// 加载本地图片UIImage *image = [UIImage imageNamed:@"heifFileName"];UIImage *image = [UIImage imageWithContentsOfFile:filePath];
// 由 网络请求的 NSData 解码UIImage *image = [UIImage imageWithData:heifImageData];

//获取所支持的图片格式数组,解码CFArrayRef decodeArr = CGImageSourceCopyTypeIdentifiers();NSArray *decodeUTI = (__bridge NSArray *)decodeArr;NSLog(@"解码支持%@", decodeUTI);
//获取所支持的图片格式数组,编码CFArrayRef encodeArr = CGImageDestinationCopyTypeIdentifiers();NSArray *encodeUTI = (__bridge NSArray *)encodeArr;NSLog(@"编码支持%@", encodeUTI);

// Any iOS Device(arm64)/Applications/Xcode.app/Contents/Developer/usr/bin/actool --output-format human-readable-text --notices --warnings --export-dependency-info /Users/xxxxx/Library/Developer/Xcode/DerivedData/ImageDemoS-auwsocxqgbwbgmfoiguzuahzizre/Build/Intermediates.noindex/ImageDemoS.build/Debug-iphoneos/ImageDemoS.build/assetcatalog_dependencies --output-partial-info-plist /Users/xxxxx/Library/Developer/Xcode/DerivedData/ImageDemoS-auwsocxqgbwbgmfoiguzuahzizre/Build/Intermediates.noindex/ImageDemoS.build/Debug-iphoneos/ImageDemoS.build/assetcatalog_generated_info.plist --app-icon AppIcon --accent-color AccentColor --compress-pngs --enable-on-demand-resources YES --development-region en --target-device iphone --target-device ipad --minimum-deployment-target 16.0 --platform iphoneos --compile /Users/xxxxx/Library/Developer/Xcode/DerivedData/ImageDemoS-auwsocxqgbwbgmfoiguzuahzizre/Build/Products/Debug-iphoneos/ImageDemoS.app /Users/xxxxxR/baidu/personal-code/ImageDemoS/ImageDemoS/Assets.xcassets /Users/xxxxx/baidu/personal-code/ImageDemoS/Media.xcassets

// iPhone6p（iOS11.4.1）/Applications/Xcode.app/Contents/Developer/usr/bin/actool --output-format human-readable-text --notices --warnings --export-dependency-info /Users/xxxxx/Library/Developer/Xcode/DerivedData/ImageDemoS-auwsocxqgbwbgmfoiguzuahzizre/Build/Intermediates.noindex/ImageDemoS.build/Debug-iphoneos/ImageDemoS.build/assetcatalog_dependencies --output-partial-info-plist /Users/xxxxx/Library/Developer/Xcode/DerivedData/ImageDemoS-auwsocxqgbwbgmfoiguzuahzizre/Build/Intermediates.noindex/ImageDemoS.build/Debug-iphoneos/ImageDemoS.build/assetcatalog_generated_info.plist --app-icon AppIcon --accent-color AccentColor --compress-pngs --enable-on-demand-resources YES --optimization space --filter-for-thinning-device-configuration iPhone7,1 --filter-for-device-os-version 11.4.1 --development-region en --target-device iphone --target-device ipad --minimum-deployment-target 9.0 --platform iphoneos --compile /Users/xxxxx/Library/Developer/Xcode/DerivedData/ImageDemoS-auwsocxqgbwbgmfoiguzuahzizre/Build/Products/Debug-iphoneos/ImageDemoS.app /Users/xxxxx/baidu/personal-code/ImageDemoS/ImageDemoS/Assets.xcassets /Users/xxxxx/baidu/personal-code/ImageDemoS/Media.xcassets

/* com.apple.actool.document.warnings *//Media.xcassets:./logHEICAlpha.imageset/[universal][][][3x][][][][][][][][][][]: warning: You're targeting iOS 9.0, but HEIF files can only be accessed from an Asset Catalog in iOS 11.0 and later.

