WIP: Implement APNG

third_party/WebKit/Source/platform/image-decoders/png/PNGImageDecoder.cpp

 /*
  * Copyright (C) 2006 Apple Computer, Inc.
  * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved.
  *
  * Portions are Copyright (C) 2001 mozilla.org
  *
  * Other contributors:
  *   Stuart Parmenter <stuart@mozilla.com>
  *
  * This library is free software; you can redistribute it and/or
@@ skipping 20 matching lines @@
  * licenses (the MPL or the GPL) and not to allow others to use your
  * version of this file under the LGPL, indicate your decision by
  * deletingthe provisions above and replace them with the notice and
  * other provisions required by the MPL or the GPL, as the case may be.
  * If you do not delete the provisions above, a recipient may use your
  * version of this file under any of the LGPL, the MPL or the GPL.
  */
 
 #include "platform/image-decoders/png/PNGImageDecoder.h"
 
+#include "platform/image-decoders/png/PNGImageReader.h"
 #include "png.h"
-#include "wtf/PtrUtil.h"
 #include <memory>
 
 #if !defined(PNG_LIBPNG_VER_MAJOR) || !defined(PNG_LIBPNG_VER_MINOR)
 #error version error: compile against a versioned libpng.
 #endif
 #if USE(QCMSLIB)
 #include "qcms.h"
 #endif
 
 #if PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 4)
 #define JMPBUF(png_ptr) png_jmpbuf(png_ptr)
 #else
 #define JMPBUF(png_ptr) png_ptr->jmpbuf
 #endif
 
-namespace {
-
-inline blink::PNGImageDecoder* imageDecoder(png_structp png)
-{
-    return static_cast<blink::PNGImageDecoder*>(png_get_progressive_ptr(png));
-}
-
-void PNGAPI pngHeaderAvailable(png_structp png, png_infop)
-{
-    imageDecoder(png)->headerAvailable();
-}
-
-void PNGAPI pngRowAvailable(png_structp png, png_bytep row, png_uint_32 rowIndex, int state)
-{
-    imageDecoder(png)->rowAvailable(row, rowIndex, state);
-}
-
-void PNGAPI pngComplete(png_structp png, png_infop)
-{
-    imageDecoder(png)->complete();
-}
-
-void PNGAPI pngFailed(png_structp png, png_const_charp)
-{
-    longjmp(JMPBUF(png), 1);
-}
-
-} // namespace
 
