Merge pull request #2080 from dreampiggy/feature_heif_image_format

Add image format detect of HEIC (One type of HEIF which use HEVC codec). This is supported natively in iOS 11 & macOS 10.13

@@ -16,7 +16,8 @@ typedef NS_ENUM(NSInteger, SDImageFormat) {
     SDImageFormatPNG,
     SDImageFormatPNG,
     SDImageFormatGIF,
     SDImageFormatGIF,
     SDImageFormatTIFF,
     SDImageFormatTIFF,
-    SDImageFormatWebP
+    SDImageFormatWebP,
+    SDImageFormatHEIC
 };
 };
 
 
 @interface NSData (ImageContentType)
 @interface NSData (ImageContentType)

@@ -14,6 +14,11 @@
 #import <MobileCoreServices/MobileCoreServices.h>
 #import <MobileCoreServices/MobileCoreServices.h>
 #endif
 #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)
 @implementation NSData (ImageContentType)
 
 
 + (SDImageFormat)sd_imageFormatForImageData:(nullable NSData *)data {
 + (SDImageFormat)sd_imageFormatForImageData:(nullable NSData *)data {
@@ -21,6 +26,7 @@
         return SDImageFormatUndefined;
         return SDImageFormatUndefined;
     }
     }
     
     
+    // File signatures table: http://www.garykessler.net/library/file_sigs.html
     uint8_t c;
     uint8_t c;
     [data getBytes:&c length:1];
     [data getBytes:&c length:1];
     switch (c) {
     switch (c) {
@@ -33,16 +39,26 @@
         case 0x49:
         case 0x49:
         case 0x4D:
         case 0x4D:
             return SDImageFormatTIFF;
             return SDImageFormatTIFF;
-        case 0x52:
-            // R as RIFF for WEBP
-            if (data.length < 12) {
-                return SDImageFormatUndefined;
+        case 0x52: {
+            if (data.length >= 12) {
+                //RIFF....WEBP
+                NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];
+                if ([testString hasPrefix:@"RIFF"] && [testString hasSuffix:@"WEBP"]) {
+                    return SDImageFormatWebP;
+                }
             }
             }
-            
-            NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(0, 12)] encoding:NSASCIIStringEncoding];
-            if ([testString hasPrefix:@"RIFF"] && [testString hasSuffix:@"WEBP"]) {
-                return SDImageFormatWebP;
+            break;
+        }
+        case 0x00: {
+            if (data.length >= 12) {
+                //....ftypheic
+                NSString *testString = [[NSString alloc] initWithData:[data subdataWithRange:NSMakeRange(4, 8)] encoding:NSASCIIStringEncoding];
+                if ([testString isEqualToString:@"ftypheic"]) {
+                    return SDImageFormatHEIC;
+                }
             }
             }
+            break;
+        }
     }
     }
     return SDImageFormatUndefined;
     return SDImageFormatUndefined;
 }
 }
@@ -62,6 +78,12 @@
         case SDImageFormatTIFF:
         case SDImageFormatTIFF:
             UTType = kUTTypeTIFF;
             UTType = kUTTypeTIFF;
             break;
             break;
+        case SDImageFormatWebP:
+            UTType = kSDUTTypeWebP;
+            break;
+        case SDImageFormatHEIC:
+            UTType = kSDUTTypeHEIC;
+            break;
         default:
         default:
             // default is kUTTypePNG
             // default is kUTTypePNG
             UTType = kUTTypePNG;
             UTType = kUTTypePNG;

@@ -33,10 +33,12 @@ CG_EXTERN BOOL SDCGImageRefContainsAlpha(_Nullable CGImageRef imageRef);
 
 
 /**
 /**
  This is the image coder protocol to provide custom image decoding/encoding.
  This is the image coder protocol to provide custom image decoding/encoding.
+ These methods are all required to implement.
  @note Pay attention that these methods are not called from main queue.
  @note Pay attention that these methods are not called from main queue.
  */
  */
 @protocol SDWebImageCoder <NSObject>
 @protocol SDWebImageCoder <NSObject>
 
