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
33namespace blink {
34
35static 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
50inline bool matchesGIFSignature(char* contents)
51{
52    return !memcmp(contents, "GIF87a", 6) || !memcmp(contents, "GIF89a", 6);
53}
54
55inline bool matchesPNGSignature(char* contents)
56{
57    return !memcmp(contents, "\x89\x50\x4E\x47\x0D\x0A\x1A\x0A", 8);
58}
59
60inline bool matchesJPEGSignature(char* contents)
61{
62    return !memcmp(contents, "\xFF\xD8\xFF", 3);
63}
64
65inline bool matchesWebPSignature(char* contents)
66{
67    return !memcmp(contents, "RIFF", 4) && !memcmp(contents + 8, "WEBPVP", 6);
68}
69
70inline bool matchesBMPSignature(char* contents)
71{
72    return !memcmp(contents, "BM", 2);
73}
74
75inline bool matchesICOSignature(char* contents)
76{
77    return !memcmp(contents, "\x00\x00\x01\x00", 4);
78}
79
80inline bool matchesCURSignature(char* contents)
81{
82    return !memcmp(contents, "\x00\x00\x02\x00", 4);
83}
84
85PassOwnPtr<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
117bool ImageDecoder::frameHasAlphaAtIndex(size_t index) const
118{
119    return !frameIsCompleteAtIndex(index) || m_frameBufferCache[index].hasAlpha();
120}
121
122bool ImageDecoder::frameIsCompleteAtIndex(size_t index) const
123{
124    return (index < m_frameBufferCache.size()) &&
125        (m_frameBufferCache[index].status() == ImageFrame::FrameComplete);
126}
127
128unsigned 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
136bool ImageDecoder::deferredImageDecodingEnabled()
137{
138    return DeferredImageDecoder::enabled();
139}
140
141size_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
157void ImageDecoder::clearFrameBuffer(size_t frameIndex)
158{
159    m_frameBufferCache[frameIndex].clearPixelData();
160}
161
162size_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
207ImagePlanes::ImagePlanes()
208{
209    for (int i = 0; i < 3; ++i) {
210        m_planes[i] = 0;
211        m_rowBytes[i] = 0;
212    }
213}
214
215ImagePlanes::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
223void* ImagePlanes::plane(int i)
224{
225    ASSERT((i >= 0) && i < 3);
226    return m_planes[i];
227}
228
229size_t ImagePlanes::rowBytes(int i) const
230{
231    ASSERT((i >= 0) && i < 3);
232    return m_rowBytes[i];
233}
234
235} // namespace blink
236