GIF解析和生成

//gif的解析, 和生成

网络转载,忘记出处了 
//制作gif是基于ImageIO.framework,所以要先添加这个库gif分解图片



- (void)viewDidLoad
{
    [super viewDidLoad];

    NSData *data = [NSData dataWithContentsOfFile:[[NSBundle mainBundle]pathForResource:@"test101" ofType:@"gif"]];

    //通过data获取image的数据源
    CGImageSourceRef source = CGImageSourceCreateWithData((__bridge CFDataRef)data, NULL);
    
    //获取帧数
    size_t count = CGImageSourceGetCount(source);
    
    NSMutableArray* tmpArray = [NSMutableArray array];
    for (size_t i = 0; i < count; i++)
    {
        //获取图像
        CGImageRef imageRef = CGImageSourceCreateImageAtIndex(source, i, NULL);
        
        //生成image
        UIImage *image = [UIImage imageWithCGImage:imageRef scale:[UIScreen mainScreen].scale orientation:UIImageOrientationUp];
        
        [tmpArray addObject:image];
        
        CGImageRelease(imageRef);
    }
    CFRelease(source);
    
    int i = 0;
    for (UIImage *img in tmpArray) {
        //写文件
        NSData *imageData = UIImagePNGRepresentation(img);
        
        NSString *pathNum = [[self backPath] stringByAppendingPathComponent:[NSString stringWithFormat:@"%d.png",i]];
        [imageData writeToFile:pathNum atomically:NO];
        i++;
    }
       
}

//返回保存图片的路径
-(NSString *)backPath{
    NSFileManager *fileManager = [NSFileManager defaultManager];
    
    NSString *path = [UniversalMethod backDocumentDirectoryPath];
    
    NSString *imageDirectory = [path stringByAppendingPathComponent:@"Normal"];
    
    [fileManager createDirectoryAtPath:imageDirectory withIntermediateDirectories:YES attributes:nil error:nil];
    return imageDirectory;
}

gif的制作
制作gif需要依赖MobileCoreServices.framework

//gif的制作
    
    //获取源数据image
    NSMutableArray *imgs = [[NSMutableArray alloc]initWithObjects:[UIImage imageNamed:@"bear_1"],[UIImage imageNamed:@"bear_2"], nil];
    
    //图像目标
    CGImageDestinationRef destination;
    
    //创建输出路径
    NSArray *document = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
    NSString *documentStr = [document objectAtIndex:0];
    NSFileManager *fileManager = [NSFileManager defaultManager];
    NSString *textDirectory = [documentStr stringByAppendingPathComponent:@"gif"];
    [fileManager createDirectoryAtPath:textDirectory withIntermediateDirectories:YES attributes:nil error:nil];
    NSString *path = [textDirectory stringByAppendingPathComponent:@"test101.gif"];
    
    
    NSLog(@"%@",path);
    
    //创建CFURL对象
    /*
     CFURLCreateWithFileSystemPath(CFAllocatorRef allocator, CFStringRef filePath, CFURLPathStyle pathStyle, Boolean isDirectory)
     
     allocator : 分配器,通常使用kCFAllocatorDefault
     filePath : 路径
     pathStyle : 路径风格,我们就填写kCFURLPOSIXPathStyle 更多请打问号自己进去帮助看
     isDirectory : 一个布尔值,用于指定是否filePath被当作一个目录路径解决时相对路径组件
     */
    CFURLRef url = CFURLCreateWithFileSystemPath (
                                                  kCFAllocatorDefault,
                                                  (CFStringRef)path,
                                                  kCFURLPOSIXPathStyle,
                                                  false);
    
    //通过一个url返回图像目标
    destination = CGImageDestinationCreateWithURL(url, kUTTypeGIF, imgs.count, NULL);
    
    //设置gif的信息,播放间隔时间,基本数据,和delay时间
    NSDictionary *frameProperties = [NSDictionary
                                     dictionaryWithObject:[NSMutableDictionary dictionaryWithObjectsAndKeys:[NSNumber numberWithFloat:0.3], (NSString *)kCGImagePropertyGIFDelayTime, nil]
                                     forKey:(NSString *)kCGImagePropertyGIFDictionary];
    
