从图像制作视频时，应用程序崩溃 [英] application crashed when make video from images
本文介绍了从图像制作视频时，应用程序崩溃的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
请找到以下代码.
-(void) writeImagesAsMovie:(NSArray *)array toPath:(NSString*)path numPhoto:(NSInteger)totPics {
ALAsset *asset = [assets objectAtIndex:0];
ALAssetRepresentation *assetRepresentation = [asset defaultRepresentation];
UIImage *getImage = [UIImage imageWithCGImage:[assetRepresentation fullScreenImage] scale:[assetRepresentation scale] orientation:(UIImageOrientation)[assetRepresentation orientation]];
UIImage *first = [getImage imageByScalingAndCroppingForSize:CGSizeMake(720.0, 960.0)];
CGSize frameSize = CGSizeMake(first.size.width,first.size.height);
NSLog(@"frameSize = %@",NSStringFromCGSize(frameSize));
NSError *error = nil;
AVAssetWriter *videoWriter = [[AVAssetWriter alloc] initWithURL:
[NSURL fileURLWithPath:path] fileType:AVFileTypeQuickTimeMovie
error:&error];
if(error) {
NSLog(@"error creating AssetWriter: %@",[error description]);
}
NSDictionary *videoSettings = [NSDictionary dictionaryWithObjectsAndKeys:
AVVideoCodecH264, AVVideoCodecKey,
[NSNumber numberWithInt:frameSize.width], AVVideoWidthKey,
[NSNumber numberWithInt:frameSize.height], AVVideoHeightKey,
AVVideoScalingModeResizeAspect,AVVideoScalingModeKey,
nil];
AVAssetWriterInput* writerInput = [AVAssetWriterInput
assetWriterInputWithMediaType:AVMediaTypeVideo
outputSettings:videoSettings];
CGAffineTransform transform = CGAffineTransformIdentity;
UIImageOrientation orient = first.imageOrientation;
CGSize imageSize = first.size;
switch(orient) {
case UIImageOrientationUp: //EXIF = 1
transform = CGAffineTransformIdentity;
break;
case UIImageOrientationUpMirrored: //EXIF = 2
transform = CGAffineTransformMakeTranslation(imageSize.width, 0.0);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
break;
case UIImageOrientationDown: //EXIF = 3
transform = CGAffineTransformMakeTranslation(imageSize.width, imageSize.height);
transform = CGAffineTransformRotate(transform, M_PI);
break;
case UIImageOrientationDownMirrored: //EXIF = 4
transform = CGAffineTransformMakeTranslation(0.0, imageSize.height);
transform = CGAffineTransformScale(transform, 1.0, -1.0);
break;
case UIImageOrientationLeftMirrored: //EXIF = 5
transform = CGAffineTransformMakeTranslation(imageSize.height, imageSize.width);
transform = CGAffineTransformScale(transform, -1.0, 1.0);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationLeft: //EXIF = 6
transform = CGAffineTransformMakeTranslation(0.0, imageSize.width);
transform = CGAffineTransformRotate(transform, 3.0 * M_PI / 2.0);
break;
case UIImageOrientationRightMirrored: //EXIF = 7
transform = CGAffineTransformMakeScale(-1.0, 1.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
case UIImageOrientationRight: //EXIF = 8
transform = CGAffineTransformMakeTranslation(imageSize.height, 0.0);
transform = CGAffineTransformRotate(transform, M_PI / 2.0);
break;
default:
[NSException raise:NSInternalInconsistencyException format:@"Invalid image orientation"];
}
writerInput.transform = transform;
NSMutableDictionary *attributes = [[NSMutableDictionary alloc] init];
[attributes setObject:[NSNumber numberWithUnsignedInt:kCVPixelFormatType_32ARGB] forKey:(NSString*)kCVPixelBufferPixelFormatTypeKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.width] forKey:(NSString*)kCVPixelBufferWidthKey];
[attributes setObject:[NSNumber numberWithUnsignedInt:frameSize.height] forKey:(NSString*)kCVPixelBufferHeightKey];
AVAssetWriterInputPixelBufferAdaptor *adaptor = [AVAssetWriterInputPixelBufferAdaptor
assetWriterInputPixelBufferAdaptorWithAssetWriterInput:writerInput
sourcePixelBufferAttributes:attributes];
[videoWriter addInput:writerInput];
// fixes all errors
writerInput.expectsMediaDataInRealTime = YES;
//Start a session:
[videoWriter startWriting];
[videoWriter startSessionAtSourceTime:kCMTimeZero];
CVPixelBufferRef buffer = NULL;
buffer = [self pixelBufferFromCGImage:[first CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:kCMTimeZero];
if (result == NO)
NSLog(@"failed to append buffer");
if(buffer) {
CVBufferRelease(buffer);
}
int fps = 2;
for(int i=0; i<totPics; i++)
{
if (adaptor.assetWriterInput.readyForMoreMediaData) {
CMTime frameTime = CMTimeMake(1, fps);
CMTime lastTime = CMTimeMake(i, fps);
CMTime presentTime = CMTimeAdd(lastTime, frameTime);
NSLog(@"presentTime = %f",CMTimeGetSeconds(presentTime));
ALAsset *asset = [assets objectAtIndex:i];
ALAssetRepresentation *assetRepresentation = [asset defaultRepresentation];
UIImage *imgGetFrame = [UIImage imageWithCGImage:[assetRepresentation fullScreenImage] scale:[assetRepresentation scale] orientation:(UIImageOrientation)[assetRepresentation orientation]];
UIImage *imgFrame = [imgGetFrame imageByScalingAndCroppingForSize:CGSizeMake(720.0, 960.0)];
buffer = [self pixelBufferFromCGImage:[imgFrame CGImage]];
BOOL result = [adaptor appendPixelBuffer:buffer withPresentationTime:presentTime];
if (result == NO) //failes on 3GS, but works on iphone 4
{
NSLog(@"failed to append buffer");
NSLog(@"The error is %@", [videoWriter error]);
}
if(buffer) {
CVBufferRelease(buffer);
}
} else {
NSLog(@"error");
}
}
//Finish the session:
[writerInput markAsFinished];
[videoWriter finishWritingWithCompletionHandler:^{
NSLog(@"Complete");
}];
CVPixelBufferPoolRelease(adaptor.pixelBufferPool);
}
-(CVPixelBufferRef) pixelBufferFromCGImage: (CGImageRef) image {
NSDictionary *options = [NSDictionary dictionaryWithObjectsAndKeys:
[NSNumber numberWithBool:YES], kCVPixelBufferCGImageCompatibilityKey,
[NSNumber numberWithBool:YES], kCVPixelBufferCGBitmapContextCompatibilityKey,
nil];
CVPixelBufferRef pxbuffer = NULL;
CVPixelBufferCreate(kCFAllocatorDefault, CGImageGetWidth(image),
CGImageGetHeight(image), kCVPixelFormatType_32ARGB, (__bridge CFDictionaryRef) options,
&pxbuffer);
CVPixelBufferLockBaseAddress(pxbuffer, 0);
void *pxdata = CVPixelBufferGetBaseAddress(pxbuffer);
CGColorSpaceRef rgbColorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef context = CGBitmapContextCreate(pxdata, CGImageGetWidth(image),
CGImageGetHeight(image), 8, 4*CGImageGetWidth(image), rgbColorSpace,
kCGImageAlphaNoneSkipFirst);
CGContextConcatCTM(context, CGAffineTransformMakeRotation(0));
CGContextDrawImage(context, CGRectMake(0, 0, CGImageGetWidth(image),
CGImageGetHeight(image)), image);
CGColorSpaceRelease(rgbColorSpace);
CGContextRelease(context);
CVPixelBufferUnlockBaseAddress(pxbuffer, 0);
return pxbuffer;
}
裁剪图像方法
-(UIImage*)imageByScalingAndCroppingForSize:(CGSize)targetSize {
UIImage *sourceImage = self;
UIImage *newImage = nil;
CGSize imageSize = sourceImage.size;
CGFloat width = imageSize.width;
CGFloat height = imageSize.height;
CGFloat targetWidth = targetSize.width;
CGFloat targetHeight = targetSize.height;
CGFloat scaleFactor = 0.0;
CGFloat scaledWidth = targetWidth;
CGFloat scaledHeight = targetHeight;
CGPoint thumbnailPoint = CGPointMake(0.0,0.0);
if (CGSizeEqualToSize(imageSize, targetSize) == NO)
{
CGFloat widthFactor = targetWidth / width;
CGFloat heightFactor = targetHeight / height;
if (widthFactor > heightFactor)
{
scaleFactor = widthFactor; // scale to fit height
}
else
{
scaleFactor = heightFactor; // scale to fit width
}
scaledWidth = width * scaleFactor;
scaledHeight = height * scaleFactor;
// center the image
if (widthFactor > heightFactor)
{
thumbnailPoint.y = (targetHeight - scaledHeight) * 0.5;
}
else
{
if (widthFactor < heightFactor)
{
thumbnailPoint.x = (targetWidth - scaledWidth) * 0.5;
}
}
}
UIGraphicsBeginImageContext(targetSize); // this will crop
CGRect thumbnailRect = CGRectZero;
thumbnailRect.origin = thumbnailPoint;
thumbnailRect.size.width = scaledWidth;
thumbnailRect.size.height = scaledHeight;
[sourceImage drawInRect:thumbnailRect];
newImage = UIGraphicsGetImageFromCurrentImageContext();
if(newImage == nil) {
NSLog(@"could not scale image");
}
//pop the context to get back to the default
UIGraphicsEndImageContext();
return newImage;
}
我已经从用户照片库传递了图像，并将图像裁剪后添加到720 x 960.
I have pass the image from the user photo library and add the image after crop it to 720 x 960.
当我拍摄100张图像时，出现内存警告错误.另外，当我在仪器中检查应用程序时，它花费了大约400 mb.因此，如果有人知道我在做什么错，请帮助我.
When I took 100 images then I got memory warning error. Also when I checked the application in instrument then it took around 400 mb. So please help me if anyone has an idea what I am doing wrong.
推荐答案
问题是您正在用完视频处理循环中的所有应用程序内存.您不能只在内存中同时分配数百张图像，当代码在iOS设备上运行时，代码将崩溃.请阅读我关于此主题的博客文章，网址为 video_and_memory_usage_on_ios_devices ，然后更改for循环为循环的每次迭代创建一个自动释放池，以修复失控的内存使用情况.另请注意，kCVPixelFormatType_32ARGB会非常慢，您应该使用kCVPixelFormatType_32BGRA.
The problem is that you are using up all app memory in your video processing loop. You cannot just allocate hundreds of images in memory at the same time, the code will crash when run on your iOS device. Please read my blog post on the subject at video_and_memory_usage_on_ios_devices and then change your for loop so that an autorelease pool is created for each iteration of the loop to fix the runaway memory usage. Also note that kCVPixelFormatType_32ARGB will be very slow, you should use kCVPixelFormatType_32BGRA.
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