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// 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 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);
}
void FastConvertYUVToRGB32Row_C(const uint8* y_buf,
const uint8* u_buf,
const uint8* v_buf,
uint8* rgb_buf,
int width,
unsigned int x_shift) {
for (int x = 0; x < width; x += 2) {
uint8 u = u_buf[x >> x_shift];
uint8 v = v_buf[x >> x_shift];
uint8 y0 = y_buf[x];
YuvPixel(y0, u, v, rgb_buf);
if ((x + 1) < width) {
uint8 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* 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;
}
}
} // extern "C"
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