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// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "third_party/blink/renderer/modules/webaudio/constant_source_node.h"
#include <algorithm>
#include "third_party/blink/renderer/bindings/modules/v8/v8_constant_source_options.h"
#include "third_party/blink/renderer/modules/webaudio/audio_node_output.h"
#include "third_party/blink/renderer/platform/audio/audio_utilities.h"
#include "third_party/blink/renderer/platform/bindings/exception_state.h"
#include "third_party/blink/renderer/platform/wtf/math_extras.h"
#include "third_party/blink/renderer/platform/wtf/std_lib_extras.h"
namespace blink {
ConstantSourceHandler::ConstantSourceHandler(AudioNode& node,
float sample_rate,
AudioParamHandler& offset)
: AudioScheduledSourceHandler(kNodeTypeConstantSource, node, sample_rate),
offset_(&offset),
sample_accurate_values_(audio_utilities::kRenderQuantumFrames) {
// A ConstantSource is always mono.
AddOutput(1);
Initialize();
}
scoped_refptr<ConstantSourceHandler> ConstantSourceHandler::Create(
AudioNode& node,
float sample_rate,
AudioParamHandler& offset) {
return base::AdoptRef(new ConstantSourceHandler(node, sample_rate, offset));
}
ConstantSourceHandler::~ConstantSourceHandler() {
Uninitialize();
}
void ConstantSourceHandler::Process(uint32_t frames_to_process) {
AudioBus* output_bus = Output(0).Bus();
DCHECK(output_bus);
if (!IsInitialized() || !output_bus->NumberOfChannels()) {
output_bus->Zero();
return;
}
// The audio thread can't block on this lock, so we call tryLock() instead.
MutexTryLocker try_locker(process_lock_);
if (!try_locker.Locked()) {
// Too bad - the tryLock() failed.
output_bus->Zero();
return;
}
size_t quantum_frame_offset;
size_t non_silent_frames_to_process;
double start_frame_offset;
// Figure out where in the current rendering quantum that the source is
// active and for how many frames.
std::tie(quantum_frame_offset, non_silent_frames_to_process,
start_frame_offset) =
UpdateSchedulingInfo(frames_to_process, output_bus);
if (!non_silent_frames_to_process) {
output_bus->Zero();
return;
}
bool is_sample_accurate = offset_->HasSampleAccurateValues();
if (is_sample_accurate && offset_->IsAudioRate()) {
DCHECK_LE(frames_to_process, sample_accurate_values_.size());
float* offsets = sample_accurate_values_.Data();
offset_->CalculateSampleAccurateValues(offsets, frames_to_process);
if (non_silent_frames_to_process > 0) {
memcpy(output_bus->Channel(0)->MutableData() + quantum_frame_offset,
offsets + quantum_frame_offset,
non_silent_frames_to_process * sizeof(*offsets));
output_bus->ClearSilentFlag();
} else {
output_bus->Zero();
}
return;
}
float value = is_sample_accurate ? offset_->FinalValue() : offset_->Value();
if (value == 0) {
output_bus->Zero();
} else {
float* dest = output_bus->Channel(0)->MutableData();
dest += quantum_frame_offset;
for (unsigned k = 0; k < non_silent_frames_to_process; ++k) {
dest[k] = value;
}
output_bus->ClearSilentFlag();
}
}
bool ConstantSourceHandler::PropagatesSilence() const {
return !IsPlayingOrScheduled() || HasFinished();
}
void ConstantSourceHandler::HandleStoppableSourceNode() {
double now = Context()->currentTime();
MutexTryLocker try_locker(process_lock_);
if (!try_locker.Locked()) {
// Can't get the lock, so just return. It's ok to handle these at a later
// time; this was just a hint anyway so stopping them a bit later is ok.
return;
}
// If we know the end time, and the source was started and the current time is
// definitely past the end time, we can stop this node. (This handles the
// case where the this source is not connected to the destination and we want
// to stop it.)
if (end_time_ != kUnknownTime && IsPlayingOrScheduled() &&
now >= end_time_ + kExtraStopFrames / Context()->sampleRate()) {
Finish();
}
}
// ----------------------------------------------------------------
ConstantSourceNode::ConstantSourceNode(BaseAudioContext& context)
: AudioScheduledSourceNode(context),
offset_(AudioParam::Create(
context,
Uuid(),
AudioParamHandler::kParamTypeConstantSourceOffset,
1,
AudioParamHandler::AutomationRate::kAudio,
AudioParamHandler::AutomationRateMode::kVariable)) {
SetHandler(ConstantSourceHandler::Create(*this, context.sampleRate(),
offset_->Handler()));
}
ConstantSourceNode* ConstantSourceNode::Create(
BaseAudioContext& context,
ExceptionState& exception_state) {
DCHECK(IsMainThread());
return MakeGarbageCollected<ConstantSourceNode>(context);
}
ConstantSourceNode* ConstantSourceNode::Create(
BaseAudioContext* context,
const ConstantSourceOptions* options,
ExceptionState& exception_state) {
DCHECK(IsMainThread());
ConstantSourceNode* node = Create(*context, exception_state);
if (!node)
return nullptr;
node->offset()->setValue(options->offset());
return node;
}
void ConstantSourceNode::Trace(Visitor* visitor) const {
visitor->Trace(offset_);
AudioScheduledSourceNode::Trace(visitor);
}
ConstantSourceHandler& ConstantSourceNode::GetConstantSourceHandler() const {
return static_cast<ConstantSourceHandler&>(Handler());
}
AudioParam* ConstantSourceNode::offset() {
return offset_;
}
void ConstantSourceNode::ReportDidCreate() {
GraphTracer().DidCreateAudioNode(this);
GraphTracer().DidCreateAudioParam(offset_);
}
void ConstantSourceNode::ReportWillBeDestroyed() {
GraphTracer().WillDestroyAudioParam(offset_);
GraphTracer().WillDestroyAudioNode(this);
}
} // namespace blink
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