summaryrefslogtreecommitdiffstats
path: root/gfx/ycbcr/yuv_row_c.cpp
diff options
context:
space:
mode:
Diffstat (limited to 'gfx/ycbcr/yuv_row_c.cpp')
-rw-r--r--gfx/ycbcr/yuv_row_c.cpp133
1 files changed, 133 insertions, 0 deletions
diff --git a/gfx/ycbcr/yuv_row_c.cpp b/gfx/ycbcr/yuv_row_c.cpp
new file mode 100644
index 0000000000..b986451ec2
--- /dev/null
+++ b/gfx/ycbcr/yuv_row_c.cpp
@@ -0,0 +1,133 @@
+// 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.
+
+#include "yuv_row.h"
+
+#define DCHECK(a)
+
+extern "C" {
+
+// C reference code that mimic the YUV assembly.
+#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_t y,
+ uint8_t u,
+ uint8_t v,
+ uint8_t* 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_t*>(rgb_buf) = (packuswb(b)) |
+ (packuswb(g) << 8) |
+ (packuswb(r) << 16) |
+ (packuswb(a) << 24);
+}
+
+void FastConvertYUVToRGB32Row_C(const uint8_t* y_buf,
+ const uint8_t* u_buf,
+ const uint8_t* v_buf,
+ uint8_t* rgb_buf,
+ int width,
+ unsigned int x_shift) {
+ for (int x = 0; x < width; x += 2) {
+ uint8_t u = u_buf[x >> x_shift];
+ uint8_t v = v_buf[x >> x_shift];
+ uint8_t y0 = y_buf[x];
+ YuvPixel(y0, u, v, rgb_buf);
+ if ((x + 1) < width) {
+ uint8_t y1 = y_buf[x + 1];
+ if (x_shift == 0) {
+ u = u_buf[x + 1];
+ v = v_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_t* y_buf,
+ const uint8_t* u_buf,
+ const uint8_t* v_buf,
+ uint8_t* 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_t* y_buf,
+ const uint8_t* u_buf,
+ const uint8_t* v_buf,
+ uint8_t* 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;
+ }
+}
+
+} // extern "C"
+