OpenSL ES

NOTE

OpenHarmony provides the OpenSL ES APIs for audio development at the native layer since SDK 8. As the version evolves, these APIs fail to meet the capability expansion requirements of the audio system and therefore are no longer recommended. Switch from OpenSL ES to OHAudio.

Introduction

Open Sound Library for Embedded Systems (OpenSL ES) is a set of audio acceleration standards for embedded systems. It provides objects and APIs for developers to implement high-performance, low-latency audio features. OpenHarmony implements some native APIs based on OpenSL ES 1.0.1 API specifications. The table Supported APIs list these APIs.

Introducing OpenSL ES

To use OpenSL ES capabilities, include the following header files:

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

Add the following dynamic link library to CMakeLists.txt:

libOpenSLES.so

Supported APIs

Object	External Interface	Interface Invocation	Supported	Description
SLEngineItf	CreateAudioPlayer	CreateAudioPlayer(SLEngineItf self, SLObjectItf pPlayer, SLDataSource pAudioSrc, SLDataSink pAudioSnk, SLuint32 numInterfaces, const SLInterfaceID pInterfaceIds, const SLboolean *pInterfaceRequired)	Yes	Creates an audio player.
SLEngineItf	CreateAudioRecorder	reateAudioRecorder(SLEngineItf self, SLObjectItf pRecorder, SLDataSource pAudioSrc, SLDataSink pAudioSnk, SLuint32 numInterfaces, const SLInterfaceID pInterfaceIds, const SLboolean *pInterfaceRequired)	Yes	Creates an audio recorder.
SLEngineItf	CreateAudioOutputMix	CreateOutputMix(SLEngineItf self, SLObjectItf pMix, SLuint32 numInterfaces, const SLInterfaceID pInterfaceIds, const SLboolean *pInterfaceRequired)	Yes	Creates an audio output mixer.
SLObjectItf	Realize	Realize(SLObjectItf self, SLboolean async)	Yes	Realizes an audio player.
SLObjectItf	getState	GetState(SLObjectItf self, SLuint32 *pState)	Yes	Obtains the state.
SLObjectItf	getInterface	GetInterface(SLObjectItf self, const SLInterfaceID iid, void *pInterface)	Yes	Obtains the interface.
SLObjectItf	Destroy	Destroy(SLObjectItf self)	Yes	Destroys an object.
SLOHBufferQueueItf	Enqueue	Enqueue(SLOHBufferQueueItf self, const void *pBuffer, SLuint32 size)	Yes	Adds a buffer to the queue.
SLOHBufferQueueItf	clear	Clear(SLOHBufferQueueItf self)	Yes	Releases the buffer queue.
SLOHBufferQueueItf	getState	GetState(SLOHBufferQueueItf self, SLOHBufferQueueState *pState)	Yes	Obtains the BufferQueue status.
SLOHBufferQueueItf	getBuffer	GetBuffer(SLOHBufferQueueItf self, SLuint8 *buffer, SLuint32 size)	Yes	Obtains a buffer.
SLOHBufferQueueItf	RegisterCallback	RegisterCallback(SLOHBufferQueueItf self, SlOHBufferQueueCallback callback, void *pContext)	Yes	Registers a callback.
SLPlayItf	SetPlayState	SetPlayState(SLPlayItf self, SLuint32 state)	Yes	Sets the playback state.
SLPlayItf	GetPlayState	GetPlayState(SLPlayItf self, SLuint32 *pState)	Yes	Obtains the playback state.
SLRecordItf	SetRecordState	SetRecordState(SLRecordItf self, SLuint32 state)	Yes	Sets the recording state.
SLRecordItf	GetRecordState	GetRecordState(SLRecordItf self, SLuint32 *pState)	Yes	Obtains the recording state.
SLVolumeItf	SetVolumeLevel	SetVolumeLevel(SLVolumeItf self, SLmillibel level)	Yes	Sets the volume.
SLVolumeItf	GetVolumeLevel	GetVolumeLevel(SLVolumeItf self, SLmillibel *pLevel)	Yes	Obtains the volume.
SLVolumeItf	GetMaxVolumeLevel	GetMaxVolumeLevel(SLVolumeItf self, SLmillibel *pMaxLevel)	Yes	Obtains the maximum volume.