android AudioRecorder简略心得

1.如何创建一个有效的AudioRecorder实例

Android各种设备的采样频率不同，输入的声道数也不同，如果采用固定的采样频率和声道数，那么得到的AudioRecorder不一定能够正常初始化。

为了正常使用，需要尝试各种不同的参数，得到在此设备上可以用的AudioRecorder实例。代码如下：

    private void createAudioRecord() {               for (int sampleRate : new int[]{44100, 8000, 11025, 16000, 22050, 32000,                47250, 48000}) {            for (short audioFormat : new short[]{                    AudioFormat.ENCODING_PCM_16BIT,                    AudioFormat.ENCODING_PCM_8BIT}) {                for (short channelConfig : new short[]{                        AudioFormat.CHANNEL_IN_MONO,                        AudioFormat.CHANNEL_IN_STEREO}) {                    // Try to initialize                    try {                        recBufSize = AudioRecord.getMinBufferSize(sampleRate,                                channelConfig, audioFormat);                        if (recBufSize < 0) {                            continue;                        }                        audioRecord = new AudioRecord(MediaRecorder.AudioSource.MIC,                                sampleRate, channelConfig, audioFormat,                                recBufSize * 2);                        if (audioRecord.getState() == AudioRecord.STATE_INITIALIZED) {                                                        return;                        }                        audioRecord.release();                        audioRecord = null;                    } catch (Exception e) {                        // Do nothing                    }                }            }        }        throw new IllegalStateException(                "getInstance() failed : no suitable audio configurations on this device.");    }

2.常见错误