I have three GIF files which are loaded as NSData.
When I use the key kCGImagePropertyGIFLoopCount
to retrieve the LoopCount, it returns a wrong value.
For the GIF which should loop infinitely, it returns 0 (correct).
For the GIF with Loop count 1, it returns 0 (incorrect).
For the GIF with Loop count 2, it returns 1 (incorrect).
-(void)prepareGif:(NSData*)data {
CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef) data, NULL);
CFDictionaryRef properties = CGImageSourceCopyProperties(source, nil);
NSDictionary* imageProperties = (__bridge NSDictionary*) properties;
NSDictionary* gifProperty = imageProperties[(NSDictionary*) kCGImagePropertyGIFDictionary];
int loopCount = [gifProperty[(NSString*) kCGImagePropertyGIFLoopCount] intValue]; // returns 0 for LoopCount 1 and LoopCount 0 and returns 1 for LoopCount 2
Here are the three GIFs:
Someone know what I am doing wrong here or is it a bug?
I found the answer.
The property is absent when it doesnt loop (i.e. playback count = 1).
It was my mistake since the gifProperty
dictionary returns objects and not primitive types. The returned object was a NSNumber, which was casted to int with a default value of 0
. I didn't check for nil