Add animation support for WebP images

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

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *
  * 1.  Redistributions of source code must retain the above copyright
  *     notice, this list of conditions and the following disclaimer.
  * 2.  Redistributions in binary form must reproduce the above copyright
@@ skipping 14 matching lines @@
  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #ifndef WEBPImageDecoder_h
 #define WEBPImageDecoder_h
 
 #include "core/platform/image-decoders/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

[Noel Gordon, 2013/04/29 18:41:57]

(avoid abbrevs) Make it WEBP_ANIMIMATION or some such.

[urvang (Google), 2013/04/30 13:14:15]

Done.

[Noel Gordon, 2013/05/01 17:55:28]

WEBP_ICC_ANIMIMATION_SUPPORT -> WEBP_ANIMIMATION_SUPPORT please.

[urvang (Google), 2013/05/01 22:25:16]

This define is to show that libwebp version in use supports ICC and animation,
so I'd really like to have both in the name.
The plan is to later remove these defines related to old libwebp versions from
Blink (but keep them in Webkit).

Note: This is different from QCMS_WEBP_COLOR_CORRECTION, as it specifies whether
to apply color correction (based on whether libqcms is available).

+#if USE(QCMSLIB)
 #define QCMS_WEBP_COLOR_CORRECTION
 #endif
+#endif
 
 namespace WebCore {
 
 class WEBPImageDecoder : public ImageDecoder {
 public:
     WEBPImageDecoder(ImageSource::AlphaOption, ImageSource::GammaAndColorProfileOption);
     virtual ~WEBPImageDecoder();
 
     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);

[Noel Gordon, 2013/04/29 18:41:57]

s/ fIter//

[urvang (Google), 2013/04/30 13:14:15]

What is special about this argument? Why should we omit the variable name only
for this argument?

[Noel Gordon, 2013/05/01 17:55:28]

http://www.chromium.org/blink/coding-style
Names 9. Leave meaningless variable names out of function declarations ...
[names-variable-name-in-function-decl]

Read Source/core/platform/graphics/GraphicsContext.h for good examples.

+    // 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();

[Noel Gordon, 2013/04/29 18:41:57]

All what? clear() was fine.

[urvang (Google), 2013/04/30 13:14:15]

'clear()' was actually renamed to 'clearDecoder()', which clears data for a
single frame (in case of animation). So I called this 'clearAll()' (was supposed
to mean clear data for all frames).

But fine, clear() is also ok.

+    void clearDecoder();
 };
 
 } // namespace WebCore
 
 #endif