录音延迟 (Android) GT-i5700

Question

我在录制音频（实时监控）时有 0.3-0.5 秒的延迟。这是我的代码：

代码来自此处： Android - 通过耳机播放音频

public class Sounds extends Activity {

private boolean isRecording;
private AudioManager am;
private int count;

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

    am = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
    am.setMicrophoneMute(true);

    while(count <= 1000000){
    Record record = new Record();  
    record.run();
    count ++;
    Log.d("COUNT", "Count is : " + count);
    }
}

public class Record extends Thread
{

        static final int bufferSize = 200000;
        final short[] buffer = new short[bufferSize];
        short[] readBuffer = new short[bufferSize];

        public void run() {  
         isRecording = true;
         android.os.Process.setThreadPriority
         (android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);

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

                        AudioRecord arec = new AudioRecord(MediaRecorder.AudioSource.MIC,
                                        11025,
                                        AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                        AudioFormat.ENCODING_PCM_16BIT,
                                        buffersize);

                        AudioTrack atrack = new AudioTrack(AudioManager.STREAM_MUSIC,
                                        11025,
                                        AudioFormat.CHANNEL_CONFIGURATION_MONO,
                                        AudioFormat.ENCODING_PCM_16BIT,
                                        buffersize,
                                        AudioTrack.MODE_STREAM);


                        am.setRouting(AudioManager.MODE_NORMAL,1,
                          AudioManager.STREAM_MUSIC);


                        int ok = am.getRouting(AudioManager.ROUTE_EARPIECE);
                        Log.d("ROUTING", "getRouting = " + ok);
                        setVolumeControlStream(AudioManager.STREAM_VOICE_CALL);
                        //am.setSpeakerphoneOn(true);
                        Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
                        am.setSpeakerphoneOn(false);
                        Log.d("SPEAKERPHONE", "Is speakerphone on? : " + am.isSpeakerphoneOn());
                        atrack.setPlaybackRate(11025);

                        byte[] buffer = new byte[buffersize];
                        arec.startRecording();
                        atrack.play();

                        while(isRecording) {
                                arec.read(buffer, 0, buffersize);
                                atrack.write(buffer, 0, buffer.length);
                        }

                        arec.stop();
                        atrack.stop();
                        isRecording = false;
        }
} 

}

你能帮我吗？ （对不起我的英语）

Answer 1

据我了解，您想要实现更低的延迟吗？如果是这样，那么目前 Android 操作系统存在一个问题，即音频延迟可能相当高，这就是为什么您在市场上看不到很多实时音频应用程序的原因。 Android 4.0 规范允许低延迟音频，但在那之前，速度可能会很快。

参考第 5.4 节：
http:// /static.googleusercontent.com/external_content/untrusted_dlcp/source.android.com/en/us/compatibility/4.0/android-4.0-cdd.pdf