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      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 "SkBitmap.h"
     35 #include "platform/geometry/IntSize.h"
     36 #include "platform/graphics/ImageBuffer.h"
     37 #include "webp/encode.h"
     38 
     39 typedef int (*WebPImporter)(WebPPicture* const, const uint8_t* const data, int rowStride);
     40 
     41 namespace blink {
     42 
     43 static int writeOutput(const uint8_t* data, size_t size, const WebPPicture* const picture)
     44 {
     45     static_cast<Vector<unsigned char>*>(picture->custom_ptr)->append(data, size);
     46     return 1;
     47 }
     48 
     49 static bool rgbPictureImport(const unsigned char* pixels, bool premultiplied, WebPImporter importRGBX, WebPImporter importRGB, WebPPicture* picture)
     50 {
     51     if (premultiplied)
     52         return importRGBX(picture, pixels, picture->width * 4);
     53 
     54     // Write the RGB pixels to an rgb data buffer, alpha premultiplied, then import the rgb data.
     55 
     56     Vector<unsigned char> rgb;
     57     size_t pixelCount = picture->height * picture->width;
     58     rgb.reserveInitialCapacity(pixelCount * 3);
     59 
     60     for (unsigned char* data = rgb.data(); pixelCount-- > 0; pixels += 4) {
     61         unsigned char alpha = pixels[3];
     62         if (alpha != 255) {
     63             *data++ = SkMulDiv255Round(pixels[0], alpha);
     64             *data++ = SkMulDiv255Round(pixels[1], alpha);
     65             *data++ = SkMulDiv255Round(pixels[2], alpha);
     66         } else {
     67             *data++ = pixels[0];
     68             *data++ = pixels[1];
     69             *data++ = pixels[2];
     70         }
     71     }
     72 
     73     return importRGB(picture, rgb.data(), picture->width * 3);
     74 }
     75 
     76 template <bool Premultiplied> inline bool importPictureBGRX(const unsigned char* pixels, WebPPicture* picture)
     77 {
     78     return rgbPictureImport(pixels, Premultiplied, &WebPPictureImportBGRX, &WebPPictureImportBGR, picture);
     79 }
     80 
     81 template <bool Premultiplied> inline bool importPictureRGBX(const unsigned char* pixels, WebPPicture* picture)
     82 {
     83     return rgbPictureImport(pixels, Premultiplied, &WebPPictureImportRGBX, &WebPPictureImportRGB, picture);
     84 }
     85 
     86 static bool encodePixels(IntSize imageSize, const unsigned char* pixels, bool premultiplied, int quality, Vector<unsigned char>* output)
     87 {
     88     WebPConfig config;
     89     if (!WebPConfigInit(&config))
     90         return false;
     91     WebPPicture picture;
     92     if (!WebPPictureInit(&picture))
     93         return false;
     94 
     95     imageSize.clampNegativeToZero();
     96     if (!imageSize.width() || imageSize.width() > WEBP_MAX_DIMENSION)
     97         return false;
     98     picture.width = imageSize.width();
     99     if (!imageSize.height() || imageSize.height() > WEBP_MAX_DIMENSION)
    100         return false;
    101     picture.height = imageSize.height();
    102 
    103     if (premultiplied && !importPictureBGRX<true>(pixels, &picture))
    104         return false;
    105     if (!premultiplied && !importPictureRGBX<false>(pixels, &picture))
    106         return false;
    107 
    108     picture.custom_ptr = output;
    109     picture.writer = &writeOutput;
    110     config.quality = quality;
    111     config.method = 3;
    112 
    113     bool success = WebPEncode(&config, &picture);
    114     WebPPictureFree(&picture);
    115     return success;
    116 }
    117 
    118 bool WEBPImageEncoder::encode(const SkBitmap& bitmap, int quality, Vector<unsigned char>* output)
    119 {
    120     SkAutoLockPixels bitmapLock(bitmap);
    121 
    122     if (bitmap.colorType() != kN32_SkColorType || !bitmap.getPixels())
    123         return false; // Only support 32 bit/pixel skia bitmaps.
    124 
    125     return encodePixels(IntSize(bitmap.width(), bitmap.height()), static_cast<unsigned char *>(bitmap.getPixels()), true, quality, output);
    126 }
    127 
    128 bool WEBPImageEncoder::encode(const ImageDataBuffer& imageData, int quality, Vector<unsigned char>* output)
    129 {
    130     return encodePixels(imageData.size(), imageData.data(), false, quality, output);
    131 }
    132 
    133 } // namespace blink
    134