GIF

imageIO介绍
image解压缩
图片帧延迟设置
bridge

gif生成

//gifPath gif图保存路径  images生成gif图的图片帧数组   return gif图保存路径
+ (NSString *)crectGIFWithGIFPath:(NSString *)gifPath images:(NSArray *)images {
    
    //设置gif保存地址
    CFURLRef urlRef = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (__bridge CFStringRef)gifPath, kCFURLPOSIXPathStyle, false);
    CGImageDestinationRef destinationRef = CGImageDestinationCreateWithURL(urlRef, kUTTypeGIF, images.count, NULL);
    
    //添加图片
    NSDictionary *imageDict = @{(__bridge NSString *)kCGImagePropertyGIFDelayTime : @.5};//延迟多久播放下一帧图片
    [images enumerateObjectsUsingBlock:^(UIImage * _Nonnull obj, NSUInteger idx, BOOL * _Nonnull stop) {
        CGImageDestinationAddImage(destinationRef, obj.CGImage, (__bridge CFDictionaryRef)@{(__bridge NSString *)kCGImagePropertyGIFDictionary:imageDict});
    }];
    
    //设置gif属性
    NSMutableDictionary *properties = [NSMutableDictionary dictionary];
    //    [properties setObject:[NSNumber numberWithBool:YES] forKey:(__bridge NSString *)kCGImagePropertyGIFHasGlobalColorMap];//是否有全局颜色图
    //    [properties setObject:(__bridge NSString *)kCGImagePropertyColorModelRGB forKey:(__bridge NSString *)kCGImagePropertyColorModel];//颜色类型
    //    [properties setObject:[NSNumber numberWithInt:8] forKey:(__bridge NSString*)kCGImagePropertyDepth];//颜色深度
    [properties setObject:@0 forKey:(__bridge NSString *)kCGImagePropertyGIFLoopCount];//是否重复 0表示无限循环下去
    CGImageDestinationSetProperties(destinationRef, (__bridge CFDictionaryRef)@{(__bridge NSString *)kCGImagePropertyGIFDictionary:properties});
    
    //完成设置
    CGImageDestinationFinalize(destinationRef);
    
    //release
    CFRelease(urlRef);
    
    return gifPath;
}

gif解析

@implementation UIImageView (pyh_animation)
- (void)pyh_animationWithImageData:(NSData *)data {
    CGImageSourceRef sourceRef = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
    size_t count = CGImageSourceGetCount(sourceRef);
    
    //图片数组
    NSMutableArray *images = [NSMutableArray array];
    for (int i = 0; i < count; i ++) {
        CGImageRef imageRef = CGImageSourceCreateImageAtIndex(sourceRef, i, NULL);
        [images addObject:[UIImage imageWithCGImage:imageRef]];
    }
    
    //属性
//    NSDictionary *propertys = (__bridge_transfer NSDictionary *)(CGImageSourceCopyProperties(sourceRef, NULL));
//    NSDictionary *imagePropertys = (__bridge_transfer NSDictionary *)(CGImageSourceCopyPropertiesAtIndex(sourceRef, 1, NULL));
    CFDictionaryRef imagePropertys = CGImageSourceCopyPropertiesAtIndex(sourceRef, 1, NULL);
    CFDictionaryRef gif = CFDictionaryGetValue(imagePropertys, kCGImagePropertyGIFDictionary);
    NSNumber *delay = CFDictionaryGetValue(gif, kCGImagePropertyGIFDelayTime);
    
    
    //动画执行
    self.animationImages = images.copy;
    self.animationRepeatCount = 0;
    self.animationDuration = delay.floatValue * count;
    
    CFRelease(sourceRef);
    CFRelease(imagePropertys);
    CFRelease(gif);
}

- (void)pyh_animationWithPath:(NSString *)path {
    CFURLRef url = CFURLCreateWithFileSystemPath(kCFAllocatorDefault, (__bridge CFStringRef)path, kCFURLPOSIXPathStyle, false);
    CGImageSourceRef sourceRef = CGImageSourceCreateWithURL(url, NULL);
    size_t count = CGImageSourceGetCount(sourceRef);
    
    //图片数组
    NSMutableArray *images = [NSMutableArray array];
    for (int i = 0; i < count; i ++) {
        CGImageRef imageRef = CGImageSourceCreateImageAtIndex(sourceRef, i, NULL);
        [images addObject:[UIImage imageWithCGImage:imageRef]];
    }
    
    //属性
    //    NSDictionary *propertys = (__bridge_transfer NSDictionary *)(CGImageSourceCopyProperties(sourceRef, NULL));
    //    NSDictionary *imagePropertys = (__bridge_transfer NSDictionary *)(CGImageSourceCopyPropertiesAtIndex(sourceRef, 1, NULL));
    CFDictionaryRef imagePropertys = CGImageSourceCopyPropertiesAtIndex(sourceRef, 1, NULL);
    CFDictionaryRef gif = CFDictionaryGetValue(imagePropertys, kCGImagePropertyGIFDictionary);
    NSNumber *delay = CFDictionaryGetValue(gif, kCGImagePropertyGIFDelayTime);
    
    //动画执行
    self.animationImages = images.copy;
    self.animationDuration = delay.floatValue * count;
    self.animationRepeatCount = 0;
    [self startAnimating];
    
    CFRelease(sourceRef);
    CFRelease(imagePropertys);
    CFRelease(gif);
}
@end