项目地址
https://github.com/979451341/OpenSLAudio
OpenSL ES 是基于NDK也就是c语言的底层开发音频的公开API,通过使用它能够做到标准化, 高性能,低响应时间的音频功能实现方法。
这次是使用OpenSL ES来做一个音乐播放器,它能够播放m4a、mp3文件,并能够暂停和调整音量
播放音乐需要做一些步骤
3.设置播放缓冲
7.调解音量
http://blog.csdn.net/u013898698/article/details/72822595
http://blog.csdn.net/ywl5320/article/details/78503768
https://github.com/979451341/OpenSLAudio
OpenSL ES 是基于NDK也就是c语言的底层开发音频的公开API,通过使用它能够做到标准化, 高性能,低响应时间的音频功能实现方法。
这次是使用OpenSL ES来做一个音乐播放器,它能够播放m4a、mp3文件,并能够暂停和调整音量
播放音乐需要做一些步骤
1.创建声音引擎
首先创建声音引擎的对象接口
result = slCreateEngine(&engineObject, 0, NULL, 0, NULL, NULL);
然后实现它
result = (*engineObject)->Realize(engineObject, SL_BOOLEAN_FALSE);
从声音引擎的对象中抓取声音引擎
result = (*engineObject)->GetInterface(engineObject, SL_IID_ENGINE, &engineEngine);
创建"输出混音器"
result = (*engineEngine)->CreateOutputMix(engineEngine, &outputMixObject, 1, ids, req);
实现输出混合音
result = (*outputMixObject)->Realize(outputMixObject, SL_BOOLEAN_FALSE);
2.创建声音播放器
创建和实现播放器
// realize the player result = (*bqPlayerObject)->Realize(bqPlayerObject, SL_BOOLEAN_FALSE);
assert(SL_RESULT_SUCCESS == result);
(void)result;
// get the play interface
result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_PLAY, &bqPlayerPlay);
assert(SL_RESULT_SUCCESS == result);
(void)result;
3.设置播放缓冲
数据格式配置
SLDataFormat_PCM format_pcm = {SL_DATAFORMAT_PCM, 1, SL_SAMPLINGRATE_8, SL_PCMSAMPLEFORMAT_FIXED_16, SL_PCMSAMPLEFORMAT_FIXED_16, SL_SPEAKER_FRONT_CENTER, SL_BYTEORDER_LITTLEENDIAN};数据定位器 就是定位要播放声音数据的存放位置,分为4种:内存位置,输入/输出设备位置,缓冲区队列位置,和midi缓冲区队列位置。
数据定位器配置
SLDataLocator_AndroidSimpleBufferQueue loc_bufq = {SL_DATALOCATOR_ANDROIDSIMPLEBUFFERQUEUE, 2};
得到了缓存队列接口,并注册
// get the buffer queue interface result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_BUFFERQUEUE, &bqPlayerBufferQueue); assert(SL_RESULT_SUCCESS == result); (void)result; // register callback on the buffer queue result = (*bqPlayerBufferQueue)->RegisterCallback(bqPlayerBufferQueue, bqPlayerCallback, NULL); assert(SL_RESULT_SUCCESS == result); (void)result;
4.获得其他接口用来控制播放
得到声音特效接口
// get the effect send interface result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_EFFECTSEND, &bqPlayerEffectSend); assert(SL_RESULT_SUCCESS == result); (void)result;
得到音量接口
// get the volume interface result = (*bqPlayerObject)->GetInterface(bqPlayerObject, SL_IID_VOLUME, &bqPlayerVolume); assert(SL_RESULT_SUCCESS == result); (void)result; // set the player's state to playing result = (*bqPlayerPlay)->SetPlayState(bqPlayerPlay, SL_PLAYSTATE_PLAYING); assert(SL_RESULT_SUCCESS == result); (void)result;
5.提供播放数据
打开音乐文件
// convert Java string to UTF-8 const char *utf8 = (*env)->GetStringUTFChars(env, filename, NULL); assert(NULL != utf8); // use asset manager to open asset by filename AAssetManager* mgr = AAssetManager_fromJava(env, assetManager); assert(NULL != mgr); AAsset* asset = AAssetManager_open(mgr, utf8, AASSET_MODE_UNKNOWN); // release the Java string and UTF-8 (*env)->ReleaseStringUTFChars(env, filename, utf8); // the asset might not be found if (NULL == asset) { return JNI_FALSE; } // open asset as file descriptor off_t start, length; int fd = AAsset_openFileDescriptor(asset, &start, &length); assert(0 <= fd); AAsset_close(asset);
设置播放数据
SLDataLocator_AndroidFD loc_fd = {SL_DATALOCATOR_ANDROIDFD, fd, start, length}; SLDataFormat_MIME format_mime = {SL_DATAFORMAT_MIME, NULL, SL_CONTAINERTYPE_UNSPECIFIED}; SLDataSource audioSrc = {&loc_fd, &format_mime};
6.播放音乐
播放音乐只需要通过播放接口改变播放状态就可以了,暂停也是,停止也是,但是暂停必须之前的播放缓存做了才行,否则那暂停就相当于停止了
result = (*fdPlayerPlay)->SetPlayState(fdPlayerPlay, isPlaying ? SL_PLAYSTATE_PLAYING : SL_PLAYSTATE_PAUSED);
7.调解音量
SLVolumeItf getVolume(){ if (fdPlayerVolume != NULL) return fdPlayerVolume; else return bqPlayerVolume;}void Java_com_ywl5320_openslaudio_MainActivity_setVolumeAudioPlayer(JNIEnv* env, jclass clazz, jint millibel){ SLresult result; SLVolumeItf volumeItf = getVolume(); if (NULL != volumeItf) { result = (*volumeItf)->SetVolumeLevel(volumeItf, millibel); assert(SL_RESULT_SUCCESS == result); (void)result; }}
8.释放资源
关闭app时释放占用资源
void Java_com_ywl5320_openslaudio_MainActivity_shutdown(JNIEnv* env, jclass clazz){ // destroy buffer queue audio player object, and invalidate all associated interfaces if (bqPlayerObject != NULL) { (*bqPlayerObject)->Destroy(bqPlayerObject); bqPlayerObject = NULL; bqPlayerPlay = NULL; bqPlayerBufferQueue = NULL; bqPlayerEffectSend = NULL; bqPlayerMuteSolo = NULL; bqPlayerVolume = NULL; } // destroy file descriptor audio player object, and invalidate all associated interfaces if (fdPlayerObject != NULL) { (*fdPlayerObject)->Destroy(fdPlayerObject); fdPlayerObject = NULL; fdPlayerPlay = NULL; fdPlayerSeek = NULL; fdPlayerMuteSolo = NULL; fdPlayerVolume = NULL; } // destroy output mix object, and invalidate all associated interfaces if (outputMixObject != NULL) { (*outputMixObject)->Destroy(outputMixObject); outputMixObject = NULL; outputMixEnvironmentalReverb = NULL; } // destroy engine object, and invalidate all associated interfaces if (engineObject != NULL) { (*engineObject)->Destroy(engineObject); engineObject = NULL; engineEngine = NULL; }}参考文章
http://blog.csdn.net/u013898698/article/details/72822595
http://blog.csdn.net/ywl5320/article/details/78503768