Adding upstream version 110.0.1.upstream/110.0.1upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 577 insertions, 0 deletions

diff --git a/gfx/ycbcr/yuv_convert.cpp b/gfx/ycbcr/yuv_convert.cpp
new file mode 100644
index 0000000000..f7d01a3ef8
--- /dev/null
+++ b/gfx/ycbcr/yuv_convert.cpp
@@ -0,0 +1,577 @@
+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// This webpage shows layout of YV12 and other YUV formats
+// http://www.fourcc.org/yuv.php
+// The actual conversion is best described here
+// http://en.wikipedia.org/wiki/YUV
+// An article on optimizing YUV conversion using tables instead of multiplies
+// http://lestourtereaux.free.fr/papers/data/yuvrgb.pdf
+//
+// YV12 is a full plane of Y and a half height, half width chroma planes
+// YV16 is a full plane of Y and a full height, half width chroma planes
+// YV24 is a full plane of Y and a full height, full width chroma planes
+// Y8   is a full plane of Y and no chroma planes (i.e., monochrome)
+//
+// ARGB pixel format is output, which on little endian is stored as BGRA.
+// The alpha is set to 255, allowing the application to use RGBA or RGB32.
+
+#include "yuv_convert.h"
+
+#include "mozilla/StaticPrefs_gfx.h"
+#include "libyuv.h"
+#include "scale_yuv_argb.h"
+// Header for low level row functions.
+#include "yuv_row.h"
+#include "mozilla/SSE.h"
+#include "mozilla/IntegerRange.h"
+
+namespace mozilla {
+
+namespace gfx {
+
+// 16.16 fixed point arithmetic
+const int kFractionBits = 16;
+const int kFractionMax = 1 << kFractionBits;
+const int kFractionMask = ((1 << kFractionBits) - 1);
+
+// clang-format off
+
+libyuv::FourCC FourCCFromYUVType(YUVType aYUVType) {
+  switch (aYUVType) {
+    case YV24: return libyuv::FOURCC_I444;
+    case YV16: return libyuv::FOURCC_I422;
+    case YV12: return libyuv::FOURCC_I420;
+    case   Y8: return libyuv::FOURCC_I400;
+    default:   return libyuv::FOURCC_ANY;
+  }
+}
+
+int GBRPlanarToARGB(const uint8_t* src_y, int y_pitch,
+                     const uint8_t* src_u, int u_pitch,
+                     const uint8_t* src_v, int v_pitch,
+                     uint8_t* rgb_buf, int rgb_pitch,
+                     int pic_width, int pic_height) {
+  // libyuv has no native conversion function for this
+  // fixme: replace with something less awful
+  for (const auto row : IntegerRange(pic_height)) {
+    for (const auto col : IntegerRange(pic_width)) {
+      rgb_buf[rgb_pitch * row + col * 4 + 0] = src_u[u_pitch * row + col];
+      rgb_buf[rgb_pitch * row + col * 4 + 1] = src_y[y_pitch * row + col];
+      rgb_buf[rgb_pitch * row + col * 4 + 2] = src_v[v_pitch * row + col];
+      rgb_buf[rgb_pitch * row + col * 4 + 3] = 255;
+    }
+  }
+  return 0;
+}
+
+// Convert a frame of YUV to 32 bit ARGB.
+void ConvertYCbCrToRGB32(const uint8_t* y_buf, const uint8_t* u_buf,
+                         const uint8_t* v_buf, uint8_t* rgb_buf, int pic_x,
+                         int pic_y, int pic_width, int pic_height, int y_pitch,
+                         int uv_pitch, int rgb_pitch, YUVType yuv_type,
+                         YUVColorSpace yuv_color_space,
+                         ColorRange color_range) {
+  // Deprecated function's conversion is accurate.
+  // libyuv converion is a bit inaccurate to get performance. It dynamically
+  // calculates RGB from YUV to use simd. In it, signed byte is used for
+  // conversion's coefficient, but it requests 129. libyuv cut 129 to 127. And
+  // only 6 bits are used for a decimal part during the dynamic calculation.
+  //
+  // The function is still fast on some old intel chips.
+  // See Bug 1256475.
+  bool use_deprecated = StaticPrefs::gfx_ycbcr_accurate_conversion() ||
+                        (supports_mmx() && supports_sse() && !supports_sse3() &&
+                         yuv_color_space == YUVColorSpace::BT601 &&
+                         color_range == ColorRange::LIMITED);
+  // The deprecated function only support BT601.
