切换清晰度（Picture quality）

typedef NS_ENUM(NSInteger,KHJVideoQuality)
{
    KHJVideoQualityUnknown              = 0x00,
    KHJVideoQualityMax                  = 0x01,
    KHJVideoQualityHigh                 = 0x02,
    KHJVideoQualityMiddle               = 0x03,
    KHJVideoQualityLow                  = 0x04,
    KHJVideoQualityMin                  = 0x05
};

KHJBaseDevice *dDevice = [[KHJAllBaseManager sharedBaseManager] searchForkey:Uid];
// 设置画面清晰度
[bDevice.mDeviceManager setVideoQuality:KHJVideoQualityMax returnBloc:^(BOOL success) {
    // success = YES 操作成功
    // success = NO 操作失败
}];

具体用法见demo.