Displaying GIF Images on iOS Using ImageIO and FLAnimatedImage

GIF is a compressed image format that combines multiple static frames with timing information to create animation, and it is widely used across Android, iOS, and PC platforms.

Core principle : In iOS, loading a GIF with [UIImage imageNamed:name] or [UIImage imageWithData:data] returns only the first frame because the system UI components do not support animated GIFs directly.

Developers can use [imageView setAnimationImages:] together with [imageView setAnimationDuration:] to animate an array of images, but this approach cannot respect per‑frame delays and may consume excessive memory.

To obtain each frame and its display duration, the low‑level ImageIO framework is used. The following code demonstrates extracting an images array from GIF data:

// ImageIO example (pseudo‑code)
CGImageSourceRef src = CGImageSourceCreateWithData((__bridge CFDataRef)gifData, NULL);
size_t count = CGImageSourceGetCount(src);
NSMutableArray *frames = [NSMutableArray array];
for (size_t i = 0; i < count; i++) {
    CGImageRef img = CGImageSourceCreateImageAtIndex(src, i, NULL);
    NSDictionary *props = (NSDictionary *)CFBridgingRelease(CGImageSourceCopyPropertiesAtIndex(src, i, NULL));
    NSNumber *delay = props[(NSString *)kCGImagePropertyGIFDelayTime];
    // store img and delay
    [frames addObject:@{@