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 | * 1. Redistributions of source code must retain the above copyright |
8 | * notice, this list of conditions and the following disclaimer. |
9 | * 2. Redistributions in binary form must reproduce the above copyright |
10 | * notice, this list of conditions and the following disclaimer in the |
11 | * documentation and/or other materials provided with the distribution. |
12 | * |
13 | * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND ANY |
14 | * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED |
15 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE |
16 | * DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE FOR ANY |
17 | * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES |
18 | * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; |
19 | * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON |
20 | * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
21 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
22 | * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
23 | */ |
24 | |
25 | #include "config.h" |
26 | |
27 | #if ENABLE(WEB_AUDIO) |
28 | |
29 | #include "WaveShaperDSPKernel.h" |
30 | |
31 | #include "WaveShaperProcessor.h" |
32 | #include <algorithm> |
33 | #include <wtf/MainThread.h> |
34 | #include <wtf/Threading.h> |
35 | |
36 | const unsigned RenderingQuantum = 128; |
37 | |
38 | namespace WebCore { |
39 | |
40 | WaveShaperDSPKernel::WaveShaperDSPKernel(WaveShaperProcessor* processor) |
41 | : AudioDSPKernel(processor) |
42 | { |
43 | if (processor->oversample() != WaveShaperProcessor::OverSampleNone) |
44 | lazyInitializeOversampling(); |
45 | } |
46 | |
47 | void WaveShaperDSPKernel::lazyInitializeOversampling() |
48 | { |
49 | ASSERT(isMainThread()); |
50 | |
51 | if (!m_tempBuffer) { |
52 | m_tempBuffer = std::make_unique<AudioFloatArray>(RenderingQuantum * 2); |
53 | m_tempBuffer2 = std::make_unique<AudioFloatArray>(RenderingQuantum * 4); |
54 | m_upSampler = std::make_unique<UpSampler>(RenderingQuantum); |
55 | m_downSampler = std::make_unique<DownSampler>(RenderingQuantum * 2); |
56 | m_upSampler2 = std::make_unique<UpSampler>(RenderingQuantum * 2); |
57 | m_downSampler2 = std::make_unique<DownSampler>(RenderingQuantum * 4); |
58 | } |
59 | } |
60 | |
61 | void WaveShaperDSPKernel::process(const float* source, float* destination, size_t framesToProcess) |
62 | { |
63 | switch (waveShaperProcessor()->oversample()) { |
64 | case WaveShaperProcessor::OverSampleNone: |
65 | processCurve(source, destination, framesToProcess); |
66 | break; |
67 | case WaveShaperProcessor::OverSample2x: |
68 | processCurve2x(source, destination, framesToProcess); |
69 | break; |
70 | case WaveShaperProcessor::OverSample4x: |
71 | processCurve4x(source, destination, framesToProcess); |
72 | break; |
73 | |
74 | default: |
75 | ASSERT_NOT_REACHED(); |
76 | } |
77 | } |
78 | |
79 | void WaveShaperDSPKernel::processCurve(const float* source, float* destination, size_t framesToProcess) |
80 | { |
81 | ASSERT(source && destination && waveShaperProcessor()); |
82 | |
83 | Float32Array* curve = waveShaperProcessor()->curve(); |
84 | if (!curve) { |
85 | // Act as "straight wire" pass-through if no curve is set. |
86 | memcpy(destination, source, sizeof(float) * framesToProcess); |
87 | return; |
88 | } |
89 | |
90 | float* curveData = curve->data(); |
91 | int curveLength = curve->length(); |
92 | |
93 | ASSERT(curveData); |
94 | |
95 | if (!curveData || !curveLength) { |
96 | memcpy(destination, source, sizeof(float) * framesToProcess); |
97 | return; |
98 | } |
99 | |
100 | // Apply waveshaping curve. |
101 | for (unsigned i = 0; i < framesToProcess; ++i) { |
102 | const float input = source[i]; |
103 | |
