Line data    Source code

       1             : /*
       2             :  * Copyright 2016 Google Inc.
       3             :  *
       4             :  * Use of this source code is governed by a BSD-style license that can be
       5             :  * found in the LICENSE file.
       6             :  */
       7             : 
       8             : #include "SkRGBAToYUV.h"
       9             : #include "SkCanvas.h"
      10             : #include "SkColorMatrixFilterRowMajor255.h"
      11             : #include "SkImage.h"
      12             : #include "SkPaint.h"
      13             : #include "SkSurface.h"
      14             : 
      15           0 : bool SkRGBAToYUV(const SkImage* image, const SkISize sizes[3], void* const planes[3],
      16             :                  const size_t rowBytes[3], SkYUVColorSpace colorSpace) {
      17             :     // Matrices that go from RGBA to YUV.
      18             :     static const SkScalar kYUVColorSpaceInvMatrices[][15] = {
      19             :         // kJPEG_SkYUVColorSpace
      20             :         { 0.299001f,  0.586998f,   0.114001f,  0.f, 0.0000821798f * 255.f,
      21             :          -0.168736f, -0.331263f,   0.499999f,  0.f, 0.499954f * 255.f,
      22             :           0.499999f, -0.418686f,  -0.0813131f, 0.f, 0.499941f * 255.f},
      23             : 
      24             :         // kRec601_SkYUVColorSpace
      25             :         { 0.256951f,  0.504421f,   0.0977346f, 0.f, 0.0625f * 255.f,
      26             :          -0.148212f, -0.290954f,   0.439166f,  0.f, 0.5f * 255.f,
      27             :           0.439166f,  -0.367886f, -0.0712802f, 0.f, 0.5f * 255.f},
      28             : 
      29             :         // kRec709_SkYUVColorSpace
      30             :         { 0.182663f,  0.614473f,  0.061971f,  0.f, 0.0625f * 255.f,
      31             :          -0.100672f, -0.338658f,  0.43933f,   0.f, 0.5f * 255.f,
      32             :           0.439142f, -0.39891f,  -0.040231f,  0.f, 0.5f * 255.f},
      33             :     };
      34             :     static_assert(kLastEnum_SkYUVColorSpace == 2, "yuv color matrix array problem");
      35             :     static_assert(kJPEG_SkYUVColorSpace     == 0, "yuv color matrix array problem");
      36             :     static_assert(kRec601_SkYUVColorSpace   == 1, "yuv color matrix array problem");
      37             :     static_assert(kRec709_SkYUVColorSpace   == 2, "yuv color matrix array problem");
      38             : 
      39           0 :     for (int i = 0; i < 3; ++i) {
      40           0 :         size_t rb = rowBytes[i] ? rowBytes[i] : sizes[i].fWidth;
      41             :         auto surface(SkSurface::MakeRasterDirect(
      42           0 :                 SkImageInfo::MakeA8(sizes[i].fWidth, sizes[i].fHeight), planes[i], rb));
      43           0 :         if (!surface) {
      44           0 :             return false;
      45             :         }
      46           0 :         SkPaint paint;
      47           0 :         paint.setFilterQuality(kLow_SkFilterQuality);
      48           0 :         paint.setBlendMode(SkBlendMode::kSrc);
      49           0 :         int rowStartIdx = 5 * i;
      50           0 :         const SkScalar* row = kYUVColorSpaceInvMatrices[colorSpace] + rowStartIdx;
      51             :         paint.setColorFilter(
      52           0 :                 SkColorMatrixFilterRowMajor255::MakeSingleChannelOutput(row));
      53           0 :         surface->getCanvas()->drawImageRect(image, SkIRect::MakeWH(image->width(), image->height()),
      54           0 :                                             SkRect::MakeIWH(surface->width(), surface->height()),
      55           0 :                                             &paint);
      56             :     }
      57           0 :     return true;
      58             : }