+  // See Bug 1210357.
+  if (yuv_color_space != YUVColorSpace::BT601) {
+    use_deprecated = false;
+  }
+  if (use_deprecated) {
+    ConvertYCbCrToRGB32_deprecated(y_buf, u_buf, v_buf, rgb_buf, pic_x, pic_y,
+                                   pic_width, pic_height, y_pitch, uv_pitch,
+                                   rgb_pitch, yuv_type);
+    return;
+  }
+
+  decltype(libyuv::I420ToARGBMatrix)* fConvertYUVToARGB = nullptr;
+  const uint8_t* src_y = nullptr;
+  const uint8_t* src_u = nullptr;
+  const uint8_t* src_v = nullptr;
+  const libyuv::YuvConstants* yuv_constant = nullptr;
+
+  switch (yuv_color_space) {
+    case YUVColorSpace::BT2020:
+      yuv_constant = color_range == ColorRange::LIMITED
+        ? &libyuv::kYuv2020Constants
+        : &libyuv::kYuvV2020Constants;
+      break;
+    case YUVColorSpace::BT709:
+      yuv_constant = color_range == ColorRange::LIMITED
+        ? &libyuv::kYuvH709Constants
+        : &libyuv::kYuvF709Constants;
+      break;
+    case YUVColorSpace::Identity:
+      MOZ_ASSERT(yuv_type == YV24, "Identity (aka RGB) with chroma subsampling is unsupported");
+      if (yuv_type == YV24) {
+        break;
+      }
+      [[fallthrough]]; // Assuming BT601 for unsupported input is better than crashing
+    default:
+      MOZ_FALLTHROUGH_ASSERT("Unsupported YUVColorSpace");
+    case YUVColorSpace::BT601:
+      yuv_constant = color_range == ColorRange::LIMITED
+        ? &libyuv::kYuvI601Constants
+        : &libyuv::kYuvJPEGConstants;
+      break;
+  }
+
+  switch (yuv_type) {
+    case YV24: {
+      src_y = y_buf + y_pitch * pic_y + pic_x;
+      src_u = u_buf + uv_pitch * pic_y + pic_x;
+      src_v = v_buf + uv_pitch * pic_y + pic_x;
+
+      if (yuv_color_space == YUVColorSpace::Identity) {
+        // Special case for RGB image
+        DebugOnly<int> err =
+          GBRPlanarToARGB(src_y, y_pitch, src_u, uv_pitch, src_v, uv_pitch,
+                            rgb_buf, rgb_pitch, pic_width, pic_height);
+        MOZ_ASSERT(!err);
+        return;
+      }
+
+      fConvertYUVToARGB = libyuv::I444ToARGBMatrix;
+      break;
+    }
+    case YV16: {
+      src_y = y_buf + y_pitch * pic_y + pic_x;
+      src_u = u_buf + uv_pitch * pic_y + pic_x / 2;
+      src_v = v_buf + uv_pitch * pic_y + pic_x / 2;
+
+      fConvertYUVToARGB = libyuv::I422ToARGBMatrix;
+      break;
+    }
+    case YV12: {
+      src_y = y_buf + y_pitch * pic_y + pic_x;
+      src_u = u_buf + (uv_pitch * pic_y + pic_x) / 2;
+      src_v = v_buf + (uv_pitch * pic_y + pic_x) / 2;
+
+      fConvertYUVToARGB = libyuv::I420ToARGBMatrix;
+      break;
+    }
+    case Y8: {
+      src_y = y_buf + y_pitch * pic_y + pic_x;
+      MOZ_ASSERT(u_buf == nullptr);
+      MOZ_ASSERT(v_buf == nullptr);
+
+      if (color_range == ColorRange::LIMITED) {
+        DebugOnly<int> err =
+            libyuv::I400ToARGB(src_y, y_pitch, rgb_buf, rgb_pitch, pic_width,
+                              pic_height);
+        MOZ_ASSERT(!err);
+      } else {
+        DebugOnly<int> err =
+            libyuv::J400ToARGB(src_y, y_pitch, rgb_buf, rgb_pitch, pic_width,
+                              pic_height);
+        MOZ_ASSERT(!err);
+      }
+
+      return;
+    }
+    default:
+      MOZ_ASSERT_UNREACHABLE("Unsupported YUV type");
+  }
+
+  DebugOnly<int> err =
+    fConvertYUVToARGB(src_y, y_pitch, src_u, uv_pitch, src_v, uv_pitch,
+                      rgb_buf, rgb_pitch, yuv_constant, pic_width, pic_height);
+  MOZ_ASSERT(!err);
+}
+
+// Convert a frame of YUV to 32 bit ARGB.
