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1 /* | 1 /* |
2 * Copyright (C) 2012 Intel Inc. All rights reserved. | 2 * Copyright (C) 2013 Google Inc. All rights reserved. |
Ken Russell (switch to Gerrit)
2013/05/23 02:29:25
The copyright notice on these new files is the wro
Chris Rogers
2013/05/24 20:09:04
Done.
| |
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 * | 7 * |
8 * 1. Redistributions of source code must retain the above copyright | 8 * 1. Redistributions of source code must retain the above copyright |
9 * notice, this list of conditions and the following disclaimer. | 9 * notice, this list of conditions and the following disclaimer. |
10 * 2. Redistributions in binary form must reproduce the above copyright | 10 * 2. Redistributions in binary form must reproduce the above copyright |
11 * notice, this list of conditions and the following disclaimer in the | 11 * notice, this list of conditions and the following disclaimer in the |
12 * documentation and/or other materials provided with the distribution. | 12 * documentation and/or other materials provided with the distribution. |
13 * 3. Neither the name of Apple Computer, Inc. ("Apple") nor the names of | 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 | 14 * its contributors may be used to endorse or promote products derived |
15 * from this software without specific prior written permission. | 15 * from this software without specific prior written permission. |
16 * | 16 * |
17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY | 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 | 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | 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 | 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES | 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | 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 | 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 | 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 | 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. | 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 */ | 27 */ |
28 | 28 |
29 #ifndef DirectConvolver_h | 29 #ifndef DownSampler_h |
30 #define DirectConvolver_h | 30 #define DownSampler_h |
31 | 31 |
32 #include "core/platform/audio/AudioArray.h" | 32 #include "core/platform/audio/AudioArray.h" |
33 | 33 #include "core/platform/audio/DirectConvolver.h" |
34 #if USE(WEBAUDIO_IPP) | |
35 #include <ipps.h> | |
36 #endif // USE(WEBAUDIO_IPP) | |
37 | 34 |
38 namespace WebCore { | 35 namespace WebCore { |
39 | 36 |
40 class DirectConvolver { | 37 // DownSampler down-samples the source stream by a factor of 2x. |
38 | |
39 class DownSampler { | |
41 public: | 40 public: |
42 DirectConvolver(size_t inputBlockSize); | 41 DownSampler(size_t inputBlockSize); |
43 | 42 |
44 void process(AudioFloatArray* convolutionKernel, const float* sourceP, float * destP, size_t framesToProcess); | 43 // The destination buffer |destP| is of size sourceFramesToProcess / 2. |
44 void process(const float* sourceP, float* destP, size_t sourceFramesToProces s); | |
45 | 45 |
46 void reset(); | 46 void reset(); |
47 | 47 |
48 // Latency based on the destination sample-rate. | |
49 size_t latencyFrames() const; | |
50 | |
48 private: | 51 private: |
52 enum { DefaultKernelSize = 256 }; | |
53 | |
49 size_t m_inputBlockSize; | 54 size_t m_inputBlockSize; |
50 | 55 |
51 #if USE(WEBAUDIO_IPP) | 56 // Computes ideal band-limited half-band filter coefficients. |
52 AudioFloatArray m_overlayBuffer; | 57 // In other words, filter out all frequencies higher than 0.25 * Nyquist. |
53 #endif // USE(WEBAUDIO_IPP) | 58 void initializeKernel(); |
54 AudioFloatArray m_buffer; | 59 AudioFloatArray m_reducedKernel; |
60 | |
61 // Half-band filter. | |
62 DirectConvolver m_convolver; | |
63 | |
64 AudioFloatArray m_tempBuffer; | |
65 AudioFloatArray m_inputBuffer; | |
55 }; | 66 }; |
56 | 67 |
57 } // namespace WebCore | 68 } // namespace WebCore |
58 | 69 |
59 #endif // DirectConvolver_h | 70 #endif // DownSampler_h |
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