基于GPUImage的相机滤镜

相机滤镜如图

GPUImage 相机

GPUImage提供了丰富的滤镜，简单的说就是4步走，

1 初始化相机

// 相机使用 GPUImageStillCamera
self.videoCamera = [[GPUImageStillCamera alloc]initWithSessionPreset:AVCaptureSessionPresetHigh cameraPosition:AVCaptureDevicePositionBack];
self.videoCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
self.videoCamera.horizontallyMirrorFrontFacingCamera = YES;

2 初始化滤镜

_mFilter = [[GPUImageStretchDistortionFilter alloc] init];

3 创建预览层并把滤镜输出至预览

self.filterView = [[GPUImageView alloc] initWithFrame:self.view.frame];
[_mFilter addTarget:self.filterView];

4 相机获取视频数据输出到滤镜

[self.videoCamera addTarget:_mFilter];
[self.videoCamera startCameraCapture];

切换滤镜的操作

// 移除之前滤镜
[self.videoCamera removeAllTargets];
_mFilter = (GPUImageFilter *)self.fillerArray[self.index % self.fillerArray.count];
[self.videoCamera addTarget:_mFilter];
[_mFilter addTarget:self.filterView];

基于GPUImga的相机滤镜

GPUImage 录像

// 录像使用GPUImageVideoCamera
videoCamera = [[GPUImageVideoCamera alloc] initWithSessionPreset:AVCaptureSessionPresetHigh cameraPosition:AVCaptureDevicePositionBack];

videoCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
videoCamera.horizontallyMirrorFrontFacingCamera = NO;
videoCamera.horizontallyMirrorRearFacingCamera = NO;

filter = [[GPUImageSepiaFilter alloc] init];
[videoCamera addTarget:filter];
GPUImageView *filterView = [[GPUImageView alloc] initWithFrame:self.view.frame];
filterView.center = self.view.center;
[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];
_movieURL = movieURL;

开始录像的操作

videoCamera.audioEncodingTarget = movieWriter;
[movieWriter startRecording];

结束录像并保存到相册

[filter removeTarget:movieWriter];
videoCamera.audioEncodingTarget = nil;
[movieWriter finishRecording];
NSLog(@"Movie completed%@",_movieURL);

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:@"错误" message:@"视频保存失败" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                 [alert show];
             } else {
                 UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"成功" message:@"已保存到相册" delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil];
                 [alert show];
             }
         });
     }];
}

基于GPUImga的录像滤镜

模仿微信相机

代码已上传至 github