+void ConvertYCbCrToRGB32_deprecated(const uint8_t* y_buf,
+                                    const uint8_t* u_buf,
+                                    const uint8_t* v_buf,
+                                    uint8_t* rgb_buf,
+                                    int pic_x,
+                                    int pic_y,
+                                    int pic_width,
+                                    int pic_height,
+                                    int y_pitch,
+                                    int uv_pitch,
+                                    int rgb_pitch,
+                                    YUVType yuv_type) {
+  unsigned int y_shift = yuv_type == YV12 ? 1 : 0;
+  unsigned int x_shift = yuv_type == YV24 ? 0 : 1;
+  // Test for SSE because the optimized code uses movntq, which is not part of MMX.
+  bool has_sse = supports_mmx() && supports_sse();
+  // There is no optimized YV24 SSE routine so we check for this and
+  // fall back to the C code.
+  has_sse &= yuv_type != YV24;
+  bool odd_pic_x = yuv_type != YV24 && pic_x % 2 != 0;
+  int x_width = odd_pic_x ? pic_width - 1 : pic_width;
+
+  for (int y = pic_y; y < pic_height + pic_y; ++y) {
+    uint8_t* rgb_row = rgb_buf + (y - pic_y) * rgb_pitch;
+    const uint8_t* y_ptr = y_buf + y * y_pitch + pic_x;
+    const uint8_t* u_ptr = u_buf + (y >> y_shift) * uv_pitch + (pic_x >> x_shift);
+    const uint8_t* v_ptr = v_buf + (y >> y_shift) * uv_pitch + (pic_x >> x_shift);
+
+    if (odd_pic_x) {
+      // Handle the single odd pixel manually and use the
+      // fast routines for the remaining.
+      FastConvertYUVToRGB32Row_C(y_ptr++,
+                                 u_ptr++,
+                                 v_ptr++,
+                                 rgb_row,
+                                 1,
+                                 x_shift);
+      rgb_row += 4;
+    }
+
+    if (has_sse) {
+      FastConvertYUVToRGB32Row(y_ptr,
+                               u_ptr,
+                               v_ptr,
+                               rgb_row,
+                               x_width);
+    }
+    else {
+      FastConvertYUVToRGB32Row_C(y_ptr,
+                                 u_ptr,
+                                 v_ptr,
+                                 rgb_row,
+                                 x_width,
+                                 x_shift);
+    }
+  }
+
+  // MMX used for FastConvertYUVToRGB32Row requires emms instruction.
+  if (has_sse)
+    EMMS();
+}
+
+// C version does 8 at a time to mimic MMX code
+static void FilterRows_C(uint8_t* ybuf, const uint8_t* y0_ptr, const uint8_t* y1_ptr,
+                         int source_width, int source_y_fraction) {
+  int y1_fraction = source_y_fraction;
+  int y0_fraction = 256 - y1_fraction;
+  uint8_t* end = ybuf + source_width;
+  do {
+    ybuf[0] = (y0_ptr[0] * y0_fraction + y1_ptr[0] * y1_fraction) >> 8;
+    ybuf[1] = (y0_ptr[1] * y0_fraction + y1_ptr[1] * y1_fraction) >> 8;
+    ybuf[2] = (y0_ptr[2] * y0_fraction + y1_ptr[2] * y1_fraction) >> 8;
+    ybuf[3] = (y0_ptr[3] * y0_fraction + y1_ptr[3] * y1_fraction) >> 8;
+    ybuf[4] = (y0_ptr[4] * y0_fraction + y1_ptr[4] * y1_fraction) >> 8;
+    ybuf[5] = (y0_ptr[5] * y0_fraction + y1_ptr[5] * y1_fraction) >> 8;
+    ybuf[6] = (y0_ptr[6] * y0_fraction + y1_ptr[6] * y1_fraction) >> 8;
+    ybuf[7] = (y0_ptr[7] * y0_fraction + y1_ptr[7] * y1_fraction) >> 8;
+    y0_ptr += 8;
+    y1_ptr += 8;
+    ybuf += 8;
+  } while (ybuf < end);
+}
+
+#ifdef MOZILLA_MAY_SUPPORT_MMX
+void FilterRows_MMX(uint8_t* ybuf, const uint8_t* y0_ptr, const uint8_t* y1_ptr,
+                    int source_width, int source_y_fraction);
+#endif
+
+#ifdef MOZILLA_MAY_SUPPORT_SSE2
+void FilterRows_SSE2(uint8_t* ybuf, const uint8_t* y0_ptr, const uint8_t* y1_ptr,
+                     int source_width, int source_y_fraction);
+#endif
+
+static inline void FilterRows(uint8_t* ybuf, const uint8_t* y0_ptr,
+                              const uint8_t* y1_ptr, int source_width,
+                              int source_y_fraction) {
+#ifdef MOZILLA_MAY_SUPPORT_SSE2
+  if (mozilla::supports_sse2()) {
+    FilterRows_SSE2(ybuf, y0_ptr, y1_ptr, source_width, source_y_fraction);
+    return;
+  }
+#endif
+
+#ifdef MOZILLA_MAY_SUPPORT_MMX
+  if (mozilla::supports_mmx()) {
+    FilterRows_MMX(ybuf, y0_ptr, y1_ptr, source_width, source_y_fraction);
+    return;
+  }
+#endif
+
+  FilterRows_C(ybuf, y0_ptr, y1_ptr, source_width, source_y_fraction);
+}
+
+
+// Scale a frame of YUV to 32 bit ARGB.
