GPUImage学习

前言

1. 一些自带滤镜

    //磨皮GPUImageBilateralFilter
    //绿巨人GPUImageHueFilter
    //移行幻影GPUImageLowPassFilter
    //怀旧GPUImageMonochromeFilter、GPUImageSepiaFilter
    //黑白GPUImageOpeningFilter
    //像素GPUImagePixellateFilter
    //油画GPUImagePosterizeFilter、GPUImageSmoothToonFilter
    //素描GPUImageSketchFilter、GPUImageThresholdSketchFilter
    //--------------GPUImageSkinToneFilter
    //血轮眼GPUImageSwirlFilter

2. 支持滤镜摄像，滤镜相机，滤镜图片，滤镜视频

 // - GPUImageVideoCamera (for live video from an iOS camera) 
// - GPUImageStillCamera (for taking photos with the camera)
 // - GPUImagePicture (for still images)
 // - GPUImageMovie (for movies)

一.使用滤镜生成UIImage对象

1. 创建一个滤镜类
2. 使用GPUImagePicture加载滤镜
3. processImage呈现图像
4. useNextFrameForImageCapture持续图片呈现(必须要加这句不然会生成nil)
5. imageFromCurrentFramebuffer生成图片

+ (UIImage *)applySoftEleganceFilter:(UIImage *)image
{
    GPUImageSoftEleganceFilter *filter = [[GPUImageSoftEleganceFilter alloc] init];
    [filter forceProcessingAtSize:CGSizeMake(image.size.width / 2.0, image.size.height / 2.0)];
    GPUImagePicture *pic = [[GPUImagePicture alloc] initWithImage:image];
    [pic addTarget:filter];
    
    [pic processImage];
    [filter useNextFrameForImageCapture];
    return [filter imageFromCurrentFramebuffer];
}

滤镜效果

二.使用滤镜相机

1. 定义相机的输出页面

   GPUImageView *cameraView = [[GPUImageView alloc] initWithFrame:CGRectMake(0, 44,GBWidth, GBWidth + 145 * GBScale - 44)];
    //设置为水平镜像，因为磨人是前置，会有镜像
    [cameraView setInputRotation:kGPUImageFlipHorizonal atIndex:0];
    cameraView.fillMode = kGPUImageFillModePreserveAspectRatioAndFill;
    [self.view addSubview:cameraView];
    self.cameraView = cameraView;

2. 定义滤镜操作对象

   stillCamera = [[GPUImageStillCamera alloc] initWithSessionPreset:@"AVCaptureSessionPresetPhoto" cameraPosition:AVCaptureDevicePositionFront];
   stillCamera.outputImageOrientation = UIInterfaceOrientationPortrait;

3. 定义滤镜需要的对象

//初始化自己需要的滤镜
filter = [[GPUImageBilateralFilter alloc] init];

4. 添加滤镜

 [stillCamera addTarget:filter];

5. 将滤镜添加到相机

[filter addTarget:cameraView];

6. 开启滤镜

[stillCamera startCameraCapture];

7. 拍照

   GPUImageStillCamera *stillCamera;
    GPUImageOutput<GPUImageInput> *filter, *secondFilter, *terminalFilter;
    
    GPUImagePicture *memoryPressurePicture1, *memoryPressurePicture2;

- (void)setupCameraView {
    //定义相机输出界面
    GPUImageView *cameraView = [[GPUImageView alloc] initWithFrame:CGRectMake(0, 44,GBWidth, GBWidth + 145 * GBScale - 44)];
    //设置为水平镜像，因为磨人是前置，会有镜像
    [cameraView setInputRotation:kGPUImageFlipHorizonal atIndex:0];
    cameraView.fillMode = kGPUImageFillModePreserveAspectRatioAndFill;
    [self.view addSubview:cameraView];
    self.cameraView = cameraView;
    //定义滤镜操作对象
    stillCamera = [[GPUImageStillCamera alloc] initWithSessionPreset:@"AVCaptureSessionPresetPhoto" cameraPosition:AVCaptureDevicePositionBack];
    stillCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
    //定义需要的滤镜
    filter = [[GPUImagePixellateFilter alloc] init];
    [stillCamera addTarget:filter];
    //滤镜添加到相机中
    [filter addTarget:cameraView];
    //开启滤镜
    [stillCamera startCameraCapture];

