顏色轉(zhuǎn)換矩陣：
extern const GLfloat kColorConversion601[];//標準清晰度
extern const GLfloat kColorConversion601FullRange[];//全彩
extern const GLfloat kColorConversion709[];//高清晰度
片段著色器：
extern NSString *const kGPUImageYUVVideoRangeConversionForRGFragmentShaderString;
extern NSString *const kGPUImageYUVFullRangeConversionForLAFragmentShaderString;
extern NSString *const kGPUImageYUVVideoRangeConversionForLAFragmentShaderString;
代理：
@protocol GPUImageVideoCameraDelegate <NSObject>
@optional
-(void)willOutputSampleBuffer:(CMSampleBufferRef)sampleBuffer;//將要輸出samp leBuffer
@end
interface：
@interface GPUImageVideoCamera : GPUImageOutput <AVCaptureVideoDataOutputSampleBufferDelegate,
AVCaptureAudioDataOutputSampleBufferDelegate>
    { 
    
    NSUInteger numberOfFramesCaptured;//已采集的幀數(shù)
    CGFloat totalFrameTimeDuringCapture;//采集的總幀數(shù)
    AVCaptureSession *_captureSession;//采集會話層
    AVCaptureDevice *_inputCamera;//視頻輸入設備
    AVCaptureDevice *_microphone;//音頻輸入設備
    AVCaptureDeviceInput *videoInput;//視頻輸入
    AVCaptureVideoDataOutput *videoOutput;//視頻數(shù)據(jù)輸出

    BOOL capturePaused;//停止采集
    GPUImageRotationMode outputRotation, internalRotation;//輸入和輸出旋轉(zhuǎn)方式
    dispatch_semaphore_t frameRenderingSemaphore;//幀渲染信號量
        
    BOOL captureAsYUV;//yuv格式采集
    GLuint luminanceTexture, chrominanceTexture;//亮度紋理、色度紋理

    __unsafe_unretained id<GPUImageVideoCameraDelegate> _delegate;//攝像頭采集協(xié)議
    }
    @property(readonly, retain, nonatomic) AVCaptureSession *captureSession;//會話層
    @property (readwrite, nonatomic, copy) NSString *captureSessionPreset;//采集分辨率
    @property (readwrite) int32_t frameRate;//幀率
    @property (readonly, getter = isFrontFacingCameraPresent) BOOL frontFacingCameraPresent;//前置攝像頭
    @property (readonly, getter = isBackFacingCameraPresent) BOOL backFacingCameraPresent;//后置攝像頭
    @property(readwrite, nonatomic) BOOL runBenchmark;//基準
    @property(readonly) AVCaptureDevice *inputCamera;//輸入攝像頭
    @property(readwrite, nonatomic) UIInterfaceOrientation outputImageOrientation;//攝像頭朝向
    @property(readwrite, nonatomic) BOOL horizontallyMirrorFrontFacingCamera, horizontallyMirrorRearFacingCamera;//前者攝像頭水平鏡像，后置攝像頭水平鏡像
    @property(nonatomic, assign) id<GPUImageVideoCameraDelegate> delegate;//攝像頭代理
    -(id)initWithSessionPreset:(NSString *)sessionPreset cameraPosition:(AVCaptureDevicePosition)cameraPosition;//根據(jù)分辨率冒冬、攝像頭朝向初始化攝像頭
    -(BOOL)addAudioInputsAndOutputs;//添加音頻的輸入和輸出
    -(BOOL)removeAudioInputsAndOutputs;//移除音頻的輸入和輸出
    -(void)removeInputsAndOutputs;//移除輸入和輸出設備
    -(void)startCameraCapture;//開始采集
    -(void)stopCameraCapture;//停止采集
    -(void)pauseCameraCapture;//暫停采集
    -(void)resumeCameraCapture;//恢復采集
    -(void)processVideoSampleBuffer:(CMSampleBufferRef)sampleBuffer;//處理視頻數(shù)據(jù)
    -(void)processAudioSampleBuffer:(CMSampleBufferRef)sampleBuffer;//處理音頻數(shù)據(jù)
    -(AVCaptureDevicePosition)cameraPosition;//攝像頭位置（前置/后置）
    -(AVCaptureConnection *)videoCaptureConnection;//視頻連接
    -(void)rotateCamera;//轉(zhuǎn)換攝像頭
    -(CGFloat)averageFrameDurationDuringCapture;//平均幀時長
    - (void)resetBenchmarkAverage;
    + (BOOL)isBackFacingCameraPresent;
    + (BOOL)isFrontFacingCameraPresent;

@end