Recording .Wav with Android AudioRecorder

Question

I have read a lot of pages about Android\'s AudioRecorder. You can see a list of them below the question.

I\'m trying to record audio with AudioRecorder, but it\'s n

Answer 1

I wrote a simple (by which you should read, not to professional standards) class to do this yesterday, and it works.

private class Wave {
    private final int LONGINT = 4;
    private final int SMALLINT = 2;
    private final int INTEGER = 4;
    private final int ID_STRING_SIZE = 4;
    private final int WAV_RIFF_SIZE = LONGINT + ID_STRING_SIZE;
    private final int WAV_FMT_SIZE = (4 * SMALLINT) + (INTEGER * 2) + LONGINT + ID_STRING_SIZE;
    private final int WAV_DATA_SIZE = ID_STRING_SIZE + LONGINT;
    private final int WAV_HDR_SIZE = WAV_RIFF_SIZE + ID_STRING_SIZE + WAV_FMT_SIZE + WAV_DATA_SIZE;
    private final short PCM = 1;
    private final int SAMPLE_SIZE = 2;
    int cursor, nSamples;
    byte[] output;

    public Wave(int sampleRate, short nChannels, short[] data, int start, int end) {
        nSamples = end - start + 1;
        cursor = 0;
        output = new byte[nSamples * SMALLINT + WAV_HDR_SIZE];
        buildHeader(sampleRate, nChannels);
        writeData(data, start, end);
    }

    // ------------------------------------------------------------
    private void buildHeader(int sampleRate, short nChannels) {
        write("RIFF");
        write(output.length);
        write("WAVE");
        writeFormat(sampleRate, nChannels);
    }

    // ------------------------------------------------------------
    public void writeFormat(int sampleRate, short nChannels) {
        write("fmt ");
        write(WAV_FMT_SIZE - WAV_DATA_SIZE);
        write(PCM);
        write(nChannels);
        write(sampleRate);
        write(nChannels * sampleRate * SAMPLE_SIZE);
        write((short) (nChannels * SAMPLE_SIZE));
        write((short) 16);
    }

    // ------------------------------------------------------------
    public void writeData(short[] data, int start, int end) {
        write("data");
        write(nSamples * SMALLINT);
        for (int i = start; i <= end; write(data[i++])) ;
    }

    // ------------------------------------------------------------
    private void write(byte b) {
        output[cursor++] = b;
    }

    // ------------------------------------------------------------
    private void write(String id) {
        if (id.length() != ID_STRING_SIZE)
            Utils.logError("String " + id + " must have four characters.");
        else {
            for (int i = 0; i < ID_STRING_SIZE; ++i) write((byte) id.charAt(i));
        }
    }

    // ------------------------------------------------------------
    private void write(int i) {
        write((byte) (i & 0xFF));
        i >>= 8;
        write((byte) (i & 0xFF));
        i >>= 8;
        write((byte) (i & 0xFF));
        i >>= 8;
        write((byte) (i & 0xFF));
    }

    // ------------------------------------------------------------
    private void write(short i) {
        write((byte) (i & 0xFF));
        i >>= 8;
        write((byte) (i & 0xFF));
    }

    // ------------------------------------------------------------
    public boolean wroteToFile(String filename) {
        boolean ok = false;

        try {
            File path = new File(getFilesDir(), filename);
            FileOutputStream outFile = new FileOutputStream(path);
            outFile.write(output);
            outFile.close();
            ok = true;
        } catch (FileNotFoundException e) {
            e.printStackTrace();
            ok = false;
        } catch (IOException e) {
            ok = false;
            e.printStackTrace();
        }
        return ok;
    }
}

Hope this helps