Hello, I am trying to create an animated sequence of HEIC images but I cannot save the frame property duration. It seems this is a well know bug: https://github.com/SDWebImage/SDWebImage/issues/3120 The kCGImagePropertyHEICSDictionary is never saved. Here's a sample project to reproduce the bug: ImageIOHEICSEncodeDecodeBug.zip Has anybody managed to save this information in a HEIC sequence? Thanks! Here's how I am writing an reading the image sequence - (void)testHEICSBug {     // First, load an animated image (GIF)     // And you can change the type into png, which is an animated PNG format. Same result     NSData *GIFData = [NSData dataWithContentsOfFile:[[NSBundle mainBundle] pathForResource:@"image1" ofType:@"gif"]];     CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)GIFData, nil);     NSUInteger frameCount = CGImageSourceGetCount(source);     NSAssert(frameCount > 1, @"GIF frame count > 1");          // Split into frames array, encode to HEICS     NSMutableData *heicsData = [NSMutableData data];     CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)heicsData, (__bridge CFStringRef)AVFileTypeHEIC, frameCount, nil);               for (int i = 0; i < frameCount; i++) {         // First get the GIF input image and duration         CGImageRef cgImage = CGImageSourceCreateImageAtIndex(source, i, nil);         NSDictionary *inputProperties = (__bridge_transfer  NSDictionary *)CGImageSourceCopyPropertiesAtIndex(source, i, nil);         NSDictionary *inputDictionary = inputProperties[(__bridge NSString *)kCGImagePropertyGIFDictionary];         NSTimeInterval duration = [inputDictionary[(__bridge NSString *)kCGImagePropertyGIFUnclampedDelayTime] doubleValue];         NSAssert(cgImage, @"CGImage not nil");         NSAssert(duration > 0, @"Input duration > 0");                                    // Then, encode into HEICS animated image         NSMutableDictionary *outputDProperties = [NSMutableDictionary dictionary];         outputDProperties[(__bridge NSString *)kCGImagePropertyHEICSDictionary] = @{(__bridge NSString *)kCGImagePropertyHEICSUnclampedDelayTime : @(duration)};         CGImageDestinationAddImage(destination, cgImage, (__bridge_retained CFDictionaryRef)outputDProperties);     }          // Output HEICS image data     BOOL result = CGImageDestinationFinalize(destination);     NSAssert(result, @"Encode HEICS failed");               // Next, try to use ImageIO to decode HEICS and check duration          CGImageSourceRef newSource = CGImageSourceCreateWithData((__bridge CFDataRef)heicsData, nil);     frameCount = CGImageSourceGetCount(newSource);     NSAssert(frameCount > 1, @"New HEICS should be aniamted image");     NSUInteger frameIndex = 1; // I pick the 2nd frame, actually any frame contains this issue.     NSDictionary *newProperties = (__bridge_transfer NSDictionary *)CGImageSourceCopyPropertiesAtIndex(newSource, frameIndex, nil);     NSDictionary *newDictionary = newProperties[(__bridge NSString *)kCGImagePropertyHEICSDictionary];     NSTimeInterval newDuration = [newDictionary[(__bridge NSString *)kCGImagePropertyHEICSUnclampedDelayTime] doubleValue];     CGImageRef newImage = CGImageSourceCreateImageAtIndex(newSource, frameIndex, nil);          // Now, check the HEICS frame duration, however, it's nil :(     // Only image is kept.     NSAssert(newImage, @"frame image is not nil");     NSAssert(newDuration > 0, @"Decode the HEICS (which encoded from GIF) will loss the frame duration"); }

Hello,I am having an hard time figuring out how memory mapped files works under iOS. Suppose that I want to read a big file, let's say 4GB. If I use memory mapped files in READ mode I should be able to get a valid pointer to a file and benefit from the page fault mechanism of virtual memory but apparently iOS can map only up to 2.5GB of data. I run the following test on an iPad Pro A1673 that has 2GB of ram and got as result:2018-04-06 17:20:12.660888+0200 TestMemory[414:316466] Data address: 0x1022240002018-04-06 17:20:12.662355+0200 TestMemory[414:316466] Data address: 0x1122240002018-04-06 17:20:12.663801+0200 TestMemory[414:316466] Data address: 0x12b9000002018-04-06 17:20:12.665235+0200 TestMemory[414:316466] Data address: 0x13b9000002018-04-06 17:20:12.666756+0200 TestMemory[414:316466] Data address: 0x14b9000002018-04-06 17:20:12.668202+0200 TestMemory[414:316466] Data address: 0x15b9000002018-04-06 17:20:12.669597+0200 TestMemory[414:316466] Data address: 0x16ff240002018-04-06 17:20:12.739549+0200 TestMemory[414:316466] Data address: 0x1e00000002018-04-06 17:20:12.747604+0200 TestMemory[414:316466] Data address: 0x1f00000002018-04-06 17:20:12.749130+0200 TestMemory[414:316466] Data address: 0x2000000002018-04-06 17:20:12.764753+0200 TestMemory[414:316466] NSData failed: Error Domain=NSCocoaErrorDomain Code=256 "The file “02808580-5D42-43BC-B5AA-628E3682A546” couldn’t be opened." UserInfo={NSFilePath=/var/mobile/Containers/Data/Application/5207275C-5525-47CA-AC4B-2AA07E05C1E9/Documents/02808580-5D42-43BC-B5AA-628E3682A546, NSUnderlyingError=0x1c0455270 {Error Domain=NSPOSIXErrorDomain Code=12 "Cannot allocate memory"}}2018-04-06 17:20:12.764801+0200 TestMemory[414:316466] Mapped 2684354560- (NSString*)createFileOfSize:(unsigned long long)size { NSString* uuid = [[NSUUID UUID] UUIDString]; NSString* documentFolderPath = [[[NSFileManager defaultManager] URLsForDirectory:NSDocumentDirectory inDomains:NSUserDomainMask] lastObject].path; NSString* filePath = [documentFolderPath stringByAppendingPathComponent:uuid]; NSFileHandle *fileHandle = [NSFileHandle fileHandleForWritingAtPath:filePath]; if (fileHandle == nil) { [[NSFileManager defaultManager] createFileAtPath:filePath contents:nil attributes:nil]; fileHandle = [NSFileHandle fileHandleForWritingAtPath:filePath]; } [fileHandle truncateFileAtOffset:size]; [fileHandle closeFile]; return filePath; } - (void)test { const unsigned long long MB = 1 &lt;&lt; 20; const unsigned long long GB = 1 &lt;&lt; 30; unsigned long long space = 4 * GB; unsigned long long size = 64 * MB; unsigned long long fileCount = space / size; NSMutableArray* mapped = [NSMutableArray array]; int i = 0; for (i = 0; i &lt; fileCount; i++) { NSString* filePath = [self createFileOfSize:size]; NSError* error = nil; NSData* data = [NSData dataWithContentsOfFile:filePath options:NSDataReadingMappedAlways error:&amp;error]; if (error) { NSLog(@"NSData failed: %@", error); break; } else { const void* bytes = [data bytes]; NSLog(@"Data address: %p", bytes); [mapped addObject:data]; } } NSLog(@"Mapped %llu", i * size); }Any idea of why we have this limitation?Thanks!Libe