1 /* 2 ============================================================================== 3 4 This file is part of the JUCE library. 5 Copyright (c) 2020 - Raw Material Software Limited 6 7 JUCE is an open source library subject to commercial or open-source 8 licensing. 9 10 The code included in this file is provided under the terms of the ISC license 11 http://www.isc.org/downloads/software-support-policy/isc-license. Permission 12 To use, copy, modify, and/or distribute this software for any purpose with or 13 without fee is hereby granted provided that the above copyright notice and 14 this permission notice appear in all copies. 15 16 JUCE IS PROVIDED "AS IS" WITHOUT ANY WARRANTY, AND ALL WARRANTIES, WHETHER 17 EXPRESSED OR IMPLIED, INCLUDING MERCHANTABILITY AND FITNESS FOR PURPOSE, ARE 18 DISCLAIMED. 19 20 ============================================================================== 21 */ 22 23 namespace juce 24 { 25 26 //============================================================================== 27 /** 28 Some shared helpers methods for using the high-performance audio paths on 29 Android devices (OpenSL and Oboe). 30 31 @tags{Audio} 32 */ 33 namespace AndroidHighPerformanceAudioHelpers 34 { 35 //============================================================================== getNativeSampleRate()36 static double getNativeSampleRate() 37 { 38 return audioManagerGetProperty ("android.media.property.OUTPUT_SAMPLE_RATE").getDoubleValue(); 39 } 40 getNativeBufferSizeHint()41 static int getNativeBufferSizeHint() 42 { 43 // This property is a hint of a native buffer size but it does not guarantee the size used. 44 auto deviceBufferSize = audioManagerGetProperty ("android.media.property.OUTPUT_FRAMES_PER_BUFFER").getIntValue(); 45 46 if (deviceBufferSize == 0) 47 return 192; 48 49 return deviceBufferSize; 50 } 51 isProAudioDevice()52 static bool isProAudioDevice() 53 { 54 static bool isSapaSupported = SystemStats::getDeviceManufacturer().containsIgnoreCase ("SAMSUNG") 55 && DynamicLibrary().open ("libapa_jni.so"); 56 57 return androidHasSystemFeature ("android.hardware.audio.pro") || isSapaSupported; 58 } 59 hasLowLatencyAudioPath()60 static bool hasLowLatencyAudioPath() 61 { 62 return androidHasSystemFeature ("android.hardware.audio.low_latency"); 63 } 64 canUseHighPerformanceAudioPath(int nativeBufferSize,int requestedBufferSize,int requestedSampleRate)65 static bool canUseHighPerformanceAudioPath (int nativeBufferSize, int requestedBufferSize, int requestedSampleRate) 66 { 67 return ((requestedBufferSize % nativeBufferSize) == 0) 68 && (requestedSampleRate == getNativeSampleRate()) 69 && isProAudioDevice(); 70 } 71 72 //============================================================================== getMinimumBuffersToEnqueue(int nativeBufferSize,double requestedSampleRate)73 static int getMinimumBuffersToEnqueue (int nativeBufferSize, double requestedSampleRate) 74 { 75 if (canUseHighPerformanceAudioPath (nativeBufferSize, nativeBufferSize, (int) requestedSampleRate)) 76 { 77 // see https://developer.android.com/ndk/guides/audio/opensl/opensl-prog-notes.html#sandp 78 // "For Android 4.2 (API level 17) and earlier, a buffer count of two or more is required 79 // for lower latency. Beginning with Android 4.3 (API level 18), a buffer count of one 80 // is sufficient for lower latency." 81 return (getAndroidSDKVersion() >= 18 ? 1 : 2); 82 } 83 84 // not using low-latency path so we can use the absolute minimum number of buffers to queue 85 return 1; 86 } 87 buffersToQueueForBufferDuration(int nativeBufferSize,int bufferDurationInMs,double sampleRate)88 static int buffersToQueueForBufferDuration (int nativeBufferSize, int bufferDurationInMs, double sampleRate) noexcept 89 { 90 auto maxBufferFrames = static_cast<int> (std::ceil (bufferDurationInMs * sampleRate / 1000.0)); 91 auto maxNumBuffers = static_cast<int> (std::ceil (static_cast<double> (maxBufferFrames) 92 / static_cast<double> (nativeBufferSize))); 93 94 return jmax (getMinimumBuffersToEnqueue (nativeBufferSize, sampleRate), maxNumBuffers); 95 } 96 getMaximumBuffersToEnqueue(int nativeBufferSize,double maximumSampleRate)97 static int getMaximumBuffersToEnqueue (int nativeBufferSize, double maximumSampleRate) noexcept 98 { 99 static constexpr int maxBufferSizeMs = 200; 100 101 return jmax (8, buffersToQueueForBufferDuration (nativeBufferSize, maxBufferSizeMs, maximumSampleRate)); 102 } 103 getAvailableBufferSizes(int nativeBufferSize,Array<double> availableSampleRates)104 static Array<int> getAvailableBufferSizes (int nativeBufferSize, Array<double> availableSampleRates) 105 { 106 auto minBuffersToQueue = getMinimumBuffersToEnqueue (nativeBufferSize, getNativeSampleRate()); 107 auto maxBuffersToQueue = getMaximumBuffersToEnqueue (nativeBufferSize, findMaximum (availableSampleRates.getRawDataPointer(), 108 availableSampleRates.size())); 109 110 Array<int> bufferSizes; 111 112 for (int i = minBuffersToQueue; i <= maxBuffersToQueue; ++i) 113 bufferSizes.add (i * nativeBufferSize); 114 115 return bufferSizes; 116 } 117 getDefaultBufferSize(int nativeBufferSize,double currentSampleRate)118 static int getDefaultBufferSize (int nativeBufferSize, double currentSampleRate) 119 { 120 static constexpr int defaultBufferSizeForLowLatencyDeviceMs = 40; 121 static constexpr int defaultBufferSizeForStandardLatencyDeviceMs = 100; 122 123 auto defaultBufferLength = (hasLowLatencyAudioPath() ? defaultBufferSizeForLowLatencyDeviceMs 124 : defaultBufferSizeForStandardLatencyDeviceMs); 125 126 auto defaultBuffersToEnqueue = buffersToQueueForBufferDuration (nativeBufferSize, defaultBufferLength, currentSampleRate); 127 return defaultBuffersToEnqueue * nativeBufferSize; 128 } 129 } 130 131 } // namespace juce 132