Get all frames of Video IOS 6

avfoundation, frame-rate, image-generation, ios, objective-c

Solution

You need to:

- use CGImageRelease as @zimmryan mentioned

- use a block of @autoreleasepool in your loop

- do not store the images in the memory, store them in your Document Directory

This is how I do it: (notice I use the sync version for extracting images, it shouldn't matter if you choose the async version)

AVURLAsset *asset = [[AVURLAsset alloc] initWithURL:url options:nil];
AVAssetImageGenerator *generator = [[AVAssetImageGenerator alloc] initWithAsset:asset];
generator.requestedTimeToleranceAfter =  kCMTimeZero;
generator.requestedTimeToleranceBefore =  kCMTimeZero;
for (Float64 i = 0; i < CMTimeGetSeconds(asset.duration) *  FPS ; i++){
  @autoreleasepool {
    CMTime time = CMTimeMake(i, FPS);
    NSError *err;
    CMTime actualTime;
    CGImageRef image = [generator copyCGImageAtTime:time actualTime:&actualTime error:&err];
    UIImage *generatedImage = [[UIImage alloc] initWithCGImage:image];
    [self saveImage: generatedImage atTime:actualTime]; // Saves the image on document directory and not memory
    CGImageRelease(image);
  }
}

EDIT:

you should always consider using @autoreleasepool when creating alot of temporary objects (see https://developer.apple.com/library/mac/documentation/cocoa/conceptual/memorymgmt/articles/mmAutoreleasePools.html)

Problem

I would like to get all frames of a Video in iOS6 into `NSArray`. I use this code: ``` -(void) getAllImagesFromVideo { imagesArray = [[NSMutableArray alloc] init]; times = [[NSMutableArray alloc] init]; for (Float64 i = 0; i < 15; i += 0.033) // For 25 fps in 15 sec of Video { CMTime time = CMTimeMakeWithSeconds(i, 60); [times addObject:[NSValue valueWithCMTime:time]]; } [imageGenerator generateCGImagesAsynchronouslyForTimes:times completionHandler:^(CMTime requestedTime, CGImageRef image, CMTime actualTime, AVAssetImageGeneratorResult result, NSError *error) { if (result == AVAssetImageGeneratorSucceeded) { UIImage *generatedImage = [[UIImage alloc] initWithCGImage:image]; [imagesArray addObject:generatedImage]; } }]; } ``` On iPad simulator the delay is 90~100 seconds, on iPad device, recieved Memory Warnings and finally crash. Any idea, solution? Using another more low-level Framework/Library? C++? Is very important for me! Help me! :) Thanks!!!

Original source