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juce_BufferingAudioSource.cpp
/*
==============================================================================
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.
==============================================================================
*/
namespace juce
{
BufferingAudioSource::BufferingAudioSource (PositionableAudioSource* s,
TimeSliceThread& thread,
bool deleteSourceWhenDeleted,
int bufferSizeSamples,
int numChannels,
bool prefillBufferOnPrepareToPlay)
: source (s, deleteSourceWhenDeleted),
backgroundThread (thread),
numberOfSamplesToBuffer (jmax (1024, bufferSizeSamples)),
numberOfChannels (numChannels),
prefillBuffer (prefillBufferOnPrepareToPlay)
{
jassert (source != nullptr);
jassert (numberOfSamplesToBuffer > 1024); // not much point using this class if you're
// not using a larger buffer..
}
BufferingAudioSource::~BufferingAudioSource()
{
releaseResources();
}
//==============================================================================
void BufferingAudioSource::prepareToPlay (int samplesPerBlockExpected, double newSampleRate)
{
auto bufferSizeNeeded = jmax (samplesPerBlockExpected * 2, numberOfSamplesToBuffer);
if (! approximatelyEqual (newSampleRate, sampleRate)
|| bufferSizeNeeded != buffer.getNumSamples()
|| ! isPrepared)
{
backgroundThread.removeTimeSliceClient (this);
isPrepared = true;
sampleRate = newSampleRate;
source->prepareToPlay (samplesPerBlockExpected, newSampleRate);
buffer.setSize (numberOfChannels, bufferSizeNeeded);
buffer.clear();
const ScopedLock sl (bufferRangeLock);
bufferValidStart = 0;
bufferValidEnd = 0;
backgroundThread.addTimeSliceClient (this);
do
{
const ScopedUnlock ul (bufferRangeLock);
backgroundThread.moveToFrontOfQueue (this);
Thread::sleep (5);
}
while (prefillBuffer
&& (bufferValidEnd - bufferValidStart < jmin (((int) newSampleRate) / 4, buffer.getNumSamples() / 2)));
}
}
void BufferingAudioSource::releaseResources()
{
isPrepared = false;
backgroundThread.removeTimeSliceClient (this);
buffer.setSize (numberOfChannels, 0);
// MSVC2017 seems to need this if statement to not generate a warning during linking.
// As source is set in the constructor, there is no way that source could
// ever equal this, but it seems to make MSVC2017 happy.
if (source != this)
source->releaseResources();
}
void BufferingAudioSource::getNextAudioBlock (const AudioSourceChannelInfo& info)
{
const auto bufferRange = getValidBufferRange (info.numSamples);
if (bufferRange.isEmpty())
{
// total cache miss
info.clearActiveBufferRegion();
return;
}
const auto validStart = bufferRange.getStart();
const auto validEnd = bufferRange.getEnd();
const ScopedLock sl (callbackLock);
if (validStart > 0)
info.buffer->clear (info.startSample, validStart); // partial cache miss at start
if (validEnd < info.numSamples)
info.buffer->clear (info.startSample + validEnd,
info.numSamples - validEnd); // partial cache miss at end
if (validStart < validEnd)
{
for (int chan = jmin (numberOfChannels, info.buffer->getNumChannels()); --chan >= 0;)
{
jassert (buffer.getNumSamples() > 0);
const auto startBufferIndex = (int) ((validStart + nextPlayPos) % buffer.getNumSamples());
const auto endBufferIndex = (int) ((validEnd + nextPlayPos) % buffer.getNumSamples());
if (startBufferIndex < endBufferIndex)
{
info.buffer->copyFrom (chan, info.startSample + validStart,
buffer,
chan, startBufferIndex,
validEnd - validStart);
}
else
{
const auto initialSize = buffer.getNumSamples() - startBufferIndex;
