Android錄音機初始化失敗

Question

我嘗試使用如下所示的audiorecorder方法錄制聲音，在HTC nexus一個android 2.3上很好，但是當我在LG和Sony上使用andoid 4.0和4.1嘗試它時，它可以工作一次，下次嘗試時，它將在startRecording java.lang.IllegalStateException: startRecording() called on an uninitialized AudioRecord.拋出異常java.lang.IllegalStateException: startRecording() called on an uninitialized AudioRecord. 怎么了？

final int RECORDER_BPP = 16;
    int RECORDER_SAMPLERATE = 16000;
    int RECORDER_CHANNELS = AudioFormat.CHANNEL_IN_MONO;
    int RECORDER_AUDIO_ENCODING = AudioFormat.ENCODING_PCM_16BIT;
    int bufferSizeInBytes = AudioRecord
            .getMinBufferSize(RECORDER_SAMPLERATE, RECORDER_CHANNELS,
                    RECORDER_AUDIO_ENCODING);
    // Initialize Audio Recorder.
    AudioRecord audioRecorder = new AudioRecord(
            MediaRecorder.AudioSource.MIC, RECORDER_SAMPLERATE,
            RECORDER_CHANNELS, RECORDER_AUDIO_ENCODING, bufferSizeInBytes);

    audioRecorder.startRecording();

Answer 1

不同的設備僅支持AudioRecord某些設置。 有一項功能可以讓您檢測特定設備支持哪些設置。

private static int[] mSampleRates = new int[]{44100, 22050, 11025, 8000};

    public AudioRecord findAudioRecord() {
        for (int rate : mSampleRates) {
            for (short audioFormat : new short[]{AudioFormat.ENCODING_PCM_8BIT, AudioFormat.ENCODING_PCM_16BIT}) {
                for (short channelConfig : new short[]{AudioFormat.CHANNEL_IN_MONO, AudioFormat.CHANNEL_IN_STEREO}) {
                    try {
                        Log.d(TAG, "Attempting rate " + rate + "Hz, bits: " + audioFormat + ", channel: " + channelConfig);
                        int bufferSize = AudioRecord.getMinBufferSize(rate, channelConfig, audioFormat);

                        if (bufferSize != AudioRecord.ERROR_BAD_VALUE) {
                            // check if we can instantiate and have a success
                            AudioRecord recorder = new AudioRecord(MediaRecorder.AudioSource.DEFAULT, rate, channelConfig, audioFormat, bufferSize);

                            if (recorder.getState() == AudioRecord.STATE_INITIALIZED) {
                                return recorder;
                            }
                        }
                    } catch (Exception e) {
                        Log.e(TAG, rate + "Exception, keep trying.", e);
                    }
                }
            }
        }
        return null;
    }

它會運行所有可用音頻格式設置的組合，並首先返回與您的設備能力匹配的內容。
您可以小幅修改它，甚至獲得設備支持的所有格式。

Answer 2

問題是由於未使用release（），因此在停止記錄器后應將其釋放，以便可以多次使用記錄器。