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1 /* | 1 /* |
2 * Copyright (C) 2010, Google Inc. All rights reserved. | 2 * Copyright (C) 2010, Google Inc. All rights reserved. |
3 * | 3 * |
4 * Redistribution and use in source and binary forms, with or without | 4 * Redistribution and use in source and binary forms, with or without |
5 * modification, are permitted provided that the following conditions | 5 * modification, are permitted provided that the following conditions |
6 * are met: | 6 * are met: |
7 * 1. Redistributions of source code must retain the above copyright | 7 * 1. Redistributions of source code must retain the above copyright |
8 * notice, this list of conditions and the following disclaimer. | 8 * notice, this list of conditions and the following disclaimer. |
9 * 2. Redistributions in binary form must reproduce the above copyright | 9 * 2. Redistributions in binary form must reproduce the above copyright |
10 * notice, this list of conditions and the following disclaimer in the | 10 * notice, this list of conditions and the following disclaimer in the |
11 * documentation and/or other materials provided with the distribution. | 11 * documentation and/or other materials provided with the distribution. |
12 * | 12 * |
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND AN
Y | 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND |
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED | 14 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
15 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | 15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
16 * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR AN
Y | 16 * ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE |
17 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | 17 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
18 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | 18 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR |
19 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND O
N | 19 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER |
20 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | 20 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
21 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS | 21 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
22 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | 22 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH |
| 23 * DAMAGE. |
23 */ | 24 */ |
24 | 25 |
25 #ifndef AudioUtilities_h | 26 #ifndef AudioUtilities_h |
26 #define AudioUtilities_h | 27 #define AudioUtilities_h |
27 | 28 |
28 #include "platform/PlatformExport.h" | 29 #include "platform/PlatformExport.h" |
29 #include "wtf/build_config.h" | 30 #include "wtf/build_config.h" |
30 #include <cstddef> | 31 #include <cstddef> |
31 | 32 |
32 namespace blink { | 33 namespace blink { |
33 namespace AudioUtilities { | 34 namespace AudioUtilities { |
34 | 35 |
35 // Rendering quantum size. This is how many frames are processed at a time for
each node in the | 36 // Rendering quantum size. This is how many frames are processed at a time for |
36 // audio graph. | 37 // each node in the audio graph. |
37 static const unsigned kRenderQuantumFrames = 128; | 38 static const unsigned kRenderQuantumFrames = 128; |
38 | 39 |
39 // Standard functions for converting to and from decibel values from linear. | 40 // Standard functions for converting to and from decibel values from linear. |
40 PLATFORM_EXPORT float linearToDecibels(float); | 41 PLATFORM_EXPORT float linearToDecibels(float); |
41 PLATFORM_EXPORT float decibelsToLinear(float); | 42 PLATFORM_EXPORT float decibelsToLinear(float); |
42 | 43 |
43 // timeConstant is the time it takes a first-order linear time-invariant system | 44 // timeConstant is the time it takes a first-order linear time-invariant system |
44 // to reach the value 1 - 1/e (around 63.2%) given a step input response. | 45 // to reach the value 1 - 1/e (around 63.2%) given a step input response. |
45 // discreteTimeConstantForSampleRate() will return the discrete time-constant fo
r the specific sampleRate. | 46 // discreteTimeConstantForSampleRate() will return the discrete time-constant |
| 47 // for the specific sampleRate. |
46 PLATFORM_EXPORT double discreteTimeConstantForSampleRate(double timeConstant, | 48 PLATFORM_EXPORT double discreteTimeConstantForSampleRate(double timeConstant, |
47 double sampleRate); | 49 double sampleRate); |
48 | 50 |
49 // Convert the time to a sample frame at the given sample rate. | 51 // Convert the time to a sample frame at the given sample rate. |
50 PLATFORM_EXPORT size_t timeToSampleFrame(double time, double sampleRate); | 52 PLATFORM_EXPORT size_t timeToSampleFrame(double time, double sampleRate); |
51 | 53 |
52 // Check that |sampleRate| is a valid rate for AudioBuffers. | 54 // Check that |sampleRate| is a valid rate for AudioBuffers. |
53 PLATFORM_EXPORT bool isValidAudioBufferSampleRate(float sampleRate); | 55 PLATFORM_EXPORT bool isValidAudioBufferSampleRate(float sampleRate); |
54 | 56 |
55 // Return max/min sample rate supported by AudioBuffers. | 57 // Return max/min sample rate supported by AudioBuffers. |
56 PLATFORM_EXPORT float minAudioBufferSampleRate(); | 58 PLATFORM_EXPORT float minAudioBufferSampleRate(); |
57 PLATFORM_EXPORT float maxAudioBufferSampleRate(); | 59 PLATFORM_EXPORT float maxAudioBufferSampleRate(); |
58 } // namespace AudioUtilities | 60 } // namespace AudioUtilities |
59 } // namespace blink | 61 } // namespace blink |
60 | 62 |
61 #endif // AudioUtilities_h | 63 #endif // AudioUtilities_h |
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