androidmediarecorderandroid-audiorecord

AudioRecord sometimes skips audio data


I use AudioRecord for recording audio in wav files. I perform read() operation in a loop on secondary thread and the data is passed into a queue in another sec. thread for writing in a file.

The issue is the following: When I choose to save the audioData in the external SD card, the audio contains some millisc of skips/distortions (only sometimes). Other users has this issue when saving on internal SD card too

This is how I instantiate the AudioRecord object:

initBufferSize = assureMinBufferSize();
if (minBufferSize == AudioRecord.ERROR_BAD_VALUE) { 
    throw new Exception("" + ErrorCodes.ERROR_CODE_0);
}
else if (minBufferSize == AudioRecord.ERROR) {
    throw new Exception("" + ErrorCodes.ERROR_CODE_0);
}

buffer = new byte[initBufferSize];
aRecorder = new AudioRecord(mSource, sRate, nChannel, AudioFormat.ENCODING_PCM_16BIT, initBufferSize);

and this is how I pool the AudioRecorder object:

private class AudioReaderRunnable implements Runnable {
    private volatile boolean stopped;

    @Override
    public void run() {                         
        while (!stopped) {
            while(mState == State.RECORDING){
                read();
            }
        }           

        Log.i(getClass().getName(), "AudioReade thread stopped!");
    }

    private void read(){

        if(aRecorder == null)
            return;

        // "dirty" patch for some null crash for some users
        if(buffer == null)
            buffer = new byte[initBufferSize];

        //int x = aRecorder.read(buffer, 0, buffer.length);
        int x = readFully(buffer, 0, buffer.length);
        if(x <= 0)
            return;

        payloadSize += x;

        mWavData.arrayCopy(buffer);

        mWavData.setGain(rGain);
        mWavData.setBitsPerSamples(bitsPerSample);
        mWavData.setNrChannels(nChannelsNumber);

        // send audio to another thread for writing
        mAudioWritter.add(audioData);               
    }

    private int readFully(byte[] data, int off, int length) {
        int read = 0;
        int result = 0;
        int requestedSize = length;

        if(aRecorder == null){
            return read;
        }

        try {           
            result = aRecorder.read(data, off, requestedSize);
        } catch (Exception e) {
            Log.e(getClass().getName(), e.getMessage(), e);
            if(aRecorder == null)
                return read;
        }

        read = result;

        while (requestedSize != result && !stopped) {
            if(aRecorder == null)
                return read;

            requestedSize -= result;                
            try {
                result = aRecorder.read(data, result - 1, requestedSize);   
            } catch (Exception e) {
                Log.e(getClass().getName(), e.getMessage(), e);
                if(aRecorder == null)
                    return read;
            }
            read += result;
        }

        return read;
    }

    public void stopThread() {
        stopped = true;
    }
}

Solution

  • Try This Code:-
    
    //This Variable are define in class
    
    private int recordingcounter;
    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;// /44100; //High voice
                                                                // recording result
                                                                // for use sample
                                                                // rate is 44100
    private static final int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_STEREO;
    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;
    
    
    //--------------------- start button click event in add-----------------------------------//
    
    bufferSize = AudioRecord.getMinBufferSize(RECORDER_SAMPLERATE, RECORDER_CHANNELS,RECORDER_AUDIO_ENCODING);
    
    try {
    
                                        startRecording();
    
                                    } catch (Exception e) {
                                        // TODO: handle exception
    
                                        // Toast.makeText(RecordingActivity.this,
                                        // e.getMessage(), Toast.LENGTH_SHORT)
                                        // .show();
    
                                    }
    
    
    
    
    
    
    
    //-------------------- stop button click event in add---------------------------//
    
    try {
    
                                    stopRecording();
    
                                } catch (Exception e) {
                                    // TODO: handle exception
                                    e.printStackTrace();
                                }
    
    
    
    
    
    
    //---------this methods are add in your class-----------------------------//
    
    
    
    // --------------------------------------------------------Sound Recording
        // Code----------------------------------------------------//
    
        private String getFilename() {
            String filepath = Environment.getExternalStorageDirectory().getPath();
            File file = new File(filepath, AUDIO_RECORDER_FOLDER);
    
            if (!file.exists()) {
                file.mkdirs();
            }
    
            return (file.getAbsolutePath() + "/" + "voiceFile" + 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")
        private void startRecording() {
            recorder = new AudioRecord(MediaRecorder.AudioSource.MIC,
                    RECORDER_SAMPLERATE, RECORDER_CHANNELS,
                    RECORDER_AUDIO_ENCODING, bufferSize);
    
            recorder.startRecording();
    
            // Log.e("Audio session", ""+recorder.getAudioSessionId());
    
            isRecording = true;
    
            recordingThread = new Thread(new Runnable() {
    
                @Override
                public void run() {
                    writeAudioDataToFile();
                }
            }, "AudioRecorder Thread");
    
            recordingThread.start();
        }
    
        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();
                }
            }
        }
    
        private void stopRecording() {
            if (null != recorder) {
                isRecording = false;
    
                recorder.stop();
                recorder.release();
    
                // Utility.Log("", "" + recorder.getRecordingState());
    
                // AppLog.logString(""+recorder.getRecordingState());
    
                recorder = null;
                recordingThread = null;
    
            }
    
            copyWaveFile(getTempFilename(), getFilename());
    
        }
    
    
    
        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;
    
                // Utility.Log("", "File size: " + totalDataLen);
    
                // 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);
        }
    

    //----------and manifest file this line-------------//

    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    
    
    <uses-permission android:name="android.permission.RECORD_AUDIO" />