android - 如何在 Android 中使用音频 api 录制音频？

Question

我有一部版本为 2.3.3 的 LG Android 手机。我需要在耳机插孔中连接一个麦克风，因为我想创建一个读取声音样本的应用程序。

如何以编程方式读取样本？

Answer 1

如果您真的想阅读 AudioSamples，我建议您使用 AudioRecord 而不是 MediaRecorder，因为它可以让您更好地控制 AudioSamples... 为此，您可以使用以下代码，AudioCapturer 是我的包装类，我用它来获取来自 AudioRecord 对象的样本。IAudioReceiver 是一个具有处理音频数据方法的接口(interface)。

public class AudioCapturer implements Runnable {

    private AudioRecord audioRecorder = null;
    private int bufferSize;
    private int samplePerSec = 16000;
    private String LOG_TAG = "AudioCapturer";
    private Thread thread = null;

    private boolean isRecording;
    private static AudioCapturer audioCapturer;

    private IAudioReceiver iAudioReceiver;

    private AudioCapturer(IAudioReceiver audioReceiver) {
        this.iAudioReceiver = audioReceiver;
    }

    public static AudioCapturer getInstance(IAudioReceiver audioReceiver) {
        if (audioCapturer == null) {
            audioCapturer = new AudioCapturer(audioReceiver);
        }
        return audioCapturer;
    }

    public void start() {

        bufferSize = AudioRecord.getMinBufferSize(samplePerSec, AudioFormat.CHANNEL_IN_MONO, AudioFormat.ENCODING_PCM_16BIT);

        if (bufferSize != AudioRecord.ERROR_BAD_VALUE && bufferSize != AudioRecord.ERROR) {

            audioRecorder = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, this.samplePerSec, AudioFormat.CHANNEL_IN_MONO,
                    AudioFormat.ENCODING_PCM_16BIT, this.bufferSize * 10); // bufferSize
                                                                            // 10x

            if (audioRecorder != null && audioRecorder.getState() == AudioRecord.STATE_INITIALIZED) {
                Log.i(LOG_TAG, "Audio Recorder created");


                audioRecorder.startRecording();
                isRecording = true;
                thread = new Thread(this);
                thread.start();

            } else {
                Log.e(LOG_TAG, "Unable to create AudioRecord instance");
            }

        } else {
            Log.e(LOG_TAG, "Unable to get minimum buffer size");
        }
    }

    public void stop() {
        isRecording = false;
        if (audioRecorder != null) {
            if (audioRecorder.getRecordingState() == AudioRecord.RECORDSTATE_RECORDING) {
                // System.out
                // .println("Stopping the recorder inside AudioRecorder");
                audioRecorder.stop();
            }
            if (audioRecorder.getState() == AudioRecord.STATE_INITIALIZED) {
                audioRecorder.release();
            }
        }
    }

    public boolean isRecording() {
        return (audioRecorder != null) ? (audioRecorder.getRecordingState() == AudioRecord.RECORDSTATE_RECORDING) : false;
    }

    @Override
    public void run() {
        android.os.Process.setThreadPriority(android.os.Process.THREAD_PRIORITY_URGENT_AUDIO);  
        while (isRecording && audioRecorder.getRecordingState() == AudioRecord.RECORDSTATE_RECORDING) {
            short[] tempBuf = new short[Constants.FRAME_SIZE / 2];
            audioRecorder.read(tempBuf, 0, tempBuf.length);     
            iAudioReceiver.capturedAudioReceived(tempBuf, false);
        }
    }

    /*
     * (non-Javadoc)
     * 
     * @see java.lang.Object#finalize()
     */
    @Override
    protected void finalize() throws Throwable {
        super.finalize();
        System.out.println("AudioCapturer finalizer");
        if (audioRecorder != null && audioRecorder.getState() == AudioRecord.STATE_INITIALIZED) {
            audioRecorder.stop();
            audioRecorder.release();
        }
        audioRecorder = null;
            iAudioReceiver = null;  
        thread = null;
    }

}

现在您可以在您的程序的主类中使用此类的对象，它会开始为您提供音频样本，您可以在 IAudioReceiver(使用这些样本的类)中处理它们。

如果您仍想使用 MediaRecorder，this link对你有用，