 namespace blink {
 
-class PNGImageReader final {
-    USING_FAST_MALLOC(PNGImageReader);
-    WTF_MAKE_NONCOPYABLE(PNGImageReader);
-public:
-    PNGImageReader(PNGImageDecoder* decoder, size_t readOffset)
-        : m_decoder(decoder)
-        , m_readOffset(readOffset)
-        , m_currentBufferSize(0)
-        , m_decodingSizeOnly(false)
-        , m_hasAlpha(false)
-#if USE(QCMSLIB)
-        , m_rowBuffer()
-#endif
-    {
-        m_png = png_create_read_struct(PNG_LIBPNG_VER_STRING, 0, pngFailed, 0);
-        m_info = png_create_info_struct(m_png);
-        png_set_progressive_read_fn(m_png, m_decoder, pngHeaderAvailable, pngRowAvailable, pngComplete);
-    }
-
-    ~PNGImageReader()
-    {
-        png_destroy_read_struct(m_png ? &m_png : 0, m_info ? &m_info : 0, 0);
-        ASSERT(!m_png && !m_info);
-
-        m_readOffset = 0;
-    }
-
-    bool decode(const SegmentReader& data, bool sizeOnly)
-    {
-        m_decodingSizeOnly = sizeOnly;
-
-        // We need to do the setjmp here. Otherwise bad things will happen.
-        if (setjmp(JMPBUF(m_png)))
-            return m_decoder->setFailed();
-
-        const char* segment;
-        while (size_t segmentLength = data.getSomeData(segment, m_readOffset)) {
-            m_readOffset += segmentLength;
-            m_currentBufferSize = m_readOffset;
-            png_process_data(m_png, m_info, reinterpret_cast<png_bytep>(const_cast<char*>(segment)), segmentLength);
-            if (sizeOnly ? m_decoder->isDecodedSizeAvailable() : m_decoder->frameIsCompleteAtIndex(0))
-                return true;
-        }
-
-        return false;
-    }
-
-    png_structp pngPtr() const { return m_png; }
-    png_infop infoPtr() const { return m_info; }
-
-    size_t getReadOffset() const { return m_readOffset; }
-    void setReadOffset(size_t offset) { m_readOffset = offset; }
-    size_t currentBufferSize() const { return m_currentBufferSize; }
-    bool decodingSizeOnly() const { return m_decodingSizeOnly; }
-    void setHasAlpha(bool hasAlpha) { m_hasAlpha = hasAlpha; }
-    bool hasAlpha() const { return m_hasAlpha; }
-
-    png_bytep interlaceBuffer() const { return m_interlaceBuffer.get(); }
-    void createInterlaceBuffer(int size) { m_interlaceBuffer = wrapArrayUnique(new png_byte[size]); }
-#if USE(QCMSLIB)
-    png_bytep rowBuffer() const { return m_rowBuffer.get(); }
-    void createRowBuffer(int size) { m_rowBuffer = wrapArrayUnique(new png_byte[size]); }
-#endif
-
-private:
-    png_structp m_png;
-    png_infop m_info;
-    PNGImageDecoder* m_decoder;
-    size_t m_readOffset;
-    size_t m_currentBufferSize;
-    bool m_decodingSizeOnly;
-    bool m_hasAlpha;
-    std::unique_ptr<png_byte[]> m_interlaceBuffer;
-#if USE(QCMSLIB)
-    std::unique_ptr<png_byte[]> m_rowBuffer;
-#endif
-};
-
 PNGImageDecoder::PNGImageDecoder(AlphaOption alphaOption, GammaAndColorProfileOption colorOptions, size_t maxDecodedBytes, size_t offset)
     : ImageDecoder(alphaOption, colorOptions, maxDecodedBytes)
     , m_offset(offset)
+    , m_metaDataDecoded(false)
+    , m_frameCount(0)
+    , m_currentFrame(0)
+    , m_repetitionCount(cAnimationLoopOnce)
 {
 }
 
