArray(is2);
completeStreams(music1,music2);
short[] music1Array = buildShortArray(music1);
short[] music2Array = buildShortArray(music2);
short[] output = new short[music1Array.length];
for(int i=0; i < output.length; i++){
float samplef1 = music1Array[i] / 32768.0f;
float samplef2 = music2Array[i] / 32768.0f;
float mixed = samplef1 + samplef2;
// reduce the volume a bit:
mixed *= 0.8;
// hard clipping
if (mixed > 1.0f) mixed = 1.0f;
if (mixed < -1.0f) mixed = -1.0f;
short outputSample = (short)(mixed * 32768.0f);
output[i] = outputSample;
}
saveToFile(output);
} catch (NotFoundException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
一旦我们有了PCM混合声音，就可以在.wav文件中进行转换，这样每个玩家都可以读取它。
/**
* Dealing with big endian streams
* @param byte0
* @param byte1
* @return a shrt with the two bytes swapped
*/
private static short swapBytes(byte byte0, byte byte1){
return (short)((byte1 & 0xff) << 8 | (byte0 & 0xff));
}
/**
* From file to byte[] array
* @param sample
* @param swap should swap bytes?
* @return
* @throws IOException
*/
public static byte[] sampleToByteArray(File sample, boolean swap) throws IOException{
ByteArrayOutputStream baos = new ByteArrayOutputStream();
BufferedInputStream bis = new BufferedInputStream(new FileInputStream(sample));
int BUFFERSIZE = 4096;
byte[] buffer = new byte[BUFFERSIZE];
while(bis.read(buffer) != - 1){
baos.write(buffer);
}
byte[] outputByteArray = baos.toByteArray();
bis.close();
baos.close();
if(swap){
for(int i=0; i < outputByteArray.length - 1; i=i+2){
byte byte0 = outputByteArray[i];
outputByteArray[i] = outputByteArray[i+1];
outputByteArray[i+1] = byte0;
}
}
return outputByteArray;
}
/**
* Read a file and returns its contents as array of shorts
* @param sample the sample file
* @param swap true if we should swap the bytes of short (reading a little-endian file), false otherwise (reading a big-endian file)
* @return
* @throws IOException
*/
public static short[] sampleToShortArray(File sample, boolean swap) throws IOException{
short[] outputArray = new short[(int)sample.length()/2];
byte[] outputByteArray = sampleToByteArray(sample,false);
for(int i=0, j=0; i < outputByteArray.length; i+= 2, j++){
if(swap){
outputArray[j] = swapBytes(outputByteArray[i], outputByteArray[i + 1]);
}
else{
outputArray[j] = swapBytes(outputByteArray[i + 1], outputByteArray[i]);
}
}
return outputArray;
}
public void completeStreams(List<Short> mListShort_1, List<Short> mListShort_2) {
//TODO: check length
int size_a = mListShort_1.size();
int size_b = mListShort_2.size();
if (size_a > size_b){
// adding series of '0'
for (int i = size_b+1; i <= size_a; i++) {
mListShort_2.set(i, (short) 0);
}
} else if (size_a < size_b) {
for (int i = size_a+1; i <= size_b; i++) {
mListShort_1.set(i, (short) 0);
}
} else {
//do nothing
}
}
致谢：nalitzis