diff options
Diffstat (limited to 'WebCore/platform/image-decoders/skia/GIFImageDecoder.cpp')
| -rw-r--r-- | WebCore/platform/image-decoders/skia/GIFImageDecoder.cpp | 493 |
1 files changed, 0 insertions, 493 deletions
diff --git a/WebCore/platform/image-decoders/skia/GIFImageDecoder.cpp b/WebCore/platform/image-decoders/skia/GIFImageDecoder.cpp deleted file mode 100644 index c03452a..0000000 --- a/WebCore/platform/image-decoders/skia/GIFImageDecoder.cpp +++ /dev/null @@ -1,493 +0,0 @@ -/* - * Copyright (C) 2006 Apple Computer, Inc. All rights reserved. - * Copyright (C) 2008, 2009 Google, Inc. - * - * 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 - * notice, this list of conditions and the following disclaimer in the - * documentation and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY - * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR - * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE COMPUTER, INC. OR - * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, - * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, - * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR - * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY - * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT - * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE - * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. - */ - -#include "config.h" -#include "GIFImageDecoder.h" -#include "GIFImageReader.h" - -namespace WebCore { - -class GIFImageDecoderPrivate { -public: - GIFImageDecoderPrivate(GIFImageDecoder* decoder = 0) - : m_reader(decoder) - , m_readOffset(0) - { - } - - ~GIFImageDecoderPrivate() - { - m_reader.close(); - } - - bool decode(SharedBuffer* data, - GIFImageDecoder::GIFQuery query = GIFImageDecoder::GIFFullQuery, - unsigned int haltFrame = -1) - { - return m_reader.read((const unsigned char*)data->data() + m_readOffset, data->size() - m_readOffset, - query, - haltFrame); - } - - unsigned frameCount() const { return m_reader.images_count; } - int repetitionCount() const { return m_reader.loop_count; } - - void setReadOffset(unsigned o) { m_readOffset = o; } - - bool isTransparent() const { return m_reader.frame_reader->is_transparent; } - - void getColorMap(unsigned char*& map, unsigned& size) const - { - if (m_reader.frame_reader->is_local_colormap_defined) { - map = m_reader.frame_reader->local_colormap; - size = (unsigned)m_reader.frame_reader->local_colormap_size; - } else { - map = m_reader.global_colormap; - size = m_reader.global_colormap_size; - } - } - - unsigned frameXOffset() const { return m_reader.frame_reader->x_offset; } - unsigned frameYOffset() const { return m_reader.frame_reader->y_offset; } - unsigned frameWidth() const { return m_reader.frame_reader->width; } - unsigned frameHeight() const { return m_reader.frame_reader->height; } - - int transparentPixel() const { return m_reader.frame_reader->tpixel; } - - unsigned duration() const { return m_reader.frame_reader->delay_time; } - -private: - GIFImageReader m_reader; - unsigned m_readOffset; -}; - -GIFImageDecoder::GIFImageDecoder() - : m_frameCountValid(true) - , m_repetitionCount(cAnimationLoopOnce) - , m_reader(0) -{ -} - -GIFImageDecoder::~GIFImageDecoder() -{ - delete m_reader; -} - -// Take the data and store it. -void GIFImageDecoder::setData(SharedBuffer* data, bool allDataReceived) -{ - if (m_failed) - return; - - // Cache our new data. - ImageDecoder::setData(data, allDataReceived); - - // Our frame count is now unknown. - m_frameCountValid = false; - - // Create the GIF reader. - if (!m_reader && !m_failed) - m_reader = new GIFImageDecoderPrivate(this); -} - -// Whether or not the size information has been decoded yet. -bool GIFImageDecoder::isSizeAvailable() const -{ - // If we have pending data to decode, send it to the GIF reader now. - if (!ImageDecoder::isSizeAvailable() && m_reader) { - if (m_failed) - return false; - - // The decoder will go ahead and aggressively consume everything up until the first - // size is encountered. - decode(GIFSizeQuery, 0); - } - - return ImageDecoder::isSizeAvailable(); -} - -// The total number of frames for the image. Will scan the image data for the answer -// (without necessarily decoding all of the individual frames). -int GIFImageDecoder::frameCount() -{ - // If the decoder had an earlier error, we will just return what we had decoded - // so far. - if (!m_frameCountValid) { - // FIXME: Scanning all the data has O(n^2) behavior if the data were to come in really - // slowly. Might be interesting to try to clone our existing read session to preserve - // state, but for now we just crawl all the data. Note that this is no worse than what - // ImageIO does on Mac right now (it also crawls all the data again). - GIFImageDecoderPrivate reader; - // This function may fail, but we want to keep any partial data it may - // have decoded, so don't mark it is invalid. If there is an overflow - // or some serious error, m_failed will have gotten set for us. - reader.decode(m_data.get(), GIFFrameCountQuery); - m_frameCountValid = true; - m_frameBufferCache.resize(reader.frameCount()); - } - - return m_frameBufferCache.size(); -} - -// The number of repetitions to perform for an animation loop. -int GIFImageDecoder::repetitionCount() const -{ - // This value can arrive at any point in the image data stream. Most GIFs - // in the wild declare it near the beginning of the file, so it usually is - // set by the time we've decoded the size, but (depending on the GIF and the - // packets sent back by the webserver) not always. Our caller is - // responsible for waiting until image decoding has finished to ask this if - // it needs an authoritative answer. In the meantime, we should default to - // "loop once". - if (m_reader) { - // Added wrinkle: ImageSource::clear() may destroy the reader, making - // the result from the reader _less_ authoritative on future calls. To - // detect this, the reader returns cLoopCountNotSeen (-2) instead of - // cAnimationLoopOnce (-1) when its current incarnation hasn't actually - // seen a loop count yet; in this case we return our previously-cached - // value. - const int repetitionCount = m_reader->repetitionCount(); - if (repetitionCount != cLoopCountNotSeen) - m_repetitionCount = repetitionCount; - } - return m_repetitionCount; -} - -RGBA32Buffer* GIFImageDecoder::frameBufferAtIndex(size_t index) -{ - if (index >= static_cast<size_t>(frameCount())) - return 0; - - RGBA32Buffer& frame = m_frameBufferCache[index]; - if (frame.status() != RGBA32Buffer::FrameComplete && m_reader) - decode(GIFFullQuery, index + 1); // Decode this frame. - return &frame; -} - -void GIFImageDecoder::clearFrameBufferCache(size_t clearBeforeFrame) -{ - // In some cases, like if the decoder was destroyed while animating, we - // can be asked to clear more frames than we currently have. - if (m_frameBufferCache.isEmpty()) - return; // Nothing to do. - - // The "-1" here is tricky. It does not mean that |clearBeforeFrame| is the - // last frame we wish to preserve, but rather that we never want to clear - // the very last frame in the cache: it's empty (so clearing it is - // pointless), it's partial (so we don't want to clear it anyway), or the - // cache could be enlarged with a future setData() call and it could be - // needed to construct the next frame (see comments below). Callers can - // always use ImageSource::clear(true, ...) to completely free the memory in - // this case. - clearBeforeFrame = std::min(clearBeforeFrame, m_frameBufferCache.size() - 1); - const Vector<RGBA32Buffer>::iterator end(m_frameBufferCache.begin() + clearBeforeFrame); - - // We need to preserve frames such that: - // * We don't clear |end| - // * We don't clear the frame we're currently decoding - // * We don't clear any frame from which a future initFrameBuffer() call - // will copy bitmap data - // All other frames can be cleared. Because of the constraints on when - // ImageSource::clear() can be called (see ImageSource.h), we're guaranteed - // not to have non-empty frames after the frame we're currently decoding. - // So, scan backwards from |end| as follows: - // * If the frame is empty, we're still past any frames we care about. - // * If the frame is complete, but is DisposeOverwritePrevious, we'll - // skip over it in future initFrameBuffer() calls. We can clear it - // unless it's |end|, and keep scanning. For any other disposal method, - // stop scanning, as we've found the frame initFrameBuffer() will need - // next. - // * If the frame is partial, we're decoding it, so don't clear it; if it - // has a disposal method other than DisposeOverwritePrevious, stop - // scanning, as we'll only need this frame when decoding the next one. - Vector<RGBA32Buffer>::iterator i(end); - for (; (i != m_frameBufferCache.begin()) && ((i->status() == RGBA32Buffer::FrameEmpty) || (i->disposalMethod() == RGBA32Buffer::DisposeOverwritePrevious)); --i) { - if ((i->status() == RGBA32Buffer::FrameComplete) && (i != end)) - i->clear(); - } - - // Now |i| holds the last frame we need to preserve; clear prior frames. - for (Vector<RGBA32Buffer>::iterator j(m_frameBufferCache.begin()); j != i; ++j) { - ASSERT(j->status() != RGBA32Buffer::FramePartial); - if (j->status() != RGBA32Buffer::FrameEmpty) - j->clear(); - } -} - -// Feed data to the GIF reader. -void GIFImageDecoder::decode(GIFQuery query, unsigned haltAtFrame) const -{ - if (m_failed) - return; - - m_failed = !m_reader->decode(m_data.get(), query, haltAtFrame); - - if (m_failed) { - delete m_reader; - m_reader = 0; - } -} - -// Callbacks from the GIF reader. -bool GIFImageDecoder::sizeNowAvailable(unsigned width, unsigned height) -{ - return setSize(width, height); -} - -void GIFImageDecoder::decodingHalted(unsigned bytesLeft) -{ - m_reader->setReadOffset(m_data->size() - bytesLeft); -} - -bool GIFImageDecoder::initFrameBuffer(unsigned frameIndex) -{ - // Initialize the frame rect in our buffer. - IntRect frameRect(m_reader->frameXOffset(), m_reader->frameYOffset(), - m_reader->frameWidth(), m_reader->frameHeight()); - - // Make sure the frameRect doesn't extend past the bottom-right of the buffer. - if (frameRect.right() > size().width()) - frameRect.setWidth(size().width() - m_reader->frameXOffset()); - if (frameRect.bottom() > size().height()) - frameRect.setHeight(size().height() - m_reader->frameYOffset()); - - RGBA32Buffer* const buffer = &m_frameBufferCache[frameIndex]; - buffer->setRect(frameRect); - - if (frameIndex == 0) { - // This is the first frame, so we're not relying on any previous data. - if (!prepEmptyFrameBuffer(buffer)) { - buffer->setStatus(RGBA32Buffer::FrameComplete); - m_failed = true; - return false; - } - } else { - // The starting state for this frame depends on the previous frame's - // disposal method. - // - // Frames that use the DisposeOverwritePrevious method are effectively - // no-ops in terms of changing the starting state of a frame compared to - // the starting state of the previous frame, so skip over them. (If the - // first frame specifies this method, it will get treated like - // DisposeOverwriteBgcolor below and reset to a completely empty image.) - const RGBA32Buffer* prevBuffer = &m_frameBufferCache[--frameIndex]; - RGBA32Buffer::FrameDisposalMethod prevMethod = - prevBuffer->disposalMethod(); - while ((frameIndex > 0) - && (prevMethod == RGBA32Buffer::DisposeOverwritePrevious)) { - prevBuffer = &m_frameBufferCache[--frameIndex]; - prevMethod = prevBuffer->disposalMethod(); - } - ASSERT(prevBuffer->status() == RGBA32Buffer::FrameComplete); - - if ((prevMethod == RGBA32Buffer::DisposeNotSpecified) || - (prevMethod == RGBA32Buffer::DisposeKeep)) { - // Preserve the last frame as the starting state for this frame. - buffer->copyBitmapData(*prevBuffer); - // This next line isn't currently necessary since the alpha state is - // currently carried along in the Skia bitmap data, but it's safe, - // future-proof, and parallel to the Cairo code. - buffer->setHasAlpha(prevBuffer->hasAlpha()); - } else { - // We want to clear the previous frame to transparent, without - // affecting pixels in the image outside of the frame. - const IntRect& prevRect = prevBuffer->rect(); - if ((frameIndex == 0) - || prevRect.contains(IntRect(IntPoint(0, 0), size()))) { - // Clearing the first frame, or a frame the size of the whole - // image, results in a completely empty image. - prepEmptyFrameBuffer(buffer); - } else { - // Copy the whole previous buffer, then clear just its frame. - buffer->copyBitmapData(*prevBuffer); - // Unnecessary (but safe); see comments on the similar call above. - buffer->setHasAlpha(prevBuffer->hasAlpha()); - SkBitmap& bitmap = buffer->bitmap(); -#ifdef ANDROID_ANIMATED_GIF - SkAutoLockPixels alp(bitmap); -#endif - for (int y = prevRect.y(); y < prevRect.bottom(); ++y) { - for (int x = prevRect.x(); x < prevRect.right(); ++x) - buffer->setRGBA(bitmap.getAddr32(x, y), 0, 0, 0, 0); - } - if ((prevRect.width() > 0) && (prevRect.height() > 0)) - buffer->setHasAlpha(true); - } - } - } - - // Update our status to be partially complete. - buffer->setStatus(RGBA32Buffer::FramePartial); - - // Reset the alpha pixel tracker for this frame. - m_currentBufferSawAlpha = false; - return true; -} - -bool GIFImageDecoder::prepEmptyFrameBuffer(RGBA32Buffer* buffer) const -{ - if (!buffer->setSize(size().width(), size().height())) - return false; - // This next line isn't currently necessary since Skia's eraseARGB() sets - // this for us, but we do it for similar reasons to the setHasAlpha() calls - // in initFrameBuffer() above. - buffer->setHasAlpha(true); - return true; -} - -void GIFImageDecoder::haveDecodedRow(unsigned frameIndex, - unsigned char* rowBuffer, // Pointer to single scanline temporary buffer - unsigned char* rowEnd, - unsigned rowNumber, // The row index - unsigned repeatCount, // How many times to repeat the row - bool writeTransparentPixels) -{ - // Initialize the frame if necessary. - RGBA32Buffer& buffer = m_frameBufferCache[frameIndex]; - if ((buffer.status() == RGBA32Buffer::FrameEmpty) && !initFrameBuffer(frameIndex)) - return; - - // Do nothing for bogus data. - if (rowBuffer == 0 || static_cast<int>(m_reader->frameYOffset() + rowNumber) >= size().height()) - return; - - unsigned colorMapSize; - unsigned char* colorMap; - m_reader->getColorMap(colorMap, colorMapSize); - if (!colorMap) - return; - -#ifdef ANDROID_ANIMATED_GIF - // Lock the pixels properly. Should be submitted back to webkit. - SkAutoLockPixels alp(buffer.bitmap()); -#endif - // The buffers that we draw are the entire image's width and height, so a final output frame is - // width * height RGBA32 values in size. - // - // A single GIF frame, however, can be smaller than the entire image, i.e., it can represent some sub-rectangle - // within the overall image. The rows we are decoding are within this - // sub-rectangle. This means that if the GIF frame's sub-rectangle is (x,y,w,h) then row 0 is really row - // y, and each row goes from x to x+w. - unsigned dstPos = (m_reader->frameYOffset() + rowNumber) * size().width() + m_reader->frameXOffset(); - unsigned* dst = buffer.bitmap().getAddr32(0, 0) + dstPos; - unsigned* dstEnd = dst + size().width() - m_reader->frameXOffset(); - unsigned* currDst = dst; - unsigned char* currentRowByte = rowBuffer; - - while (currentRowByte != rowEnd && currDst < dstEnd) { - if ((!m_reader->isTransparent() || *currentRowByte != m_reader->transparentPixel()) && *currentRowByte < colorMapSize) { - unsigned colorIndex = *currentRowByte * 3; - unsigned red = colorMap[colorIndex]; - unsigned green = colorMap[colorIndex + 1]; - unsigned blue = colorMap[colorIndex + 2]; - RGBA32Buffer::setRGBA(currDst, red, green, blue, 255); - } else { - m_currentBufferSawAlpha = true; - // We may or may not need to write transparent pixels to the buffer. - // If we're compositing against a previous image, it's wrong, and if - // we're writing atop a cleared, fully transparent buffer, it's - // unnecessary; but if we're decoding an interlaced gif and - // displaying it "Haeberli"-style, we must write these for passes - // beyond the first, or the initial passes will "show through" the - // later ones. - if (writeTransparentPixels) - RGBA32Buffer::setRGBA(currDst, 0, 0, 0, 0); - } - currDst++; - currentRowByte++; - } - - if (repeatCount > 1) { - // Copy the row |repeatCount|-1 times. - unsigned num = currDst - dst; - unsigned data_size = num * sizeof(unsigned); - unsigned width = size().width(); - unsigned* end = buffer.bitmap().getAddr32(0, 0) + width * size().height(); - currDst = dst + width; - for (unsigned i = 1; i < repeatCount; i++) { - if (currDst + num > end) // Protect against a buffer overrun from a bogus repeatCount. - break; - memcpy(currDst, dst, data_size); - currDst += width; - } - } -} - -void GIFImageDecoder::frameComplete(unsigned frameIndex, unsigned frameDuration, RGBA32Buffer::FrameDisposalMethod disposalMethod) -{ - // Initialize the frame if necessary. Some GIFs insert do-nothing frames, - // in which case we never reach haveDecodedRow() before getting here. - RGBA32Buffer& buffer = m_frameBufferCache[frameIndex]; - if ((buffer.status() == RGBA32Buffer::FrameEmpty) && !initFrameBuffer(frameIndex)) - return; - - buffer.setStatus(RGBA32Buffer::FrameComplete); - buffer.setDuration(frameDuration); - buffer.setDisposalMethod(disposalMethod); - - if (!m_currentBufferSawAlpha) { - // The whole frame was non-transparent, so it's possible that the entire - // resulting buffer was non-transparent, and we can setHasAlpha(false). - if (buffer.rect().contains(IntRect(IntPoint(0, 0), size()))) - buffer.setHasAlpha(false); - else if (frameIndex > 0) { - // Tricky case. This frame does not have alpha only if everywhere - // outside its rect doesn't have alpha. To know whether this is - // true, we check the start state of the frame -- if it doesn't have - // alpha, we're safe. - // - // First skip over prior DisposeOverwritePrevious frames (since they - // don't affect the start state of this frame) the same way we do in - // initFrameBuffer(). - const RGBA32Buffer* prevBuffer = &m_frameBufferCache[--frameIndex]; - while ((frameIndex > 0) - && (prevBuffer->disposalMethod() == RGBA32Buffer::DisposeOverwritePrevious)) - prevBuffer = &m_frameBufferCache[--frameIndex]; - - // Now, if we're at a DisposeNotSpecified or DisposeKeep frame, then - // we can say we have no alpha if that frame had no alpha. But - // since in initFrameBuffer() we already copied that frame's alpha - // state into the current frame's, we need do nothing at all here. - // - // The only remaining case is a DisposeOverwriteBgcolor frame. If - // it had no alpha, and its rect is contained in the current frame's - // rect, we know the current frame has no alpha. - if ((prevBuffer->disposalMethod() == RGBA32Buffer::DisposeOverwriteBgcolor) - && !prevBuffer->hasAlpha() && buffer.rect().contains(prevBuffer->rect())) - buffer.setHasAlpha(false); - } - } -} - -void GIFImageDecoder::gifComplete() -{ - if (m_reader) - m_repetitionCount = m_reader->repetitionCount(); - delete m_reader; - m_reader = 0; -} - -} // namespace WebCore |