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 "third_party/blink/renderer/platform/audio/reverb_convolver_stage.h"
30
31 #include <algorithm>
32 #include <memory>
33 #include <utility>
34
35 #include "third_party/blink/renderer/platform/audio/reverb_accumulation_buffer.h"
36 #include "third_party/blink/renderer/platform/audio/reverb_convolver.h"
37 #include "third_party/blink/renderer/platform/audio/reverb_input_buffer.h"
38 #include "third_party/blink/renderer/platform/audio/vector_math.h"
39
40 namespace blink {
41
ReverbConvolverStage(const float * impulse_response,size_t,size_t reverb_total_latency,size_t stage_offset,size_t stage_length,size_t fft_size,size_t render_phase,size_t render_slice_size,ReverbAccumulationBuffer * accumulation_buffer,float scale,bool direct_mode)42 ReverbConvolverStage::ReverbConvolverStage(
43 const float* impulse_response,
44 size_t,
45 size_t reverb_total_latency,
46 size_t stage_offset,
47 size_t stage_length,
48 size_t fft_size,
49 size_t render_phase,
50 size_t render_slice_size,
51 ReverbAccumulationBuffer* accumulation_buffer,
52 float scale,
53 bool direct_mode)
54 : accumulation_buffer_(accumulation_buffer),
55 accumulation_read_index_(0),
56 input_read_index_(0),
57 direct_mode_(direct_mode) {
58 DCHECK(impulse_response);
59 DCHECK(accumulation_buffer);
60
61 if (!direct_mode_) {
62 fft_kernel_ = std::make_unique<FFTFrame>(fft_size);
63 fft_kernel_->DoPaddedFFT(impulse_response + stage_offset, stage_length);
64 // Account for the normalization (if any) of the convolver. By linearity,
65 // we can scale the FFT by the factor instead of the input. We do it this
66 // way so we don't need to create a temporary for the scaled result before
67 // computing the FFT.
68 if (scale != 1) {
69 fft_kernel_->ScaleFFT(scale);
70 }
71 fft_convolver_ = std::make_unique<FFTConvolver>(fft_size);
72 } else {
73 DCHECK(!stage_offset);
74 DCHECK_LE(stage_length, fft_size / 2);
75
76 auto direct_kernel = std::make_unique<AudioFloatArray>(fft_size / 2);
77 direct_kernel->CopyToRange(impulse_response, 0, stage_length);
78 // Account for the normalization (if any) of the convolver node.
79 if (scale != 1) {
80 vector_math::Vsmul(direct_kernel->Data(), 1, &scale,
81 direct_kernel->Data(), 1, stage_length);
82 }
83 direct_convolver_ = std::make_unique<DirectConvolver>(
84 render_slice_size, std::move(direct_kernel));
85 }
86 temporary_buffer_.Allocate(render_slice_size);
87
88 // The convolution stage at offset stageOffset needs to have a corresponding
89 // delay to cancel out the offset.
90 size_t total_delay = stage_offset + reverb_total_latency;
91
92 // But, the FFT convolution itself incurs fftSize / 2 latency, so subtract
93 // this out...
94 size_t half_size = fft_size / 2;
95 if (!direct_mode_) {
96 DCHECK_GE(total_delay, half_size);
97 if (total_delay >= half_size)
98 total_delay -= half_size;
99 }
100
101 // We divide up the total delay, into pre and post delay sections so that we
102 // can schedule at exactly the moment when the FFT will happen. This is
103 // coordinated with the other stages, so they don't all do their FFTs at the
104 // same time...
105 int max_pre_delay_length = std::min(half_size, total_delay);
106 pre_delay_length_ = total_delay > 0 ? render_phase % max_pre_delay_length : 0;
107 if (pre_delay_length_ > total_delay)
108 pre_delay_length_ = 0;
109
110 post_delay_length_ = total_delay - pre_delay_length_;
111 pre_read_write_index_ = 0;
112 frames_processed_ = 0; // total frames processed so far
113
114 size_t delay_buffer_size =
115 pre_delay_length_ < fft_size ? fft_size : pre_delay_length_;
116 delay_buffer_size = delay_buffer_size < render_slice_size ? render_slice_size
117 : delay_buffer_size;
118 pre_delay_buffer_.Allocate(delay_buffer_size);
119 }
120
ProcessInBackground(ReverbConvolver * convolver,uint32_t frames_to_process)121 void ReverbConvolverStage::ProcessInBackground(ReverbConvolver* convolver,
122 uint32_t frames_to_process) {
123 ReverbInputBuffer* input_buffer = convolver->InputBuffer();
124 float* source =
125 input_buffer->DirectReadFrom(&input_read_index_, frames_to_process);
126 Process(source, frames_to_process);
127 }
128
Process(const float * source,uint32_t frames_to_process)129 void ReverbConvolverStage::Process(const float* source,
130 uint32_t frames_to_process) {
131 DCHECK(source);
132 if (!source)
133 return;
134
135 // Deal with pre-delay stream : note special handling of zero delay.
136
137 const float* pre_delayed_source;
138 float* pre_delayed_destination;
139 float* temporary_buffer;
140 bool is_temporary_buffer_safe = false;
141 if (pre_delay_length_ > 0) {
142 // Handles both the read case (call to process() ) and the write case
143 // (memcpy() )
144 bool is_pre_delay_safe =
145 pre_read_write_index_ + frames_to_process <= pre_delay_buffer_.size();
146 DCHECK(is_pre_delay_safe);
147 if (!is_pre_delay_safe)
148 return;
149
150 is_temporary_buffer_safe = frames_to_process <= temporary_buffer_.size();
151
152 pre_delayed_destination = pre_delay_buffer_.Data() + pre_read_write_index_;
153 pre_delayed_source = pre_delayed_destination;
154 temporary_buffer = temporary_buffer_.Data();
155 } else {
156 // Zero delay
157 pre_delayed_destination = nullptr;
158 pre_delayed_source = source;
159 temporary_buffer = pre_delay_buffer_.Data();
160
161 is_temporary_buffer_safe = frames_to_process <= pre_delay_buffer_.size();
162 }
163
164 DCHECK(is_temporary_buffer_safe);
165 if (!is_temporary_buffer_safe)
166 return;
167
168 if (frames_processed_ < pre_delay_length_) {
169 // For the first m_preDelayLength frames don't process the convolver,
170 // instead simply buffer in the pre-delay. But while buffering the
171 // pre-delay, we still need to update our index.
172 accumulation_buffer_->UpdateReadIndex(&accumulation_read_index_,
173 frames_to_process);
174 } else {
175 // Now, run the convolution (into the delay buffer).
176 // An expensive FFT will happen every fftSize / 2 frames.
177 // We process in-place here...
178 if (!direct_mode_)
179 fft_convolver_->Process(fft_kernel_.get(), pre_delayed_source,
180 temporary_buffer, frames_to_process);
181 else
182 direct_convolver_->Process(pre_delayed_source, temporary_buffer,
183 frames_to_process);
184
185 // Now accumulate into reverb's accumulation buffer.
186 accumulation_buffer_->Accumulate(temporary_buffer, frames_to_process,
187 &accumulation_read_index_,
188 post_delay_length_);
189 }
190
191 // Finally copy input to pre-delay.
192 if (pre_delay_length_ > 0) {
193 memcpy(pre_delayed_destination, source, sizeof(float) * frames_to_process);
194 pre_read_write_index_ += frames_to_process;
195
196 DCHECK_LE(pre_read_write_index_, pre_delay_length_);
197 if (pre_read_write_index_ >= pre_delay_length_)
198 pre_read_write_index_ = 0;
199 }
200
201 frames_processed_ += frames_to_process;
202 }
203
Reset()204 void ReverbConvolverStage::Reset() {
205 if (!direct_mode_)
206 fft_convolver_->Reset();
207 else
208 direct_convolver_->Reset();
209 pre_delay_buffer_.Zero();
210 accumulation_read_index_ = 0;
211 input_read_index_ = 0;
212 frames_processed_ = 0;
213 }
214
215 } // namespace blink
216