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/*
* Copyright (C) 2010, 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.
*/
#ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DELAY_H_
#define THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DELAY_H_
#include "third_party/blink/renderer/platform/audio/audio_array.h"
#include "third_party/blink/renderer/platform/platform_export.h"
namespace blink {
// Implementation of a generic delay line with no dependencies. It does not
// have any thread affinity and there is no consideration on thread safety.
class PLATFORM_EXPORT Delay final {
public:
Delay(double max_delay_time,
float sample_rate,
unsigned render_quantum_frames);
// Handles k-rate processing. Call `SetDelayFrames()` or `SetDelayTime()` to
// set the delay before calling this function.
void ProcessKRate(const float* source,
float* destination,
uint32_t frames_to_process);
// Handles a-rate processing. Fill the return value of `DelayTimes()` with
// the delay value for each frame before calling this function.
void ProcessARate(const float* source,
float* destination,
uint32_t frames_to_process);
void Reset();
float MaxDelayTime() const { return max_delay_time_; }
// Set the delay in frames for `ProcessKRate()`
void SetDelayFrames(double number_of_frames) {
desired_delay_frames_ = number_of_frames;
}
// Set the delay in seconds for `ProcessKRate()`
void SetDelayTime(double seconds) {
desired_delay_frames_ = seconds * sample_rate_;
}
// Fill the return value of this before calling `ProcessARate()`
base::span<float> DelayTimes() { return delay_times_.as_span(); }
protected:
// Main processing loop for ProcessARate using scalar operations. Returns the
// new write_index.
int ProcessARateScalar(unsigned start,
int w_index,
float* destination,
uint32_t frames_to_process) const;
// Vector version of ProcessARateScalar. Returns the number of samples
// process by this function and the updated wirte_index_.
std::tuple<unsigned, int> ProcessARateVector(
float* destination,
uint32_t frames_to_process) const;
// Handle NaN values in `delay_times`. Replace NaN with `max_time`.
void HandleNaN(float* delay_times,
uint32_t frames_to_process,
float max_time);
double DelayTime(float sample_rate);
size_t BufferLengthForDelay(double delay_time,
double sample_rate,
unsigned render_quantum_frames) const;
AudioFloatArray buffer_;
// Time is usually best kept as a double, but AudioParams are inherently
// floats, so make this a float to keep everything consistent.
float max_delay_time_;
int write_index_ = 0;
double desired_delay_frames_ = 0;
AudioFloatArray delay_times_;
// Temporary buffer used to hold the second sample for interpolation if
// needed.
AudioFloatArray temp_buffer_;
float sample_rate_;
};
} // namespace blink
#endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_AUDIO_DELAY_H_
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