+void ScaleYCbCrToRGB32(const uint8_t* y_buf,
+                       const uint8_t* u_buf,
+                       const uint8_t* v_buf,
+                       uint8_t* rgb_buf,
+                       int source_width,
+                       int source_height,
+                       int width,
+                       int height,
+                       int y_pitch,
+                       int uv_pitch,
+                       int rgb_pitch,
+                       YUVType yuv_type,
+                       YUVColorSpace yuv_color_space,
+                       ScaleFilter filter) {
+  bool use_deprecated =
+      StaticPrefs::gfx_ycbcr_accurate_conversion() ||
+#if defined(XP_WIN) && defined(_M_X64)
+      // libyuv does not support SIMD scaling on win 64bit. See Bug 1295927.
+      supports_sse3() ||
+#endif
+      (supports_mmx() && supports_sse() && !supports_sse3());
+  // The deprecated function only support BT601.
+  // See Bug 1210357.
+  if (yuv_color_space != YUVColorSpace::BT601) {
+    use_deprecated = false;
+  }
+  if (use_deprecated) {
+    ScaleYCbCrToRGB32_deprecated(y_buf, u_buf, v_buf,
+                                 rgb_buf,
+                                 source_width, source_height,
+                                 width, height,
+                                 y_pitch, uv_pitch,
+                                 rgb_pitch,
+                                 yuv_type,
+                                 ROTATE_0,
+                                 filter);
+    return;
+  }
+
+  DebugOnly<int> err =
+    libyuv::YUVToARGBScale(y_buf, y_pitch,
+                           u_buf, uv_pitch,
+                           v_buf, uv_pitch,
+                           FourCCFromYUVType(yuv_type),
+                           yuv_color_space,
+                           source_width, source_height,
+                           rgb_buf, rgb_pitch,
+                           width, height,
+                           libyuv::kFilterBilinear);
+  MOZ_ASSERT(!err);
+  return;
+}
+
+// Scale a frame of YUV to 32 bit ARGB.
+void ScaleYCbCrToRGB32_deprecated(const uint8_t* y_buf,
+                                  const uint8_t* u_buf,
+                                  const uint8_t* v_buf,
+                                  uint8_t* rgb_buf,
+                                  int source_width,
+                                  int source_height,
+                                  int width,
+                                  int height,
+                                  int y_pitch,
+                                  int uv_pitch,
+                                  int rgb_pitch,
+                                  YUVType yuv_type,
+                                  Rotate view_rotate,
+                                  ScaleFilter filter) {
+  bool has_mmx = supports_mmx();
+
+  // 4096 allows 3 buffers to fit in 12k.
+  // Helps performance on CPU with 16K L1 cache.
+  // Large enough for 3830x2160 and 30" displays which are 2560x1600.
+  const int kFilterBufferSize = 4096;
+  // Disable filtering if the screen is too big (to avoid buffer overflows).
+  // This should never happen to regular users: they don't have monitors
+  // wider than 4096 pixels.
+  // TODO(fbarchard): Allow rotated videos to filter.
