Provide a way to detect HEIC encoding compatibility. So that we can avoid encoding to this format.

SDWebImage/NSData+ImageContentType.m

@@ -14,6 +14,11 @@
 #import <MobileCoreServices/MobileCoreServices.h>
 #endif
 
+// Currently Image/IO does not support WebP
+#define kSDUTTypeWebP ((__bridge CFStringRef)@"public.webp")
+// AVFileTypeHEIC is defined in AVFoundation via iOS 11, we use this without import AVFoundation
+#define kSDUTTypeHEIC ((__bridge CFStringRef)@"public.heic")
+
 @implementation NSData (ImageContentType)
 
 + (SDImageFormat)sd_imageFormatForImageData:(nullable NSData *)data {
@@ -48,7 +53,7 @@
             if (data.length >= 12) {
                 //....ftypheic
                 NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(4, 8)] encoding:NSASCIIStringEncoding];
-                if ([testString hasPrefix:@"ftyp"] && [testString hasSuffix:@"heic"]) {
+                if ([testString isEqualToString:@"ftypheic"]) {
                     return SDImageFormatHEIC;
                 }
             }
@@ -73,6 +78,12 @@
         case SDImageFormatTIFF:
             UTType = kUTTypeTIFF;
             break;
+        case SDImageFormatWebP:
+            UTType = kSDUTTypeWebP;
+            break;
+        case SDImageFormatHEIC:
+            UTType = kSDUTTypeHEIC;
+            break;
         default:
             // default is kUTTypePNG
             UTType = kUTTypePNG;

SDWebImage/SDWebImageImageIOCoder.m

@@ -397,6 +397,8 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
         // Do not support WebP encoding
         case SDImageFormatWebP:
             return NO;
+        case SDImageFormatHEIC:
+            return [[self class] canEncodeToHEICFormat];
         default:
             return YES;
     }
@@ -469,6 +471,28 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
     return YES;
 }
 
++ (BOOL)canEncodeToHEICFormat
+{
+    static BOOL canEncode = NO;
+    static dispatch_once_t onceToken;
+    dispatch_once(&onceToken, ^{
+        NSMutableData *imageData = [NSMutableData data];
+        CFStringRef imageUTType = [NSData sd_UTTypeFromSDImageFormat:SDImageFormatHEIC];
+        
+        // Create an image destination.
+        CGImageDestinationRef imageDestination = CGImageDestinationCreateWithData((__bridge CFMutableDataRef)imageData, imageUTType, 1, NULL);
+        if (!imageDestination) {
+            // Can encode to HEIC
+            canEncode = NO;
+        } else {
+            // Can't encode to HEIF
+            CFRelease(imageDestination);
+            canEncode = YES;
+        }
+    });
+    return canEncode;
+}
+
 #if SD_UIKIT || SD_WATCH
 #pragma mark EXIF orientation tag converter
 + (UIImageOrientation)sd_imageOrientationFromImageData:(nonnull NSData *)imageData {