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/*
* Copyright (C) 2012, 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 "config.h"
#if ENABLE(WEB_AUDIO)
#include "AudioScheduledSourceNode.h"
#include "AudioContext.h"
#include "AudioUtilities.h"
#include "Event.h"
#include "EventNames.h"
#include "ScriptController.h"
#include "ScriptExecutionContext.h"
#include <algorithm>
#include <wtf/IsoMallocInlines.h>
#include <wtf/MathExtras.h>
#include <wtf/Scope.h>
#if PLATFORM(IOS_FAMILY)
#include "ScriptController.h"
#endif
namespace WebCore {
WTF_MAKE_ISO_ALLOCATED_IMPL(AudioScheduledSourceNode);
AudioScheduledSourceNode::AudioScheduledSourceNode(BaseAudioContext& context, NodeType type)
: AudioNode(context, type)
, ActiveDOMObject(context.scriptExecutionContext())
{
}
void AudioScheduledSourceNode::updateSchedulingInfo(size_t quantumFrameSize, AudioBus& outputBus, size_t& quantumFrameOffset, size_t& nonSilentFramesToProcess, double& startFrameOffset)
{
nonSilentFramesToProcess = 0;
quantumFrameOffset = 0;
startFrameOffset = 0;
ASSERT(quantumFrameSize == AudioUtilities::renderQuantumSize);
if (quantumFrameSize != AudioUtilities::renderQuantumSize)
return;
double sampleRate = this->sampleRate();
// quantumStartFrame : Start frame of the current time quantum.
// quantumEndFrame : End frame of the current time quantum.
// startFrame : Start frame for this source.
// endFrame : End frame for this source.
size_t quantumStartFrame = context().currentSampleFrame();
size_t quantumEndFrame = quantumStartFrame + quantumFrameSize;
// Round up if the start time isn't on a frame boundary so we don't start too early.
size_t startFrame = AudioUtilities::timeToSampleFrame(m_startTime, sampleRate, AudioUtilities::SampleFrameRounding::Up);
size_t endFrame = 0;
if (m_endTime) {
// The end frame is the end time rounded up because it is an exclusive upper
// bound of the end time. We also need to take care to handle huge end
// times and clamp the corresponding frame to the largest size_t value.
endFrame = AudioUtilities::timeToSampleFrame(*m_endTime, sampleRate, AudioUtilities::SampleFrameRounding::Up);
}
// If we know the end time and it's already passed, then don't bother doing any more rendering this cycle.
if (m_endTime && endFrame <= quantumStartFrame)
finish();
if (m_playbackState == UNSCHEDULED_STATE || m_playbackState == FINISHED_STATE || startFrame >= quantumEndFrame) {
// Output silence.
outputBus.zero();
return;
}
// Check if it's time to start playing.
if (m_playbackState == SCHEDULED_STATE) {
// Increment the active source count only if we're transitioning from SCHEDULED_STATE to PLAYING_STATE.
m_playbackState = PLAYING_STATE;
// NOTE: startFrameOffset is usually negative, but may not be because of
// the rounding that may happen in computing |startFrame| above.
startFrameOffset = m_startTime * sampleRate - startFrame;
}
quantumFrameOffset = startFrame > quantumStartFrame ? startFrame - quantumStartFrame : 0;
quantumFrameOffset = std::min(quantumFrameOffset, quantumFrameSize); // clamp to valid range
nonSilentFramesToProcess = quantumFrameSize - quantumFrameOffset;
if (!nonSilentFramesToProcess) {
// Output silence.
outputBus.zero();
return;
}
// Handle silence before we start playing.
// Zero any initial frames representing silence leading up to a rendering start time in the middle of the quantum.
if (quantumFrameOffset) {
for (unsigned i = 0; i < outputBus.numberOfChannels(); ++i)
memset(outputBus.channel(i)->mutableData(), 0, sizeof(float) * quantumFrameOffset);
}
// Handle silence after we're done playing.
// If the end time is somewhere in the middle of this time quantum, then zero out the
// frames from the end time to the very end of the quantum.
if (m_endTime && endFrame >= quantumStartFrame && endFrame < quantumEndFrame) {
size_t zeroStartFrame = endFrame - quantumStartFrame;
size_t framesToZero = quantumFrameSize - zeroStartFrame;
ASSERT(zeroStartFrame < quantumFrameSize);
ASSERT(framesToZero <= quantumFrameSize);
ASSERT(zeroStartFrame + framesToZero <= quantumFrameSize);
bool isSafe = zeroStartFrame < quantumFrameSize && framesToZero <= quantumFrameSize && zeroStartFrame + framesToZero <= quantumFrameSize;
if (isSafe) {
if (framesToZero > nonSilentFramesToProcess)
nonSilentFramesToProcess = 0;
else
nonSilentFramesToProcess -= framesToZero;
for (unsigned i = 0; i < outputBus.numberOfChannels(); ++i)
memset(outputBus.channel(i)->mutableData() + zeroStartFrame, 0, sizeof(float) * framesToZero);
}
finish();
}
}
ExceptionOr<void> AudioScheduledSourceNode::startLater(double when)
{
ASSERT(isMainThread());
ALWAYS_LOG(LOGIDENTIFIER, when);
if (m_playbackState != UNSCHEDULED_STATE)
return Exception { InvalidStateError, "Cannot call start() more than once"_s };
if (!std::isfinite(when) || when < 0)
return Exception { RangeError, "when value should be positive"_s };
context().sourceNodeWillBeginPlayback(*this);
m_startTime = when;
m_playbackState = SCHEDULED_STATE;
return { };
}
ExceptionOr<void> AudioScheduledSourceNode::stopLater(double when)
{
ASSERT(isMainThread());
ALWAYS_LOG(LOGIDENTIFIER, when);
if (m_playbackState == UNSCHEDULED_STATE)
return Exception { InvalidStateError, "cannot call stop without calling start first."_s };
if (!std::isfinite(when) || when < 0)
return Exception { RangeError, "when value should be positive"_s };
m_endTime = when;
return { };
}
bool AudioScheduledSourceNode::virtualHasPendingActivity() const
{
return m_hasEndedEventListener && m_playbackState != FINISHED_STATE && !isMarkedForDeletion() && !context().isClosed();
}
void AudioScheduledSourceNode::eventListenersDidChange()
{
m_hasEndedEventListener = hasEventListeners(eventNames().endedEvent);
}
void AudioScheduledSourceNode::finish()
{
ASSERT(!hasFinished());
// Let the context dereference this AudioNode.
context().sourceNodeDidFinishPlayback(*this);
m_playbackState = FINISHED_STATE;
// Heap allocations are forbidden on the audio thread for performance reasons so we need to
// explicitly allow the following allocation(s).
DisableMallocRestrictionsForCurrentThreadScope disableMallocRestrictions;
callOnMainThread([this, protectedThis = Ref { *this }, pendingActivity = makePendingActivity(*this)] {
if (context().isStopped())
return;
this->dispatchEvent(Event::create(eventNames().endedEvent, Event::CanBubble::No, Event::IsCancelable::No));
});
}
} // namespace WebCore
#endif // ENABLE(WEB_AUDIO)
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