assetutil -I Assets.car > Assets.json

SizeOnDisk：这是图片在Assets.car里实际的体积Encoding：编码方式，HEIF就是HEIC图片的编码方式Compression：压缩算法

 /// 获取图片信息和像素/// - Parameters:///   - image: <#image description#> -(void)dumpImageInfo:(UIImage *)image{    // 获取CGImageRef    CGImageRef cgimage = image.CGImage;     size_t width  = CGImageGetWidth(cgimage);    size_t height = CGImageGetHeight(cgimage);    size_t bpr = CGImageGetBytesPerRow(cgimage);    size_t bpp = CGImageGetBitsPerPixel(cgimage);    size_t bpc = CGImageGetBitsPerComponent(cgimage);    size_t bytes_per_pixel = bpp / bpc;        CGBitmapInfo info = CGImageGetBitmapInfo(cgimage);    NSLog(        @"n"//        "===== %@ =====n"        "CGImageGetHeight: %dn"        "CGImageGetWidth:  %dn"        "CGImageGetColorSpace: %@n"        "CGImageGetBitsPerPixel:     %dn"        "CGImageGetBitsPerComponent: %dn"        "CGImageGetBytesPerRow:      %dn"        "CGImageGetBitmapInfo: 0x%.8Xn"        "  kCGBitmapAlphaInfoMask     = %sn"        "  kCGBitmapFloatComponents   = %sn"        "  kCGBitmapByteOrderMask     = %sn"        "  kCGBitmapByteOrderDefault  = %sn"        "  kCGBitmapByteOrder16Little = %sn"        "  kCGBitmapByteOrder32Little = %sn"        "  kCGBitmapByteOrder16Big    = %sn"        "  kCGBitmapByteOrder32Big    = %sn",//        file,        (int)width,        (int)height,        CGImageGetColorSpace(cgimage),        (int)bpp,        (int)bpc,        (int)bpr,        (unsigned)info,        (info & kCGBitmapAlphaInfoMask)     ? "YES" : "NO",        (info & kCGBitmapFloatComponents)   ? "YES" : "NO",        (info & kCGBitmapByteOrderMask)     ? "YES" : "NO",        (info & kCGBitmapByteOrderDefault)  ? "YES" : "NO",        (info & kCGBitmapByteOrder16Little) ? "YES" : "NO",        (info & kCGBitmapByteOrder32Little) ? "YES" : "NO",        (info & kCGBitmapByteOrder16Big)    ? "YES" : "NO",        (info & kCGBitmapByteOrder32Big)    ? "YES" : "NO"    );        // 获取位图数据    CGDataProviderRef provider = CGImageGetDataProvider(cgimage);    NSData* data = (__bridge NSData *)CGDataProviderCopyData(provider);//    [data autorelease];    const uint8_t* bytes = [data bytes];      printf("Pixel Data:n");    for(size_t row = 0; row < height; row++)    {        for(size_t col = 0; col < width; col++)        {            const uint8_t* pixel =                &bytes[row * bpr + col * bytes_per_pixel];              printf("(");            for(size_t x = 0; x < bytes_per_pixel; x++)            {                printf("%.2d", pixel[x]);                if( x < bytes_per_pixel - 1 )                    printf(",");            }              printf(")");            if( col < width - 1 )                printf(", ");        }          printf("n");    }}

/// 从支持解码的图片创建CGImageRef/// - Parameter path: 图片路径CGImageRef createCGImageFromFile (NSString* path){    // Get the URL for the pathname passed to the function.    NSURL *url = [NSURL fileURLWithPath:path];    CGImageRef        myImage = NULL;    CGImageSourceRef  myImageSource;    CFDictionaryRef   myOptions = NULL;    CFStringRef       myKeys[2];    CFTypeRef         myValues[2];     // Set up options if you want them. The options here are for    // caching the image in a decoded form and for using floating-point    // values if the image format supports them.    myKeys[0] = kCGImageSourceShouldCache;    myValues[0] = (CFTypeRef)kCFBooleanTrue;    myKeys[1] = kCGImageSourceShouldAllowFloat;    myValues[1] = (CFTypeRef)kCFBooleanTrue;    // Create the dictionary    myOptions = CFDictionaryCreate(NULL, (const void **) myKeys,                   (const void **) myValues, 2,                   &kCFTypeDictionaryKeyCallBacks,                   & kCFTypeDictionaryValueCallBacks);    // Create an image source from the URL.    myImageSource = CGImageSourceCreateWithURL((CFURLRef)url, myOptions);    CFRelease(myOptions);    // Make sure the image source exists before continuing    if (myImageSource == NULL){        fprintf(stderr, "Image source is NULL.");        return  NULL;    }    // Create an image from the first item in the image source.    myImage = CGImageSourceCreateImageAtIndex(myImageSource, 0, NULL);     CFRelease(myImageSource);    // Make sure the image exists before continuing    if (myImage == NULL){         fprintf(stderr, "Image not created from image source.");         return NULL;    }     return myImage;}

