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如何以 16khz 16 位单声道小端格式转换或录制 .wav 文件?

我想在 16000 khz 16 位单声道小端 wav 文件中从 android 设备实现音频录制。

我已经像这样在android中实现了逻辑。我使用一个类名作为 extaudiorecorder。

public class ExtAudioRecorder {
    private final static int[] sampleRates = {44100, 22050, 11025, 16000};

    public static ExtAudioRecorder getInstanse(Boolean recordingCompressed) {
        ExtAudioRecorder result = null;
        if(recordingCompressed) {
            result = new ExtAudioRecorder(false, AudioSource.MIC, sampleRates[3],
                                          AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                          AudioFormat.ENCODING_PCM_16BIT);
        } 
        else {
            int i=0;
            do {
                result = new ExtAudioRecorder(true, AudioSource.MIC, sampleRates[i],
                                              AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                              AudioFormat.ENCODING_PCM_16BIT);
            } while((++i<sampleRates.length) & 
                   !(result.getState() == ExtAudioRecorder.State.INITIALIZING));
        }
        return result;
    }

    /**
    * INITIALIZING : recorder is initializing;
    * READY : recorder has been initialized, recorder not yet started
    * RECORDING : recording
    * ERROR : reconstruction needed
    * STOPPED: reset needed
    */
    public enum State {INITIALIZING, READY, RECORDING, ERROR, STOPPED};
    public static final boolean RECORDING_UNCOMPRESSED = true;
    public static final boolean RECORDING_COMPRESSED = false;

    // The interval in which the recorded samples are output to the file
    // Used only in uncompressed mode
    private static final int TIMER_INTERVAL = 120;

    // Toggles uncompressed recording on/off; 
    // RECORDING_UNCOMPRESSED / RECORDING_COMPRESSED
    private boolean rUncompressed;

    // Recorder used for uncompressed recording
    private AudioRecord audioRecorder = null;

    // Recorder used for compressed recording
    private MediaRecorder mediaRecorder = null;

    // Stores current amplitude (only in uncompressed mode)
    private int cAmplitude = 0;

    // Output file path
    private String filePath = null;

    // Recorder state; see State
    private State state;

    // File writer (only in uncompressed mode)
    private RandomAccessFile randomAccessWriter;

    // Number of channels, sample rate, sample size(size in bits), buffer size, audio source, sample size(see AudioFormat)
    private short nChannels;
    private int sRate;
    private short bSamples;
    private int bufferSize;
    private int aSource;
    private int aFormat;

    // Number of frames written to file on each output(only in uncompressed mode)
    private int framePeriod;

    // Buffer for output(only in uncompressed mode)
    private byte[] buffer;

    // Number of bytes written to file after header(only in uncompressed mode)
    // after stop() is called, this size is written to the header/data chunk in the wave file
    private int payloadSize;

    /**
    * Returns the state of the recorder in a RehearsalAudioRecord.State typed object.
    * Useful, as no exceptions are thrown.
    * @return recorder state
    */
    public State getState() { return state; }

    /**
    * Method used for recording.
    */
    private AudioRecord.OnRecordPositionUpdateListener updateListener = new AudioRecord.OnRecordPositionUpdateListener() {
        public void onPeriodicNotification(AudioRecord recorder) {
            audioRecorder.read(buffer, 0, buffer.length); // Fill buffer
                try { 
                    randomAccessWriter.write(buffer); // Write buffer to file
                    payloadSize += buffer.length;
                    if (bSamples == 16) {
                        for (int i=0; i<buffer.length/2; i++) { // 16bit sample size
                            short curSample = getShort(buffer[i*2], buffer[i*2+1]);
                            if (curSample > cAmplitude) { // Check amplitude
                                cAmplitude = curSample;
                            }
                        }
                    }
                    else { // 8bit sample size
                        for (int i=0; i<buffer.length; i++) {
                            if (buffer[i] > cAmplitude) { // Check amplitude
                                cAmplitude = buffer[i];
                            }
                        }
                    }
                }
                catch (IOException e) {
                    Log.e(ExtAudioRecorder.class.getName(), 
                          "Error occured in updateListener, recording is aborted");
                    //stop();
                }
            }

            public void onMarkerReached(AudioRecord recorder) {
                // NOT USED
            }
        };

