From 8625362cac6fbec43f953e684c54eba46ad213c0 Mon Sep 17 00:00:00 2001 From: Tim Mayberry Date: Thu, 10 Sep 2015 11:44:39 +1000 Subject: [PATCH] Add DSPLoadCalculator class to libardour This is similar to the class in the PortaudioBackend but uses an average of the values if raw load is under 80% --- libs/ardour/ardour/dsp_load_calculator.h | 100 +++++++++++++++++++++++ libs/ardour/dsp_load_calculator.cc | 80 ++++++++++++++++++ libs/ardour/wscript | 1 + 3 files changed, 181 insertions(+) create mode 100644 libs/ardour/ardour/dsp_load_calculator.h create mode 100644 libs/ardour/dsp_load_calculator.cc diff --git a/libs/ardour/ardour/dsp_load_calculator.h b/libs/ardour/ardour/dsp_load_calculator.h new file mode 100644 index 0000000000..911f1e3f14 --- /dev/null +++ b/libs/ardour/ardour/dsp_load_calculator.h @@ -0,0 +1,100 @@ +/* + * Copyright (C) 2015 Tim Mayberry + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#ifndef ARDOUR_DSP_LOAD_CALCULATOR_H +#define ARDOUR_DSP_LOAD_CALCULATOR_H + +#include +#include +#include + +#include + +namespace ARDOUR { + +class DSPLoadCalculator { +public: + DSPLoadCalculator() + : m_max_time_us(0) + , m_start_timestamp_us(0) + , m_stop_timestamp_us(0) + , m_dsp_load(0) + , m_value_history (max_value_history()) + , m_num_values(0) + { + + } + + void set_max_time_us(uint64_t max_time_us) { + assert(m_max_time_us != 0); + m_max_time_us = max_time_us; + + // Use average of last 1/4 second of values so responsiveness + // remains consistent independent of max time + uint32_t max_dsp_samples_per_qtr_second = (250000 / m_max_time_us); + m_num_values = + std::min(max_value_history() - 1, max_dsp_samples_per_qtr_second); + + m_value_history.reset(); + } + + + uint64_t get_max_time_us() const { return m_max_time_us; } + + void set_start_timestamp_us(uint64_t start_timestamp_us) + { + m_start_timestamp_us = start_timestamp_us; + } + + void set_stop_timestamp_us(uint64_t stop_timestamp_us); + + uint64_t elapsed_time_us() + { + return m_stop_timestamp_us - m_start_timestamp_us; + } + + /** + * @return a decimal value between 0.0 and 1.0 representing the percentage + * of time spent between start and stop in proportion to the max expected time + * in microseconds(us). + */ + float get_dsp_load() const + { + if (m_dsp_load > m_max_time_us) { + return 1.0f; + } + if (m_dsp_load < 0.0f) { + return 0.0f; + } + return m_dsp_load; + } +private: // methods + static uint32_t max_value_history () { return 16; } + +private: // data + uint64_t m_max_time_us; + uint64_t m_start_timestamp_us; + uint64_t m_stop_timestamp_us; + float m_dsp_load; + RingBuffer m_value_history; + uint32_t m_num_values; +}; + +} // namespace ARDOUR + +#endif // ARDOUR_DSP_LOAD_CALCULATOR_H diff --git a/libs/ardour/dsp_load_calculator.cc b/libs/ardour/dsp_load_calculator.cc new file mode 100644 index 0000000000..d30b417ad5 --- /dev/null +++ b/libs/ardour/dsp_load_calculator.cc @@ -0,0 +1,80 @@ +/* + * Copyright (C) 2015 Tim Mayberry + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + */ + +#include "ardour/dsp_load_calculator.h" + +namespace ARDOUR { + +void +DSPLoadCalculator::set_stop_timestamp_us(uint64_t stop_timestamp_us) +{ + // We could only bother with calculations if a certain amount of time + // has passed, or the Raw DSP value is > X% different than last calc + // which would mean consistent overhead for small values of m_max_time_us + + m_stop_timestamp_us = stop_timestamp_us; + float load = 0; + + if (elapsed_time_us() > m_max_time_us) { + load = 1.0f; + } else { + load = elapsed_time_us() / (float)m_max_time_us; + } + + assert(m_value_history.write_space() >= 1); + + // push raw load value onto history + m_value_history.write(&load, 1); + + // if load is under 80% use an average of past values + if (elapsed_time_us() < ((m_max_time_us * 80) / 100)) { + + RingBuffer::rw_vector vec; + m_value_history.get_read_vector(&vec); + uint32_t values_read = 0; + float dsp_accumulator = 0.0f; + + // iterate through the read vectors accumulating the dsp load + for (unsigned int i = 0; i < vec.len[0]; ++i) { + dsp_accumulator += vec.buf[0][i]; + values_read++; + } + + for (unsigned int i = 0; i < vec.len[1]; ++i) { + dsp_accumulator += vec.buf[1][i]; + values_read++; + } + + load = dsp_accumulator / (float)values_read; + + const float alpha = 0.2f * (m_max_time_us * 1e-6f); + m_dsp_load = m_dsp_load + alpha * (load - m_dsp_load) + 1e-12; + + } else { + // Use raw load value otherwise 100% may never be indicated because of + // averaging/LPF etc + m_dsp_load = load; + } + + if (m_value_history.read_space() >= m_num_values) { + // "remove" the oldest value + m_value_history.increment_read_idx(1); + } +} + +} // namespace ARDOUR diff --git a/libs/ardour/wscript b/libs/ardour/wscript index c0049b55fe..becb2e117d 100644 --- a/libs/ardour/wscript +++ b/libs/ardour/wscript @@ -65,6 +65,7 @@ libardour_sources = [ 'delivery.cc', 'directory_names.cc', 'diskstream.cc', + 'dsp_load_calculator.cc', 'element_import_handler.cc', 'element_importer.cc', 'engine_slave.cc',