 PNGImageDecoder::~PNGImageDecoder()
 {
 }
 
+size_t PNGImageDecoder::decodeFrameCount()
+{
+    if (!m_metaDataDecoded)
+        parse(PNGParseQuery::PNGMetaDataQuery);
+    return m_frameCount;
+}
+
+inline bool frameComplete(ImageFrame& frame)
+{
+    return frame.getStatus() == ImageFrame::FrameComplete;
+}
+
+void PNGImageDecoder::decode(size_t index)
+{
+    m_currentFrame = index;
+    m_reader->decode(*m_data, index);
+}
+
+void PNGImageDecoder::parse(PNGParseQuery query)
+{
+    if (failed())
+        return;
+
+    if (!m_reader)
+        m_reader = wrapUnique(new PNGImageReader(this, m_offset));
+
+    if (!m_reader->parse(*m_data, query) && isAllDataReceived())
+        setFailed();
+
+    if (query == PNGParseQuery::PNGMetaDataQuery)
+        m_frameCount = m_reader->frameCount();
+}
+
+void PNGImageDecoder::setRepetitionCount(size_t repetitionCount)
+{
+    m_repetitionCount = (repetitionCount == 0) ? cAnimationLoopInfinite
+                            : repetitionCount;
+}
+
+// This matches the existing behavior to loop once if decoding fails, but this
+// should be changed to stick with m_repetitionCount to match other browsers.
+// See crbug.com/267883
+int PNGImageDecoder::repetitionCount() const
+{
+    if (m_metaDataDecoded && isAllDataReceived() && m_reader->frameCount() == 1)
+        return cAnimationNone;
+    return failed() ? cAnimationLoopOnce : m_repetitionCount;
+}
+
+// These are mapped according to:
+// https://wiki.mozilla.org/APNG_Specification#.60fcTL.60:_The_Frame_Control_Chunk
+static inline ImageFrame::DisposalMethod getDisposalMethod(uint8_t disposalMethod)
+{
+    switch (disposalMethod) {
+        case 0:
+            return ImageFrame::DisposalMethod::DisposeKeep;
+        case 1:
+            return ImageFrame::DisposalMethod::DisposeOverwriteBgcolor;
+        case 2:
+            return ImageFrame::DisposalMethod::DisposeOverwritePrevious;
+        default:
+            return ImageFrame::DisposalMethod::DisposeNotSpecified;
+    }
+}
+
+
+// These are mapped according to:
+// https://wiki.mozilla.org/APNG_Specification#.60fcTL.60:_The_Frame_Control_Chunk
+static inline ImageFrame::AlphaBlendSource getAlphaBlend(uint8_t alphaBlend)
+{
+    if (alphaBlend == 1)
+        return ImageFrame::AlphaBlendSource::BlendAtopPreviousFrame;
+    return ImageFrame::AlphaBlendSource::BlendAtopBgcolor;
+}
+
+void PNGImageDecoder::initializeNewFrame(size_t index)
+{
+    const PNGImageReader::FrameInfo& frameInfo = m_reader->frameInfo(index);
+    ImageFrame* buffer = &m_frameBufferCache[index];
+
+    IntRect frameRectWithinSize = intersection(frameInfo.frameRect,
+                                               {IntPoint(), size()});
+    buffer->setOriginalFrameRect(frameRectWithinSize);
+    buffer->setDuration(frameInfo.duration);
+    buffer->setDisposalMethod(getDisposalMethod(frameInfo.disposalMethod));
+    buffer->setAlphaBlendSource(getAlphaBlend(frameInfo.alphaBlend));
+}
+
 void PNGImageDecoder::headerAvailable()
 {
     png_structp png = m_reader->pngPtr();
     png_infop info = m_reader->infoPtr();
     png_uint_32 width = png_get_image_width(png, info);
     png_uint_32 height = png_get_image_height(png, info);
 
-    // Protect against large PNGs. See http://bugzil.la/251381 for more details.
-    const unsigned long maxPNGSize = 1000000UL;
-    if (width > maxPNGSize || height > maxPNGSize) {
-        longjmp(JMPBUF(png), 1);
-        return;
-    }
+    // Only set the size of the image once. Since single frames also use this
+    // method, we don't want them to override the size to their frame rect.
+    if (!isDecodedSizeAvailable()) {
+        // Protect against large PNGs. See http://bugzil.la/251381 for more details.
+        const unsigned long maxPNGSize = 1000000UL;
+        if (width > maxPNGSize || height > maxPNGSize) {
+            longjmp(JMPBUF(png), 1);
+            return;
+        }
 
-    // Set the image size now that the image header is available.
-    if (!setSize(width, height)) {
-        longjmp(JMPBUF(png), 1);
-        return;
+        // Set the image size now that the image header is available.
+        if (!setSize(width, height)) {
+            longjmp(JMPBUF(png), 1);
+            return;
+        }
     }
 
     int bitDepth, colorType, interlaceType, compressionType, filterType, channels;
     png_get_IHDR(png, info, &width, &height, &bitDepth, &colorType, &interlaceType, &compressionType, &filterType);
 
     // The options we set here match what Mozilla does.
 
     // Expand to ensure we use 24-bit for RGB and 32-bit for RGBA.
     if (colorType == PNG_COLOR_TYPE_PALETTE || (colorType == PNG_COLOR_TYPE_GRAY && bitDepth < 8))
         png_set_expand(png);
@@ skipping 58 matching lines @@
     // Tell libpng to send us rows for interlaced pngs.
     if (interlaceType == PNG_INTERLACE_ADAM7)
         png_set_interlace_handling(png);
 
