Question

当我使用以下代码播放文件时：

private void PlayAudioFileViaAudioTrack(int ResId) throws IOException {

    int intSize = android.media.AudioTrack.getMinBufferSize(11025, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);

    AudioTrack at = new AudioTrack(AudioManager.STREAM_MUSIC, 11025, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, intSize,
            AudioTrack.MODE_STREAM);

    int count = 256 * 1024; // 256 kb
    byte[] byteData = null;
    byteData = new byte[(int) count];
    InputStream in = null;
    AssetFileDescriptor fd = null;
    fd = mResources.openRawResourceFd(ResId);
    in = mResources.openRawResource(ResId);

    int bytesRead = 0, amount = 0;
    int size = (int) fd.getLength();
    at.play();
    while (bytesRead < size) {
        amount = in.read(byteData, 0, count);
        if (amount != -1) {
            at.write(byteData, 0, amount);
        }
    }
    in.close();
    at.stop();
    at.release();

}

我唯一听到的是静电，白噪声。我检查过我的.wav文件具有相同的属性（samplerate，bitrate）。我不太了解原始音频数据（PCM），所以我想知道是否有人能看到我的代码有什么问题。

Answer 1

从您的代码

我可以看到您只是从wav文件中读取数据并将它们导入AudioTrack。您可以在此处看到Wav文件有一个小标题https://ccrma.stanford.edu/courses/422/projects/WaveFormat/因此您必须跳过标题并将文件描述符指向实际音频数据所在的正确位置。

当您播放音频文件并处理字节操作时，您应该处理Endianess。看看Using AudioTrack in Android to play a WAV file

在我的代码下面（缺少一些检查和WAV标题跳过），在Nexus One和Galaxy S中均可使用频率为8000Hz和16位编码的wav文件。

public void playWav(){
    int minBufferSize = AudioTrack.getMinBufferSize(8000, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT);
    int bufferSize = 512;
    AudioTrack at = new AudioTrack(AudioManager.STREAM_MUSIC, 8000, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, minBufferSize, AudioTrack.MODE_STREAM);
    String filepath = Environment.getExternalStorageDirectory().getAbsolutePath();

    int i = 0;
    byte[] s = new byte[bufferSize];
    try {
        FileInputStream fin = new FileInputStream(filepath + "/REFERENCE.wav");
        DataInputStream dis = new DataInputStream(fin);

        at.play();
        while((i = dis.read(s, 0, bufferSize)) > -1){
            at.write(s, 0, i);

        }
        at.stop();
        at.release();
        dis.close();
        fin.close();

    } catch (FileNotFoundException e) {
        // TODO
        e.printStackTrace();
    } catch (IOException e) {
        // TODO
        e.printStackTrace();
    }       
}

Answer 2

看起来比我做的更复杂。我用这个播放了声音。我认为.wav文件也可以正常工作。

MediaPlayer mpPlayProgram = new MediaPlayer();
mpPlayProgram.setDataSource("/sdcard/file.mp3");
mpPlayProgram.prepare();
mpPlayProgram.start();
mpPlayProgram.release();

对于静态资源，它更容易：

MediaPlayer mpStart = MediaPlayer.create(this, resID);
mpStart.start();
mpStart.release();

Answer 3

如果您已保存wav格式的文件并希望使用AudioTrack播放，请遵循以下代码：

             File file=new File(Environment.getExternalStorageDirectory()+"/AudioRecorder/fahim.wav");

               InputStream is;
             DataInputStream         dis = null ;
             BufferedInputStream     bis;

            try 
            {
                is = new FileInputStream(file);
                bis = new BufferedInputStream(is, 8000);
                dis  = new DataInputStream(bis);      //  Create a DataInputStream to read the audio data from the saved file

            }
            catch (FileNotFoundException e1) 
            {
                ShowToast("fILE NOT FOUND:"+e1.getMessage());
            }

            int i = 0;                                                          //  Read the file into the "music" array
            music=new byte[(int) file.length()];
            try 
            {
                while (dis.available() > 0)
                {
                    music[i] = dis.readByte();                                      //  This assignment does not reverse the order
                    i++;
                }
            } 
            catch (IOException e) 
            {
                ShowToast("I/O Exception:"+e.getMessage());
            }

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

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

            AudioTrack at = new AudioTrack(AudioManager.STREAM_MUSIC, 11025, AudioFormat.CHANNEL_CONFIGURATION_MONO, AudioFormat.ENCODING_PCM_16BIT, minBufferSize, AudioTrack.MODE_STREAM);
            at.play();

            ShowToast("size:"+music.length);
            //*/
            at.write(music, 0, music.length);

Android AudioTrack播放.wav文件，只获得白噪声

3 个答案: