1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
/*
* Copyright (C) 2010, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH
* DAMAGE.
*/
#include <algorithm>
#include <memory>
#include "third_party/blink/renderer/platform/audio/audio_resampler.h"
#include "third_party/blink/renderer/platform/wtf/math_extras.h"
namespace blink {
const double AudioResampler::kMaxRate = 8.0;
AudioResampler::AudioResampler() : rate_(1.0) {
kernels_.push_back(std::make_unique<AudioResamplerKernel>(this));
source_bus_ = AudioBus::Create(1, 0, false);
}
AudioResampler::AudioResampler(unsigned number_of_channels) : rate_(1.0) {
for (unsigned i = 0; i < number_of_channels; ++i)
kernels_.push_back(std::make_unique<AudioResamplerKernel>(this));
source_bus_ = AudioBus::Create(number_of_channels, 0, false);
}
void AudioResampler::ConfigureChannels(unsigned number_of_channels) {
unsigned current_size = kernels_.size();
if (number_of_channels == current_size)
return; // already setup
// First deal with adding or removing kernels.
if (number_of_channels > current_size) {
for (unsigned i = current_size; i < number_of_channels; ++i)
kernels_.push_back(std::make_unique<AudioResamplerKernel>(this));
} else
kernels_.resize(number_of_channels);
// Reconfigure our source bus to the new channel size.
source_bus_ = AudioBus::Create(number_of_channels, 0, false);
}
void AudioResampler::Process(AudioSourceProvider* provider,
AudioBus* destination_bus,
size_t frames_to_process) {
DCHECK(provider);
if (!provider)
return;
unsigned number_of_channels = kernels_.size();
// Make sure our configuration matches the bus we're rendering to.
bool channels_match =
(destination_bus &&
destination_bus->NumberOfChannels() == number_of_channels);
DCHECK(channels_match);
if (!channels_match)
return;
// Setup the source bus.
for (unsigned i = 0; i < number_of_channels; ++i) {
// Figure out how many frames we need to get from the provider, and a
// pointer to the buffer.
size_t frames_needed;
float* fill_pointer =
kernels_[i]->GetSourcePointer(frames_to_process, &frames_needed);
DCHECK(fill_pointer);
if (!fill_pointer)
return;
source_bus_->SetChannelMemory(i, fill_pointer, frames_needed);
}
// Ask the provider to supply the desired number of source frames.
provider->ProvideInput(source_bus_.get(), source_bus_->length());
// Now that we have the source data, resample each channel into the
// destination bus.
// FIXME: optimize for the common stereo case where it's faster to process
// both left/right channels in the same inner loop.
for (unsigned i = 0; i < number_of_channels; ++i) {
float* destination = destination_bus->Channel(i)->MutableData();
kernels_[i]->Process(destination, frames_to_process);
}
}
void AudioResampler::SetRate(double rate) {
if (std::isnan(rate) || std::isinf(rate) || rate <= 0.0)
return;
rate_ = std::min(AudioResampler::kMaxRate, rate);
}
void AudioResampler::Reset() {
unsigned number_of_channels = kernels_.size();
for (unsigned i = 0; i < number_of_channels; ++i)
kernels_[i]->Reset();
}
} // namespace blink
|
