我正在编写一个使用AVFoundation进行相机操作的iPhone应用程序,我正试图将UIImage从相机保存到相机胶卷中。
目前这样做......
[imageCaptureOutput captureStillImageAsynchronouslyFromConnection:[imageCaptureOutput.connections objectAtIndex:0]
completionHandler:^(CMSampleBufferRef imageDataSampleBuffer, NSError *error)
{
if (imageDataSampleBuffer != NULL)
{
NSData *imageData = [AVCaptureStillImageOutput jpegStillImageNSDataRepresentation:imageDataSampleBuffer];
UIImage *image = [[UIImage alloc] initWithData:imageData];
MyCameraAppDelegate *delegate = [[UIApplication sharedApplication] delegate];
[delegate processImage:image];
}
}];
我一直在观看WWDC教程视频,我认为2行(NSData ...和UIImage ...)是从imageDataSampleBuffer到UIImage的很长一段路。
将图像保存到库中似乎需要太长时间。
有没有人知道是否有单行过渡来使UIImage脱离这个?
感谢您的帮助!
奥利弗
答案 0 :(得分:3)
我认为在完成处理程序块中执行此操作可能会更有效,但是你是对的,它可以节省占用最大块时间的库。
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(imageDataSampleBuffer);
CVPixelBufferLockBaseAddress(imageBuffer, 0);
uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
size_t width = CVPixelBufferGetWidth(imageBuffer);
size_t height = CVPixelBufferGetHeight(imageBuffer);
CVPixelBufferUnlockBaseAddress(imageBuffer, 0);
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
CGImageRef cgImage = CGBitmapContextCreateImage(context);
CGContextRelease(context);
CGColorSpaceRelease(colorSpace);
if ( /*wanna save metadata on iOS4.1*/ ) {
CFDictionaryRef metadataDict = CMCopyDictionaryOfAttachments(NULL, imageDataSampleBuffer, kCMAttachmentMode_ShouldPropagate);
[assetsLibraryInstance writeImageToSavedPhotosAlbum:cgImage metadata:metadataDict completionBlock:^(NSURL *assetURL, NSError *error) { /*do something*/ }];
CFRelease(metadataDict);
} else {
[assetsLibraryInstance writeImageToSavedPhotosAlbum:cgImage orientation:ALAssetOrientationRight completionBlock:^(NSURL *assetURL, NSError *error) { /*do something*/ }];
// i think this is the correct orientation for Portrait, or Up if deviceOr'n is L'Left, Down if L'Right
}
CGImageRelease(cgImage);