ui/gfx/buffer_format_util.cc

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "ui/gfx/buffer_format_util.h"
   6
   7 #include "base/logging.h"
   8 #include "base/numerics/safe_math.h"
   9
  10 namespace gfx {
  11
  12 size_t NumberOfPlanesForBufferFormat(BufferFormat format) {
  13   switch (format) {
  14     case BufferFormat::ATC:
  15     case BufferFormat::ATCIA:
  16     case BufferFormat::DXT1:
  17     case BufferFormat::DXT5:
  18     case BufferFormat::ETC1:
  19     case BufferFormat::R_8:
  20     case BufferFormat::RGBA_4444:
  21     case BufferFormat::RGBA_8888:
  22     case BufferFormat::BGRX_8888:
  23     case BufferFormat::BGRA_8888:
  24     case BufferFormat::UYVY_422:
  25       return 1;
  26     case BufferFormat::YUV_420_BIPLANAR:
  27       return 2;
  28     case BufferFormat::YUV_420:
  29       return 3;
  30   }
  31   NOTREACHED();
  32   return 0;
  33 }
  34
  35 size_t SubsamplingFactorForBufferFormat(BufferFormat format, int plane) {
  36   switch (format) {
  37     case BufferFormat::ATC:
  38     case BufferFormat::ATCIA:
  39     case BufferFormat::DXT1:
  40     case BufferFormat::DXT5:
  41     case BufferFormat::ETC1:
  42     case BufferFormat::R_8:
  43     case BufferFormat::RGBA_4444:
  44     case BufferFormat::RGBA_8888:
  45     case BufferFormat::BGRX_8888:
  46     case BufferFormat::BGRA_8888:
  47     case BufferFormat::UYVY_422:
  48       return 1;
  49     case BufferFormat::YUV_420: {
  50       static size_t factor[] = {1, 2, 2};
  51       DCHECK_LT(static_cast<size_t>(plane), arraysize(factor));
  52       return factor[plane];
  53     }
  54     case gfx::BufferFormat::YUV_420_BIPLANAR: {
  55       static size_t factor[] = {1, 2};
  56       DCHECK_LT(static_cast<size_t>(plane), arraysize(factor));
  57       return factor[plane];
  58     }
  59   }
  60   NOTREACHED();
  61   return 0;
  62 }
  63
  64 size_t RowSizeForBufferFormat(size_t width, BufferFormat format, int plane) {
  65   size_t row_size = 0;
  66   bool valid = RowSizeForBufferFormatChecked(width, format, plane, &row_size);
  67   DCHECK(valid);
  68   return row_size;
  69 }
  70
  71 bool RowSizeForBufferFormatChecked(
  72     size_t width, BufferFormat format, int plane, size_t* size_in_bytes) {
  73   base::CheckedNumeric<size_t> checked_size = width;
  74   switch (format) {
  75     case BufferFormat::ATCIA:
  76     case BufferFormat::DXT5:
  77       DCHECK_EQ(0, plane);
  78       *size_in_bytes = width;
  79       return true;
  80     case BufferFormat::ATC:
  81     case BufferFormat::DXT1:
  82     case BufferFormat::ETC1:
  83       DCHECK_EQ(0, plane);
  84       DCHECK_EQ(0u, width % 2);
  85       *size_in_bytes = width / 2;
  86       return true;
  87     case BufferFormat::R_8:
  88       checked_size += 3;
  89       if (!checked_size.IsValid())
  90         return false;
  91       *size_in_bytes = checked_size.ValueOrDie() & ~0x3;
  92       return true;
  93     case BufferFormat::RGBA_4444:
  94     case BufferFormat::UYVY_422:
  95       checked_size *= 2;
  96       if (!checked_size.IsValid())
  97         return false;
  98       *size_in_bytes = checked_size.ValueOrDie();
  99       return true;
 100     case BufferFormat::BGRX_8888:
 101     case BufferFormat::RGBA_8888:
 102     case BufferFormat::BGRA_8888:
 103       checked_size *= 4;
 104       if (!checked_size.IsValid())
 105         return false;
 106       *size_in_bytes = checked_size.ValueOrDie();
 107       return true;
 108     case BufferFormat::YUV_420:
 109       DCHECK_EQ(0u, width % 2);
 110       *size_in_bytes = width / SubsamplingFactorForBufferFormat(format, plane);
 111       return true;
 112     case gfx::BufferFormat::YUV_420_BIPLANAR:
 113       DCHECK_EQ(width % 2, 0u);
 114       *size_in_bytes = width;
 115       return true;
 116   }
 117   NOTREACHED();
 118   return false;
 119 }
 120
 121 size_t BufferSizeForBufferFormat(
 122     const Size& size, BufferFormat format) {
 123   size_t buffer_size = 0;
 124   bool valid = BufferSizeForBufferFormatChecked(size, format, &buffer_size);
 125   DCHECK(valid);
 126   return buffer_size;
 127 }
 128
 129 bool BufferSizeForBufferFormatChecked(
 130     const Size& size, BufferFormat format, size_t* size_in_bytes) {
 131   base::CheckedNumeric<size_t> checked_size = 0;
 132   size_t num_planes = NumberOfPlanesForBufferFormat(format);
 133   for (size_t i = 0; i < num_planes; ++i) {
 134     size_t row_size = 0;
 135     if (!RowSizeForBufferFormatChecked(size.width(), format, i, &row_size))
 136       return false;
 137     base::CheckedNumeric<size_t> checked_plane_size = row_size;
 138     checked_plane_size *= size.height() /
 139                           SubsamplingFactorForBufferFormat(format, i);
 140     if (!checked_plane_size.IsValid())
 141       return false;
 142     checked_size += checked_plane_size.ValueOrDie();
 143     if (!checked_size.IsValid())
 144       return false;
 145   }
 146   *size_in_bytes = checked_size.ValueOrDie();
 147   return true;
 148 }
 149
 150 }  // namespace gfx