Gifu/source/ImageSourceHelpers.swift

35 lines
1.1 KiB
Swift

import UIKit
import ImageIO
import MobileCoreServices
func CGImageSourceContainsAnimatedGIF(imageSource: CGImageSource) -> Bool {
let isTypeGIF = UTTypeConformsTo(CGImageSourceGetType(imageSource), kUTTypeGIF)
let imageCount = CGImageSourceGetCount(imageSource)
return isTypeGIF != 0 && imageCount > 1
}
func CGImageSourceGIFFrameDuration(imageSource: CGImageSource, index: Int) -> NSTimeInterval {
let containsAnimatedGIF = CGImageSourceContainsAnimatedGIF(imageSource)
if !containsAnimatedGIF { return 0.0 }
var duration = 0.0
let imageProperties = CGImageSourceCopyPropertiesAtIndex(imageSource, UInt(index), nil) as NSDictionary
let GIFProperties: NSDictionary? = imageProperties[kCGImagePropertyGIFDictionary] as? NSDictionary
if let properties = GIFProperties {
duration = properties[kCGImagePropertyGIFUnclampedDelayTime] as Double
if duration <= 0 {
duration = properties[kCGImagePropertyGIFDelayTime] as Double
}
}
let threshold = 0.02 - Double(FLT_EPSILON)
if duration > 0 && duration < threshold {
duration = 0.1
}
return duration
}