info.buffer->copyFrom (chan, info.startSample + validStart,
buffer,
chan, startBufferIndex,
initialSize);
info.buffer->copyFrom (chan, info.startSample + validStart + initialSize,
buffer,
chan, 0,
(validEnd - validStart) - initialSize);
}
}
}
nextPlayPos += info.numSamples;
}
bool BufferingAudioSource::waitForNextAudioBlockReady (const AudioSourceChannelInfo& info, uint32 timeout)
{
if (source == nullptr || source->getTotalLength() <= 0)
return false;
if ((nextPlayPos + info.numSamples < 0)
|| (! isLooping() && nextPlayPos > getTotalLength()))
return true;
const auto startTime = Time::getMillisecondCounter();
auto now = startTime;
auto elapsed = (now >= startTime ? now - startTime
: (std::numeric_limits<uint32>::max() - startTime) + now);
while (elapsed <= timeout)
{
const auto bufferRange = getValidBufferRange (info.numSamples);
const auto validStart = bufferRange.getStart();
const auto validEnd = bufferRange.getEnd();
if (validStart <= 0
&& validStart < validEnd
&& validEnd >= info.numSamples)
{
return true;
}
if (elapsed < timeout
&& ! bufferReadyEvent.wait (static_cast<int> (timeout - elapsed)))
{
return false;
}
now = Time::getMillisecondCounter();
elapsed = (now >= startTime ? now - startTime
: (std::numeric_limits<uint32>::max() - startTime) + now);
}
return false;
}
int64 BufferingAudioSource::getNextReadPosition() const
{
jassert (source->getTotalLength() > 0);
const auto pos = nextPlayPos.load();
return (source->isLooping() && nextPlayPos > 0)
? pos % source->getTotalLength()
: pos;
}
void BufferingAudioSource::setNextReadPosition (int64 newPosition)
{
const ScopedLock sl (bufferRangeLock);
nextPlayPos = newPosition;
backgroundThread.moveToFrontOfQueue (this);
}
Range<int> BufferingAudioSource::getValidBufferRange (int numSamples) const
{
const ScopedLock sl (bufferRangeLock);
const auto pos = nextPlayPos.load();
return { (int) (jlimit (bufferValidStart, bufferValidEnd, pos) - pos),
(int) (jlimit (bufferValidStart, bufferValidEnd, pos + numSamples) - pos) };
}
bool BufferingAudioSource::readNextBufferChunk()
{
int64 newBVS, newBVE, sectionToReadStart, sectionToReadEnd;
{
const ScopedLock sl (bufferRangeLock);
if (wasSourceLooping != isLooping())
{
wasSourceLooping = isLooping();
bufferValidStart = 0;
bufferValidEnd = 0;
}
newBVS = jmax ((int64) 0, nextPlayPos.load());
newBVE = newBVS + buffer.getNumSamples() - 4;
sectionToReadStart = 0;
sectionToReadEnd = 0;
constexpr int maxChunkSize = 2048;
if (newBVS < bufferValidStart || newBVS >= bufferValidEnd)
{
newBVE = jmin (newBVE, newBVS + maxChunkSize);
sectionToReadStart = newBVS;
sectionToReadEnd = newBVE;
bufferValidStart = 0;
bufferValidEnd = 0;
}
else if (std::abs ((int) (newBVS - bufferValidStart)) > 512
|| std::abs ((int) (newBVE - bufferValidEnd)) > 512)
{
newBVE = jmin (newBVE, bufferValidEnd + maxChunkSize);
sectionToReadStart = bufferValidEnd;
sectionToReadEnd = newBVE;
bufferValidStart = newBVS;
bufferValidEnd = jmin (bufferValidEnd, newBVE);
}
}
if (sectionToReadStart == sectionToReadEnd)
return false;
jassert (buffer.getNumSamples() > 0);
const auto bufferIndexStart = (int) (sectionToReadStart % buffer.getNumSamples());
const auto bufferIndexEnd = (int) (sectionToReadEnd % buffer.getNumSamples());
if (bufferIndexStart < bufferIndexEnd)
{
readBufferSection (sectionToReadStart,
(int) (sectionToReadEnd - sectionToReadStart),
bufferIndexStart);
}
else
{
const auto initialSize = buffer.getNumSamples() - bufferIndexStart;
readBufferSection (sectionToReadStart,
initialSize,