    //设置gif信息
    NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithCapacity:2];
    
    [dict setObject:[NSNumber numberWithBool:YES] forKey:(NSString*)kCGImagePropertyGIFHasGlobalColorMap];
    
    [dict setObject:(NSString *)kCGImagePropertyColorModelRGB forKey:(NSString *)kCGImagePropertyColorModel];
    
    [dict setObject:[NSNumber numberWithInt:8] forKey:(NSString*)kCGImagePropertyDepth];
    
    [dict setObject:[NSNumber numberWithInt:0] forKey:(NSString *)kCGImagePropertyGIFLoopCount];
    NSDictionary *gifProperties = [NSDictionary dictionaryWithObject:dict
                                                              forKey:(NSString *)kCGImagePropertyGIFDictionary];
    //合成gif
    for (UIImage* dImg in imgs)
    {
        CGImageDestinationAddImage(destination, dImg.CGImage, (__bridge CFDictionaryRef)frameProperties);
    }
    CGImageDestinationSetProperties(destination, (__bridge CFDictionaryRef)gifProperties);
    CGImageDestinationFinalize(destination);
    CFRelease(destination);

---

gif 解析方法

From: http://blog.csdn.net/qxuewei/article/details/50782855

原生方法:

1.UIWebView
特点:加载速度略长,性能更优，播放的gif动态图更加流畅。

-(void)showGifImageWithWebView{

    NSData *gifData = [NSData dataWithContentsOfFile: [[NSBundle mainBundle] pathForResource:@"earthGif" ofType:@"gif"]];

    UIWebView *imageWebView = [[UIWebView alloc] initWithFrame:CGRectMake(112, 302, 132, 102)];

    imageWebView.userInteractionEnabled = NO;

    [imageWebView loadData:gifData MIMEType:@"image/gif" textEncodingName:nil baseURL:nil];

    [self.view addSubview:imageWebView];
}

2.UIImagView
加载的方式更加快速,性能不如UIWebView,优点:易于扩展

1)
增加一个UIImageView的类别(category),增加两个方法
UIImage+Tool
.h

#import <UIKit/UIKit.h>

@interface UIImageView (Tool)

/** 解析gif文件数据的方法 block中会将解析的数据传递出来 */
-(void)getGifImageWithUrk:(NSURL *)url returnData:(void(^)(NSArray<UIImage *> * imageArray,NSArray<NSNumber *>*timeArray,CGFloat totalTime, NSArray<NSNumber *>* widths, NSArray<NSNumber *>* heights))dataBlock;

/** 为UIImageView添加一个设置gif图内容的方法： */
-(void)yh_setImage:(NSURL *)imageUrl;

@end

.m

#import "UIImageView+Tool.h"

#import <ImageIO/ImageIO.h>

@implementation UIImageView (Tool)




-(void)getGifImageWithUrk:(NSURL *)url returnData:(void(^)(NSArray<UIImage *> * imageArray, NSArray<NSNumber *>*timeArray,CGFloat totalTime, NSArray<NSNumber *>* widths,NSArray<NSNumber *>* heights))dataBlock{

    CGImageSourceRef source = CGImageSourceCreateWithURL((CFURLRef)url, NULL);

    size_t count = CGImageSourceGetCount(source);

    float allTime=0;

    NSMutableArray * imageArray = [[NSMutableArray alloc]init];

    NSMutableArray * timeArray = [[NSMutableArray alloc]init];

    NSMutableArray * widthArray = [[NSMutableArray alloc]init];

    NSMutableArray * heightArray = [[NSMutableArray alloc]init];

    for (size_t i=0; i<count; i++) {
        CGImageRef image = CGImageSourceCreateImageAtIndex(source, i, NULL);
        [imageArray addObject:(__bridge UIImage *)(image)];
        CGImageRelease(image);