+  if (source_width > kFilterBufferSize || view_rotate)
+    filter = FILTER_NONE;
+
+  unsigned int y_shift = yuv_type == YV12 ? 1 : 0;
+  // Diagram showing origin and direction of source sampling.
+  // ->0   4<-
+  // 7       3
+  //
+  // 6       5
+  // ->1   2<-
+  // Rotations that start at right side of image.
+  if ((view_rotate == ROTATE_180) ||
+      (view_rotate == ROTATE_270) ||
+      (view_rotate == MIRROR_ROTATE_0) ||
+      (view_rotate == MIRROR_ROTATE_90)) {
+    y_buf += source_width - 1;
+    u_buf += source_width / 2 - 1;
+    v_buf += source_width / 2 - 1;
+    source_width = -source_width;
+  }
+  // Rotations that start at bottom of image.
+  if ((view_rotate == ROTATE_90) ||
+      (view_rotate == ROTATE_180) ||
+      (view_rotate == MIRROR_ROTATE_90) ||
+      (view_rotate == MIRROR_ROTATE_180)) {
+    y_buf += (source_height - 1) * y_pitch;
+    u_buf += ((source_height >> y_shift) - 1) * uv_pitch;
+    v_buf += ((source_height >> y_shift) - 1) * uv_pitch;
+    source_height = -source_height;
+  }
+
+  // Handle zero sized destination.
+  if (width == 0 || height == 0)
+    return;
+  int source_dx = source_width * kFractionMax / width;
+  int source_dy = source_height * kFractionMax / height;
+  int source_dx_uv = source_dx;
+
+  if ((view_rotate == ROTATE_90) ||
+      (view_rotate == ROTATE_270)) {
+    int tmp = height;
+    height = width;
+    width = tmp;
+    tmp = source_height;
+    source_height = source_width;
+    source_width = tmp;
+    int original_dx = source_dx;
+    int original_dy = source_dy;
+    source_dx = ((original_dy >> kFractionBits) * y_pitch) << kFractionBits;
+    source_dx_uv = ((original_dy >> kFractionBits) * uv_pitch) << kFractionBits;
+    source_dy = original_dx;
+    if (view_rotate == ROTATE_90) {
+      y_pitch = -1;
+      uv_pitch = -1;
+      source_height = -source_height;
+    } else {
+      y_pitch = 1;
+      uv_pitch = 1;
+    }
+  }
+
+  // Need padding because FilterRows() will write 1 to 16 extra pixels
+  // after the end for SSE2 version.
+  uint8_t yuvbuf[16 + kFilterBufferSize * 3 + 16];
+  uint8_t* ybuf =
+      reinterpret_cast<uint8_t*>(reinterpret_cast<uintptr_t>(yuvbuf + 15) & ~15);
+  uint8_t* ubuf = ybuf + kFilterBufferSize;
+  uint8_t* vbuf = ubuf + kFilterBufferSize;
+  // TODO(fbarchard): Fixed point math is off by 1 on negatives.
+  int yscale_fixed = (source_height << kFractionBits) / height;
+
+  // TODO(fbarchard): Split this into separate function for better efficiency.
+  for (int y = 0; y < height; ++y) {
+    uint8_t* dest_pixel = rgb_buf + y * rgb_pitch;
+    int source_y_subpixel = (y * yscale_fixed);
+    if (yscale_fixed >= (kFractionMax * 2)) {
+      source_y_subpixel += kFractionMax / 2;  // For 1/2 or less, center filter.
+    }
+    int source_y = source_y_subpixel >> kFractionBits;
+
+    const uint8_t* y0_ptr = y_buf + source_y * y_pitch;
+    const uint8_t* y1_ptr = y0_ptr + y_pitch;
+
+    const uint8_t* u0_ptr = u_buf + (source_y >> y_shift) * uv_pitch;
+    const uint8_t* u1_ptr = u0_ptr + uv_pitch;
+    const uint8_t* v0_ptr = v_buf + (source_y >> y_shift) * uv_pitch;
+    const uint8_t* v1_ptr = v0_ptr + uv_pitch;
+
+    // vertical scaler uses 16.8 fixed point
+    int source_y_fraction = (source_y_subpixel & kFractionMask) >> 8;
+    int source_uv_fraction =
+        ((source_y_subpixel >> y_shift) & kFractionMask) >> 8;
+
+    const uint8_t* y_ptr = y0_ptr;
+    const uint8_t* u_ptr = u0_ptr;
+    const uint8_t* v_ptr = v0_ptr;
+    // Apply vertical filtering if necessary.