    /** 
    * Default constructor
    * Instantiates a new recorder, in case of compressed recording the parameters can be left as 0.
    * In case of errors, no exception is thrown, but the state is set to ERROR
    */ 
    public ExtAudioRecorder(boolean uncompressed, int audioSource, int sampleRate, 
                            int channelConfig, int audioFormat) {
        try {
            rUncompressed = uncompressed;
            if (rUncompressed) { // RECORDING_UNCOMPRESSED
                if (audioFormat == AudioFormat.ENCODING_PCM_16BIT) {
                    bSamples = 16;
                }
                else { bSamples = 8; }

                if (channelConfig == AudioFormat.CHANNEL_CONFIGURATION_MONO) {
                    nChannels = 1;
                }
                else { nChannels = 2; }

                aSource = audioSource;
                sRate   = sampleRate;
                aFormat = audioFormat;

                framePeriod = sampleRate * TIMER_INTERVAL / 1000;
                bufferSize = framePeriod * 2 * bSamples * nChannels / 8;
                    if (bufferSize < AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat))
                    { // Check to make sure buffer size is not smaller than the smallest allowed one 
                        bufferSize = AudioRecord.getMinBufferSize(sampleRate, channelConfig, audioFormat);
                        // Set frame period and timer interval accordingly
                        framePeriod = bufferSize / ( 2 * bSamples * nChannels / 8 );
                        Log.w(ExtAudioRecorder.class.getName(), "Increasing buffer size to " + Integer.toString(bufferSize));
                    }

                    audioRecorder = new AudioRecord(audioSource, sampleRate, channelConfig, audioFormat, bufferSize);

                    if (audioRecorder.getState() != AudioRecord.STATE_INITIALIZED)
                        throw new Exception("AudioRecord initialization failed");
                    audioRecorder.setRecordPositionUpdateListener(updateListener);
                    audioRecorder.setPositionNotificationPeriod(framePeriod);
                } else
                { // RECORDING_COMPRESSED
                    mediaRecorder = new MediaRecorder();
                    mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
                    mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
                    mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);               
                }
                cAmplitude = 0;
                filePath = null;
                state = State.INITIALIZING;
            } catch (Exception e)
            {
                if (e.getMessage() != null)
                {
                    Log.e(ExtAudioRecorder.class.getName(), e.getMessage());
                }
                else
                {
                    Log.e(ExtAudioRecorder.class.getName(), "Unknown error occured while initializing recording");
                }
                state = State.ERROR;
            }
        }

        /**
         * Sets output file path, call directly after construction/reset.
         *  
         * @param output file path
         * 
         */
        public void setOutputFile(String argPath)
        {
            try
            {
                if (state == State.INITIALIZING)
                {
                    filePath = argPath;
                    if (!rUncompressed)
                    {
                        mediaRecorder.setOutputFile(filePath);                  
                    }
                }
            }
            catch (Exception e)
            {
                if (e.getMessage() != null)
                {
                    Log.e(ExtAudioRecorder.class.getName(), e.getMessage());
                }
                else
                {
                    Log.e(ExtAudioRecorder.class.getName(), "Unknown error occured while setting output path");
                }
                state = State.ERROR;
            }
        }

        /**
         * 
         * Returns the largest amplitude sampled since the last call to this method.
         * 
         * @return returns the largest amplitude since the last call, or 0 when not in recording state. 
         * 
         */
        public int getMaxAmplitude()
        {
            if (state == State.RECORDING)
            {
                if (rUncompressed)
                {
                    int result = cAmplitude;
                    cAmplitude = 0;
                    return result;
                }
                else
                {
                    try
                    {
                        return mediaRecorder.getMaxAmplitude();
                    }
                    catch (IllegalStateException e)
                    {
                        return 0;
                    }
                }
            }
            else
            {
                return 0;
            }
        }


        /**
         * 
        * Prepares the recorder for recording, in case the recorder is not in the INITIALIZING state and the file path was not set
        * the recorder is set to the ERROR state, which makes a reconstruction necessary.
        * In case uncompressed recording is toggled, the header of the wave file is written.
        * In case of an exception, the state is changed to ERROR
        *    
        */
        public void prepare()
        {
            try
            {
                if (state == State.INITIALIZING)
                {
                    if (rUncompressed)
                    {
                        if ((audioRecorder.getState() == AudioRecord.STATE_INITIALIZED) & (filePath != null))
                        {
                            // write file header

                            randomAccessWriter = new RandomAccessFile(filePath, "rw");

