Merge pull request #14 from SDWebImage/bugfix_webp_blend_canvas

Fix the logic for Animated WebP images which contains a subsequence blend from the first frame, impact the `SDAnimatedImage`

Author: kinarobin

SDWebImageWebPCoder.xcodeproj/project.pbxproj

@@ -8,6 +8,7 @@
 
 /* Begin PBXBuildFile section */
 0EF5B6264833B7BC20894578 /* Pods_SDWebImageWebPCoderTests.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 46F21AD7D1692EBAC4D0FF33 /* Pods_SDWebImageWebPCoderTests.framework */; };
+3219F3B2228B0453003822A6 /* TestImageBlendAnimated.webp in Resources */ = {isa = PBXBuildFile; fileRef = 3219F3B1228B0453003822A6 /* TestImageBlendAnimated.webp */; };
 806E77B32136A2E900A316D2 /* UIImage+WebP.m in Sources */ = {isa = PBXBuildFile; fileRef = 806E77AA2136A2E900A316D2 /* UIImage+WebP.m */; };
 806E77B42136A2E900A316D2 /* SDImageWebPCoder.h in Headers */ = {isa = PBXBuildFile; fileRef = 806E77AB2136A2E900A316D2 /* SDImageWebPCoder.h */; settings = {ATTRIBUTES = (Public, ); }; };
 806E77B62136A2E900A316D2 /* UIImage+WebP.h in Headers */ = {isa = PBXBuildFile; fileRef = 806E77AD2136A2E900A316D2 /* UIImage+WebP.h */; settings = {ATTRIBUTES = (Public, ); }; };
@@ -44,6 +45,7 @@
 /* Begin PBXFileReference section */
 28D8AA3D3015E075692FD3E3 /* Pods-SDWebImageWebPCoderTests.debug.xcconfig */ = {isa = PBXFileReference; includeInIndex = 1; lastKnownFileType = text.xcconfig; name = "Pods-SDWebImageWebPCoderTests.debug.xcconfig"; path = "SDWebImageWebPCoderTests/Pods/Target Support Files/Pods-SDWebImageWebPCoderTests/Pods-SDWebImageWebPCoderTests.debug.xcconfig"; sourceTree = "<group>"; };
 3217BE7B220547EB003D0310 /* SDWebImageWebPCoder.modulemap */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = "sourcecode.module-map"; path = SDWebImageWebPCoder.modulemap; sourceTree = "<group>"; };
+3219F3B1228B0453003822A6 /* TestImageBlendAnimated.webp */ = {isa = PBXFileReference; lastKnownFileType = file; path = TestImageBlendAnimated.webp; sourceTree = "<group>"; };
 46F21AD7D1692EBAC4D0FF33 /* Pods_SDWebImageWebPCoderTests.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_SDWebImageWebPCoderTests.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 806E779D2136A1C000A316D2 /* SDWebImageWebPCoder.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = SDWebImageWebPCoder.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 806E77AA2136A2E900A316D2 /* UIImage+WebP.m */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.objc; path = "UIImage+WebP.m"; sourceTree = "<group>"; };
@@ -205,6 +207,7 @@
 children = (
 808C919A213FD2B2004B0F7C /* TestImageStatic.webp */,
 808C919B213FD2B2004B0F7C /* TestImageAnimated.webp */,
+3219F3B1228B0453003822A6 /* TestImageBlendAnimated.webp */,
 );
 path = Images;
 sourceTree = "<group>";
@@ -453,6 +456,7 @@
 isa = PBXResourcesBuildPhase;
 buildActionMask = 2147483647;
 files = (
+3219F3B2228B0453003822A6 /* TestImageBlendAnimated.webp in Resources */,
 808C919D213FD2B2004B0F7C /* TestImageAnimated.webp in Resources */,
 808C919C213FD2B2004B0F7C /* TestImageStatic.webp in Resources */,
 );
@@ -620,8 +624,14 @@
 "DEBUG=1",
 "$(inherited)",
 );
-"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchos*]" = "WEBP_USE_INTRINSICS=1 $(inherited)";
-"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchsimulator*]" = "WEBP_USE_INTRINSICS=1 $(inherited)";
+"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchos*]" = (
+"WEBP_USE_INTRINSICS=1",
+"$(inherited)",
+);
+"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchsimulator*]" = (
+"WEBP_USE_INTRINSICS=1",
+"$(inherited)",
+);
 GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 GCC_WARN_UNDECLARED_SELECTOR = YES;
@@ -689,8 +699,14 @@
 GCC_C_LANGUAGE_STANDARD = gnu11;
 GCC_NO_COMMON_BLOCKS = YES;
 GCC_PREPROCESSOR_DEFINITIONS = "$(inherited)";
-"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchos*]" = "WEBP_USE_INTRINSICS=1 $(inherited)";
-"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchsimulator*]" = "WEBP_USE_INTRINSICS=1 $(inherited)";
+"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchos*]" = (
+"WEBP_USE_INTRINSICS=1",
+"$(inherited)",
+);
+"GCC_PREPROCESSOR_DEFINITIONS[sdk=watchsimulator*]" = (
+"WEBP_USE_INTRINSICS=1",
+"$(inherited)",
+);
 GCC_WARN_64_TO_32_BIT_CONVERSION = YES;
 GCC_WARN_ABOUT_RETURN_TYPE = YES_ERROR;
 GCC_WARN_UNDECLARED_SELECTOR = YES;

