Output of .wav file not as 16000khz 16 bit sampling rate

Question

Possible Duplicate:
how to convert or record .wav file in 16khz 16bit mono little-endian?

I had tried To Record the sound in android device with the following code .i can successfully recorded but the file not good in quality...basically i want to the .wave file with the 16000khz 16 bit with mono little endian format..please tell me where i m doing mistakes.. i had use the google.code androidrecorder2 source for this

package com.varma.samples.audiorecorder;

import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.IOException;

import android.annotation.SuppressLint;
import android.app.Activity;
import android.media.AudioFormat;
import android.media.AudioRecord;
import android.media.MediaRecorder;
import android.os.Bundle;
import android.os.Environment;
import android.view.View;
import android.widget.Button;

public class RecorderActivity extends Activity {
    private static final int RECORDER_BPP = 16;
    private static final String AUDIO_RECORDER_FILE_EXT_WAV = ".wav";
    private static final String AUDIO_RECORDER_FOLDER = "AudioRecorder";
    private static final String AUDIO_RECORDER_TEMP_FILE = "record_temp.raw";
    private static final int RECORDER_SAMPLERATE = 16000;
    private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_CONFIGURATION_MONO;
    private static final int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;

    private AudioRecord recorder = null;
    private int bufferSize = 0;
    private Thread recordingThread = null;
    private boolean isRecording = false;

    @SuppressLint("NewApi")
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        setButtonHandlers();
        enableButtons(false);

        bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE,RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING);
    }

    private void setButtonHandlers() {
        ((Button)findViewById(R.id.btnStart)).setOnClickListener(btnClick);
        ((Button)findViewById(R.id.btnStop)).setOnClickListener(btnClick);
    }

    private void enableButton(int id,boolean isEnable){
        ((Button)findViewById(id)).setEnabled(isEnable);
    }

    private void enableButtons(boolean isRecording) {
        enableButton(R.id.btnStart,!isRecording);
        enableButton(R.id.btnStop,isRecording);
    }

    private String getFilename(){
        String filepath = Environment.getExternalStorageDirectory().getPath();
        File file = new File(filepath,AUDIO_RECORDER_FOLDER);

        if(!file.exists()){
            file.mkdirs();
        }

        return (file.getAbsolutePath() + "/" + System.currentTimeMillis() + AUDIO_RECORDER_FILE_EXT_WAV);
    }

    private String getTempFilename(){
        String filepath = Environment.getExternalStorageDirectory().getPath();
        File file = new File(filepath,AUDIO_RECORDER_FOLDER);

        if(!file.exists()){
            file.mkdirs();
        }

        File tempFile = new File(filepath,AUDIO_RECORDER_TEMP_FILE);

        if(tempFile.exists())
            tempFile.delete();

        return (file.getAbsolutePath() + "/" + AUDIO_RECORDER_TEMP_FILE);
    }

    @SuppressLint({ "NewApi", "NewApi" })
    private void startRecording(){
        recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
                        RECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING, bufferSize);

        recorder.startRecording();

        isRecording = true;

        recordingThread = new Thread(new Runnable() {

            @Override
            public void run() {
                writeAudioDataToFile();
            }
        },"AudioRecorder Thread");

        recordingThread.start();
    }

    @SuppressLint({ "NewApi", "NewApi", "NewApi" })
    private void writeAudioDataToFile(){
        byte data[] = new byte[bufferSize];
        String filename = getTempFilename();
        FileOutputStream os = null;

        try {
            os = new FileOutputStream(filename);
        } catch (FileNotFoundException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }

        int read = 0;

        if(null != os){
            while(isRecording){
                read = recorder.read(data, 0, bufferSize);

                if(AudioRecord.ERROR_INVALID_OPERATION != read){
                    try {
                        os.write(data);
                    } catch (IOException e) {
                        e.printStackTrace();
                    }
                }
            }

            try {
                os.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    @SuppressLint({ "NewApi", "NewApi" })
    private void stopRecording(){
        if(null != recorder){
            isRecording = false;