                            randomAccessWriter.setLength(0); // Set file length to 0, to prevent unexpected behavior in case the file already existed
                            randomAccessWriter.writeBytes("RIFF");
                            randomAccessWriter.writeInt(0); // Final file size not known yet, write 0 
                            randomAccessWriter.writeBytes("WAVE");
                            randomAccessWriter.writeBytes("fmt ");
                            randomAccessWriter.writeInt(Integer.reverseBytes(16)); // Sub-chunk size, 16 for PCM
                            randomAccessWriter.writeShort(Short.reverseBytes((short) 1)); // AudioFormat, 1 for PCM
                            randomAccessWriter.writeShort(Short.reverseBytes(nChannels));// Number of channels, 1 for mono, 2 for stereo
                            randomAccessWriter.writeInt(Integer.reverseBytes(sRate)); // Sample rate
                            randomAccessWriter.writeInt(Integer.reverseBytes(sRate*bSamples*nChannels/8)); // Byte rate, SampleRate*NumberOfChannels*BitsPerSample/8
                            randomAccessWriter.writeShort(Short.reverseBytes((short)(nChannels*bSamples/8))); // Block align, NumberOfChannels*BitsPerSample/8
                            randomAccessWriter.writeShort(Short.reverseBytes(bSamples)); // Bits per sample
                            randomAccessWriter.writeBytes("data");
                            randomAccessWriter.writeInt(0); // Data chunk size not known yet, write 0

                            buffer = new byte[framePeriod*bSamples/8*nChannels];
                            state = State.READY;
                        }
                        else
                        {
                            Log.e(ExtAudioRecorder.class.getName(), "prepare() method called on uninitialized recorder");
                            state = State.ERROR;
                        }
                    }
                    else
                    {
                        mediaRecorder.prepare();
                        state = State.READY;
                    }
                }
                else
                {
                    Log.e(ExtAudioRecorder.class.getName(), "prepare() method called on illegal state");
                    release();
                    state = State.ERROR;
                }
            }
            catch(Exception e)
            {
                if (e.getMessage() != null)
                {
                    Log.e(ExtAudioRecorder.class.getName(), e.getMessage());
                }
                else
                {
                    Log.e(ExtAudioRecorder.class.getName(), "Unknown error occured in prepare()");
                }
                state = State.ERROR;
            }
        }

        /**
         * 
         * 
         *  Releases the resources associated with this class, and removes the unnecessary files, when necessary
         *  
         */
        public void release()
        {
            if (state == State.RECORDING)
            {
                stop();
            }
            else
            {
                if ((state == State.READY) & (rUncompressed))
                {
                    try
                    {
                        randomAccessWriter.close(); // Remove prepared file
                    }
                    catch (IOException e)
                    {
                        Log.e(ExtAudioRecorder.class.getName(), "I/O exception occured while closing output file");
                    }
                    (new File(filePath)).delete();
                }
            }

            if (rUncompressed)
            {
                if (audioRecorder != null)
                {
                    audioRecorder.release();
                }
            }
            else
            {
                if (mediaRecorder != null)
                {
                    mediaRecorder.release();
                }
            }
        }

        /**
         * 
         * 
         * Resets the recorder to the INITIALIZING state, as if it was just created.
         * In case the class was in RECORDING state, the recording is stopped.
         * In case of exceptions the class is set to the ERROR state.
         * 
         */
        public void reset()
        {
            try
            {
                if (state != State.ERROR)
                {
                    release();
                    filePath = null; // Reset file path
                    cAmplitude = 0; // Reset amplitude
                    if (rUncompressed)
                    {
                        audioRecorder = new AudioRecord(aSource, sRate, nChannels+1, aFormat, bufferSize);
                    }
                    else
                    {
                        mediaRecorder = new MediaRecorder();
                        mediaRecorder.setAudioSource(MediaRecorder.AudioSource.MIC);
                        mediaRecorder.setOutputFormat(MediaRecorder.OutputFormat.THREE_GPP);
                        mediaRecorder.setAudioEncoder(MediaRecorder.AudioEncoder.AMR_NB);
                    }
                    state = State.INITIALIZING;
                }
            }
            catch (Exception e)
            {
                Log.e(ExtAudioRecorder.class.getName(), e.getMessage());
                state = State.ERROR;
            }
        }