     // Update our info now.
     png_read_update_info(png, info);
     channels = png_get_channels(png, info);
     ASSERT(channels == 3 || channels == 4);
 
     m_reader->setHasAlpha(channels == 4);
-
-    if (m_reader->decodingSizeOnly()) {
-        // If we only needed the size, halt the reader.
-#if PNG_LIBPNG_VER_MAJOR > 1 || (PNG_LIBPNG_VER_MAJOR == 1 && PNG_LIBPNG_VER_MINOR >= 5)
-        // '0' argument to png_process_data_pause means: Do not cache unprocessed data.
-        m_reader->setReadOffset(m_reader->currentBufferSize() - png_process_data_pause(png, 0));
-#else
-        m_reader->setReadOffset(m_reader->currentBufferSize() - png->buffer_size);
-        png->buffer_size = 0;
-#endif
-    }
 }
 
 void PNGImageDecoder::rowAvailable(unsigned char* rowBuffer, unsigned rowIndex, int)
 {
+
     if (m_frameBufferCache.isEmpty())
         return;
 
     // Initialize the framebuffer if needed.
-    ImageFrame& buffer = m_frameBufferCache[0];
+    ImageFrame& buffer = m_frameBufferCache[m_currentFrame];
     if (buffer.getStatus() == ImageFrame::FrameEmpty) {
         png_structp png = m_reader->pngPtr();
         if (!buffer.setSizeAndColorProfile(size().width(), size().height(), colorProfile())) {
             longjmp(JMPBUF(png), 1);
             return;
         }
 
         unsigned colorChannels = m_reader->hasAlpha() ? 4 : 3;
         if (PNG_INTERLACE_ADAM7 == png_get_interlace_type(png, m_reader->infoPtr())) {
             m_reader->createInterlaceBuffer(colorChannels * size().width() * size().height());
             if (!m_reader->interlaceBuffer()) {
                 longjmp(JMPBUF(png), 1);
                 return;
             }
         }
 
 #if USE(QCMSLIB)
         if (colorTransform()) {
             m_reader->createRowBuffer(colorChannels * size().width());
             if (!m_reader->rowBuffer()) {
                 longjmp(JMPBUF(png), 1);
                 return;
             }
         }
 #endif
         buffer.setStatus(ImageFrame::FramePartial);
         buffer.setHasAlpha(false);
+    }
 
-        // For PNGs, the frame always fills the entire image.
-        buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));
-    }
+    // This frameRect is already clipped, so that it fits within the size of the
+    // image. This is done in initializeNewFrame() after a frameCount() call.
+    const IntRect& frameRect = buffer.originalFrameRect();
 
     /* libpng comments (here to explain what follows).
      *
      * this function is called for every row in the image. If the
      * image is interlacing, and you turned on the interlace handler,
      * this function will be called for every row in every pass.
      * Some of these rows will not be changed from the previous pass.
      * When the row is not changed, the new_row variable will be NULL.
      * The rows and passes are called in order, so you don't really
      * need the row_num and pass, but I'm supplying them because it
      * may make your life easier.
      */
 
     // Nothing to do if the row is unchanged, or the row is outside
     // the image bounds: libpng may send extra rows, ignore them to
     // make our lives easier.
     if (!rowBuffer)
         return;
-    int y = rowIndex;
-    if (y < 0 || y >= size().height())
+    int y = rowIndex + frameRect.y();
+    ASSERT(y >= 0);
+    if (y >= size().height())
         return;
 
     /* libpng comments (continued).
      *
      * For the non-NULL rows of interlaced images, you must call
      * png_progressive_combine_row() passing in the row and the
      * old row.  You can call this function for NULL rows (it will
      * just return) and for non-interlaced images (it just does the
      * memcpy for you) if it will make the code easier. Thus, you
      * can just do this for all cases:
@@ skipping 19 matching lines @@
 
 #if USE(QCMSLIB)
     if (qcms_transform* transform = colorTransform()) {
         qcms_transform_data(transform, row, m_reader->rowBuffer(), size().width());
         row = m_reader->rowBuffer();
     }
 #endif
 
