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
121
122
123
124
125
126
127
|
/*
==============================================================================
This file is part of the JUCE library.
Copyright (c) 2022 - Raw Material Software Limited
JUCE is an open source library subject to commercial or open-source
licensing.
The code included in this file is provided under the terms of the ISC license
http://www.isc.org/downloads/software-support-policy/isc-license. Permission
To use, copy, modify, and/or distribute this software for any purpose with or
without fee is hereby granted provided that the above copyright notice and
this permission notice appear in all copies.
JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER
EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE
DISCLAIMED.
==============================================================================
*/
//==============================================================================
/**
Some shared helpers methods for using the high-performance audio paths on
Android devices (OpenSL and Oboe).
@tags{Audio}
*/
namespace juce::AndroidHighPerformanceAudioHelpers
{
//==============================================================================
static double getNativeSampleRate()
{
return audioManagerGetProperty ("android.media.property.OUTPUT_SAMPLE_RATE").getDoubleValue();
}
static int getNativeBufferSizeHint()
{
// This property is a hint of a native buffer size but it does not guarantee the size used.
auto deviceBufferSize = audioManagerGetProperty ("android.media.property.OUTPUT_FRAMES_PER_BUFFER").getIntValue();
if (deviceBufferSize == 0)
return 192;
return deviceBufferSize;
}
static bool isProAudioDevice()
{
static bool isSapaSupported = SystemStats::getDeviceManufacturer().containsIgnoreCase ("SAMSUNG")
&& DynamicLibrary().open ("libapa_jni.so");
return androidHasSystemFeature ("android.hardware.audio.pro") || isSapaSupported;
}
static bool hasLowLatencyAudioPath()
{
return androidHasSystemFeature ("android.hardware.audio.low_latency");
}
static bool canUseHighPerformanceAudioPath (int nativeBufferSize, int requestedBufferSize, int requestedSampleRate)
{
return ((requestedBufferSize % nativeBufferSize) == 0)
&& approximatelyEqual ((double) requestedSampleRate, getNativeSampleRate())
&& isProAudioDevice();
}
//==============================================================================
static int getMinimumBuffersToEnqueue (int nativeBufferSize, double requestedSampleRate)
{
if (canUseHighPerformanceAudioPath (nativeBufferSize, nativeBufferSize, (int) requestedSampleRate))
{
// see https://developer.android.com/ndk/guides/audio/opensl/opensl-prog-notes.html#sandp
// "For Android 4.2 (API level 17) and earlier, a buffer count of two or more is required
// for lower latency. Beginning with Android 4.3 (API level 18), a buffer count of one
// is sufficient for lower latency."
return (getAndroidSDKVersion() >= 18 ? 1 : 2);
}
// not using low-latency path so we can use the absolute minimum number of buffers to queue
return 1;
}
static int buffersToQueueForBufferDuration (int nativeBufferSize, int bufferDurationInMs, double sampleRate) noexcept
{
auto maxBufferFrames = static_cast<int> (std::ceil (bufferDurationInMs * sampleRate / 1000.0));
auto maxNumBuffers = static_cast<int> (std::ceil (static_cast<double> (maxBufferFrames)
/ static_cast<double> (nativeBufferSize)));
return jmax (getMinimumBuffersToEnqueue (nativeBufferSize, sampleRate), maxNumBuffers);
}
static int getMaximumBuffersToEnqueue (int nativeBufferSize, double maximumSampleRate) noexcept
{
static constexpr int maxBufferSizeMs = 200;
return jmax (8, buffersToQueueForBufferDuration (nativeBufferSize, maxBufferSizeMs, maximumSampleRate));
}
static Array<int> getAvailableBufferSizes (int nativeBufferSize, Array<double> availableSampleRates)
{
auto minBuffersToQueue = getMinimumBuffersToEnqueue (nativeBufferSize, getNativeSampleRate());
auto maxBuffersToQueue = getMaximumBuffersToEnqueue (nativeBufferSize, findMaximum (availableSampleRates.getRawDataPointer(),
availableSampleRates.size()));
Array<int> bufferSizes;
for (int i = minBuffersToQueue; i <= maxBuffersToQueue; ++i)
bufferSizes.add (i * nativeBufferSize);
return bufferSizes;
}
static int getDefaultBufferSize (int nativeBufferSize, double currentSampleRate)
{
static constexpr int defaultBufferSizeForLowLatencyDeviceMs = 40;
static constexpr int defaultBufferSizeForStandardLatencyDeviceMs = 100;
auto defaultBufferLength = (hasLowLatencyAudioPath() ? defaultBufferSizeForLowLatencyDeviceMs
: defaultBufferSizeForStandardLatencyDeviceMs);
auto defaultBuffersToEnqueue = buffersToQueueForBufferDuration (nativeBufferSize, defaultBufferLength, currentSampleRate);
return defaultBuffersToEnqueue * nativeBufferSize;
}
} // namespace juce::AndroidHighPerformanceAudioHelpers
|