        NSDictionary * info = (__bridge NSDictionary*)CGImageSourceCopyPropertiesAtIndex(source, i, NULL);
        CGFloat width = [[info objectForKey:(__bridge NSString *)kCGImagePropertyPixelWidth] floatValue];
        CGFloat height = [[info objectForKey:(__bridge NSString *)kCGImagePropertyPixelHeight] floatValue];
        [widthArray addObject:[NSNumber numberWithFloat:width]];
        [heightArray addObject:[NSNumber numberWithFloat:height]];
        NSDictionary * timeDic = [info objectForKey:(__bridge NSString *)kCGImagePropertyGIFDictionary];
        CGFloat time = [[timeDic objectForKey:(__bridge NSString *)kCGImagePropertyGIFDelayTime]floatValue];
        allTime+=time;
        [timeArray addObject:[NSNumber numberWithFloat:time]];
    }
    CFRelease(source);
    dataBlock(imageArray,timeArray,allTime,widthArray,heightArray);
}


-(void)yh_setImage:(NSURL *)imageUrl{
    __weak id __self = self;
    [self getGifImageWithUrk:imageUrl returnData:^(NSArray<UIImage *> *imageArray, NSArray<NSNumber *> *timeArray, CGFloat totalTime, NSArray<NSNumber *> *widths, NSArray<NSNumber *> *heights) {

        CAKeyframeAnimation *animation = [CAKeyframeAnimation animationWithKeyPath:@"contents"];
        NSMutableArray * times = [[NSMutableArray alloc]init];
        float currentTime = 0;

        for (int i=0; i<imageArray.count; i++) {
            [times addObject:[NSNumber numberWithFloat:currentTime/totalTime]];
            currentTime+=[timeArray[i] floatValue];
        }
        [animation setKeyTimes:times];
        [animation setValues:imageArray];
        [animation setTimingFunction:[CAMediaTimingFunction functionWithName:kCAMediaTimingFunctionLinear]];

        animation.repeatCount= MAXFLOAT;

        animation.duration = totalTime;

        [[(UIImageView *)__self layer]addAnimation:animation forKey:@"gifAnimation"];
    }];
}

@end

在加载gif的地方使用
导入 UIImageView+Tool

-(void)showGifImageWithImageView{

    UIImageView * imageView = [[UIImageView alloc]initWithFrame:CGRectMake(112, 342, 132, 102)];
    NSURL * url = [[NSURL alloc]initFileURLWithPath:[[NSBundle mainBundle] pathForResource:@"earthGif.gif" ofType:nil]];
    [imageView yh_setImage:url];
    [self.view addSubview:imageView];

}

第三方:
1.YLGIFImage
github链接: [https://github.com/liyong03/YLGIFImage][1]

[1]: https://github.com/liyong03/YLGIFImage

#import “YLGIFImage.h”

#import "YLImageView.h"

-(void)showGifImageWithYLImageView{
    YLImageView* imageView = [[YLImageView alloc] initWithFrame:CGRectMake(112, 342, 132, 102)];
    CGFloat centerX = self.view.center.x;
    [imageView setCenter:CGPointMake(centerX, 402)];
    [self.view addSubview:imageView];
    imageView.image = [YLGIFImage imageNamed:@"earthGif.gif"];
}

2.FLAnimatedImage
github链接:[https://github.com/Flipboard/FLAnimatedImage][2]

[2]: https://github.com/Flipboard/FLAnimatedImage

-(void)showGifImageWithFLAnimatedImage{

    NSString *pathForFile = [[NSBundle mainBundle] pathForResource: @"earthGif" ofType:@"gif"];

    NSData *dataOfGif = [NSData dataWithContentsOfFile: pathForFile];

    FLAnimatedImage *image = [FLAnimatedImage animatedImageWithGIFData:dataOfGif];

    FLAnimatedImageView *imageView = [[FLAnimatedImageView alloc] init];

    imageView.animatedImage = image;
    imageView.frame = CGRectMake(112, 342, 132, 102);
    [self.view addSubview:imageView];
}