third_party/WebKit/Source/platform/image-encoders/skia/WEBPImageEncoder.cpp

   1 /*
   2  * Copyright (c) 2011, 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 are
   6  * met:
   7  *
   8  *     * Redistributions of source code must retain the above copyright
   9  * notice, this list of conditions and the following disclaimer.
  10  *     * Redistributions in binary form must reproduce the above
  11  * copyright notice, this list of conditions and the following disclaimer
  12  * in the documentation and/or other materials provided with the
  13  * distribution.
  14  *     * Neither the name of Google Inc. nor the names of its
  15  * contributors may be used to endorse or promote products derived from
  16  * this software without specific prior written permission.
  17  *
  18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
  19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
  20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
  21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
  22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
  23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
  24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
  28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  29  */
  30
  31 #include "config.h"
  32 #include "platform/image-encoders/skia/WEBPImageEncoder.h"
  33
  34 #include "platform/geometry/IntSize.h"
  35 #include "platform/graphics/ImageBuffer.h"
  36 #include "webp/encode.h"
  37
  38 typedef int (*WebPImporter)(WebPPicture* const, const uint8_t* const data, int rowStride);
  39
  40 namespace blink {
  41
  42 static int writeOutput(const uint8_t* data, size_t size, const WebPPicture* const picture)
  43 {
  44     static_cast<Vector<unsigned char>*>(picture->custom_ptr)->append(data, size);
  45     return 1;
  46 }
  47
  48 static bool rgbPictureImport(const unsigned char* pixels, WebPImporter importRGB, WebPPicture* picture)
  49 {
  50     // Write the RGB pixels to an rgb data buffer, alpha premultiplied, then import the rgb data.
  51
  52     size_t pixelCount = picture->height * picture->width;
  53
  54     OwnPtr<unsigned char[]> rgb = adoptArrayPtr(new unsigned char[pixelCount * 3]);
  55     if (!rgb.get())
  56         return false;
  57
  58     for (unsigned char* data = rgb.get(); pixelCount-- > 0; pixels += 4) {
  59         unsigned char alpha = pixels[3];
  60         if (alpha != 255) {
  61             *data++ = SkMulDiv255Round(pixels[0], alpha);
  62             *data++ = SkMulDiv255Round(pixels[1], alpha);
  63             *data++ = SkMulDiv255Round(pixels[2], alpha);
  64         } else {
  65             *data++ = pixels[0];
  66             *data++ = pixels[1];
  67             *data++ = pixels[2];
  68         }
  69     }
  70
  71     return importRGB(picture, rgb.get(), picture->width * 3);
  72 }
  73
  74 static bool encodePixels(IntSize imageSize, const unsigned char* pixels, int quality, Vector<unsigned char>* output)
  75 {
  76     if (imageSize.width() <= 0 || imageSize.width() > WEBP_MAX_DIMENSION)
  77         return false;
  78     if (imageSize.height() <= 0 || imageSize.height() > WEBP_MAX_DIMENSION)
  79         return false;
  80
  81     WebPConfig config;
  82     if (!WebPConfigInit(&config))
  83         return false;
  84     WebPPicture picture;
  85     if (!WebPPictureInit(&picture))
  86         return false;
  87
  88     picture.width = imageSize.width();
  89     picture.height = imageSize.height();
  90
  91     if (!rgbPictureImport(pixels, &WebPPictureImportRGB, &picture))
  92         return false;
  93
  94     picture.custom_ptr = output;
  95     picture.writer = &writeOutput;
  96     config.quality = quality;
  97     config.method = 3;
  98
  99     bool success = WebPEncode(&config, &picture);
 100     WebPPictureFree(&picture);
 101     return success;
 102 }
 103
 104 bool WEBPImageEncoder::encode(const ImageDataBuffer& imageData, int quality, Vector<unsigned char>* output)
 105 {
 106     if (!imageData.pixels())
 107         return false;
 108
 109     return encodePixels(IntSize(imageData.width(), imageData.height()), imageData.pixels(), quality, output);
 110 }
 111
 112 } // namespace blink