1 /* 2 * Copyright (C) Research In Motion Limited 2009-2010. All rights reserved. 3 * 4 * This library is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU Library General Public 6 * License as published by the Free Software Foundation; either 7 * version 2 of the License, or (at your option) any later version. 8 * 9 * This library is distributed in the hope that it will be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 12 * Library General Public License for more details. 13 * 14 * You should have received a copy of the GNU Library General Public License 15 * along with this library; see the file COPYING.LIB. If not, write to 16 * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 17 * Boston, MA 02110-1301, USA. 18 * 19 */ 20 21 #include "config.h" 22 #include "platform/image-decoders/ImageDecoder.h" 23 24 #include "platform/graphics/DeferredImageDecoder.h" 25 #include "platform/image-decoders/bmp/BMPImageDecoder.h" 26 #include "platform/image-decoders/gif/GIFImageDecoder.h" 27 #include "platform/image-decoders/ico/ICOImageDecoder.h" 28 #include "platform/image-decoders/jpeg/JPEGImageDecoder.h" 29 #include "platform/image-decoders/png/PNGImageDecoder.h" 30 #include "platform/image-decoders/webp/WEBPImageDecoder.h" 31 #include "wtf/PassOwnPtr.h" 32 33 namespace blink { 34 35 static unsigned copyFromSharedBuffer(char* buffer, unsigned bufferLength, const SharedBuffer& sharedBuffer, unsigned offset) 36 { 37 unsigned bytesExtracted = 0; 38 const char* moreData; 39 while (unsigned moreDataLength = sharedBuffer.getSomeData(moreData, offset)) { 40 unsigned bytesToCopy = std::min(bufferLength - bytesExtracted, moreDataLength); 41 memcpy(buffer + bytesExtracted, moreData, bytesToCopy); 42 bytesExtracted += bytesToCopy; 43 if (bytesExtracted == bufferLength) 44 break; 45 offset += bytesToCopy; 46 } 47 return bytesExtracted; 48 } 49 50 inline bool matchesGIFSignature(char* contents) 51 { 52 return !memcmp(contents, "GIF87a", 6) || !memcmp(contents, "GIF89a", 6); 53 } 54 55 inline bool matchesPNGSignature(char* contents) 56 { 57 return !memcmp(contents, "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A", 8); 58 } 59 60 inline bool matchesJPEGSignature(char* contents) 61 { 62 return !memcmp(contents, "\xFF\xD8\xFF", 3); 63 } 64 65 inline bool matchesWebPSignature(char* contents) 66 { 67 return !memcmp(contents, "RIFF", 4) && !memcmp(contents + 8, "WEBPVP", 6); 68 } 69 70 inline bool matchesBMPSignature(char* contents) 71 { 72 return !memcmp(contents, "BM", 2); 73 } 74 75 inline bool matchesICOSignature(char* contents) 76 { 77 return !memcmp(contents, "\x00\x00\x01\x00", 4); 78 } 79 80 inline bool matchesCURSignature(char* contents) 81 { 82 return !memcmp(contents, "\x00\x00\x02\x00", 4); 83 } 84 85 PassOwnPtr<ImageDecoder> ImageDecoder::create(const SharedBuffer& data, ImageSource::AlphaOption alphaOption, ImageSource::GammaAndColorProfileOption gammaAndColorProfileOption) 86 { 87 static const unsigned longestSignatureLength = sizeof("RIFF????WEBPVP") - 1; 88 ASSERT(longestSignatureLength == 14); 89 90 size_t maxDecodedBytes = blink::Platform::current()->maxDecodedImageBytes(); 91 92 char contents[longestSignatureLength]; 93 if (copyFromSharedBuffer(contents, longestSignatureLength, data, 0) < longestSignatureLength) 94 return nullptr; 95 96 if (matchesJPEGSignature(contents)) 97 return adoptPtr(new JPEGImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)); 98 99 if (matchesPNGSignature(contents)) 100 return adoptPtr(new PNGImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)); 101 102 if (matchesGIFSignature(contents)) 103 return adoptPtr(new GIFImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)); 104 105 if (matchesICOSignature(contents) || matchesCURSignature(contents)) 106 return adoptPtr(new ICOImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)); 107 108 if (matchesWebPSignature(contents)) 109 return adoptPtr(new WEBPImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)); 110 111 if (matchesBMPSignature(contents)) 112 return adoptPtr(new BMPImageDecoder(alphaOption, gammaAndColorProfileOption, maxDecodedBytes)); 