bufferIndexStart);
readBufferSection (sectionToReadStart + initialSize,
(int) (sectionToReadEnd - sectionToReadStart) - initialSize,
0);
}
{
const ScopedLock sl2 (bufferRangeLock);
bufferValidStart = newBVS;
bufferValidEnd = newBVE;
}
bufferReadyEvent.signal();
return true;
}
void BufferingAudioSource::readBufferSection (int64 start, int length, int bufferOffset)
{
if (source->getNextReadPosition() != start)
source->setNextReadPosition (start);
AudioSourceChannelInfo info (&buffer, bufferOffset, length);
const ScopedLock sl (callbackLock);
source->getNextAudioBlock (info);
}
int BufferingAudioSource::useTimeSlice()
{
return readNextBufferChunk() ? 1 : 100;
}
} // namespace juce
juce::AudioBuffer::getNumChannels
int getNumChannels() const noexcept
Definition juce_AudioSampleBuffer.h:236
juce::AudioBuffer::clear
void clear() noexcept
Definition juce_AudioSampleBuffer.h:556
juce::AudioBuffer::copyFrom
void copyFrom(int destChannel, int destStartSample, const AudioBuffer &source, int sourceChannel, int sourceStartSample, int numSamples) noexcept
Definition juce_AudioSampleBuffer.h:938
juce::BufferingAudioSource::getNextAudioBlock
void getNextAudioBlock(const AudioSourceChannelInfo &) override
Definition juce_BufferingAudioSource.cpp:101
juce::BufferingAudioSource::setNextReadPosition
void setNextReadPosition(int64 newPosition) override
Definition juce_BufferingAudioSource.cpp:213
juce::BufferingAudioSource::getTotalLength
int64 getTotalLength() const override
Definition juce_BufferingAudioSource.h:89
juce::BufferingAudioSource::~BufferingAudioSource
~BufferingAudioSource() override
Definition juce_BufferingAudioSource.cpp:44
juce::BufferingAudioSource::BufferingAudioSource
BufferingAudioSource(PositionableAudioSource *source, TimeSliceThread &backgroundThread, bool deleteSourceWhenDeleted, int numberOfSamplesToBuffer, int numberOfChannels=2, bool prefillBufferOnPrepareToPlay=true)
Definition juce_BufferingAudioSource.cpp:26
juce::BufferingAudioSource::waitForNextAudioBlockReady
bool waitForNextAudioBlockReady(const AudioSourceChannelInfo &info, uint32 timeout)
Definition juce_BufferingAudioSource.cpp:160
juce::BufferingAudioSource::isLooping
bool isLooping() const override
Definition juce_BufferingAudioSource.h:92
juce::BufferingAudioSource::releaseResources
void releaseResources() override
Definition juce_BufferingAudioSource.cpp:87
juce::BufferingAudioSource::getNextReadPosition
int64 getNextReadPosition() const override
Definition juce_BufferingAudioSource.cpp:203
juce::BufferingAudioSource::prepareToPlay
void prepareToPlay(int samplesPerBlockExpected, double sampleRate) override
Definition juce_BufferingAudioSource.cpp:50
juce::PositionableAudioSource::PositionableAudioSource
PositionableAudioSource()=default
juce::Range
Definition juce_Range.h:40
juce::Thread::sleep
static void JUCE_CALLTYPE sleep(int milliseconds)
juce::TimeSliceClient::useTimeSlice
virtual int useTimeSlice()=0
juce::Time::getMillisecondCounter
static uint32 getMillisecondCounter() noexcept
Definition juce_Time.cpp:241
juce::AudioSourceChannelInfo
Definition juce_AudioSource.h:33
juce::AudioSourceChannelInfo::numSamples
int numSamples
Definition juce_AudioSource.h:81
juce::AudioSourceChannelInfo::clearActiveBufferRegion
void clearActiveBufferRegion() const
Definition juce_AudioSource.h:84
juce::AudioSourceChannelInfo::buffer
AudioBuffer< float > * buffer
Definition juce_AudioSource.h:73
juce::AudioSourceChannelInfo::startSample
int startSample
Definition juce_AudioSource.h:77