/// 将任意一种格式的图片由UIImage编码为HEIC图片存储/// - Parameters:///   - image: <#image description#>///   - path: <#path description#>- (void)generateNewHEIC:(UIImage *)image savePath:(NSString *)path{        NSMutableData *imageData = [NSMutableData data];    // HEIC图片编码格式    CFStringRef imageUTType =  CFSTR("public.heic");    CGImageDestinationRef destination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)imageData, imageUTType, 1, NULL);    if (!destination) {        // 无法编码，基本上是因为目标格式不支持        NSLog(@"无法编码");        return;    }    CGImageRef imageRef = image.CGImage; // 待编码的CGImage    // 可选元信息，比如EXIF方向    CGImagePropertyOrientation exifOrientation = kCGImagePropertyOrientationDown;    NSMutableDictionary *frameProperties = [NSMutableDictionary dictionary];//    imageProperties[(__bridge_transfer NSString *) kCGImagePropertyExifDictionary] = @(exifOrientation);    // 添加图像和元信息    CGImageDestinationAddImage(destination, imageRef, (__bridge CFDictionaryRef)frameProperties);    if (CGImageDestinationFinalize(destination) == NO) {        // 编码失败        imageData = nil;    }    // 编码成功，清理……    CFRelease(destination);    // 保存新生成的HEIC图片    if(imageData) {        NSURL *url = [NSURL fileURLWithPath:path];        [imageData writeToURL:url atomically:YES];    }}

% file -b BaiduBoxApp.app/BaiduBoxApp #获取Mach-O架构Mach-O 64-bit executable arm64
% otool -arch arm64 -oV BaiduBoxApp.app/BaiduBoxApp > ovrelease.txt #解析Mach-O内容

'Contents of (__DATA,__objc_classlist) section',  # classlist节标识'Contents of (__DATA,__objc_classrefs) section',  # classrefs节标'Contents of (__DATA,__objc_superrefs) section',  # 父类节标'Contents of (__DATA,__objc_catlist) section',  # category节标'Contents of (__DATA,__objc_protolist) section','Contents of (__DATA,__objc_selrefs) section','Contents of (__DATA,__objc_imageinfo) section'

// class is initialized#define RW_INITIALIZED        (1<<29)
struct objc_class : objc_object {
    bool isInitialized() {    return getMeta()->data()->flags & RW_INITIALIZED;    }};

#define RW_INITIALIZED        (1<<29)
# if __arm64__#   define ISA_MASK        0x0000000ffffffff8ULL# elif __x86_64__#   define ISA_MASK        0x00007ffffffffff8ULL# endif
struct lazyFake_objc_class : lazyFake_objc_object {    //提供metaClass函数，获取元类对象    lazyFake_objc_class* metaClass() {        #if __LP64__        //isa指针需要经过一次 &ISA_MASK操作之后才得到真正的地址            return (lazyFake_objc_class *)((long long)isa & ISA_MASK);        #else            return (lazyFake_objc_class *)((long long)isa);        #endif    }    bool isInitialized() {        return metaClass()->data()->flags & RW_INITIALIZED;    }};

Dl_info info;dladdr(&_mh_execute_header, &info);classes = objc_copyClassNamesForImage(info.dli_fname, &classCount);

struct lazyFake_objc_class *objectClass = (__bridge struct lazyFake_objc_class *)cls;
BOOL isInitial = objectClass->isInitialized();