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media/libvpx/vp8/common/quant_common.c@ac0c01689b40 (annotated)

media/libvpx/vp8/common/quant_common.c

Thu, 15 Jan 2015 15:59:08 +0100

author

Michael Schloh von Bennewitz <michael@schloh.com>

date

Thu, 15 Jan 2015 15:59:08 +0100

branch

TOR_BUG_9701

changeset 10

ac0c01689b40

permissions

-rw-r--r--

Implement a real Private Browsing Mode condition by changing the API/ABI;
This solves Tor bug #9701, complying with disk avoidance documented in
https://www.torproject.org/projects/torbrowser/design/#disk-avoidance.

michael@0	1	/*
michael@0	2	* Copyright (c) 2010 The WebM project authors. All Rights Reserved.
michael@0	3	*
michael@0	4	* Use of this source code is governed by a BSD-style license
michael@0	5	* that can be found in the LICENSE file in the root of the source
michael@0	6	* tree. An additional intellectual property rights grant can be found
michael@0	7	* in the file PATENTS. All contributing project authors may
michael@0	8	* be found in the AUTHORS file in the root of the source tree.
michael@0	9	*/
michael@0	10
michael@0	11
michael@0	12	#include "quant_common.h"
michael@0	13
michael@0	14	static const int dc_qlookup[QINDEX_RANGE] =
michael@0	15	{
michael@0	16	4, 5, 6, 7, 8, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 17,
michael@0	17	18, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 25, 25, 26, 27, 28,
michael@0	18	29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43,
michael@0	19	44, 45, 46, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58,
michael@0	20	59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74,
michael@0	21	75, 76, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89,
michael@0	22	91, 93, 95, 96, 98, 100, 101, 102, 104, 106, 108, 110, 112, 114, 116, 118,
michael@0	23	122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 143, 145, 148, 151, 154, 157,
michael@0	24	};
michael@0	25
michael@0	26	static const int ac_qlookup[QINDEX_RANGE] =
michael@0	27	{
michael@0	28	4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19,
michael@0	29	20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35,
michael@0	30	36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,
michael@0	31	52, 53, 54, 55, 56, 57, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76,
michael@0	32	78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108,
michael@0	33	110, 112, 114, 116, 119, 122, 125, 128, 131, 134, 137, 140, 143, 146, 149, 152,
michael@0	34	155, 158, 161, 164, 167, 170, 173, 177, 181, 185, 189, 193, 197, 201, 205, 209,
michael@0	35	213, 217, 221, 225, 229, 234, 239, 245, 249, 254, 259, 264, 269, 274, 279, 284,
michael@0	36	};
michael@0	37
michael@0	38
michael@0	39	int vp8_dc_quant(int QIndex, int Delta)
michael@0	40	{
michael@0	41	int retval;
michael@0	42
michael@0	43	QIndex = QIndex + Delta;
michael@0	44
michael@0	45	if (QIndex > 127)
michael@0	46	QIndex = 127;
michael@0	47	else if (QIndex < 0)
michael@0	48	QIndex = 0;
michael@0	49
michael@0	50	retval = dc_qlookup[ QIndex ];
michael@0	51	return retval;
michael@0	52	}
michael@0	53
michael@0	54	int vp8_dc2quant(int QIndex, int Delta)
michael@0	55	{
michael@0	56	int retval;
michael@0	57
michael@0	58	QIndex = QIndex + Delta;
michael@0	59
michael@0	60	if (QIndex > 127)
michael@0	61	QIndex = 127;
michael@0	62	else if (QIndex < 0)
michael@0	63	QIndex = 0;
michael@0	64
michael@0	65	retval = dc_qlookup[ QIndex ] * 2;
michael@0	66	return retval;
michael@0	67
michael@0	68	}
michael@0	69	int vp8_dc_uv_quant(int QIndex, int Delta)
michael@0	70	{
michael@0	71	int retval;
michael@0	72
michael@0	73	QIndex = QIndex + Delta;
michael@0	74
michael@0	75	if (QIndex > 127)
michael@0	76	QIndex = 127;
michael@0	77	else if (QIndex < 0)
michael@0	78	QIndex = 0;
michael@0	79
michael@0	80	retval = dc_qlookup[ QIndex ];
michael@0	81
michael@0	82	if (retval > 132)
michael@0	83	retval = 132;
michael@0	84
michael@0	85	return retval;
michael@0	86	}
michael@0	87
michael@0	88	int vp8_ac_yquant(int QIndex)
michael@0	89	{
michael@0	90	int retval;
michael@0	91
michael@0	92	if (QIndex > 127)
michael@0	93	QIndex = 127;
michael@0	94	else if (QIndex < 0)
michael@0	95	QIndex = 0;
michael@0	96
michael@0	97	retval = ac_qlookup[ QIndex ];
michael@0	98	return retval;
michael@0	99	}
michael@0	100
michael@0	101	int vp8_ac2quant(int QIndex, int Delta)
michael@0	102	{
michael@0	103	int retval;
michael@0	104
michael@0	105	QIndex = QIndex + Delta;
michael@0	106
michael@0	107	if (QIndex > 127)
michael@0	108	QIndex = 127;
michael@0	109	else if (QIndex < 0)
michael@0	110	QIndex = 0;
michael@0	111
michael@0	112	/* For all x in [0..284], x*155/100 is bitwise equal to (x*101581) >> 16.
michael@0	113	* The smallest precision for that is '(x*6349) >> 12' but 16 is a good
michael@0	114	* word size. */
michael@0	115	retval = (ac_qlookup[ QIndex ] * 101581) >> 16;
michael@0	116
michael@0	117	if (retval < 8)
michael@0	118	retval = 8;
michael@0	119
michael@0	120	return retval;
michael@0	121	}
michael@0	122	int vp8_ac_uv_quant(int QIndex, int Delta)
michael@0	123	{
michael@0	124	int retval;
michael@0	125
michael@0	126	QIndex = QIndex + Delta;
michael@0	127
michael@0	128	if (QIndex > 127)
michael@0	129	QIndex = 127;
michael@0	130	else if (QIndex < 0)
michael@0	131	QIndex = 0;
michael@0	132
michael@0	133	retval = ac_qlookup[ QIndex ];
michael@0	134	return retval;
michael@0	135	}