GPUImage - 低FPS

Question

我目前正在使用 GPU框架来录制视频以及 WhiteBalance和曝光过滤器，但FPS非常差（约12 FPS）。我在GPUImage原始演示代码（ SimpleVideoFilter ）中使用了上述过滤器，但结果相同。

以下是我用来录制带有组合滤镜的视频的方法。这些是iPhone 5，iPod Touch的结果，支持最多30 FPS。

任何想法 FPS高达28 或 AVCaptureSessionPresetHigh 和WhiteBalance，Exposure过滤器一起!!谢谢!!

-(void)recordVideo{

    videoCamera = [[GPUImageVideoCamera alloc] initWithSessionPreset:AVCaptureSessionPresetHigh cameraPosition:AVCaptureDevicePositionBack];
    videoCamera.outputImageOrientation = UIInterfaceOrientationPortrait;
    videoCamera.horizontallyMirrorFrontFacingCamera = NO;
    videoCamera.horizontallyMirrorRearFacingCamera = NO;

    filter = [[GPUImageFilterGroup alloc] init];
    [videoCamera addTarget:filter];

    GPUImageFilterGroup *group = (GPUImageFilterGroup *)filter;
    GPUImageWhiteBalanceFilter *whiteBalance = [[GPUImageWhiteBalanceFilter alloc] init];
    [group addFilter:whiteBalance];

    GPUImageExposureFilter *exposureFilter = [[GPUImageExposureFilter alloc] init];
    [group addFilter:exposureFilter];
    [whiteBalance addTarget:exposureFilter];

    [group setInitialFilters:[NSArray arrayWithObject:whiteBalance]];
    [group setTerminalFilter:exposureFilter];

    filter = group;
    [videoCamera addTarget:filter];

    GPUImageView *filterView = (GPUImageView *)self.view;
    NSString *pathToMovie = [NSHomeDirectory() stringByAppendingPathComponent:@"Documents/Movie.m4v"];
    unlink([pathToMovie UTF8String]);
    NSURL *movieURL = [NSURL fileURLWithPath:pathToMovie];
    movieWriter.encodingLiveVideo = YES;
    movieWriter = [[GPUImageMovieWriter alloc] initWithMovieURL:movieURL size:CGSizeMake(1080.0, 1920.0)];
    [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");
        });
    });

}