iOS 音视频

typedef NS_OPTIONS(NSUInteger, AVAudioSessionCategoryOptions)
{
 /* MixWithOthers is only valid with AVAudioSessionCategoryPlayAndRecord, AVAudioSessionCategoryPlayback, and  AVAudioSessionCategoryMultiRoute */
 AVAudioSessionCategoryOptionMixWithOthers   = 0x1,

 /* DuckOthers is only valid with AVAudioSessionCategoryAmbient, AVAudioSessionCategoryPlayAndRecord, AVAudioSessionCategoryPlayback, and AVAudioSessionCategoryMultiRoute */
 AVAudioSessionCategoryOptionDuckOthers    = 0x2,

 /* AllowBluetooth is only valid with AVAudioSessionCategoryRecord and AVAudioSessionCategoryPlayAndRecord */
 AVAudioSessionCategoryOptionAllowBluetooth __TVOS_PROHIBITED __WATCHOS_PROHIBITED  = 0x4,

 /* DefaultToSpeaker is only valid with AVAudioSessionCategoryPlayAndRecord */
 AVAudioSessionCategoryOptionDefaultToSpeaker __TVOS_PROHIBITED __WATCHOS_PROHIBITED  = 0x8,

 /* InterruptSpokenAudioAndMixWithOthers is only valid with AVAudioSessionCategoryPlayAndRecord, AVAudioSessionCategoryPlayback, and AVAudioSessionCategoryMultiRoute */
 AVAudioSessionCategoryOptionInterruptSpokenAudioAndMixWithOthers NS_AVAILABLE_IOS(9_0)  = 0x11,

    /* AllowBluetoothA2DP is only valid with AVAudioSessionCategoryPlayAndRecord */
    AVAudioSessionCategoryOptionAllowBluetoothA2DP NS_AVAILABLE_IOS(10_0) = 0x20,

    /* AllowAirPlay is only valid with AVAudioSessionCategoryPlayAndRecord */
    AVAudioSessionCategoryOptionAllowAirPlay NS_AVAILABLE_IOS(10_0) __WATCHOS_PROHIBITED = 0x40,
} NS_AVAILABLE_IOS(6_0);