 
+@required
 #pragma mark - Decoding
 #pragma mark - Decoding
 /**
 /**
  Returns YES if this coder can decode some data. Otherwise, the data should be passed to another coder.
  Returns YES if this coder can decode some data. Otherwise, the data should be passed to another coder.
@@ -90,10 +92,12 @@ CG_EXTERN BOOL SDCGImageRefContainsAlpha(_Nullable CGImageRef imageRef);
 
 
 /**
 /**
  This is the image coder protocol to provide custom progressive image decoding.
  This is the image coder protocol to provide custom progressive image decoding.
+ These methods are all required to implement.
  @note Pay attention that these methods are not called from main queue.
  @note Pay attention that these methods are not called from main queue.
  */
  */
 @protocol SDWebImageProgressiveCoder <SDWebImageCoder>
 @protocol SDWebImageProgressiveCoder <SDWebImageCoder>
 
 
+@required
 /**
 /**
  Returns YES if this coder can incremental decode some data. Otherwise, it should be passed to another coder.
  Returns YES if this coder can incremental decode some data. Otherwise, it should be passed to another coder.
  
  

@@ -66,8 +66,8 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
 #pragma mark - Decode
 #pragma mark - Decode
 - (BOOL)canDecodeFromData:(nullable NSData *)data {
 - (BOOL)canDecodeFromData:(nullable NSData *)data {
     switch ([NSData sd_imageFormatForImageData:data]) {
     switch ([NSData sd_imageFormatForImageData:data]) {
-        // Do not support WebP decoding
         case SDImageFormatWebP:
         case SDImageFormatWebP:
+            // Do not support WebP decoding
             return NO;
             return NO;
         default:
         default:
             return YES;
             return YES;
@@ -76,8 +76,8 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
 
 
 - (BOOL)canIncrementallyDecodeFromData:(NSData *)data {
 - (BOOL)canIncrementallyDecodeFromData:(NSData *)data {
     switch ([NSData sd_imageFormatForImageData:data]) {
     switch ([NSData sd_imageFormatForImageData:data]) {
-        // Support static GIF progressive decoding
         case SDImageFormatWebP:
         case SDImageFormatWebP:
+            // Do not support WebP progressive decoding
             return NO;
             return NO;
         default:
         default:
             return YES;
             return YES;
@@ -394,9 +394,12 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
 #pragma mark - Encode
 #pragma mark - Encode
 - (BOOL)canEncodeToFormat:(SDImageFormat)format {
 - (BOOL)canEncodeToFormat:(SDImageFormat)format {
     switch (format) {
     switch (format) {
-        // Do not support WebP encoding
         case SDImageFormatWebP:
         case SDImageFormatWebP:
+            // Do not support WebP encoding
             return NO;
             return NO;
+        case SDImageFormatHEIC:
+            // Check HEIC encoding compatibility
+            return [[self class] canEncodeToHEICFormat];
         default:
         default:
             return YES;
             return YES;
     }
     }
@@ -469,6 +472,28 @@ static const CGFloat kDestSeemOverlap = 2.0f;   // the numbers of pixels to over
     return YES;
     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't encode to HEIC
+            canEncode = NO;
+        } else {
+            // Can encode to HEIC
+            CFRelease(imageDestination);
+            canEncode = YES;
+        }
+    });
+    return canEncode;
+}
+
 #if SD_UIKIT || SD_WATCH
 #if SD_UIKIT || SD_WATCH
 #pragma mark EXIF orientation tag converter
 #pragma mark EXIF orientation tag converter
 + (UIImageOrientation)sd_imageOrientationFromImageData:(nonnull NSData *)imageData {
 + (UIImageOrientation)sd_imageOrientationFromImageData:(nonnull NSData *)imageData {