The Tor Browser / file comparison
comparison: content/media/webaudio/blink/ZeroPole.cpp
content/media/webaudio/blink/ZeroPole.cpp
- branch
- TOR_BUG_9701
- changeset 8
- 97036ab72558
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| -1:000000000000 | 0:35b89adee2dd |
|---|---|
| 1 /* | |
| 2 * Copyright (C) 2011 Google Inc. All rights reserved. | |
| 3 * | |
| 4 * Redistribution and use in source and binary forms, with or without | |
| 5 * modification, are permitted provided that the following conditions | |
| 6 * are met: | |
| 7 * | |
| 8 * 1. Redistributions of source code must retain the above copyright | |
| 9 * notice, this list of conditions and the following disclaimer. | |
| 10 * 2. Redistributions in binary form must reproduce the above copyright | |
| 11 * notice, this list of conditions and the following disclaimer in the | |
| 12 * documentation and/or other materials provided with the distribution. | |
| 13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of | |
| 14 * its contributors may be used to endorse or promote products derived | |
| 15 * from this software without specific prior written permission. | |
| 16 * | |
| 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY | |
| 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | |
| 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY | |
| 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | |
| 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | |
| 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND | |
| 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
| 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
| 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| 27 */ | |
| 28 | |
| 29 #include "ZeroPole.h" | |
| 30 | |
| 31 #include <cmath> | |
| 32 #include <float.h> | |
| 33 | |
| 34 namespace WebCore { | |
| 35 | |
| 36 void ZeroPole::process(const float *source, float *destination, int framesToProcess) | |
| 37 { | |
| 38 float zero = m_zero; | |
| 39 float pole = m_pole; | |
| 40 | |
| 41 // Gain compensation to make 0dB @ 0Hz | |
| 42 const float k1 = 1 / (1 - zero); | |
| 43 const float k2 = 1 - pole; | |
| 44 | |
| 45 // Member variables to locals. | |
| 46 float lastX = m_lastX; | |
| 47 float lastY = m_lastY; | |
| 48 | |
| 49 for (int i = 0; i < framesToProcess; ++i) { | |
| 50 float input = source[i]; | |
| 51 | |
| 52 // Zero | |
| 53 float output1 = k1 * (input - zero * lastX); | |
| 54 lastX = input; | |
| 55 | |
| 56 // Pole | |
| 57 float output2 = k2 * output1 + pole * lastY; | |
| 58 lastY = output2; | |
| 59 | |
| 60 destination[i] = output2; | |
| 61 } | |
| 62 | |
| 63 // Locals to member variables. Flush denormals here so we don't | |
| 64 // slow down the inner loop above. | |
| 65 if (lastX == 0.0f && lastY != 0.0f && fabsf(lastY) < FLT_MIN) { | |
| 66 // Flush future values to zero (until there is new input). | |
| 67 lastY = 0.0; | |
| 68 // Flush calculated values. | |
| 69 for (int i = framesToProcess; i-- && fabsf(destination[i]) < FLT_MIN; ) { | |
| 70 destination[i] = 0.0f; | |
| 71 } | |
| 72 } | |
| 73 | |
| 74 m_lastX = lastX; | |
| 75 m_lastY = lastY; | |
| 76 } | |
| 77 | |
| 78 } // namespace WebCore |
