1 /*
2 * Copyright (C) 2010 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 "config.h"
30
31 #if ENABLE(WEB_AUDIO)
32
33 #include "platform/audio/ReverbConvolverStage.h"
34
35 #include "platform/audio/ReverbAccumulationBuffer.h"
36 #include "platform/audio/ReverbConvolver.h"
37 #include "platform/audio/ReverbInputBuffer.h"
38 #include "platform/audio/VectorMath.h"
39 #include "wtf/PassOwnPtr.h"
40
41 namespace blink {
42
43 using namespace VectorMath;
44
ReverbConvolverStage(const float * impulseResponse,size_t,size_t reverbTotalLatency,size_t stageOffset,size_t stageLength,size_t fftSize,size_t renderPhase,size_t renderSliceSize,ReverbAccumulationBuffer * accumulationBuffer,bool directMode)45 ReverbConvolverStage::ReverbConvolverStage(const float* impulseResponse, size_t, size_t reverbTotalLatency, size_t stageOffset, size_t stageLength,
46 size_t fftSize, size_t renderPhase, size_t renderSliceSize, ReverbAccumulationBuffer* accumulationBuffer, bool directMode)
47 : m_accumulationBuffer(accumulationBuffer)
48 , m_accumulationReadIndex(0)
49 , m_inputReadIndex(0)
50 , m_directMode(directMode)
51 {
52 ASSERT(impulseResponse);
53 ASSERT(accumulationBuffer);
54
55 if (!m_directMode) {
56 m_fftKernel = adoptPtr(new FFTFrame(fftSize));
57 m_fftKernel->doPaddedFFT(impulseResponse + stageOffset, stageLength);
58 m_fftConvolver = adoptPtr(new FFTConvolver(fftSize));
59 } else {
60 ASSERT(!stageOffset);
61 ASSERT(stageLength <= fftSize / 2);
62
63 m_directKernel = adoptPtr(new AudioFloatArray(fftSize / 2));
64 m_directKernel->copyToRange(impulseResponse, 0, stageLength);
65 m_directConvolver = adoptPtr(new DirectConvolver(renderSliceSize));
66 }
67 m_temporaryBuffer.allocate(renderSliceSize);
68
69 // The convolution stage at offset stageOffset needs to have a corresponding delay to cancel out the offset.
70 size_t totalDelay = stageOffset + reverbTotalLatency;
71
72 // But, the FFT convolution itself incurs fftSize / 2 latency, so subtract this out...
73 size_t halfSize = fftSize / 2;
74 if (!m_directMode) {
75 ASSERT(totalDelay >= halfSize);
76 if (totalDelay >= halfSize)
77 totalDelay -= halfSize;
78 }
79
80 // We divide up the total delay, into pre and post delay sections so that we can schedule at exactly the moment when the FFT will happen.
81 // This is coordinated with the other stages, so they don't all do their FFTs at the same time...
82 int maxPreDelayLength = std::min(halfSize, totalDelay);
83 m_preDelayLength = totalDelay > 0 ? renderPhase % maxPreDelayLength : 0;
84 if (m_preDelayLength > totalDelay)
85 m_preDelayLength = 0;
86
87 m_postDelayLength = totalDelay - m_preDelayLength;
88 m_preReadWriteIndex = 0;
89 m_framesProcessed = 0; // total frames processed so far
90
91 size_t delayBufferSize = m_preDelayLength < fftSize ? fftSize : m_preDelayLength;
92 delayBufferSize = delayBufferSize < renderSliceSize ? renderSliceSize : delayBufferSize;
93 m_preDelayBuffer.allocate(delayBufferSize);
94 }
95
processInBackground(ReverbConvolver * convolver,size_t framesToProcess)96 void ReverbConvolverStage::processInBackground(ReverbConvolver* convolver, size_t framesToProcess)
97 {
98 ReverbInputBuffer* inputBuffer = convolver->inputBuffer();
99 float* source = inputBuffer->directReadFrom(&m_inputReadIndex, framesToProcess);
100 process(source, framesToProcess);
101 }
102
process(const float * source,size_t framesToProcess)103 void ReverbConvolverStage::process(const float* source, size_t framesToProcess)
104 {
105 ASSERT(source);
106 if (!source)
107 return;
108
109 // Deal with pre-delay stream : note special handling of zero delay.
110
111 const float* preDelayedSource;
112 float* preDelayedDestination;
113 float* temporaryBuffer;
114 bool isTemporaryBufferSafe = false;
115 if (m_preDelayLength > 0) {
116 // Handles both the read case (call to process() ) and the write case (memcpy() )
117 bool isPreDelaySafe = m_preReadWriteIndex + framesToProcess <= m_preDelayBuffer.size();
118 ASSERT(isPreDelaySafe);
119 if (!isPreDelaySafe)
120 return;
121
122 isTemporaryBufferSafe = framesToProcess <= m_temporaryBuffer.size();
123
124 preDelayedDestination = m_preDelayBuffer.data() + m_preReadWriteIndex;
125 preDelayedSource = preDelayedDestination;
126 temporaryBuffer = m_temporaryBuffer.data();
127 } else {
128 // Zero delay
129 preDelayedDestination = 0;
130 preDelayedSource = source;
131 temporaryBuffer = m_preDelayBuffer.data();
132
133 isTemporaryBufferSafe = framesToProcess <= m_preDelayBuffer.size();
134 }
135
136 ASSERT(isTemporaryBufferSafe);
137 if (!isTemporaryBufferSafe)
138 return;
139
140 if (m_framesProcessed < m_preDelayLength) {
141 // For the first m_preDelayLength frames don't process the convolver, instead simply buffer in the pre-delay.
142 // But while buffering the pre-delay, we still need to update our index.
143 m_accumulationBuffer->updateReadIndex(&m_accumulationReadIndex, framesToProcess);
144 } else {
145 // Now, run the convolution (into the delay buffer).
146 // An expensive FFT will happen every fftSize / 2 frames.
147 // We process in-place here...
148 if (!m_directMode)
149 m_fftConvolver->process(m_fftKernel.get(), preDelayedSource, temporaryBuffer, framesToProcess);
150 else
151 m_directConvolver->process(m_directKernel.get(), preDelayedSource, temporaryBuffer, framesToProcess);
152
153 // Now accumulate into reverb's accumulation buffer.
154 m_accumulationBuffer->accumulate(temporaryBuffer, framesToProcess, &m_accumulationReadIndex, m_postDelayLength);
155 }
156
157 // Finally copy input to pre-delay.
158 if (m_preDelayLength > 0) {
159 memcpy(preDelayedDestination, source, sizeof(float) * framesToProcess);
160 m_preReadWriteIndex += framesToProcess;
161
162 ASSERT(m_preReadWriteIndex <= m_preDelayLength);
163 if (m_preReadWriteIndex >= m_preDelayLength)
164 m_preReadWriteIndex = 0;
165 }
166
167 m_framesProcessed += framesToProcess;
168 }
169
reset()170 void ReverbConvolverStage::reset()
171 {
172 if (!m_directMode)
173 m_fftConvolver->reset();
174 else
175 m_directConvolver->reset();
176 m_preDelayBuffer.zero();
177 m_accumulationReadIndex = 0;
178 m_inputReadIndex = 0;
179 m_framesProcessed = 0;
180 }
181
182 } // namespace blink
183
184 #endif // ENABLE(WEB_AUDIO)
185