音视频开发-AVAudioSession错误

[aurioc] 1029: failed: ‘!pri’ (enable 2, outf< 2 ch, 44100 Hz, Float32, non-inter> inf< 2 ch, 0 Hz, Float32, non-inter>)
[aurioc] 1029: failed: ‘!int’ (enable 2, outf< 2 ch, 44100 Hz, Float32, non-inter> inf< 2 ch, 0 Hz, Float32, non-inter>)

常见错误如上，alcOpenDevice(NULL);接口产生的错误，获取不到当前device

/*!
	@enum AVAudioSession error codes
	@abstract   These are the error codes returned from the AVAudioSession API.
	@constant   AVAudioSessionErrorCodeNone
		Operation succeeded.
	@constant   AVAudioSessionErrorCodeMediaServicesFailed
		The app attempted to use the audio session during or after a Media Services failure.  App should
 		wait for a AVAudioSessionMediaServicesWereResetNotification and then rebuild all its state.
	@constant	AVAudioSessionErrorCodeIsBusy
 		The app attempted to set its audio session inactive or change its AVAudioSessionIOType, but it is still actively playing and/or recording.
 	@constant	AVAudioSessionErrorCodeIncompatibleCategory
 		The app tried to perform an operation on a session but its category does not support it.
 		For instance, if the app calls setPreferredInputNumberOfChannels: while in a playback-only category.
	@constant	AVAudioSessionErrorCodeCannotInterruptOthers
		The app's audio session is non-mixable and trying to go active while in the background.
 		This is allowed only when the app is the NowPlaying app.
	@constant	AVAudioSessionErrorCodeMissingEntitlement
		The app does not have the required entitlements to perform an operation.
	@constant	AVAudioSessionErrorCodeSiriIsRecording
 		The app tried to do something with the audio session that is not allowed while Siri is recording.
 	@constant	AVAudioSessionErrorCodeCannotStartPlaying
		The app is not allowed to start recording and/or playing, usually because of a lack of audio key in
 		its Info.plist.  This could also happen if the app has this key but uses a category that can't record 
 		and/or play in the background (AVAudioSessionCategoryAmbient, AVAudioSessionCategorySoloAmbient, etc.).
	@constant	AVAudioSessionErrorCodeCannotStartRecording
		The app is not allowed to start recording, usually because it is starting a mixable recording from the
 		background and is not an Inter-App Audio app.
	@constant	AVAudioSessionErrorCodeBadParam
 		An illegal value was used for a property.
	@constant	AVAudioSessionErrorCodeInsufficientPriority
 		The app was not allowed to set the audio category because another app (Phone, etc.) is controlling it.
	@constant	AVAudioSessionErrorCodeResourceNotAvailable
		The operation failed because the device does not have sufficient hardware resources to complete the action. 
		For example, the operation requires audio input hardware, but the device has no audio input available.
	@constant	AVAudioSessionErrorCodeUnspecified
 		An unspecified error has occurred.
*/

typedef NS_ENUM(NSInteger, AVAudioSessionErrorCode)
{
	AVAudioSessionErrorCodeNone							=  0,
	AVAudioSessionErrorCodeMediaServicesFailed			= 'msrv',			/* 0x6D737276, 1836282486	*/
	AVAudioSessionErrorCodeIsBusy						= '!act',			/* 0x21616374, 560030580	*/
	AVAudioSessionErrorCodeIncompatibleCategory			= '!cat',			/* 0x21636174, 560161140	*/
	AVAudioSessionErrorCodeCannotInterruptOthers		= '!int',			/* 0x21696E74, 560557684	*/
	AVAudioSessionErrorCodeMissingEntitlement			= 'ent?',			/* 0x656E743F, 1701737535	*/
	AVAudioSessionErrorCodeSiriIsRecording				= 'siri',			/* 0x73697269, 1936290409	*/
	AVAudioSessionErrorCodeCannotStartPlaying			= '!pla',			/* 0x21706C61, 561015905	*/
	AVAudioSessionErrorCodeCannotStartRecording			= '!rec',			/* 0x21726563, 561145187	*/
	AVAudioSessionErrorCodeBadParam						= -50,
	AVAudioSessionErrorCodeInsufficientPriority			= '!pri',			/* 0x21707269, 561017449	*/
	AVAudioSessionErrorCodeResourceNotAvailable			= '!res',			/* 0x21726573, 561145203	*/
	AVAudioSessionErrorCodeUnspecified					= 'what'			/* 0x77686174, 2003329396	*/
};

AVAudioSessionErrorCodeNone
操作成功。
AVAudioSessionErrorCodeMediaServicesFailed
尝试在媒体服务失败期间或之后使用音频会话。
AVAudioSessionErrorCodeIsBusy
尝试将其音频会话设置为非活动状态，但仍在播放和/或录制。
AVAudioSessionErrorCodeIncompatibleCategory
试图执行当前类别中不允许的操作。
AVAudioSessionErrorCodeCannotInterruptOthers
尝试在应用程序处于后台时使不可混音的音频会话处于活动状态。
AVAudioSessionErrorCodeMissingEntitlement
试图执行应用程序没有所需权利的操作。
AVAudioSessionErrorCodeSiriIsRecording
Siri正在录制时尝试执行不允许的操作。
AVAudioSessionErrorCodeCannotStartPlaying
试图开始音频播放，但不允许播放。
AVAudioSessionErrorCodeCannotStartRecording
试图开始录音，但失败了。
AVAudioSessionErrorCodeBadParam
试图将属性设置为非法值。
AVAudioSessionErrorInsufficientPriority
该应用程序不允许设置音频类别，因为它正在被另一个应用程序使用。
AVAudioSessionErrorCodeResourceNotAvailable
由于设备没有足够的硬件资源来完成操作而失败的操作。
AVAudioSessionErrorCodeUnspecified
没有更多的错误信息可用。当音频系统处于不一致状态时，通常会产生这种错误类型。

出现 AVAudioSessionErrorCodeInsufficientPriority = '!pri' , 需要设置混合模式(AVAudioSessionCategoryOptionMixWithOthers)，否则不允许非混合模式下，另个一个App或者系统在使用音频的情况下，占用音频Sesssion

学习不断，有错误请指出，如果对你有帮助，点个?