​ OpenSL ES 是无授权费、跨平台、针对嵌入式系统精心优化的硬件音频加速API。该库都允许使用C或C ++来实现高性能，低延迟的音频操作。 ​ Android的OpenSL ES库同样位于NDK的platforms文件夹内。关于OpenSL ES的使用可以进入ndk-sample查看native-audio工程:https://github.com/googlesamples/android-ndk/blob/master/native-audio/app/src/main/cpp/native-audio-jni.c OpenSL ES的开发流程主要有如下7个步骤： ​ 1、创建接口对象 ​ 2、设置混音器 ​ 3、创建播放器 ​ 4、设置播放回调函数 ​ 5、设置播放状态 ​ 6、启动回调函数 ​ 7、释放 1、创建引擎与接口 SLresult result; // 创建引擎 SLObjectItf engineObject result = slCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL); if (SL_RESULT_SUCCESS != result) { return; } // 初始化引擎 result = (*engineObject)->Realize(engineObject, SL_BOOLEAN_FALSE); if (SL_RESULT_SUCCESS != result) { return; } // 获取引擎接口SLEngineItf engineInterface result = (*engineObject)->GetInterface(engineObject, SL_IID_ENGINE, &engineInterface); if (SL_RESULT_SUCCESS != result) { return; }

2、设置混音器 // 创建混音器SLObjectItf outputMixObject result = (*engineInterface)->CreateOutputMix(engineInterface, &outputMixObject, 0, 0, 0); if (SL_RESULT_SUCCESS != result) { return; } // 初始化混音器outputMixObject result = (*outputMixObject)->Realize(outputMixObject, SL_BOOLEAN_FALSE); if (SL_RESULT_SUCCESS != result) { return; }

//不启用混响可以不用获取接口
// 获得混音器接口
//result = (*outputMixObject)->GetInterface(outputMixObject, SL_IID_ENVIRONMENTALREVERB,
 //                                         &outputMixEnvironmentalReverb);
//if (SL_RESULT_SUCCESS == result) {
    //设置混响 ： 默认。
    //SL_I3DL2_ENVIRONMENT_PRESET_ROOM: 室内
    //SL_I3DL2_ENVIRONMENT_PRESET_AUDITORIUM : 礼堂 等
    //const SLEnvironmentalReverbSettings settings = SL_I3DL2_ENVIRONMENT_PRESET_DEFAULT;
    //(*outputMixEnvironmentalReverb)->SetEnvironmentalReverbProperties(
     //       outputMixEnvironmentalReverb, &settings);
//}

3、创建播放器 /** * 配置输入声音信息 */ //创建buffer缓冲类型的队列 2个队列 SLDataLocator_AndroidSimpleBufferQueue android_queue = {SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE,2}; //pcm数据格式 SLDataFormat_PCM pcm = {SL_DATAFORMAT_PCM, 2, SL_SAMPLINGRATE_44_1, SL_PCMSAMPLEFORMAT_FIXED_16, SL_PCMSAMPLEFORMAT_FIXED_16, SL_SPEAKER_FRONT_LEFT | SL_SPEAKER_FRONT_RIGHT, SL_BYTEORDER_LITTLEENDIAN};

//数据源 将上述配置信息放到这个数据源中
SLDataSource slDataSource = {&android_queue, &pcm};


//设置混音器
SLDataLocator_OutputMix outputMix = {SL_DATALOCATOR_OUTPUTMIX, outputMixObject};
SLDataSink audioSnk = {&outputMix, NULL};
//需要的接口
const SLInterfaceID ids[1] = {SL_IID_BUFFERQUEUE};
const SLboolean req[1] = {SL_BOOLEAN_TRUE};
//创建播放器
(*engineInterface)->CreateAudioPlayer(engineInterface, &bqPlayerObject, &slDataSource,
                                   &audioSnk, 1,
                                   ids, req);
//初始化播放器
(*bqPlayerObject)->Realize(bqPlayerObject, SL_BOOLEAN_FALSE);

// 得到接口后调用 获取Player接口 (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_PLAY, &bqPlayerInterface);

4、设置播放回调 //获取播放器队列接口 (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_BUFFERQUEUE, &bqPlayerBufferQueue); //设置回调 (*bqPlayerBufferQueue)->RegisterCallback(bqPlayerBufferQueue, bqPlayerCallback, this);

5、设置播放状态 // 设置播放状态 (*bqPlayerInterface)->SetPlayState(bqPlayerInterface, SL_PLAYSTATE_PLAYING);

6、启动回调函数 bqPlayerCallback(bqPlayerBufferQueue, this);

7、释放 //设置停止状态 if (bqPlayerInterface) { (*bqPlayerInterface)->SetPlayState(bqPlayerInterface, SL_PLAYSTATE_STOPPED); bqPlayerInterface = 0; } //销毁播放器 if (bqPlayerObject) { (*bqPlayerObject)->Destroy(bqPlayerObject); bqPlayerObject = 0; bqPlayerBufferQueue = 0; } //销毁混音器 if (outputMixObject) { (*outputMixObject)->Destroy(outputMixObject); outputMixObject = 0; } //销毁引擎 if (engineObject) { (*engineObject)->Destroy(engineObject); engineObject = 0; engineInterface = 0; }