    [self.cameraView setInputRotation:kGPUImageFlipHorizonal atIndex:0];
}

三.使用滤镜录像

1.创建录像机对象GPUImageVideoCamera
2.创建滤镜对象
3.创建视频的输出页面
4.创建视频写入GPUImageMovieWriter
5.添加视频写入添加滤镜
6.开始录像
7.保存

    GPUImageVideoCamera *videoCamera;
    GPUImageOutput<GPUImageInput> *filter;
    GPUImageMovieWriter *movieWriter;

   videoCamera = [[GPUImageVideoCamera alloc] initWithSessionPreset:AVCaptureSessionPreset640x480 cameraPosition:AVCaptureDevicePositionBack];
    
    videoCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
    videoCamera.horizontallyMirrorFrontFacingCamera = NO;
    videoCamera.horizontallyMirrorRearFacingCamera = NO;
    
    filter = [[GPUImageSepiaFilter alloc] init];
    [videoCamera addTarget:filter];
    
    GPUImageView *filterView = [[GPUImageView alloc] initWithFrame:CGRectMake(0, 44,GBWidth, GBWidth + 145 * GBScale - 44)];
    filterView.fillMode = kGPUImageFillModePreserveAspectRatioAndFill;
    [self.view addSubview:filterView];
    NSString *pathToMovie = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Movie.m4v"];
    unlink([pathToMovie UTF8String]); // If a file already exists, AVAssetWriter won't let you record new frames, so delete the old movie
    NSURL *movieURL = [NSURL fileURLWithPath:pathToMovie];
    
    movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(480.0, 640.0)];
    movieWriter.encodingLiveVideo = YES;
    [filter addTarget:movieWriter];
    [filter addTarget:filterView];
    
    [videoCamera startCameraCapture];
    
    double delayToStartRecording = 0.5;
    dispatch_time_t startTime = dispatch_time(DISPATCH_TIME_NOW, delayToStartRecording * NSEC_PER_SEC);
    dispatch_after(startTime, dispatch_get_main_queue(), ^(void){
        NSLog(@"Start recording");
        
        videoCamera.audioEncodingTarget = movieWriter;
        [movieWriter startRecording];
 
        double delayInSeconds = 10.0;
        dispatch_time_t stopTime = dispatch_time(DISPATCH_TIME_NOW, delayInSeconds * NSEC_PER_SEC);
        dispatch_after(stopTime, dispatch_get_main_queue(), ^(void){
            
            [filter removeTarget:movieWriter];
            videoCamera.audioEncodingTarget = nil;
            [movieWriter finishRecording];
            NSLog(@"Movie completed");
            
            ALAssetsLibrary *library = [[ALAssetsLibrary alloc] init];
            if ([library videoAtPathIsCompatibleWithSavedPhotosAlbum:movieURL])
            {
                [library writeVideoAtPathToSavedPhotosAlbum:movieURL completionBlock:^(NSURL *assetURL, NSError *error)
                 {
                     dispatch_async(dispatch_get_main_queue(), ^{
                         
                         if (error) {
                             UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Error" message:@"Video Saving Failed"
                                                                            delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                             [alert show];
                         } else {
                             UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Video Saved" message:@"Saved To Photo Album"
                                                                            delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
                             [alert show];
                         }
                     });
                 }];
            }
            //            [videoCamera.inputCamera lockForConfiguration:nil];
            //            [videoCamera.inputCamera setTorchMode:AVCaptureTorchModeOff];
            //            [videoCamera.inputCamera unlockForConfiguration];
        });
    });

Demo下载链接：https://pan.baidu.com/s/1miKwbfq