Tim Mayberry
a65b1ddedc
The class uses the same algorithm as in the coreaudio and alsa backends and should probably go into libardour at some point
89 lines
2.2 KiB
C++
89 lines
2.2 KiB
C++
/*
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* Copyright (C) 2015 Tim Mayberry <mojofunk@gmail.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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#ifndef DSP_LOAD_CALCULATOR_H
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#define DSP_LOAD_CALCULATOR_H
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#include <stdint.h>
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class DSPLoadCalculator {
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public:
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DSPLoadCalculator()
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: m_max_time_us(0)
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, m_start_timestamp_us(0)
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, m_stop_timestamp_us(0)
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, m_dsp_load(0.0f)
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{
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}
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void set_max_time_us(uint64_t max_time_us) { m_max_time_us = max_time_us; }
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uint64_t get_max_time_us() { return m_max_time_us; }
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void set_start_timestamp_us(uint64_t start_timestamp_us)
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{
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m_start_timestamp_us = start_timestamp_us;
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}
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void set_stop_timestamp_us(uint64_t stop_timestamp_us)
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{
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m_stop_timestamp_us = stop_timestamp_us;
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if (elapsed_time_us() > m_max_time_us) {
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m_dsp_load = 1.0f;
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} else {
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const float load = elapsed_time_us() / (float)m_max_time_us;
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if (load > m_dsp_load) {
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m_dsp_load = load;
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} else {
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const float alpha = 0.2f * (m_max_time_us * 1e-6f);
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m_dsp_load = m_dsp_load + alpha * (load - m_dsp_load) + 1e-12;
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}
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}
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}
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uint64_t elapsed_time_us()
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{
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return m_stop_timestamp_us - m_start_timestamp_us;
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}
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/**
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* @return a decimal value between 0.0 and 1.0 representing the percentage
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* of time spent between start and stop in proportion to the max expected time
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* in microseconds(us).
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*/
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float get_dsp_load()
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{
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if (m_dsp_load > m_max_time_us) {
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return 1.0f;
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}
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if (m_dsp_load < 0.0f) {
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return 0.0f;
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}
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return m_dsp_load;
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}
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private:
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uint64_t m_max_time_us;
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uint64_t m_start_timestamp_us;
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uint64_t m_stop_timestamp_us;
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float m_dsp_load;
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};
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#endif // DSP_LOAD_CALCULATOR_H
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