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
39typedef int (*WebPImporter)(WebPPicture* const, const uint8_t* const data, int rowStride);
40
41namespace blink {
42
43static 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
49static 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
76template <bool Premultiplied> inline bool importPictureBGRX(const unsigned char* pixels, WebPPicture* picture)
77{
78    return rgbPictureImport(pixels, Premultiplied, &WebPPictureImportBGRX, &WebPPictureImportBGR, picture);
79}
80
81template <bool Premultiplied> inline bool importPictureRGBX(const unsigned char* pixels, WebPPicture* picture)
82{
83    return rgbPictureImport(pixels, Premultiplied, &WebPPictureImportRGBX, &WebPPictureImportRGB, picture);
84}
85
86static 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
118bool 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
128bool 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