michael@0: // Copyright (c) 2010 The Chromium Authors. All rights reserved.
michael@0: // Use of this source code is governed by a BSD-style license that can be
michael@0: // found in the LICENSE file.
michael@0: 
michael@0: #include "yuv_row.h"
michael@0: 
michael@0: #define DCHECK(a)
michael@0: 
michael@0: extern "C" {
michael@0: 
michael@0: // C reference code that mimic the YUV assembly.
michael@0: #define packuswb(x) ((x) < 0 ? 0 : ((x) > 255 ? 255 : (x)))
michael@0: #define paddsw(x, y) (((x) + (y)) < -32768 ? -32768 : \
michael@0:     (((x) + (y)) > 32767 ? 32767 : ((x) + (y))))
michael@0: 
michael@0: static inline void YuvPixel(uint8 y,
michael@0:                             uint8 u,
michael@0:                             uint8 v,
michael@0:                             uint8* rgb_buf) {
michael@0: 
michael@0:   int b = kCoefficientsRgbY[256+u][0];
michael@0:   int g = kCoefficientsRgbY[256+u][1];
michael@0:   int r = kCoefficientsRgbY[256+u][2];
michael@0:   int a = kCoefficientsRgbY[256+u][3];
michael@0: 
michael@0:   b = paddsw(b, kCoefficientsRgbY[512+v][0]);
michael@0:   g = paddsw(g, kCoefficientsRgbY[512+v][1]);
michael@0:   r = paddsw(r, kCoefficientsRgbY[512+v][2]);
michael@0:   a = paddsw(a, kCoefficientsRgbY[512+v][3]);
michael@0: 
michael@0:   b = paddsw(b, kCoefficientsRgbY[y][0]);
michael@0:   g = paddsw(g, kCoefficientsRgbY[y][1]);
michael@0:   r = paddsw(r, kCoefficientsRgbY[y][2]);
michael@0:   a = paddsw(a, kCoefficientsRgbY[y][3]);
michael@0: 
michael@0:   b >>= 6;
michael@0:   g >>= 6;
michael@0:   r >>= 6;
michael@0:   a >>= 6;
michael@0: 
michael@0:   *reinterpret_cast<uint32*>(rgb_buf) = (packuswb(b)) |
michael@0:                                         (packuswb(g) << 8) |
michael@0:                                         (packuswb(r) << 16) |
michael@0:                                         (packuswb(a) << 24);
michael@0: }
michael@0: 
michael@0: void FastConvertYUVToRGB32Row_C(const uint8* y_buf,
michael@0:                                 const uint8* u_buf,
michael@0:                                 const uint8* v_buf,
michael@0:                                 uint8* rgb_buf,
michael@0:                                 int width,
michael@0:                                 unsigned int x_shift) {
michael@0:   for (int x = 0; x < width; x += 2) {
michael@0:     uint8 u = u_buf[x >> x_shift];
michael@0:     uint8 v = v_buf[x >> x_shift];
michael@0:     uint8 y0 = y_buf[x];
michael@0:     YuvPixel(y0, u, v, rgb_buf);
michael@0:     if ((x + 1) < width) {
michael@0:       uint8 y1 = y_buf[x + 1];
michael@0:       if (x_shift == 0) {
michael@0:         u = u_buf[x + 1];
michael@0:         v = v_buf[x + 1];
michael@0:       }
michael@0:       YuvPixel(y1, u, v, rgb_buf + 4);
michael@0:     }
michael@0:     rgb_buf += 8;  // Advance 2 pixels.
michael@0:   }
michael@0: }
michael@0: 
michael@0: // 16.16 fixed point is used.  A shift by 16 isolates the integer.
michael@0: // A shift by 17 is used to further subsample the chrominence channels.
michael@0: // & 0xffff isolates the fixed point fraction.  >> 2 to get the upper 2 bits,
michael@0: // for 1/65536 pixel accurate interpolation.
michael@0: void ScaleYUVToRGB32Row_C(const uint8* y_buf,
michael@0:                           const uint8* u_buf,
michael@0:                           const uint8* v_buf,
michael@0:                           uint8* rgb_buf,
michael@0:                           int width,
michael@0:                           int source_dx) {
michael@0:   int x = 0;
michael@0:   for (int i = 0; i < width; i += 2) {
michael@0:     int y = y_buf[x >> 16];
michael@0:     int u = u_buf[(x >> 17)];
michael@0:     int v = v_buf[(x >> 17)];
michael@0:     YuvPixel(y, u, v, rgb_buf);
michael@0:     x += source_dx;
michael@0:     if ((i + 1) < width) {
michael@0:       y = y_buf[x >> 16];
michael@0:       YuvPixel(y, u, v, rgb_buf+4);
michael@0:       x += source_dx;
michael@0:     }
michael@0:     rgb_buf += 8;
michael@0:   }
michael@0: }
michael@0: 
michael@0: void LinearScaleYUVToRGB32Row_C(const uint8* y_buf,
michael@0:                                 const uint8* u_buf,
michael@0:                                 const uint8* v_buf,
michael@0:                                 uint8* rgb_buf,
michael@0:                                 int width,
michael@0:                                 int source_dx) {
michael@0:   int x = 0;
michael@0:   if (source_dx >= 0x20000) {
michael@0:     x = 32768;
michael@0:   }
michael@0:   for (int i = 0; i < width; i += 2) {
michael@0:     int y0 = y_buf[x >> 16];
michael@0:     int y1 = y_buf[(x >> 16) + 1];
michael@0:     int u0 = u_buf[(x >> 17)];
michael@0:     int u1 = u_buf[(x >> 17) + 1];
michael@0:     int v0 = v_buf[(x >> 17)];
michael@0:     int v1 = v_buf[(x >> 17) + 1];
michael@0:     int y_frac = (x & 65535);
michael@0:     int uv_frac = ((x >> 1) & 65535);
michael@0:     int y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
michael@0:     int u = (uv_frac * u1 + (uv_frac ^ 65535) * u0) >> 16;
michael@0:     int v = (uv_frac * v1 + (uv_frac ^ 65535) * v0) >> 16;
michael@0:     YuvPixel(y, u, v, rgb_buf);
michael@0:     x += source_dx;
michael@0:     if ((i + 1) < width) {
michael@0:       y0 = y_buf[x >> 16];
michael@0:       y1 = y_buf[(x >> 16) + 1];
michael@0:       y_frac = (x & 65535);
michael@0:       y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
michael@0:       YuvPixel(y, u, v, rgb_buf+4);
michael@0:       x += source_dx;
michael@0:     }
michael@0:     rgb_buf += 8;
michael@0:   }
michael@0: }
michael@0: 
michael@0: }  // extern "C"
michael@0: