Writing PCM recorded data into a .wav file (java android)

I've been wrestling with this exact same question for hours now, and my issue was mostly that when recording in 16 bits you have to be very careful about what you write to the output. The WAV file expects the data in Little Endian format, but using writeShort writes it to the output as Big Endian. I also got interesting results when using the other functions so I returned to writing bytes in the correct order and that works.

I used a Hex editor extensively while debugging this. I can recommend you do the same. Also, the header in the answer above works, I used it to check versus my own code and this header is rather foolproof.

As per the header is concern, I had followed this code (if it's helps you some way).

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);

Are you certain of the byte order? "RIFF", "WAV", "fmt", and "data" look fine but the numbers in the header may need to be a different order (little endian vs. big endian). You also don't need to convert to bytes manually using your intToByteArray method. You could use the writeInt and writeShort methods of DataOutputStream. For the first one, this would look something like:

outFile.writeInt(Integer.reverseBytes((int)myChunkSize));

For the shorts it'd be like:

outFile.writeShort(Short.reverseBytes((short)myFormat))

This way you also don't need to provide the offset and length (0, 4) numbers. It's nice.