            recorder.stop();
            recorder.release();

            recorder = null;
            recordingThread = null;
        }

        copyWaveFile(getTempFilename(),getFilename());
        deleteTempFile();
    }

    private void deleteTempFile() {
        File file = new File(getTempFilename());

        file.delete();
    }

    private void copyWaveFile(String inFilename,String outFilename){
        FileInputStream in = null;
        FileOutputStream out = null;
        long totalAudioLen = 0;
        long totalDataLen = totalAudioLen + 36;
        long longSampleRate = RECORDER_SAMPLERATE;
        int channels = 2;
        long byteRate = RECORDER_BPP * RECORDER_SAMPLERATE * channels/8;

        byte[] data = new byte[bufferSize];

        try {
            in = new FileInputStream(inFilename);
            out = new FileOutputStream(outFilename);
            totalAudioLen = in.getChannel().size();
            totalDataLen = totalAudioLen + 36;

            AppLog.logString("File size: " + totalDataLen);

            WriteWaveFileHeader(out, totalAudioLen, totalDataLen,
                    longSampleRate, channels, byteRate);

            while(in.read(data) != -1){
                out.write(data);
            }

            in.close();
            out.close();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    private void WriteWaveFileHeader(
            FileOutputStream out, long totalAudioLen,
            long totalDataLen, long longSampleRate, int channels,
            long byteRate) throws IOException {

        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);
    }

    private View.OnClickListener btnClick = new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            switch(v.getId()){
                case R.id.btnStart:{
                    AppLog.logString("Start Recording");

                    enableButtons(true);
                    startRecording();

                    break;
                }
                case R.id.btnStop:{
                    AppLog.logString("Start Recording");

                    enableButtons(false);
                    stopRecording();

                    break;
                }
            }
        }
    }; 
}

The ouput of wav file is on this link..

http://www.filefactory.com/file/20ibb9itlal1/n/1347267058768.wav

I just Found one problem is that the ouput file is still in stereo foramt.i ahve one wav converter software for windows7 and when i add my ouput file in that its showing me that the foramt is in stereo ...i had never give option of channel_configuration_stereo Still why?

Please Please Guide me.its been a week i m trying to sort out.. Thanx in Advance

thanx but i ahd tried that but with that i still getting too bad quality like slow motion play of wav sound..wht happening is now file is showing me that it have 16000 hz and in mono.but when i record from android device and when i record voice from audacity software with the same configuration then why its still not in good format? — BhavikKama, Sep 11 '12 at 12:52

score 1 · Answer 1 · edited Sep 11 '12 at 08:27

1

In your copyWaveFile function, you set channels = 2;

This get written to the header in WriteWaveFileHeader().

Two things I find useful when playing with .WAV files are:

a hex editor to look at the header with,
and this page describing what it should look like.

edited Sep 11 '12 at 08:27

Mike Aski

9,180
4
46
63

answered Sep 11 '12 at 07:44

Shitesh

1,111
1
10
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1

but if i make it channels=1 then its quality goes very low.its giving me 16000hz with 706kbps of bitrate and mono format but this wav file play like its played in slow motion...why happening like this – BhavikKama Sep 11 '12 at 09:16
http://www.filefactory.com/file/55sbx2log443/n/1347355143822.wav ..after changing the channels=1 its give me mono but file is not in qood quality...u can hear my ouput of wave file with above link – BhavikKama Sep 11 '12 at 09:38
It seems like your actual data is still in two channels (with one of them being empty). Perhaps try Michael Burr's suggestion above? – Shitesh Sep 11 '12 at 11:22
I had Tried as Michel SAid.but thats not working out..some how as mike asked me above about the channels =2;is for stereo then i make it to 1.and thats somehow worked to ouput me as mono 16000 hz wav file.but that file is not good as the one can create with the readymade audacity software with the same configuration – BhavikKama Sep 11 '12 at 12:55

Output of .wav file not as 16000khz 16 bit sampling rate

1 Answers1