OpenSL ES音频库学习

	SLObjectItf engineObject;           //引擎始祖对象
    SLEngineItf engineInterface;        //引擎接口
	slCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL);
    (*engineObject)->Realize(engineObject, SL_BOOLEAN_FALSE);
    (*engineObject)->GetInterface(engineObject, SL_IID_ENGINE, &engineInterface);

typedef struct SLDataSource_ {
	void *pLocator;			//输入数据类别
	void *pFormat;			//输入数据格式
} SLDataSource;

typedef struct SLDataSink_ {
	void *pLocator;
	void *pFormat;
} SLDataSink;

SLDataLocator_Address
SLDataLocator_BufferQueue
SLDataLocator_IODevice
SLDataLocator_MIDIBufferQueue
SLDataLocator_URI

//录音源source
slHelper->ioDevice.locatorType = SL_DATALOCATOR_IODEVICE;       //源头是io设备
slHelper->ioDevice.deviceType = SL_IODEVICE_AUDIOINPUT;         //音频输入
slHelper->ioDevice.deviceID = SL_DEFAULTDEVICEID_AUDIOINPUT;
slHelper->ioDevice.device = NULL;           //device ID生效的前提必须device NULL

//输出
queue.locatorType = SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE;  //输出到缓冲队列
queue.numBuffers = 2;     //2个缓冲队列

pcmFormat.formatType = SL_DATAFORMAT_PCM;     //录音数据格式
pcmFormat.numChannels = channels;
pcmFormat.samplesPerSec = sampleRate;
pcmFormat.bitsPerSample = SL_PCMSAMPLEFORMAT_FIXED_16;        //每个采样点bit
pcmFormat.containerSize = SL_PCMSAMPLEFORMAT_FIXED_16;
pcmFormat.channelMask = getChannelMask(channels);             //根据声道数确定掩码
pcmFormat.endianness = SL_BYTEORDER_LITTLEENDIAN;             //字节小端模式

sink.pLocator = &(queue);
sink.pFormat = &(pcmFormat);

///Recorder/////
SLInterfaceID id[] = {SL_IID_ANDROIDSIMPLEBUFFERQUEUE};
SLboolean required[] = {SL_BOOLEAN_TRUE};

(*engineInterface)->CreateAudioRecorder(engineInterface, &recorderObject
                          , &source, &sink, 1, id, required);
(*recorderObject)->Realize(recorderObject, SL_BOOLEAN_FALSE);

//Register
(*recorderObject)->GetInterface(recorderObject, SL_IID_ANDROIDSIMPLEBUFFERQUEUE,
                              &(androidBufferQueueItf));

(*androidBufferQueueItf)->RegisterCallback(androidBufferQueueItf, openSLCallBack, NULL);

//start recorder
(*recorderObject)->GetInterface(recorderObject, SL_IID_RECORD, &recorderInterface);
(*recorderInterface)->SetRecordState(recorderInterface, SL_RECORDSTATE_RECORDING);