+    // TODO(fbarchard): Remove memcpy when not necessary.
+    if (filter & mozilla::gfx::FILTER_BILINEAR_V) {
+      if (yscale_fixed != kFractionMax &&
+          source_y_fraction && ((source_y + 1) < source_height)) {
+        FilterRows(ybuf, y0_ptr, y1_ptr, source_width, source_y_fraction);
+      } else {
+        memcpy(ybuf, y0_ptr, source_width);
+      }
+      y_ptr = ybuf;
+      ybuf[source_width] = ybuf[source_width-1];
+      int uv_source_width = (source_width + 1) / 2;
+      if (yscale_fixed != kFractionMax &&
+          source_uv_fraction &&
+          (((source_y >> y_shift) + 1) < (source_height >> y_shift))) {
+        FilterRows(ubuf, u0_ptr, u1_ptr, uv_source_width, source_uv_fraction);
+        FilterRows(vbuf, v0_ptr, v1_ptr, uv_source_width, source_uv_fraction);
+      } else {
+        memcpy(ubuf, u0_ptr, uv_source_width);
+        memcpy(vbuf, v0_ptr, uv_source_width);
+      }
+      u_ptr = ubuf;
+      v_ptr = vbuf;
+      ubuf[uv_source_width] = ubuf[uv_source_width - 1];
+      vbuf[uv_source_width] = vbuf[uv_source_width - 1];
+    }
+    if (source_dx == kFractionMax) {  // Not scaled
+      FastConvertYUVToRGB32Row(y_ptr, u_ptr, v_ptr,
+                               dest_pixel, width);
+    } else if (filter & FILTER_BILINEAR_H) {
+        LinearScaleYUVToRGB32Row(y_ptr, u_ptr, v_ptr,
+                                 dest_pixel, width, source_dx);
+    } else {
+// Specialized scalers and rotation.
+#if defined(MOZILLA_MAY_SUPPORT_SSE) && defined(_MSC_VER) && defined(_M_IX86) && !defined(__clang__)
+      if(mozilla::supports_sse()) {
+        if (width == (source_width * 2)) {
+          DoubleYUVToRGB32Row_SSE(y_ptr, u_ptr, v_ptr,
+                                  dest_pixel, width);
+        } else if ((source_dx & kFractionMask) == 0) {
+          // Scaling by integer scale factor. ie half.
+          ConvertYUVToRGB32Row_SSE(y_ptr, u_ptr, v_ptr,
+                                   dest_pixel, width,
+                                   source_dx >> kFractionBits);
+        } else if (source_dx_uv == source_dx) {  // Not rotated.
+          ScaleYUVToRGB32Row(y_ptr, u_ptr, v_ptr,
+                             dest_pixel, width, source_dx);
+        } else {
+          RotateConvertYUVToRGB32Row_SSE(y_ptr, u_ptr, v_ptr,
+                                         dest_pixel, width,
+                                         source_dx >> kFractionBits,
+                                         source_dx_uv >> kFractionBits);
+        }
+      }
+      else {
+        ScaleYUVToRGB32Row_C(y_ptr, u_ptr, v_ptr,
+                             dest_pixel, width, source_dx);
+      }
+#else
+      (void)source_dx_uv;
+      ScaleYUVToRGB32Row(y_ptr, u_ptr, v_ptr,
+                         dest_pixel, width, source_dx);
+#endif
+    }
+  }
+  // MMX used for FastConvertYUVToRGB32Row and FilterRows requires emms.
+  if (has_mmx)
+    EMMS();
+}
+void ConvertI420AlphaToARGB32(const uint8_t* y_buf,
+                              const uint8_t* u_buf,
+                              const uint8_t* v_buf,
+                              const uint8_t* a_buf,
+                              uint8_t* argb_buf,
+                              int pic_width,
+                              int pic_height,
+                              int ya_pitch,
+                              int uv_pitch,
+                              int argb_pitch) {
+
+  // The downstream graphics stack expects an attenuated input, hence why the
+  // attenuation parameter is set.
+  DebugOnly<int> err = libyuv::I420AlphaToARGB(y_buf, ya_pitch,
+                                               u_buf, uv_pitch,
+                                               v_buf, uv_pitch,
+                                               a_buf, ya_pitch,
+                                               argb_buf, argb_pitch,
+                                               pic_width, pic_height, 1);
+  MOZ_ASSERT(!err);
+}
+
+} // namespace gfx
+} // namespace mozilla