104 | // Calculate a virtual index based on input -1 -> +1 with 0 being at the center of the curve data. |
105 | // Then linearly interpolate between the two points in the curve. |
106 | double virtualIndex = 0.5 * (input + 1) * curveLength; |
107 | int index1 = static_cast<int>(virtualIndex); |
108 | int index2 = index1 + 1; |
109 | double interpolationFactor = virtualIndex - index1; |
110 | |
111 | // Clip index to the input range of the curve. |
112 | // This takes care of input outside of nominal range -1 -> +1 |
113 | index1 = std::max(index1, 0); |
114 | index1 = std::min(index1, curveLength - 1); |
115 | index2 = std::max(index2, 0); |
116 | index2 = std::min(index2, curveLength - 1); |
117 | |
118 | double value1 = curveData[index1]; |
119 | double value2 = curveData[index2]; |
120 | |
121 | double output = (1.0 - interpolationFactor) * value1 + interpolationFactor * value2; |
122 | destination[i] = output; |
123 | } |
124 | } |
125 | |
126 | void WaveShaperDSPKernel::processCurve2x(const float* source, float* destination, size_t framesToProcess) |
127 | { |
128 | bool isSafe = framesToProcess == RenderingQuantum; |
129 | ASSERT(isSafe); |
130 | if (!isSafe) |
131 | return; |
132 | |
133 | float* tempP = m_tempBuffer->data(); |
134 | |
135 | m_upSampler->process(source, tempP, framesToProcess); |
136 | |
137 | // Process at 2x up-sampled rate. |
138 | processCurve(tempP, tempP, framesToProcess * 2); |
139 | |
140 | m_downSampler->process(tempP, destination, framesToProcess * 2); |
141 | } |
142 | |
143 | void WaveShaperDSPKernel::processCurve4x(const float* source, float* destination, size_t framesToProcess) |
144 | { |
145 | bool isSafe = framesToProcess == RenderingQuantum; |
146 | ASSERT(isSafe); |
147 | if (!isSafe) |
148 | return; |
149 | |
150 | float* tempP = m_tempBuffer->data(); |
151 | float* tempP2 = m_tempBuffer2->data(); |
152 | |
153 | m_upSampler->process(source, tempP, framesToProcess); |
154 | m_upSampler2->process(tempP, tempP2, framesToProcess * 2); |
155 | |
156 | // Process at 4x up-sampled rate. |
157 | processCurve(tempP2, tempP2, framesToProcess * 4); |
158 | |
159 | m_downSampler2->process(tempP2, tempP, framesToProcess * 4); |
160 | m_downSampler->process(tempP, destination, framesToProcess * 2); |
161 | } |
162 | |
163 | void WaveShaperDSPKernel::reset() |
164 | { |
165 | if (m_upSampler) { |
166 | m_upSampler->reset(); |
167 | m_downSampler->reset(); |
168 | m_upSampler2->reset(); |
169 | m_downSampler2->reset(); |
170 | } |
171 | } |
172 | |
173 | double WaveShaperDSPKernel::latencyTime() const |
174 | { |
175 | size_t latencyFrames = 0; |
176 | WaveShaperDSPKernel* kernel = const_cast<WaveShaperDSPKernel*>(this); |
177 | |
178 | switch (kernel->waveShaperProcessor()->oversample()) { |
179 | case WaveShaperProcessor::OverSampleNone: |
180 | break; |
181 | case WaveShaperProcessor::OverSample2x: |
182 | latencyFrames += m_upSampler->latencyFrames(); |
183 | latencyFrames += m_downSampler->latencyFrames(); |
184 | break; |
185 | case WaveShaperProcessor::OverSample4x: |
186 | { |
187 | // Account for first stage upsampling. |
188 | latencyFrames += m_upSampler->latencyFrames(); |
189 | latencyFrames += m_downSampler->latencyFrames(); |
190 | |
191 | // Account for second stage upsampling. |
192 | // and divide by 2 to get back down to the regular sample-rate. |
193 | size_t latencyFrames2 = (m_upSampler2->latencyFrames() + m_downSampler2->latencyFrames()) / 2; |
194 | latencyFrames += latencyFrames2; |
195 | break; |
196 | } |
197 | default: |
198 | ASSERT_NOT_REACHED(); |
199 | } |
200 | |
201 | return static_cast<double>(latencyFrames) / sampleRate(); |
202 | } |
203 | |
204 | } // namespace WebCore |
205 | |
206 | #endif // ENABLE(WEB_AUDIO) |
207 | |