Resubmit - Rewrite color space conversions suite using YASM"

media/base/simd/convert_yuv_to_rgb_c.cc

+// Copyright (c) 2011 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.
+
+#include "media/base/simd/convert_yuv_to_rgb.h"
+// TODO(hclam): Shouldn't depend on yuv_row.h.
+#include "media/base/yuv_row.h"
+
+#define packuswb(x) ((x) < 0 ? 0 : ((x) > 255 ? 255 : (x)))
+#define paddsw(x, y) (((x) + (y)) < -32768 ? -32768 : \
+    (((x) + (y)) > 32767 ? 32767 : ((x) + (y))))
+
+static inline void YUVPixel(uint8 y,
+                            uint8 u,
+                            uint8 v,
+                            uint8* rgb_buf) {
+
+  int b = kCoefficientsRgbY[256+u][0];
+  int g = kCoefficientsRgbY[256+u][1];
+  int r = kCoefficientsRgbY[256+u][2];
+  int a = kCoefficientsRgbY[256+u][3];
+
+  b = paddsw(b, kCoefficientsRgbY[512+v][0]);
+  g = paddsw(g, kCoefficientsRgbY[512+v][1]);
+  r = paddsw(r, kCoefficientsRgbY[512+v][2]);
+  a = paddsw(a, kCoefficientsRgbY[512+v][3]);
+
+  b = paddsw(b, kCoefficientsRgbY[y][0]);
+  g = paddsw(g, kCoefficientsRgbY[y][1]);
+  r = paddsw(r, kCoefficientsRgbY[y][2]);
+  a = paddsw(a, kCoefficientsRgbY[y][3]);
+
+  b >>= 6;
+  g >>= 6;
+  r >>= 6;
+  a >>= 6;
+
+  *reinterpret_cast<uint32*>(rgb_buf) = (packuswb(b)) |
+                                        (packuswb(g) << 8) |
+                                        (packuswb(r) << 16) |
+                                        (packuswb(a) << 24);
+}
+
+extern "C" {
+
+void ConvertYUVToRGB32Row_C(const uint8* y_buf,
+                            const uint8* u_buf,
+                            const uint8* v_buf,
+                            uint8* rgb_buf,
+                            int width) {
+  for (int x = 0; x < width; x += 2) {
+    uint8 u = u_buf[x >> 1];
+    uint8 v = v_buf[x >> 1];
+    uint8 y0 = y_buf[x];
+    YUVPixel(y0, u, v, rgb_buf);
+    if ((x + 1) < width) {
+      uint8 y1 = y_buf[x + 1];
+      YUVPixel(y1, u, v, rgb_buf + 4);
+    }
+    rgb_buf += 8;  // Advance 2 pixels.
+  }
+}
+
+// 16.16 fixed point is used.  A shift by 16 isolates the integer.
+// A shift by 17 is used to further subsample the chrominence channels.
+// & 0xffff isolates the fixed point fraction.  >> 2 to get the upper 2 bits,
+// for 1/65536 pixel accurate interpolation.
+void ScaleYUVToRGB32Row_C(const uint8* y_buf,
+                          const uint8* u_buf,
+                          const uint8* v_buf,
+                          uint8* rgb_buf,
+                          int width,
+                          int source_dx) {
+  int x = 0;
+  for (int i = 0; i < width; i += 2) {
+    int y = y_buf[x >> 16];
+    int u = u_buf[(x >> 17)];
+    int v = v_buf[(x >> 17)];
+    YUVPixel(y, u, v, rgb_buf);
+    x += source_dx;
+    if ((i + 1) < width) {
+      y = y_buf[x >> 16];
+      YUVPixel(y, u, v, rgb_buf+4);
+      x += source_dx;
+    }
+    rgb_buf += 8;
+  }
+}
+
+void LinearScaleYUVToRGB32Row_C(const uint8* y_buf,
+                                const uint8* u_buf,
+                                const uint8* v_buf,
+                                uint8* rgb_buf,
+                                int width,
+                                int source_dx) {
+  int x = 0;
+  if (source_dx >= 0x20000) {
+    x = 32768;
+  }
+  for (int i = 0; i < width; i += 2) {
+    int y0 = y_buf[x >> 16];
+    int y1 = y_buf[(x >> 16) + 1];
+    int u0 = u_buf[(x >> 17)];
+    int u1 = u_buf[(x >> 17) + 1];
+    int v0 = v_buf[(x >> 17)];
+    int v1 = v_buf[(x >> 17) + 1];
+    int y_frac = (x & 65535);
+    int uv_frac = ((x >> 1) & 65535);
+    int y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
+    int u = (uv_frac * u1 + (uv_frac ^ 65535) * u0) >> 16;
+    int v = (uv_frac * v1 + (uv_frac ^ 65535) * v0) >> 16;
+    YUVPixel(y, u, v, rgb_buf);
+    x += source_dx;
+    if ((i + 1) < width) {
+      y0 = y_buf[x >> 16];
+      y1 = y_buf[(x >> 16) + 1];
+      y_frac = (x & 65535);
+      y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
+      YUVPixel(y, u, v, rgb_buf+4);
+      x += source_dx;
+    }
+    rgb_buf += 8;
+  }
+}
+
+}
+
+namespace media {
+
+void ConvertYUVToRGB32_C(const uint8* yplane,
+                         const uint8* uplane,
+                         const uint8* vplane,
+                         uint8* rgbframe,
+                         int width,
+                         int height,
+                         int ystride,
+                         int uvstride,
+                         int rgbstride,
+                         YUVType yuv_type) {
+  unsigned int y_shift = yuv_type;
+  for (int y = 0; y < height; ++y) {
+    uint8* rgb_row = rgbframe + y * rgbstride;
+    const uint8* y_ptr = yplane + y * ystride;
+    const uint8* u_ptr = uplane + (y >> y_shift) * uvstride;
+    const uint8* v_ptr = vplane + (y >> y_shift) * uvstride;
+
+    ConvertYUVToRGB32Row_C(y_ptr,
+                           u_ptr,
+                           v_ptr,
+                           rgb_row,
+                           width);
+  }
+}
+
+}  // namespace media