无法在 Android 中播放使用 AudioRecord 录制的 pcm 文件

Posted 2023-02-25

【中文标题】无法在 Android 中播放使用 AudioRecord 录制的 pcm 文件

【英文标题】：Unable to play the pcm file recorded using AudioRecord in Android

【发布时间】：2016-09-22 15:30:05

【问题描述】：

我正在开发一个 android 应用程序。在我的应用程序中，我需要使用 AudionRecord 录制音频并需要播放它。但是在播放录制的 pcm 文件时抛出错误。主要问题是我也无法记录错误，因为我必须在真实设备上进行测试并且无法在模拟器上运行。因为当我在模拟器上运行并录制时，我的应用程序崩溃了。

这是我的活动

public class MainActivity extends AppCompatActivity 

    Boolean recording;
    private Thread recordingThread = null;
    DataOutputStream dataOutputStream;
    short[] audioData;


    private Button btnPlay,btnStop,btnRecord;
    private String outputFile = null;
    //outputFile = Environment.getExternalStorageDirectory().getAbsolutePath()+"/recording.3gp";
    @Override
    protected void onCreate(Bundle savedInstanceState) 
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        initialize();
        initViews();
        setUpViews();
    

    private void initialize()
    

    

    private void initViews()
    
        btnPlay = (Button)findViewById(R.id.btn_play);
        btnRecord = (Button)findViewById(R.id.btn_record);
        btnStop = (Button)findViewById(R.id.btn_stop);
    

    private void setUpViews()
    
        btnRecord.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
                startRecord();
            
        );

        btnStop.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
                recording = false;
                Toast.makeText(getBaseContext(),"Stopped",Toast.LENGTH_SHORT).show();
            
        );

        btnPlay.setOnClickListener(new View.OnClickListener() 
            @Override
            public void onClick(View v) 
                playRecord();
            
        );
    

    private void startRecord()

        File file = new File(Environment.getExternalStorageDirectory(), "test.pcm");

        try 
            file.createNewFile();

            OutputStream outputStream = new FileOutputStream(file);
            BufferedOutputStream bufferedOutputStream = new BufferedOutputStream(outputStream);
            dataOutputStream = new DataOutputStream(bufferedOutputStream);

            final int minBufferSize = AudioRecord.getMinBufferSize(11025,
                    AudioFormat.CHANNEL_CONFIGURATION_MONO,
                    AudioFormat.ENCODING_PCM_16BIT);

            audioData = new short[minBufferSize];

            final AudioRecord audioRecord = new AudioRecord(MediaRecorder.Audiosource.MIC,
                    11025,
                    AudioFormat.CHANNEL_CONFIGURATION_MONO,
                    AudioFormat.ENCODING_PCM_16BIT,
                    minBufferSize);

            audioRecord.startRecording();

            Toast.makeText(getBaseContext(),"Recording",Toast.LENGTH_SHORT).show();


            recordingThread = new Thread(new Runnable() 
                public void run() 
                    while(recording)
                        int numberOfShort = audioRecord.read(audioData, 0, minBufferSize);
                        for(int i = 0; i < numberOfShort; i++)
                            try
                                dataOutputStream.writeShort(audioData[i]);
                            
                            catch (IOException e)
                            
                                Toast.makeText(getBaseContext(),e.getMessage(),Toast.LENGTH_SHORT).show();
                            
                        
                    
                
            , "AudioRecorder Thread");

            audioRecord.stop();
            dataOutputStream.close();

         catch (IOException e) 
            e.printStackTrace();
        

    

    private void playRecord()

        File file = new File(Environment.getExternalStorageDirectory(), "test.pcm");

        int shortSizeInBytes = Short.SIZE/Byte.SIZE;

        int bufferSizeInBytes = (int)(file.length()/shortSizeInBytes);
        short[] audioData = new short[bufferSizeInBytes];

        try 
            InputStream inputStream = new FileInputStream(file);
            BufferedInputStream bufferedInputStream = new BufferedInputStream(inputStream);
            DataInputStream dataInputStream = new DataInputStream(bufferedInputStream);

            int i = 0;
            while(dataInputStream.available() > 0)
                audioData[i] = dataInputStream.readShort();
                i++;
            

            dataInputStream.close();

            AudioTrack audioTrack = new AudioTrack(
                    AudioManager.STREAM_MUSIC,
                    11025,
                    AudioFormat.CHANNEL_CONFIGURATION_MONO,
                    AudioFormat.ENCODING_PCM_16BIT,
                    bufferSizeInBytes,
                    AudioTrack.MODE_STREAM);

            audioTrack.play();
            audioTrack.write(audioData, 0, bufferSizeInBytes);


         catch (FileNotFoundException e) 
            e.printStackTrace();
         catch (IOException e) 
            e.printStackTrace();
        
    

问题在于播放录制的 pcm。当我单击播放按钮时，应用程序抛出致命错误并停止。我也无法记录错误。 pcm 文件也确实存在于定义的路径中。我的代码有什么问题？为什么不能播放？

如下图所示，pcm文件录制完成后创建成功

【问题讨论】：

audioRecord.startRecording(); ... 几个 CPU 周期后 ... audioRecord.stop(); ... recordingThread 永远不会启动 ... 等等...

【参考方案1】：

没有看到 Logcat，很难在代码中找出问题所在。看看这个关于“如何使用 AudioTrack 播放 pcm 文件”的工作代码：

private void PlayAudioFileViaAudioTrack(String filePath) throws IOException

// We keep temporarily filePath globally as we have only two sample sounds now..
if (filePath==null)
return;

int intSize = android.media.AudioTrack.getMinBufferSize(44100, AudioFormat.CHANNEL_CONFIGURATION_STEREO,
AudioFormat.ENCODING_PCM_16BIT); 

AudioTrack at = new AudioTrack(AudioManager.STREAM_MUSIC, 44100, AudioFormat.CHANNEL_CONFIGURATION_STEREO,
AudioFormat.ENCODING_PCM_16BIT, intSize, AudioTrack.MODE_STREAM); 


if (at==null) 
Log.d("TCAudio", "audio track is not initialised ");
return; 


int count = 512 * 1024; // 512 kb
//Reading the file..
byte[] byteData = null; 
File file = null; 
file = new File(filePath);

byteData = new byte[(int)count];
FileInputStream in = null;
try 
in = new FileInputStream( file );

 catch (FileNotFoundException e) 
// TODO Auto-generated catch block
e.printStackTrace();


int bytesread = 0, ret = 0;
int size = (int) file.length();
at.play();
while (bytesread < size)  
   ret = in.read( byteData,0, count); 
   if (ret != -1)  // Write the byte array to the track 
    at.write(byteData,0, ret); 
    bytesread += ret; 
     

    else break; 
 
    in.close();    
    at.stop(); 
    at.release(); 

来自http://jongladwin.blogspot.co.uk/2010/03/android-play-pcmwav-audio-buffer-using.html的代码