113 114 return nullptr; 115 } 116 117 bool ImageDecoder::frameHasAlphaAtIndex(size_t index) const 118 { 119 return !frameIsCompleteAtIndex(index) || m_frameBufferCache[index].hasAlpha(); 120 } 121 122 bool ImageDecoder::frameIsCompleteAtIndex(size_t index) const 123 { 124 return (index < m_frameBufferCache.size()) && 125 (m_frameBufferCache[index].status() == ImageFrame::FrameComplete); 126 } 127 128 unsigned ImageDecoder::frameBytesAtIndex(size_t index) const 129 { 130 if (m_frameBufferCache.size() <= index || m_frameBufferCache[index].status() == ImageFrame::FrameEmpty) 131 return 0; 132 // FIXME: Use the dimension of the requested frame. 133 return m_size.area() * sizeof(ImageFrame::PixelData); 134 } 135 136 bool ImageDecoder::deferredImageDecodingEnabled() 137 { 138 return DeferredImageDecoder::enabled(); 139 } 140 141 size_t ImageDecoder::clearCacheExceptFrame(size_t clearExceptFrame) 142 { 143 // Don't clear if there are no frames or only one frame. 144 if (m_frameBufferCache.size() <= 1) 145 return 0; 146 147 size_t frameBytesCleared = 0; 148 for (size_t i = 0; i < m_frameBufferCache.size(); ++i) { 149 if (i != clearExceptFrame) { 150 frameBytesCleared += frameBytesAtIndex(i); 151 clearFrameBuffer(i); 152 } 153 } 154 return frameBytesCleared; 155 } 156 157 void ImageDecoder::clearFrameBuffer(size_t frameIndex) 158 { 159 m_frameBufferCache[frameIndex].clearPixelData(); 160 } 161 162 size_t ImageDecoder::findRequiredPreviousFrame(size_t frameIndex, bool frameRectIsOpaque) 163 { 164 ASSERT(frameIndex <= m_frameBufferCache.size()); 165 if (!frameIndex) { 166 // The first frame doesn't rely on any previous data. 167 return kNotFound; 168 } 169 170 const ImageFrame* currBuffer = &m_frameBufferCache[frameIndex]; 171 if ((frameRectIsOpaque || currBuffer->alphaBlendSource() == ImageFrame::BlendAtopBgcolor) 172 && currBuffer->originalFrameRect().contains(IntRect(IntPoint(), size()))) 173 return kNotFound; 174 175 // The starting state for this frame depends on the previous frame's 176 // disposal method. 177 size_t prevFrame = frameIndex - 1; 178 const ImageFrame* prevBuffer = &m_frameBufferCache[prevFrame]; 179 ASSERT(prevBuffer->requiredPreviousFrameIndexValid()); 180 181 switch (prevBuffer->disposalMethod()) { 182 case ImageFrame::DisposeNotSpecified: 183 case ImageFrame::DisposeKeep: 184 // prevFrame will be used as the starting state for this frame. 185 // FIXME: Be even smarter by checking the frame sizes and/or alpha-containing regions. 186 return prevFrame; 187 case ImageFrame::DisposeOverwritePrevious: 188 // Frames that use the DisposeOverwritePrevious method are effectively 189 // no-ops in terms of changing the starting state of a frame compared to 190 // the starting state of the previous frame, so skip over them and 191 // return the required previous frame of it. 192 return prevBuffer->requiredPreviousFrameIndex(); 193 case ImageFrame::DisposeOverwriteBgcolor: 194 // If the previous frame fills the whole image, then the current frame 195 // can be decoded alone. Likewise, if the previous frame could be 196 // decoded without reference to any prior frame, the starting state for 197 // this frame is a blank frame, so it can again be decoded alone. 198 // Otherwise, the previous frame contributes to this frame. 199 return (prevBuffer->originalFrameRect().contains(IntRect(IntPoint(), size())) 200 || (prevBuffer->requiredPreviousFrameIndex() == kNotFound)) ? kNotFound : prevFrame; 201 default: 202 ASSERT_NOT_REACHED(); 203 return kNotFound; 204 } 205 } 206 207 ImagePlanes::ImagePlanes() 208 { 209 for (int i = 0; i < 3; ++i) { 210 m_planes[i] = 0; 211 m_rowBytes[i] = 0; 212 } 213 } 214 215 ImagePlanes::ImagePlanes(void* planes[3], size_t rowBytes[3]) 216 { 217 for (int i = 0; i < 3; ++i) { 218 m_planes[i] = planes[i]; 219 m_rowBytes[i] = rowBytes[i]; 220 } 221 } 222 223 void* ImagePlanes::plane(int i) 224 { 225 ASSERT((i >= 0) && i < 3); 226 return m_planes[i]; 227 } 228 229 size_t ImagePlanes::rowBytes(int i) const 230 { 231 ASSERT((i >= 0) && i < 3); 232 return m_rowBytes[i]; 233 } 234 235 } // namespace blink 236
