AudioRecord：获取缓冲区超时

Question

我的应用程序经常出现以下错误：

09-25 15:52:24.875: E/AudioHardware(144): -----AudioStreamInALSA::read(0x42db0040, 512) END ERROR
09-25 15:52:24.875: E/AudioFlinger(144): Error reading audio input
09-25 15:52:24.882: D/AudioHardware(144): AudioStreamInALSA::setParameters() routing=0
09-25 15:52:25.394: W/AudioRecord(7359): obtainBuffer timed out (is the CPU pegged?) user=00000000, server=00000000
09-25 15:52:25.398: D/AudioHardware(144): AudioStreamInALSA::setParameters() input_source=1;routing=262144

我创建 AudioRecord 实例的代码是：

int minValue = AudioRecord.getMinBufferSize(sampleRate,
        AudioFormat.CHANNEL_IN_MONO, 
        AudioFormat.ENCODING_PCM_16BIT);

// Gets a buffer size that is greater than the minimun required and is multiple of the chunk size
BUFFER_SIZE_IN_BYTES = getBufferSizeInChunks(minValue);

AudioRecord audioRecord =  new AudioRecord(
        MediaRecorder.AudioSource.MIC,
        sampleRate,
        AudioFormat.CHANNEL_IN_MONO,
        AudioFormat.ENCODING_PCM_16BIT ,
        BUFFER_SIZE_IN_BYTES );

AudioRecord 实例如下：

@Override
public void run() {
    try{
        android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);

        recorder = initAudioRecord();
        if (recorder.getState() != AudioRecord.STATE_INITIALIZED) {
            return;
        }

        // Audio input buffer
        byte[] audio_data = new byte[BUFFER_SIZE_IN_BYTES];

        while (!Thread.interrupted() && keepRunning) {
            recorder.startRecording();
            recorder.read(audio_data, 0, BUFFER_SIZE_IN_BYTES);


            recorder.stop();

                // Here I deal with the audio_data ...

                // UI feedback
                PostToUI(frequency);

            }

    }
    catch(Exception e){
        e.printStackTrace();
    }
}

private void PostToUI(final double frequency) {
    handler.post(new Runnable() {
        public void run() {
            uiHandler.updateUi(frequency);
        }
    });
}

如图所示，一个单独的线程不断处理音频输入（只要不调用 Activity 的onPause()）

有人知道吗？

完整日志：

09-27 14:05:29.246: D/AudioHardware(144): AudioStreamInALSA::setParameters() input_source=1;routing=262144
09-27 14:05:29.246: V/AudioHardware(144): openMixer_l() mMixerOpenCnt: 0
09-27 14:05:29.246: V/AudioHardware(144): setInputSource_l(1)
09-27 14:05:29.246: V/AudioHardware(144): closeMixer_l() mMixerOpenCnt: 1
09-27 14:05:29.246: D/AudioHardware(144): AudioHardware pcm capture is exiting standby.
09-27 14:05:29.246: V/AudioHardware(144): AudioStreamInALSA exit standby mNeedEchoReference 0 mEchoReference 0x0
09-27 14:05:29.246: V/AudioHardware(144): open pcm_in driver
09-27 14:05:29.312: V/AudioHardware(144): openMixer_l() mMixerOpenCnt: 0
09-27 14:05:29.312: V/AudioHardware(144): read() wakeup setting route Main Mic
09-27 14:05:41.593: D/Finsky(12273): [1] 5.onFinished: Installation state replication succeeded.
09-27 14:05:49.332: W/AudioHardware(144): read error: -1
09-27 14:05:49.332: D/AudioHardware(144): AudioHardware pcm capture is going to standby.
09-27 14:05:49.332: V/AudioHardware(144): closeMixer_l() mMixerOpenCnt: 1
09-27 14:05:49.375: E/AudioHardware(144): -----AudioStreamInALSA::read(0x42b2d040, 512) END ERROR
09-27 14:05:49.375: E/AudioFlinger(144): Error reading audio input
09-27 14:05:49.386: D/AudioHardware(144): AudioStreamInALSA::setParameters() routing=0
09-27 14:05:49.906: W/AudioRecord(13013): obtainBuffer timed out (is the CPU pegged?) user=00000000, server=00000000
09-27 14:05:49.910: D/AudioHardware(144): AudioStreamInALSA::setParameters() input_source=1;routing=262144
09-27 14:05:49.914: V/AudioHardware(144): openMixer_l() mMixerOpenCnt: 0
09-27 14:05:49.914: V/AudioHardware(144): setInputSource_l(1)
09-27 14:05:49.914: V/AudioHardware(144): closeMixer_l() mMixerOpenCnt: 1
09-27 14:05:49.921: D/AudioHardware(144): AudioHardware pcm capture is exiting standby.
09-27 14:05:49.921: V/AudioHardware(144): AudioStreamInALSA exit standby mNeedEchoReference 0 mEchoReference 0x0
09-27 14:05:49.921: V/AudioHardware(144): open pcm_in driver
09-27 14:05:50.000: V/AudioHardware(144): openMixer_l() mMixerOpenCnt: 0

Answer 1

我有类似的问题。不幸的是，我不得不用 AudioRecord 创建多个线程，所以使用 while(recorder.getRecordingState() == AudioRecord.RECORDSTATE_RECORDING){ 没有帮助:(

最后我挖掘了这个话题：Android AudioRecord - Won't Initialize 2nd time 之后 audioRecord.release(); 工作正常 :)

也许它会在未来帮助某人......

Answer 2

有什么原因，为什么你不断地打开和关闭录音机？ 我会这样说：

    // Audio input buffer
    byte[] audio_data = new byte[BUFFER_SIZE_IN_BYTES];

    recorder.startRecording();
    while (!Thread.interrupted() && keepRunning) {
        recorder.read(audio_data, 0, BUFFER_SIZE_IN_BYTES);
            // Here I deal with the audio_data ...
            // UI feedback
            PostToUI(frequency);
    }
    recorder.stop();

我可以想象，记录器可以提供的不仅仅是缓冲区大小，但您总是只读取该数量的字节。

在我的应用程序中，我有一些方法可以从我的 run() 方法之外启动和停止记录器（我认为您在设置 keepRunning 时也这样做）。在其他地方停止录音机时，您 只需要像这样调整你的while循环：

while(recorder.getRecordingState() == AudioRecord.RECORDSTATE_RECORDING){