SDWebImageWebPCoder/Classes/SDImageWebPCoder.m

@@ -46,8 +46,8 @@ @interface SDWebPCoderFrame : NSObject
 @property (nonatomic, assign) NSUInteger offsetY; // Frame origin.y in canvas (left-bottom based)
 @property (nonatomic, assign) BOOL hasAlpha; // Whether frame contains alpha
 @property (nonatomic, assign) BOOL isFullSize; // Whether frame size is equal to canvas size
-@property (nonatomic, assign) WebPMuxAnimBlend blend; // Frame dispose method
-@property (nonatomic, assign) WebPMuxAnimDispose dispose; // Frame blend operation
+@property (nonatomic, assign) BOOL shouldBlend; // Frame dispose method
+@property (nonatomic, assign) BOOL shouldDispose; // Frame blend operation
 @property (nonatomic, assign) NSUInteger blendFromIndex; // The nearest previous frame index which blend mode is WEBP_MUX_BLEND
 
 @end
@@ -719,20 +719,20 @@ - (BOOL)scanAndCheckFramesValidWithDemuxer:(WebPDemuxer *)demuxer {
  frame.width = iter.width;
  frame.height = iter.height;
  frame.hasAlpha = iter.has_alpha;
- frame.dispose = iter.dispose_method;
- frame.blend = iter.blend_method;
+ frame.shouldDispose = iter.dispose_method == WEBP_MUX_DISPOSE_BACKGROUND;
+ frame.shouldBlend = iter.blend_method == WEBP_MUX_BLEND;
  frame.offsetX = iter.x_offset;
  frame.offsetY = canvasHeight - iter.y_offset - iter.height;
 
  BOOL sizeEqualsToCanvas = (iter.width == canvasWidth && iter.height == canvasHeight);
  BOOL offsetIsZero = (iter.x_offset == 0 && iter.y_offset == 0);
  frame.isFullSize = (sizeEqualsToCanvas && offsetIsZero);
 
- if ((!frame.blend || !frame.hasAlpha) && frame.isFullSize) {
+ if ((!frame.shouldBlend || !frame.hasAlpha) && frame.isFullSize) {
  lastBlendIndex = iterIndex;
  frame.blendFromIndex = iterIndex;
  } else {
- if (frame.dispose && frame.isFullSize) {
+ if (frame.shouldDispose && frame.isFullSize) {
  frame.blendFromIndex = lastBlendIndex;
  lastBlendIndex = iterIndex + 1;
  } else {

SDWebImageWebPCoderTests/Images/TestImageBlendAnimated.webp

@@ -28,6 +28,11 @@ @interface SDAnimatedImageView ()
 @property (nonatomic, assign) BOOL isProgressive;
 @end
 
+@interface SDWebPCoderFrame : NSObject
+@property (nonatomic, assign) NSUInteger index; // Frame index (zero based)
+@property (nonatomic, assign) NSUInteger blendFromIndex; // The nearest previous frame index which blend mode is WEBP_MUX_BLEND
+@end
+
 @implementation SDWebImageWebPCoderTests
 
 + (void)setUp {
@@ -126,6 +131,47 @@ - (void)test32AnimatedImageViewCategoryProgressive {
  [self waitForExpectationsWithTimeout:kAsyncTestTimeout handler:nil];
 }
 
+- (void)test33AnimatedImageBlendMethod {
+ // Test the optimization for blend and disposal method works without problem
+ NSURL *animatedWebPURL = [[NSBundle bundleForClass:[self class]] URLForResource:@"TestImageBlendAnimated" withExtension:@"webp"];
+ NSData *data = [NSData dataWithContentsOfURL:animatedWebPURL];
+ SDImageWebPCoder *coder = [[SDImageWebPCoder alloc] initWithAnimatedImageData:data options:nil];
+ XCTAssertNotNil(coder);
+ /**
+ This WebP image frames info is below:
+ Canvas size: 400 x 400
+ Features present: animation transparency
+ Background color : 0xFF000000 Loop Count : 0
+ Number of frames: 12
+ No.: width height alpha x_offset y_offset duration dispose blend image_size compression
+ 1: 400 400 no 0 0 70 none no 5178 lossless
+ 2: 400 400 yes 0 0 70 none yes 1386 lossless
+ 3: 400 400 yes 0 0 70 none yes 1472 lossless
+ 4: 400 394 yes 0 6 70 none yes 3212 lossless
+ 5: 371 394 yes 0 6 70 none yes 1888 lossless
+ 6: 394 382 yes 6 6 70 none yes 3346 lossless
+ 7: 400 388 yes 0 0 70 none yes 3786 lossless
+ 8: 394 383 yes 0 0 70 none yes 1858 lossless
+ 9: 394 394 yes 0 6 70 none yes 3794 lossless
+ 10: 372 394 yes 22 6 70 none yes 3458 lossless
+ 11: 400 400 no 0 0 70 none no 5270 lossless
+ 12: 320 382 yes 0 6 70 none yes 2506 lossless
+ */
+ NSArray<SDWebPCoderFrame *> *frames = [coder valueForKey:@"_frames"];
+ XCTAssertEqual(frames.count, 12);
+ for (SDWebPCoderFrame *frame in frames) {
+ switch (frame.index) {
+ // frame: 11 blend == no, means clear the canvas
+ case 10:
+ case 11:
+ XCTAssertEqual(frame.blendFromIndex, 10);
+ break;
+ default:
+ XCTAssertEqual(frame.blendFromIndex, 0);
+ break;
+ }
+ }
+}
 
 @end