字节数组音频连接Android

时间:2016-09-14 09:39:48

标签: android arrays audio byte concatenation

我正在尝试连接字节数组音频。(音频是.wav,并转换为字节数组)。 我目前的代码似乎连接起来。但是当我播放结果时,它只播放最终数组中的第一个字节样本。 你知道为什么下一个字节不播放吗?

     int length = 0;
     for (byte[] array : ListSamplesByte) {
     length += array.length;
     }
     byte[] result = new byte[length];
     int pos = 0;
     for (byte[] array : ListSamplesByte) {
         System.arraycopy(array, 0, result, pos, array.length);
         pos += array.length;
     }

     byte[] playByte = result;
     MediaPlayer.playAudio(playByte);

编辑1:所有文件都是44100Hz,16位PCM。即使所有字节数组都相同,它也只播放第一个字节数组。我认为问题与块中没有添加或删除的标题或字节有关。

1 个答案:

答案 0 :(得分:1)

我找到了解决方案。 这是连接的过程,请注意我所有的wav文件具有相同的采样率,通道。

首先,我需要一些关于WAV文件结构的知识。 wav文件由原始数据后跟的头(前44个字节)组成。 http://soundfile.sapp.org/doc/WaveFormat/

1)将您的wav文件转换为字节数组

2)查看HeaderInformation()下面的函数,它接受你的字节数组的参数,它创建一个InputDataStream并读取bytes数组以获取头信息,最重要的是得到ChunkSize长度(字节4 -8)和原始数据长度(字节44)。

 public class AudioConcatenate {
 long myChunkSize;
 long mySubChunk1Size;
 int myFormat;
 long myChannels;
 long mySampleRate;
 long myByteRate;
 int myBlockAlign;
 int myBitsPerSample;
 long myDataSize;
 long totalChunkSize;

 byte[] myData;
 int byteRate=176400;
 long longSampleRate=44100;

 protected ArrayList<Long> ListDataSize= new ArrayList<Long>();
 protected ArrayList<byte[]> ListDataByte = new ArrayList<byte[]>();
 protected ArrayList<Long> ListChunkSize = new ArrayList<>();

 public AudioConcatenate(){
 }

 protected void HeaderInformation(byte[] SoundSample) {
 myData = null;
 DataInputStream inFile = newDataInputStream(newByteArrayInputStream(sample));
 byte[] tmpLong = new byte[4];
 byte[] tmpInt = new byte[2];

    try {
        while (inFile.available() > 0) {
            String chunkID = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();
            inFile.read(tmpLong); // read the ChunkSize
            myChunkSize = byteArrayToLong(tmpLong)+silenceArray.length;
            String format = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();
            String subChunk1ID = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();
            inFile.read(tmpLong); // read the SubChunk1Size
            mySubChunk1Size = byteArrayToLong(tmpLong);
            inFile.read(tmpInt); // read the audio format.  This should be 1 for PCM
            myFormat = byteArrayToInt(tmpInt);
            inFile.read(tmpInt); // read the # of channels (1 or 2)
            myChannels = byteArrayToInt(tmpInt);
            inFile.read(tmpLong); // read the samplerate
            mySampleRate = byteArrayToLong(tmpLong);
            inFile.read(tmpLong); // read the byterate
            myByteRate = byteArrayToLong(tmpLong);
            inFile.read(tmpInt); // read the blockalign
            myBlockAlign = byteArrayToInt(tmpInt);
            inFile.read(tmpInt); // read the bitspersample
            myBitsPerSample = byteArrayToInt(tmpInt);
            String dataChunkID = "" + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte() + (char) inFile.readByte();
            inFile.read(tmpLong); // read the size of the data
            myDataSize = byteArrayToLong(tmpLong)+silenceArray.length;
            // read the data chunk
            myData = new byte[(int) myDataSize];
            inFile.read(myData);

            ListDataSize.add(myDataSize);
            ListDataByte.add(FinalDataArray);
            ListChunkSize.add(myChunkSize);
        }
    } catch (IOException e) {
        e.printStackTrace();
    }
}
}

函数末尾的byte []三个arraylist用于存储块大小,存储原始数据的字节数组和数据字节数组的大小。这样,每次调用声音函数时,它都会存储基本数据。

4)一旦你为多声音调用此功能。 我们需要重新创建wav标头,它将计算多个声音的长度。我们必须计算ChunkSize的总大小,以及原始数据的总大小。

public long  TotalDataSize(){
    int i;
    long sum = 0;
    for(i = 0; i < ListDataSize.size(); i++) {
        sum += ListDataSize.get(i);
    }
    return sum;
}


public long TotalChunkSize(){
    int i;
    long sum = 0;
    for(i = 0; i < ListChunkSize.size(); i++) {
        sum += ListChunkSize.get(i);
    }
    return sum;
}

We create the header and we include the new size, total chunkSize at byte [4-8], total data byte[40-43] 

  public byte[] WriteHeader(){
    byte[] header = new byte[44];
    long totalDataSize= TotalDataSize();
    long totalChunkSize=TotalChunkSize();

    header[0] = 'R';  // RIFF/WAVE header
    header[1] = 'I';
    header[2] = 'F';
    header[3] = 'F';
    header[4] = (byte) (totalChunkSize & 0xff);
    header[5] = (byte) ((totalChunkSize >> 8) & 0xff);
    header[6] = (byte) ((totalChunkSize >> 16) & 0xff);
    header[7] = (byte) ((totalChunkSize >> 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) 2;
    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] = 16;  // bits per sample
    header[35] = 0;
    header[36] = 'd';
    header[37] = 'a';
    header[38] = 't';
    header[39] = 'a';
    header[40] = (byte) (totalDataSize & 0xff);
    header[41] = (byte) ((totalDataSize >> 8) & 0xff);
    header[42] = (byte) ((totalDataSize >> 16) & 0xff);
    header[43] = (byte) ((totalDataSize >> 24) & 0xff);
    return header;
}

6)连接函数:  首先,我们创建一个新的ArrayList“ListFinalSound”来构造最终的声音。    我们首先添加新标题,然后添加byte []原始数据。

 public byte[] ConcatenateSound(){

 ListFinalSound.add(WriteHeader()); 
 for (byte[] arrayRawData : ListDataByte) {
     ListFinalSound.add(arrayRawData); 
  }

 /* sum the length of each byte array to get the total and create later a new  byte array of the total length.**/
 int length = 0;
 for (byte[] array : ListFinalSound) {
 length += array.length;
 }

/* we concatenate with the use of System.arraycopy.
 For each loop it'll increment the position and concatenate the byte array**/

 byte[] ConcatenateSounds = new byte[length];
 int pos = 0;
 for (byte[] array : ListFinalSound) {
 System.arraycopy(array, 0, ConcatenateSounds, pos, array.length); 
 pos += array.length;
 }
 return ConcatenateSounds;
}     

7)ConcatenateSound()函数返回连接。