Add animation support for WebP images

Source/core/platform/image-decoders/webp/WEBPImageDecoder.h

Index: Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
diff --git a/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h b/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
index ea74c8e117331796b92cdc7bd4dfc731a99ef571..2b92f14c7bd396793fb3befeb63523da3792c268 100644
--- a/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
+++ b/Source/core/platform/image-decoders/webp/WEBPImageDecoder.h
@@ -32,9 +32,13 @@
 #include "ImageDecoder.h"
 
 #include "webp/decode.h"
-#if USE(QCMSLIB) && (WEBP_DECODER_ABI_VERSION > 0x200)
+#if (WEBP_DECODER_ABI_VERSION > 0x200)
+#include "webp/demux.h"
+#define WEBP_ICC_ANIM_SUPPORT

[Alpha Left Google, 2013/04/25 22:07:12]

Can you have this always defined such that animated WebP code is always
compiled? What is the reason to have this define given we can turn this off in
runtime.

[urvang (Google), 2013/04/26 01:46:23]

It's basically to support different versions of libwebp.
This was useful in WebKit where different ports used different versions of
libwebp, but probably not needed in Blink.

I'll do a cleanup separately to remove the code for previous libwebp versions --
as there is more such code. Also, it will help migrating the patch to webkit.

+#if USE(QCMSLIB)
 #define QCMS_WEBP_COLOR_CORRECTION
 #endif
+#endif
 
 namespace WebCore {
 
@@ -45,29 +49,58 @@ public:
 
     virtual String filenameExtension() const { return "webp"; }
     virtual bool isSizeAvailable();
+    virtual size_t frameCount();
     virtual ImageFrame* frameBufferAtIndex(size_t index);
+#ifdef WEBP_ICC_ANIM_SUPPORT
+    virtual void setData(SharedBuffer* data, bool allDataReceived);
+    virtual int repetitionCount() const { return m_repetitionCount; }
+    virtual void clearFrameBufferCache(size_t clearBeforeFrame);
+#endif
 
 private:
-    bool decode(bool onlySize);
+    bool decode(const uint8_t* dataBytes, size_t dataSize, bool onlySize, size_t frameIndex);
 
     WebPIDecoder* m_decoder;
     WebPDecBuffer m_decoderBuffer;
-    bool m_hasAlpha;
     int m_formatFlags;
 
 #ifdef QCMS_WEBP_COLOR_CORRECTION
     qcms_transform* colorTransform() const { return m_transform; }
     void createColorTransform(const char* data, size_t);
-    void readColorProfile(const uint8_t* data, size_t);
-    void applyColorProfile(const uint8_t* data, size_t, ImageFrame&);
+    void readColorProfile();
 
     bool m_haveReadProfile;
     qcms_transform* m_transform;
+#endif
+
+#ifdef WEBP_ICC_ANIM_SUPPORT
+    // Recreates demux object when new data is available, and sets canvas size, format flags,
+    // animation properties etc as appropriate. Returns true on success. On
+    // failure, this will mark the image as failed.
+    bool updateDemuxer();
+    // Called to initialize the frame buffer at the given index based on
+    // the previous frame's disposal method. Returns true on success. On
+    // failure, this will mark the image as failed.
+    bool initFrameBuffer(const WebPIterator& fIter, size_t frameIndex);
+    // Apply color profile, and perform necessary post-processing for frame disposal.
+    void applyPostProcessing(size_t frameIndex);
+
+    // Number of rows decoded and post-processed so far in the current frame. It
+    // is used by applyPostProcessing() to decode and post-process incrementally.
     int m_decodedHeight;
+
+    bool m_haveAlreadyParsedThisData;
+    WebPDemuxer* m_demux;
+    WebPDemuxState m_demuxState;
+
+    bool m_haveReadAnimParams;
+    int m_repetitionCount;
 #else
-    void applyColorProfile(const uint8_t*, size_t, ImageFrame&) { };
+    void applyPostProcessing(size_t) { };
 #endif
-    void clear();
+
+    void clearAll();
+    void clearDecoder();
 };
 
 } // namespace WebCore