# OpenSL ES

> phone | 2in1 | tablet | tv | wearable

> 说明
>
> HarmonyOS上的OpenSL ES接口，是早期SDK8版本开始提供，用于支持应用Native层音频开发的接口。但随着版本演进，接口定义的可扩展性不足，不再能满足音频系统的能力拓展，因此当前已不再推荐应用开发者继续使用此接口进行音频功能开发。请开发者[从OpenSL ES切换到OHAudio](https://developer.huawei.com/consumer/cn/doc/harmonyos-guides/replace-opensles-by-ohaudio)。

## 简介

OpenSL ES（Open Sound Library for Embedded Systems）即嵌入式音频加速标准。为开发者提供了标准化、高性能以及低响应时间的音频功能开发的对象和接口。相对于开源免费的OpenSL ES，HarmonyOS基于[OpenSL ES](https://www.khronos.org/opensles/) 1.0.1 API规范实现了部分Native API，相关接口开放情况如表[支持的API](#支持的api)所示。

## 引入OpenSL ES能力

如果开发者需要使用OpenSL ES相关功能，首先请添加头文件：

    #include <SLES/OpenSLES.h>
    #include <SLES/OpenSLES_OpenHarmony.h>
    #include <SLES/OpenSLES_Platform.h>

其次在CMakeLists.txt中添加以下链接动态库：

    libOpenSLES.so

## 支持的API

|对象|对外接口|接口调用详情|是否支持|说明|
|:-----------------|:-------------------|:-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|:---|:---------------|
|SLEngineItf|CreateAudioPlayer|CreateAudioPlayer(SLEngineItf self, SLObjectItf *pPlayer, SLDataSource *pAudioSrc, SLDataSink *pAudioSnk, SLuint32 numInterfaces, const SLInterfaceID *pInterfaceIds, const SLboolean *pInterfaceRequired)|是|创建音频播放机。|
|SLEngineItf|CreateAudioRecorder|CreateAudioRecorder(SLEngineItf self, SLObjectItf *pRecorder, SLDataSource *pAudioSrc, SLDataSink *pAudioSnk, SLuint32 numInterfaces, const SLInterfaceID *pInterfaceIds, const SLboolean *pInterfaceRequired)|是|创建音频录制器。|
|SLEngineItf|CreateAudioOutputMix|CreateOutputMix(SLEngineItf self, SLObjectItf *pMix, SLuint32 numInterfaces, const SLInterfaceID *pInterfaceIds, const SLboolean *pInterfaceRequired)|是|创建混音器。|
|SLObjectItf|Realize|Realize(SLObjectItf self, SLboolean async)|是|创建音频播放机。|
|SLObjectItf|getState|GetState(SLObjectItf self, SLuint32 *pState)|是|获取状态。|
|SLObjectItf|getInterface|GetInterface(SLObjectItf self, const SLInterfaceID iid, void *pInterface)|是|获取接口。|
|SLObjectItf|Destroy|Destroy(SLObjectItf self)|是|销毁对象。|
|SLOHBufferQueueItf|Enqueue|Enqueue(SLOHBufferQueueItf self, const void *pBuffer, SLuint32 size)|是|将buffer加入实际队列中。|
|SLOHBufferQueueItf|clear|Clear(SLOHBufferQueueItf self)|是|释放buffer队列|
|SLOHBufferQueueItf|getState|GetState(SLOHBufferQueueItf self, SLOHBufferQueueState *pState)|是|获取BufferQueue状态。|
|SLOHBufferQueueItf|getBuffer|GetBuffer(SLOHBufferQueueItf self, SLuint8 **buffer, SLuint32 *size)|是|获取buffer。|
|SLOHBufferQueueItf|RegisterCallback|RegisterCallback(SLOHBufferQueueItf self, SlOHBufferQueueCallback callback, void *pContext)|是|注册回调函数。|
|SLPlayItf|SetPlayState|SetPlayState(SLPlayItf self, SLuint32 state)|是|设置播放状态。|
|SLPlayItf|GetPlayState|GetPlayState(SLPlayItf self, SLuint32 *pState)|是|获取播放状态。|
|SLRecordItf|SetRecordState|SetRecordState(SLRecordItf self, SLuint32 state)|是|设置录制状态。|
|SLRecordItf|GetRecordState|GetRecordState(SLRecordItf self, SLuint32 *pState)|是|获取录制状态。|
|SLVolumeItf|SetVolumeLevel|SetVolumeLevel(SLVolumeItf self, SLmillibel level)|是|设置音量。|
|SLVolumeItf|GetVolumeLevel|GetVolumeLevel(SLVolumeItf self, SLmillibel *pLevel)|是|获取音量。|
|SLVolumeItf|GetMaxVolumeLevel|GetMaxVolumeLevel(SLVolumeItf self, SLmillibel *pMaxLevel)|是|获取最大音量。|