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gfx/ycbcr/yuv_row_c.cpp@97036ab72558 (annotated)

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.

michael@0	1	// Copyright (c) 2010 The Chromium Authors. All rights reserved.
michael@0	2	// Use of this source code is governed by a BSD-style license that can be
michael@0	3	// found in the LICENSE file.
michael@0	4
michael@0	5	#include "yuv_row.h"
michael@0	6
michael@0	7	#define DCHECK(a)
michael@0	8
michael@0	9	extern "C" {
michael@0	10
michael@0	11	// C reference code that mimic the YUV assembly.
michael@0	12	#define packuswb(x) ((x) < 0 ? 0 : ((x) > 255 ? 255 : (x)))
michael@0	13	#define paddsw(x, y) (((x) + (y)) < -32768 ? -32768 : \
michael@0	14	(((x) + (y)) > 32767 ? 32767 : ((x) + (y))))
michael@0	15
michael@0	16	static inline void YuvPixel(uint8 y,
michael@0	17	uint8 u,
michael@0	18	uint8 v,
michael@0	19	uint8* rgb_buf) {
michael@0	20
michael@0	21	int b = kCoefficientsRgbY[256+u][0];
michael@0	22	int g = kCoefficientsRgbY[256+u][1];
michael@0	23	int r = kCoefficientsRgbY[256+u][2];
michael@0	24	int a = kCoefficientsRgbY[256+u][3];
michael@0	25
michael@0	26	b = paddsw(b, kCoefficientsRgbY[512+v][0]);
michael@0	27	g = paddsw(g, kCoefficientsRgbY[512+v][1]);
michael@0	28	r = paddsw(r, kCoefficientsRgbY[512+v][2]);
michael@0	29	a = paddsw(a, kCoefficientsRgbY[512+v][3]);
michael@0	30
michael@0	31	b = paddsw(b, kCoefficientsRgbY[y][0]);
michael@0	32	g = paddsw(g, kCoefficientsRgbY[y][1]);
michael@0	33	r = paddsw(r, kCoefficientsRgbY[y][2]);
michael@0	34	a = paddsw(a, kCoefficientsRgbY[y][3]);
michael@0	35
michael@0	36	b >>= 6;
michael@0	37	g >>= 6;
michael@0	38	r >>= 6;
michael@0	39	a >>= 6;
michael@0	40
michael@0	41	*reinterpret_cast<uint32*>(rgb_buf) = (packuswb(b)) |
michael@0	42	(packuswb(g) << 8) |
michael@0	43	(packuswb(r) << 16) |
michael@0	44	(packuswb(a) << 24);
michael@0	45	}
michael@0	46
michael@0	47	void FastConvertYUVToRGB32Row_C(const uint8* y_buf,
michael@0	48	const uint8* u_buf,
michael@0	49	const uint8* v_buf,
michael@0	50	uint8* rgb_buf,
michael@0	51	int width,
michael@0	52	unsigned int x_shift) {
michael@0	53	for (int x = 0; x < width; x += 2) {
michael@0	54	uint8 u = u_buf[x >> x_shift];
michael@0	55	uint8 v = v_buf[x >> x_shift];
michael@0	56	uint8 y0 = y_buf[x];
michael@0	57	YuvPixel(y0, u, v, rgb_buf);
michael@0	58	if ((x + 1) < width) {
michael@0	59	uint8 y1 = y_buf[x + 1];
michael@0	60	if (x_shift == 0) {
michael@0	61	u = u_buf[x + 1];
michael@0	62	v = v_buf[x + 1];
michael@0	63	}
michael@0	64	YuvPixel(y1, u, v, rgb_buf + 4);
michael@0	65	}
michael@0	66	rgb_buf += 8; // Advance 2 pixels.
michael@0	67	}
michael@0	68	}
michael@0	69
michael@0	70	// 16.16 fixed point is used. A shift by 16 isolates the integer.
michael@0	71	// A shift by 17 is used to further subsample the chrominence channels.
michael@0	72	// & 0xffff isolates the fixed point fraction. >> 2 to get the upper 2 bits,
michael@0	73	// for 1/65536 pixel accurate interpolation.
michael@0	74	void ScaleYUVToRGB32Row_C(const uint8* y_buf,
michael@0	75	const uint8* u_buf,
michael@0	76	const uint8* v_buf,
michael@0	77	uint8* rgb_buf,
michael@0	78	int width,
michael@0	79	int source_dx) {
michael@0	80	int x = 0;
michael@0	81	for (int i = 0; i < width; i += 2) {
michael@0	82	int y = y_buf[x >> 16];
michael@0	83	int u = u_buf[(x >> 17)];
michael@0	84	int v = v_buf[(x >> 17)];
michael@0	85	YuvPixel(y, u, v, rgb_buf);
michael@0	86	x += source_dx;
michael@0	87	if ((i + 1) < width) {
michael@0	88	y = y_buf[x >> 16];
michael@0	89	YuvPixel(y, u, v, rgb_buf+4);
michael@0	90	x += source_dx;
michael@0	91	}
michael@0	92	rgb_buf += 8;
michael@0	93	}
michael@0	94	}
michael@0	95
michael@0	96	void LinearScaleYUVToRGB32Row_C(const uint8* y_buf,
michael@0	97	const uint8* u_buf,
michael@0	98	const uint8* v_buf,
michael@0	99	uint8* rgb_buf,
michael@0	100	int width,
michael@0	101	int source_dx) {
michael@0	102	int x = 0;
michael@0	103	if (source_dx >= 0x20000) {
michael@0	104	x = 32768;
michael@0	105	}
michael@0	106	for (int i = 0; i < width; i += 2) {
michael@0	107	int y0 = y_buf[x >> 16];
michael@0	108	int y1 = y_buf[(x >> 16) + 1];
michael@0	109	int u0 = u_buf[(x >> 17)];
michael@0	110	int u1 = u_buf[(x >> 17) + 1];
michael@0	111	int v0 = v_buf[(x >> 17)];
michael@0	112	int v1 = v_buf[(x >> 17) + 1];
michael@0	113	int y_frac = (x & 65535);
michael@0	114	int uv_frac = ((x >> 1) & 65535);
michael@0	115	int y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
michael@0	116	int u = (uv_frac * u1 + (uv_frac ^ 65535) * u0) >> 16;
michael@0	117	int v = (uv_frac * v1 + (uv_frac ^ 65535) * v0) >> 16;
michael@0	118	YuvPixel(y, u, v, rgb_buf);
michael@0	119	x += source_dx;
michael@0	120	if ((i + 1) < width) {
michael@0	121	y0 = y_buf[x >> 16];
michael@0	122	y1 = y_buf[(x >> 16) + 1];
michael@0	123	y_frac = (x & 65535);
michael@0	124	y = (y_frac * y1 + (y_frac ^ 65535) * y0) >> 16;
michael@0	125	YuvPixel(y, u, v, rgb_buf+4);
michael@0	126	x += source_dx;
michael@0	127	}
michael@0	128	rgb_buf += 8;
michael@0	129	}
michael@0	130	}
michael@0	131
michael@0	132	} // extern "C"
michael@0	133