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      1 /*
      2  * Copyright (C) 2010 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions
      6  * are met:
      7  *
      8  * 1.  Redistributions of source code must retain the above copyright
      9  *     notice, this list of conditions and the following disclaimer.
     10  * 2.  Redistributions in binary form must reproduce the above copyright
     11  *     notice, this list of conditions and the following disclaimer in the
     12  *     documentation and/or other materials provided with the distribution.
     13  * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of
     14  *     its contributors may be used to endorse or promote products derived
     15  *     from this software without specific prior written permission.
     16  *
     17  * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY
     18  * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
     19  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
     20  * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY
     21  * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
     22  * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     23  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
     24  * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
     26  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     27  */
     28 
     29 #include "config.h"
     30 #include "WEBPImageDecoder.h"
     31 
     32 #if USE(WEBP)
     33 
     34 #include "webp/decode.h"
     35 
     36 namespace WebCore {
     37 
     38 WEBPImageDecoder::WEBPImageDecoder(ImageSource::AlphaOption alphaOption,
     39                                    ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption)
     40     : ImageDecoder(alphaOption, gammaAndColorProfileOption)
     41     , m_decoder(0)
     42     , m_lastVisibleRow(0)
     43 {
     44 }
     45 
     46 WEBPImageDecoder::~WEBPImageDecoder()
     47 {
     48 }
     49 
     50 bool WEBPImageDecoder::isSizeAvailable()
     51 {
     52     if (!ImageDecoder::isSizeAvailable())
     53          decode(true);
     54 
     55     return ImageDecoder::isSizeAvailable();
     56 }
     57 
     58 ImageFrame* WEBPImageDecoder::frameBufferAtIndex(size_t index)
     59 {
     60     if (index)
     61         return 0;
     62 
     63     if (m_frameBufferCache.isEmpty()) {
     64         m_frameBufferCache.resize(1);
     65         m_frameBufferCache[0].setPremultiplyAlpha(m_premultiplyAlpha);
     66     }
     67 
     68     ImageFrame& frame = m_frameBufferCache[0];
     69     if (frame.status() != ImageFrame::FrameComplete)
     70         decode(false);
     71     return &frame;
     72 }
     73 
     74 
     75 bool WEBPImageDecoder::decode(bool onlySize)
     76 {
     77     // Minimum number of bytes needed to ensure one can parse size information.
     78     static const size_t sizeOfHeader = 30;
     79     // Number of bytes per pixel.
     80     static const int bytesPerPixel = 3;
     81 
     82     if (failed())
     83         return false;
     84 
     85     const size_t dataSize = m_data->size();
     86     if (dataSize < sizeOfHeader)
     87         return true;
     88 
     89     int width, height;
     90     const uint8_t* dataBytes = reinterpret_cast<const uint8_t*>(m_data->data());
     91     if (!WebPGetInfo(dataBytes, dataSize, &width, &height))
     92         return setFailed();
     93     if (!ImageDecoder::isSizeAvailable() && !setSize(width, height))
     94         return setFailed();
     95     if (onlySize)
     96         return true;
     97 
     98     bool allDataReceived = isAllDataReceived();
     99     int stride = width * bytesPerPixel;
    100     ASSERT(!m_frameBufferCache.isEmpty());
    101     ImageFrame& buffer = m_frameBufferCache[0];
    102     if (buffer.status() == ImageFrame::FrameEmpty) {
    103         ASSERT(width == size().width());
    104         ASSERT(height == size().height());
    105         if (!buffer.setSize(width, height))
    106             return setFailed();
    107         buffer.setStatus(allDataReceived ? ImageFrame::FrameComplete : ImageFrame::FramePartial);
    108         // FIXME: We currently hard code false below because libwebp doesn't support alpha yet.
    109         buffer.setHasAlpha(false);
    110         buffer.setOriginalFrameRect(IntRect(IntPoint(), size()));
    111         m_rgbOutput.resize(height * stride);
    112     }
    113     int newLastVisibleRow = 0; // Last completed row.
    114     if (allDataReceived) {
    115         if (!WebPDecodeRGBInto(dataBytes, dataSize, m_rgbOutput.data(), m_rgbOutput.size(), stride))
    116             return setFailed();
    117         newLastVisibleRow = height;
    118     } else {
    119         if (!m_decoder) {
    120             m_decoder = WebPINewRGB(MODE_RGB, m_rgbOutput.data(), m_rgbOutput.size(), stride);
    121             if (!m_decoder)
    122                 return setFailed();
    123         }
    124         const VP8StatusCode status = WebPIUpdate(m_decoder, dataBytes, dataSize);
    125         if (status != VP8_STATUS_OK && status != VP8_STATUS_SUSPENDED)
    126             return setFailed();
    127         if (!WebPIDecGetRGB(m_decoder, &newLastVisibleRow, 0, 0, 0))
    128             return setFailed();
    129         ASSERT(newLastVisibleRow >= 0);
    130         ASSERT(newLastVisibleRow <= height);
    131     }
    132     // FIXME: remove this data copy.
    133     for (int y = m_lastVisibleRow; y < newLastVisibleRow; ++y) {
    134         const uint8_t* const src = &m_rgbOutput[y * stride];
    135         for (int x = 0; x < width; ++x)
    136             buffer.setRGBA(x, y, src[bytesPerPixel * x + 0], src[bytesPerPixel * x + 1], src[bytesPerPixel * x + 2], 0xff);
    137     }
    138     m_lastVisibleRow = newLastVisibleRow;
    139     if (m_lastVisibleRow == height)
    140          buffer.setStatus(ImageFrame::FrameComplete);
    141     return m_lastVisibleRow == height;
    142 }
    143 
    144 }
    145 
    146 #endif
    147