// 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"