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