     // Write the decoded row pixels to the frame buffer. The repetitive
     // form of the row write loops is for speed.
-    ImageFrame::PixelData* address = buffer.getAddr(0, y);
+    ImageFrame::PixelData* address = buffer.getAddr(frameRect.x(), y);
     unsigned alphaMask = 255;
-    int width = size().width();
 
     png_bytep pixel = row;
     if (hasAlpha) {
         if (buffer.premultiplyAlpha()) {
-            for (int x = 0; x < width; ++x, pixel += 4) {
+            for (int x = frameRect.x(); x < frameRect.maxX(); ++x, pixel += 4) {
                 buffer.setRGBAPremultiply(address++, pixel[0], pixel[1], pixel[2], pixel[3]);
                 alphaMask &= pixel[3];
             }
         } else {
-            for (int x = 0; x < width; ++x, pixel += 4) {
+            for (int x = frameRect.x(); x < frameRect.maxX(); ++x, pixel += 4) {
                 buffer.setRGBARaw(address++, pixel[0], pixel[1], pixel[2], pixel[3]);
                 alphaMask &= pixel[3];
             }
         }
     } else {
-        for (int x = 0; x < width; ++x, pixel += 3) {
+        for (int x = frameRect.x(); x < frameRect.maxX(); ++x, pixel += 3) {
             buffer.setRGBARaw(address++, pixel[0], pixel[1], pixel[2], 255);
         }
     }
 
     if (alphaMask != 255 && !buffer.hasAlpha())
         buffer.setHasAlpha(true);
 
     buffer.setPixelsChanged(true);
 }
 
+bool PNGImageDecoder::frameIsCompleteAtIndex(size_t index) const
+{
+    // @TODO(joostouwerling): show complete frames even if a later frame fails.
+    if (failed())
+        return false;
+    if (index >= m_frameBufferCache.size())
+        return false;
+    if (index == 0)
+        return ImageDecoder::frameIsCompleteAtIndex(index);
+    return true;
+}
+
+float PNGImageDecoder::frameDurationAtIndex(size_t index) const
+{
+    return (index < m_frameBufferCache.size() ? 
+                m_frameBufferCache[index].duration() : 0);
+}
+
 void PNGImageDecoder::complete()
 {
     if (m_frameBufferCache.isEmpty())
         return;
-
-    m_frameBufferCache[0].setStatus(ImageFrame::FrameComplete);
-}
-
-inline bool isComplete(const PNGImageDecoder* decoder)
-{
-    return decoder->frameIsCompleteAtIndex(0);
-}
-
-void PNGImageDecoder::decode(bool onlySize)
-{
-    if (failed())
-        return;
-
-    if (!m_reader)
-        m_reader = wrapUnique(new PNGImageReader(this, m_offset));
-
-    // If we couldn't decode the image but have received all the data, decoding
-    // has failed.
-    if (!m_reader->decode(*m_data, onlySize) && isAllDataReceived())
-        setFailed();
-
-    // If decoding is done or failed, we don't need the PNGImageReader anymore.
-    if (isComplete(this) || failed())
-        m_reader.reset();
+    m_frameBufferCache[m_currentFrame].setStatus(ImageFrame::FrameComplete);

[scroggo_chromium, 2016/10/31 13:35:12]

From
https://codereview.chromium.org/2386453003/diff/200001/third_party/WebKit/Sou...
you stated:

"You mean a frame that says it has |n| rows of |m| columns, but provides
less data than that? I commented elsewhere on this as well, but my take
is that the decoder can take this into account if it receives the
complete() call before it has received all the data it anticipated."

I assume here is the place to account for that? I think we should probably do at
least one of two things:

1) call setFailed() - but keeping in mind that failure currently means to stop,
but it should probably mean to loop the already decoded frames (if looping is
indicated) - see crbug.com/267883 (again).

2) set the status to FramePartial - but the decoder may try to continue decoding
later [1], and which would redecode the frame based on how this class is
written.

[1]
https://cs.chromium.org/chromium/src/third_party/WebKit/Source/platform/image...

[joostouwerling, 2016/10/31 18:40:19]

Acknowledged, that is the approach I wanted to take. The implementation will
depend on what libpng does in the case of more/less data, as I've explained at
[1].

[1]:
https://codereview.chromium.org/2386453003/diff/200001/third_party/WebKit/Sou...

 }
 
 } // namespace blink