GPUImageRawDataInput: GPUImageRawDataInput: GPUImageRawDataInput:
#import "RawDataViewController.h"
#import "GPUImage.h"
@interface RawDataViewController(a)
@property (nonatomic.strong) GPUImageRawDataInput *rawDataInput;
@property (nonatomic.strong) GPUImageRawDataOutput *rawDataOutput;
@property (nonatomic.strong) GPUImageBrightnessFilter *filter;
@property (nonatomic.strong) GPUImageView *filterView;
@end
@implementation RawDataViewController
- (void)viewDidLoad {
[super viewDidLoad];
self.filterView = [[GPUImageView alloc] initWithFrame:CGRectMake(0.100.self.view.frame.size.width, 300)];
[self.view addSubview:self.filterView];
// 1. UIImage -> CGImage -> CFDataRef -> UInt8 * data
UIImage *image = [UIImage imageNamed:@"img1.jpg"];
CGImageRef newImageSource = [image CGImage];
CFDataRef dataFromImageDataProvider = CGDataProviderCopyData(CGImageGetDataProvider(newImageSource));
GLubyte* imageData = (GLubyte *)CFDataGetBytePtr(dataFromImageDataProvider);
// 2. UInt8 * data -> GPUImageRawDataInput
self.rawDataInput = [[GPUImageRawDataInput alloc] initWithBytes:imageData size:image.size pixelFormat:GPUPixelFormatRGBA];
self.filter = [[GPUImageBrightnessFilter alloc] init];
self.filter.brightness = 0.1;
[self.rawDataInput addTarget:self.filter];
// 3. Output to GPUImageView
[self.filter addTarget:self.filterView];
// 4. Output to raw data output
self.rawDataOutput = [[GPUImageRawDataOutput alloc] initWithImageSize:image.size resultsInBGRAFormat:YES];
[self.filter addTarget:self.rawDataOutput];
// important
[self.filter useNextFrameForImageCapture];
[self.rawDataInput processData];
// 5. read data from GPUImageRawDataOutput
[self.rawDataOutput lockFramebufferForReading];
GLubyte *outputBytes = [self.rawDataOutput rawBytesForImage];
NSInteger bytesPerRow = [self.rawDataOutput bytesPerRowInOutput];
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB(a);CGDataProviderRef provider = CGDataProviderCreateWithData(NULL, outputBytes, bytesPerRow * image.size.height, NULL);
CGImageRef cgImage = CGImageCreate(image.size.width, image.size.height, 8.32, bytesPerRow, rgbColorSpace, kCGImageAlphaPremultipliedFirst|kCGBitmapByteOrder32Little, provider, NULL.true, kCGRenderingIntentDefault);
[self.rawDataOutput unlockFramebufferAfterReading];
// Break to this line and view outImage
UIImage *outImage = [UIImage imageWithCGImage:cgImage];
NSLog(@ "% @", outImage);
}
@end
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Usage scenarios
This example can be used in the following scenarios:
- Use FFMPEG to read a frame of video stream into RGBA data;
- Pass data to GPUImageRawDataInput -> Add filter -> Output to GPUImageRawDataOutput
- Fetch RGBA data from GPUImageRawDataOutput, and then give it to FFMPEG encoding to write a new video file
Note:
- This process can be completed using GPUImage without ffmPEG; When cross-platform codec and filter is needed, OpenGL can be used to filter the video stream.
- To view UIImage from a breakpoint in Xcode: