AudioRecord PCM數據沒用？

Question

我在我的android應用程序中使用了麥克風錄製，並且在播放數據時使用AudioPlayer類時播放效果非常好。我的問題是我想爲此數據添加一個wav標題，以便可以在應用程序之外播放。我非常肯定在用其他音頻文件在十六進制編輯器中播放後創建標題工作的方法，這會導致記錄的pcm數據在wav文件中不能用作原始數據？

任何人都可以解釋這一點嗎？我可以將pcm/wav文件作爲原始文件導入大膽文件，並且可以完美播放，但是當我嘗試打開wav時，我只會聽到噪音，再次暗示pcm數據有問題。

錄音設置：

int frequency = 22050; 
int channelConfiguration = AudioFormat.CHANNEL_CONFIGURATION_MONO; 
int audioEncoding = AudioFormat.ENCODING_PCM_16BIT; 

頭變量：

byte[] clipData = data; 
long myDataSize = clipData.length; 
long mySubChunk1Size = 16; 
int myBitsPerSample= 16; 
int myFormat = 1; 
long myChannels = 1; 
long mySampleRate = 22050; 
long myByteRate = mySampleRate * myChannels * myBitsPerSample/8; 
int myBlockAlign = (int) (myChannels * myBitsPerSample/8); 
long myChunk2Size = myDataSize * myChannels * myBitsPerSample/8; 
long myChunkSize = 36 + myChunk2Size; 

try 
     { 
      File audioDirectory = new File(Environment 
        .getExternalStorageDirectory().getAbsolutePath() 
        + "/Directory/"); 
      audioDirectory.mkdir(); 
      File file = new File(audioDirectory, "test.wav"); 
      if (file.exists()) 
       file.delete(); 

      // Create the new file. 
      try { 
       file.createNewFile(); 
      } catch (IOException e) { 
       throw new IllegalStateException("Failed to create " 
         + file.toString()); 
      } 
      OutputStream os = new FileOutputStream(file); 
      BufferedOutputStream bos = new BufferedOutputStream(os); 
      DataOutputStream outFile = new DataOutputStream(bos); 

      // write the wav file per the wav file format 
      outFile.writeBytes("RIFF");     // 00 - RIFF 
      outFile.write(intToByteArray((int)myChunkSize), 0, 4);  // 04 - how big is the rest of this file? 
      outFile.writeBytes("WAVE");     // 08 - WAVE 
      outFile.writeBytes("fmt ");     // 12 - fmt 
      outFile.write(intToByteArray((int)mySubChunk1Size), 0, 4); // 16 - size of this chunk 
      outFile.write(shortToByteArray((short)myFormat), 0, 2);  // 20 - what is the audio format? 1 for PCM = Pulse Code Modulation 
      outFile.write(shortToByteArray((short)myChannels), 0, 2); // 22 - mono or stereo? 1 or 2? (or 5 or ???) 
      outFile.write(intToByteArray((int)mySampleRate), 0, 4);  // 24 - samples per second (numbers per second) 
      outFile.write(intToByteArray((int)myByteRate), 0, 4);  // 28 - bytes per second 
      outFile.write(shortToByteArray((short)myBlockAlign), 0, 2); // 32 - # of bytes in one sample, for all channels 
      outFile.write(shortToByteArray((short)myBitsPerSample), 0, 2); // 34 - how many bits in a sample(number)? usually 16 or 24 
      outFile.writeBytes("data");     // 36 - data 
      outFile.write(intToByteArray((int)myDataSize), 0, 4);  // 40 - how big is this data chunk 
      outFile.write(clipData);      // 44 - the actual data itself - just a long string of numbers 
     } 

轉換器

public static int byteArrayToInt(byte[] b) 
    { 
     int start = 0; 
     int low = b[start] & 0xff; 
     int high = b[start+1] & 0xff; 
     return (int)(high << 8 | low); 
    } 


    // these two routines convert a byte array to an unsigned integer 
    public static long byteArrayToLong(byte[] b) 
    { 
     int start = 0; 
     int i = 0; 
     int len = 4; 
     int cnt = 0; 
     byte[] tmp = new byte[len]; 
     for (i = start; i < (start + len); i++) 
     { 
      tmp[cnt] = b[i]; 
      cnt++; 
     } 
     long accum = 0; 
     i = 0; 
     for (int shiftBy = 0; shiftBy < 32; shiftBy += 8) 
     { 
      accum |= ((long)(tmp[i] & 0xff)) << shiftBy; 
      i++; 
     } 
     return accum; 
    } 


// =========================== 
// CONVERT JAVA TYPES TO BYTES 
// =========================== 
    // returns a byte array of length 4 
    private static byte[] intToByteArray(int i) 
    { 
     byte[] b = new byte[4]; 
     b[0] = (byte) (i & 0x00FF); 
     b[1] = (byte) ((i >> 8) & 0x000000FF); 
     b[2] = (byte) ((i >> 16) & 0x000000FF); 
     b[3] = (byte) ((i >> 24) & 0x000000FF); 
     return b; 
    } 

    // convert a short to a byte array 
    public static byte[] shortToByteArray(short data) 
    { 
     return new byte[]{(byte)(data & 0xff),(byte)((data >>> 8) & 0xff)}; 
    } 

Answer 1

你的概率巧妙地設置標題屬性錯誤。 WAV格式標題應該是44個字節，然後是原始音頻數據。這裏是WAV格式的描述：

http://www.sonicspot.com/guide/wavefiles.html

如果您已經創建了一個標題和附加的原始數據，並將得到的文件播放沒有錯誤，但聽起來像噪音，那麼最有可能的罪魁禍首是原始音頻使用每個樣本2字節，但您將標頭中的BitsPerSample屬性設置爲8.

您正在使用的方法（將WAV標頭預先添加到原始音頻）是完全有效的，應該可以正常工作。

更新：嘿，不應該轉換方法是

// convert a short to a byte array 
    public static byte[] shortToByteArray(short data) 
    { 
     return new byte[]{(byte)(data & 0xff),(byte)((data >> 8) & 0xff)}; 
    } 

？我不確定什麼>>>在變化的世界中意味着什麼。

Answer 2

看看在rehearshal助理代碼編寫的WAV頭here