gfx/ycbcr/yuv_row_c.cpp@97036ab72558
gfx/ycbcr/yuv_row_c.cpp
Tue, 06 Jan 2015 21:39:09 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Tue, 06 Jan 2015 21:39:09 +0100
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
- permissions
- -rw-r--r--
Conditionally force memory storage according to privacy.thirdparty.isolate;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.
1 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
5 #include "yuv_row.h"
7 #define DCHECK(a)
9 extern "C" {
11 // C reference code that mimic the YUV assembly.
12 #define packuswb(x) ((x) < 0 ? 0 : ((x) > 255 ? 255 : (x)))
13 #define paddsw(x, y) (((x) + (y)) < -32768 ? -32768 : \
14 (((x) + (y)) > 32767 ? 32767 : ((x) + (y))))
16 static inline void YuvPixel(uint8 y,
17 uint8 u,
18 uint8 v,
19 uint8* rgb_buf) {
21 int b = kCoefficientsRgbY[256+u][0];
22 int g = kCoefficientsRgbY[256+u][1];
23 int r = kCoefficientsRgbY[256+u][2];
24 int a = kCoefficientsRgbY[256+u][3];
26 b = paddsw(b, kCoefficientsRgbY[512+v][0]);
27 g = paddsw(g, kCoefficientsRgbY[512+v][1]);
28 r = paddsw(r, kCoefficientsRgbY[512+v][2]);
29 a = paddsw(a, kCoefficientsRgbY[512+v][3]);
31 b = paddsw(b, kCoefficientsRgbY[y][0]);
32 g = paddsw(g, kCoefficientsRgbY[y][1]);
33 r = paddsw(r, kCoefficientsRgbY[y][2]);
34 a = paddsw(a, kCoefficientsRgbY[y][3]);
36 b >>= 6;
37 g >>= 6;
38 r >>= 6;
39 a >>= 6;
41 *reinterpret_cast<uint32*>(rgb_buf) = (packuswb(b)) |
42 (packuswb(g) << 8) |
43 (packuswb(r) << 16) |
44 (packuswb(a) << 24);
45 }
47 void FastConvertYUVToRGB32Row_C(const uint8* y_buf,
48 const uint8* u_buf,
49 const uint8* v_buf,
50 uint8* rgb_buf,
51 int width,
52 unsigned int x_shift) {
53 for (int x = 0; x < width; x += 2) {
54 uint8 u = u_buf[x >> x_shift];
55 uint8 v = v_buf[x >> x_shift];
56 uint8 y0 = y_buf[x];
57 YuvPixel(y0, u, v, rgb_buf);
58 if ((x + 1) < width) {
59 uint8 y1 = y_buf[x + 1];
60 if (x_shift == 0) {
61 u = u_buf[x + 1];
62 v = v_buf[x + 1];
63 }
64 YuvPixel(y1, u, v, rgb_buf + 4);
65 }
66 rgb_buf += 8; // Advance 2 pixels.
67 }
68 }
70 // 16.16 fixed point is used. A shift by 16 isolates the integer.
71 // A shift by 17 is used to further subsample the chrominence channels.
72 // & 0xffff isolates the fixed point fraction. >> 2 to get the upper 2 bits,
73 // for 1/65536 pixel accurate interpolation.
74 void ScaleYUVToRGB32Row_C(const uint8* y_buf,
75 const uint8* u_buf,
76 const uint8* v_buf,
77 uint8* rgb_buf,
78 int width,
79 int source_dx) {
80 int x = 0;
81 for (int i = 0; i < width; i += 2) {
82 int y = y_buf[x >> 16];
83 int u = u_buf[(x >> 17)];
84 int v = v_buf[(x >> 17)];
85 YuvPixel(y, u, v, rgb_buf);
86 x += source_dx;
87 if ((i + 1) < width) {
88 y = y_buf[x >> 16];
89 YuvPixel(y, u, v, rgb_buf+4);
90 x += source_dx;
91 }
92 rgb_buf += 8;
93 }
94 }
96 void LinearScaleYUVToRGB32Row_C(const uint8* y_buf,
97 const uint8* u_buf,
98 const uint8* v_buf,
99 uint8* rgb_buf,
100 int width,
101 int source_dx) {
102 int x = 0;
103 if (source_dx >= 0x20000) {
104 x = 32768;
105 }
106 for (int i = 0; i < width; i += 2) {
107 int y0 = y_buf[x >> 16];
108 int y1 = y_buf[(x >> 16) + 1];
109 int u0 = u_buf[(x >> 17)];
110 int u1 = u_buf[(x >> 17) + 1];
111 int v0 = v_buf[(x >> 17)];
112 int v1 = v_buf[(x >> 17) + 1];
113 int y_frac = (x & 65535);
114 int uv_frac = ((x >> 1) & 65535);
115 int y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
116 int u = (uv_frac * u1 + (uv_frac ^ 65535) * u0) >> 16;
117 int v = (uv_frac * v1 + (uv_frac ^ 65535) * v0) >> 16;
118 YuvPixel(y, u, v, rgb_buf);
119 x += source_dx;
120 if ((i + 1) < width) {
121 y0 = y_buf[x >> 16];
122 y1 = y_buf[(x >> 16) + 1];
123 y_frac = (x & 65535);
124 y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
125 YuvPixel(y, u, v, rgb_buf+4);
126 x += source_dx;
127 }
128 rgb_buf += 8;
129 }
130 }
132 } // extern "C"
