读取iPhone视频帧时出现内存问题
我在从iPhone库中选择的现有视频中读取视频帧时出现内存问题。首先,我将UIImage帧本身添加到一个数组中,但我认为数组过了一段时间后对于内存来说太大了,所以我将UIImage保存在documents文件夹中,并将imagepath添加到数组中。但是,即使使用工具检查分配,我仍然会收到相同的内存警告。总分配内存从未超过2.5mb。也没有发现任何泄漏。。。有人能想到什么吗读取iPhone视频帧时出现内存问题,iphone,ios,video,frame,avurlasset,Iphone,Ios,Video,Frame,Avurlasset,我在从iPhone库中选择的现有视频中读取视频帧时出现内存问题。首先,我将UIImage帧本身添加到一个数组中,但我认为数组过了一段时间后对于内存来说太大了,所以我将UIImage保存在documents文件夹中,并将imagepath添加到数组中。但是,即使使用工具检查分配,我仍然会收到相同的内存警告。总分配内存从未超过2.5mb。也没有发现任何泄漏。。。有人能想到什么吗 -(void)addFrame:(UIImage *)image { NSString *imgPath = [N
-(void)addFrame:(UIImage *)image
{
NSString *imgPath = [NSString stringWithFormat:@"%@/Analysis%d-%d.png", docFolder, currentIndex, framesArray.count];
[UIImagePNGRepresentation(image) writeToFile:imgPath atomically:YES];
[framesArray addObject:imgPath];
frameCount++;
}
-(void)imagePickerController:(UIImagePickerController *)picker didFinishPickingMediaWithInfo:(NSDictionary *)info
{
[picker dismissModalViewControllerAnimated:YES];
[framesArray removeAllObjects];
frameCount = 0;
// incoming video
NSURL *videoURL = [info valueForKey:UIImagePickerControllerMediaURL];
//NSLog(@"Video : %@", videoURL);
// AVURLAsset to read input movie (i.e. mov recorded to local storage)
NSDictionary *inputOptions = [NSDictionary dictionaryWithObject:[NSNumber numberWithBool:YES] forKey:AVURLAssetPreferPreciseDurationAndTimingKey];
AVURLAsset *inputAsset = [[AVURLAsset alloc] initWithURL:videoURL options:inputOptions];
// Load the input asset tracks information
[inputAsset loadValuesAsynchronouslyForKeys:[NSArray arrayWithObject:@"tracks"] completionHandler: ^{
NSError *error = nil;
nrFrames = CMTimeGetSeconds([inputAsset duration]) * 30;
NSLog(@"Total frames = %d", nrFrames);
// Check status of "tracks", make sure they were loaded
AVKeyValueStatus tracksStatus = [inputAsset statusOfValueForKey:@"tracks" error:&error];
if (!tracksStatus == AVKeyValueStatusLoaded)
// failed to load
return;
/* Read video samples from input asset video track */
AVAssetReader *reader = [AVAssetReader assetReaderWithAsset:inputAsset error:&error];
NSMutableDictionary *outputSettings = [NSMutableDictionary dictionary];
[outputSettings setObject: [NSNumber numberWithInt:kCVPixelFormatType_32BGRA] forKey: (NSString*)kCVPixelBufferPixelFormatTypeKey];
AVAssetReaderTrackOutput *readerVideoTrackOutput = [AVAssetReaderTrackOutput assetReaderTrackOutputWithTrack:[[inputAsset tracksWithMediaType:AVMediaTypeVideo] objectAtIndex:0] outputSettings:outputSettings];
// Assign the tracks to the reader and start to read
[reader addOutput:readerVideoTrackOutput];
if ([reader startReading] == NO) {
// Handle error
NSLog(@"Error reading");
}
NSAutoreleasePool *pool = [NSAutoreleasePool new];
while (reader.status == AVAssetReaderStatusReading)
{
if(!memoryProblem)
{
CMSampleBufferRef sampleBufferRef = [readerVideoTrackOutput copyNextSampleBuffer];
if (sampleBufferRef)
{
CVImageBufferRef imageBuffer = CMSampleBufferGetImageBuffer(sampleBufferRef);
/*Lock the image buffer*/
CVPixelBufferLockBaseAddress(imageBuffer,0);
/*Get information about the image*/
uint8_t *baseAddress = (uint8_t *)CVPixelBufferGetBaseAddress(imageBuffer);
size_t bytesPerRow = CVPixelBufferGetBytesPerRow(imageBuffer);
size_t width = CVPixelBufferGetWidth(imageBuffer);
size_t height = CVPixelBufferGetHeight(imageBuffer);
/*We unlock the image buffer*/
CVPixelBufferUnlockBaseAddress(imageBuffer,0);
/*Create a CGImageRef from the CVImageBufferRef*/
CGColorSpaceRef colorSpace = CGColorSpaceCreateDeviceRGB();
CGContextRef newContext = CGBitmapContextCreate(baseAddress, width, height, 8, bytesPerRow, colorSpace, kCGBitmapByteOrder32Little | kCGImageAlphaPremultipliedFirst);
CGImageRef newImage = CGBitmapContextCreateImage(newContext);
/*We release some components*/
CGContextRelease(newContext);
CGColorSpaceRelease(colorSpace);
UIImage *image= [UIImage imageWithCGImage:newImage scale:[UIScreen mainScreen].scale orientation:UIImageOrientationRight];
//[self addFrame:image];
[self performSelectorOnMainThread:@selector(addFrame:) withObject:image waitUntilDone:YES];
/*We release the CGImageRef*/
CGImageRelease(newImage);
CMSampleBufferInvalidate(sampleBufferRef);
CFRelease(sampleBufferRef);
sampleBufferRef = NULL;
}
}
else
{
break;
}
}
[pool release];
NSLog(@"Finished");
}];
}
你做一件事,然后尝试 将
NSAutoreleasePool
移动到循环中,同时将其从循环中排出
因此,它将如下所示:
while (reader.status == AVAssetReaderStatusReading)
{
NSAutoreleasePool *pool = [NSAutoreleasePool new];
.....
[pool drain];
}
你是个天才,这很有效!!!我真想知道,你是怎么想的?当将自动释放池放入while循环内时,为什么这会起作用?如果它在循环外,则池将仅在循环结束时被排空。但在循环结束之前,内存会累积并崩溃。因此,如果它在内部,在每次迭代中,自动释放的对象都会被释放。