        /**
         * 
         * 
         * Starts the recording, and sets the state to RECORDING.
         * Call after prepare().
         * 
         */
        public void start()
        {
            if (state == State.READY)
            {
                if (rUncompressed)
                {
                    payloadSize = 0;
                    audioRecorder.startRecording();
                    audioRecorder.read(buffer, 0, buffer.length);
                }
                else
                {
                    mediaRecorder.start();
                }
                state = State.RECORDING;
            }
            else
            {
                Log.e(ExtAudioRecorder.class.getName(), "start() called on illegal state");
                state = State.ERROR;
            }
        }

        /**
         * 
         * 
         *  Stops the recording, and sets the state to STOPPED.
         * In case of further usage, a reset is needed.
         * Also finalizes the wave file in case of uncompressed recording.
         * 
         */
        public void stop()
        {
            if (state == State.RECORDING)
            {
                if (rUncompressed)
                {
                    audioRecorder.stop();

                    try
                    {
                        randomAccessWriter.seek(4); // Write size to RIFF header
                        randomAccessWriter.writeInt(Integer.reverseBytes(36+payloadSize));

                        randomAccessWriter.seek(40); // Write size to Subchunk2Size field
                        randomAccessWriter.writeInt(Integer.reverseBytes(payloadSize));

                        randomAccessWriter.close();
                    }
                    catch(IOException e)
                    {
                        Log.e(ExtAudioRecorder.class.getName(), "I/O exception occured while closing output file");
                        state = State.ERROR;
                    }
                }
                else
                {
                    mediaRecorder.stop();
                }
                state = State.STOPPED;
            }
            else
            {
                Log.e(ExtAudioRecorder.class.getName(), "stop() called on illegal state");
                state = State.ERROR;
            }
        }

        /* 
         * 
         * Converts a byte[2] to a short, in LITTLE_ENDIAN format
         * 
         */
        private short getShort(byte argB1, byte argB2)
        {
            return (short)(argB1 | (argB2 << 8));
        }

    }

并且我在我的主要活动中使用该类,如这里..我在按钮单击时录制声音并在另一个按钮单击时停止它

包 com.test.android_recorder;

import android.os.Bundle;
import android.os.Environment;
import android.app.Activity;
import android.view.Menu;
import android.widget.Button;
import android.widget.TextView;
import android.view.View;
import android.view.View.OnClickListener;

public class AndroidRecorder extends Activity {
     ExtAudioRecorder extAudioRecorder;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(com.test.android_recorder.R.layout.activity_android_recorder);
        Button button = (Button) findViewById(R.id.button1);

        Button buttonstop = (Button) findViewById(R.id.buttonstop);

        // Start recording
           extAudioRecorder = ExtAudioRecorder.getInstanse(true);   


        button.setOnClickListener(new OnClickListener()
        {
          public void onClick(View v)
          {

TextView txt1=(TextView)findViewById(com.test.android_recorder.R.id.textView1);
              txt1.setText("Button clciked");

                 // Compressed recording (AMR)
                    //extAudioRecorder = ExtAudioRecorder.getInstanse(false); // Uncompressed recording (WAV)

                    extAudioRecorder.setOutputFile(Environment.getExternalStorageDirectory().getAbsolutePath() + "/javarecorder");
                    extAudioRecorder.prepare();
                    extAudioRecorder.start();


              // ImageView iv = (ImageView) findViewById(R.id.imageview1);
             //iv.setVisibility(View.VISIBLE);
          }
        });



        buttonstop.setOnClickListener(new OnClickListener()
        {
          public void onClick(View v)
          {

//TextView txt1=(TextView)findViewById(com.test.android_recorder.R.id.textView1);
             // txt1.setText("Button clciked");
              // ImageView iv = (ImageView) findViewById(R.id.imageview1);
             //iv.setVisibility(View.VISIBLE);

              // Stop recording
              extAudioRecorder.stop();
              extAudioRecorder.release();
          }
        });




        /*


*/
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(com.test.android_recorder.R.menu.activity_android_recorder, menu);
        return true;
    }
}

我的问题是现在文件正在录制,但录制的文件太嘈杂且不清楚。我想在 sphinx 4 语音识别中使用这个录制的文件。它需要 16000KHZ 16 位单声道大端..但是当我使用录制的文件时我的 sphhinx4 语音识别然后它给了我不受支持的源错误...我想让我的 wav 文件质量好...我该怎么办?请帮帮我

4

1 回答 1

0
private final static int[] sampleRates = {44100, 22050, 11025, 8000};

这些采样率都不是 16khz。

编辑: illegal state通常表示您没有在manifest.xml.

于 2012-09-06T11:51:38.317 回答