Files
ardour/libs/audiographer/src/general/limiter.cc
2021-12-24 19:54:00 +01:00

153 lines
3.5 KiB
C++

/*
* Copyright (C) 2021 Robin Gareus <robin@gareus.org>
*
* 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.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "audiographer/general/limiter.h"
namespace AudioGrapher
{
Limiter::Limiter (float sample_rate, unsigned int channels, samplecnt_t size)
: _enabled (false)
, _buf (0)
, _size (0)
, _cnt (0)
, _spp (0)
, _pos (0)
{
_limiter.init (sample_rate, channels);
_limiter.set_truepeak (true);
_limiter.set_inpgain (0);
_limiter.set_threshold (-1);
_limiter.set_release (0.01);
_latency = _limiter.get_latency ();
_buf = new float[size];
_size = size;
}
Limiter::~Limiter ()
{
delete [] _buf;
}
void
Limiter::set_input_gain (float dB)
{
_enabled = _enabled || dB != 0;
_limiter.set_inpgain (dB);
}
void
Limiter::set_threshold (float dB)
{
_enabled = true;
_limiter.set_threshold (dB);
}
void
Limiter::set_release (float s)
{
_limiter.set_release (s);
}
void
Limiter::set_duration (samplecnt_t s)
{
if (_pos != 0 || !_result) {
return;
}
_spp = ceilf ((s + 2.f) / (float) _result->width);
}
void
Limiter::set_result (ARDOUR::ExportAnalysisPtr r)
{
_result = r;
}
void
Limiter::stats (samplecnt_t n_samples)
{
if (!_result || _spp == 0) {
return;
}
_cnt += n_samples;
while (_cnt >= _spp) {
float peak, gmax, gmin;
_limiter.get_stats (&peak, &gmax, &gmin);
_cnt -= _spp;
assert (_pos < _result->width);
_result->limiter_pk[_pos++] = peak;
}
}
void Limiter::process (ProcessContext<float> const& ctx)
{
const samplecnt_t n_samples = ctx.samples_per_channel ();
const int n_channels = ctx.channels ();
if (!_enabled) {
ProcessContext<float> c_out (ctx);
ListedSource<float>::output (c_out);
return;
}
_limiter.process (n_samples, ctx.data (), _buf);
stats (n_samples);
if (_latency > 0) {
samplecnt_t ns = n_samples > _latency ? n_samples - _latency : 0;
if (ns > 0) {
ProcessContext<float> ctx_out (ctx, &_buf[n_channels * _latency], n_channels * ns);
ctx_out.remove_flag (ProcessContext<float>::EndOfInput);
this->output (ctx_out);
}
if (n_samples >= _latency) {
_latency = 0;
} else {
_latency -= n_samples;
}
} else {
ProcessContext<float> ctx_out (ctx, _buf);
ctx_out.remove_flag (ProcessContext<float>::EndOfInput);
this->output (ctx_out);
}
if (ctx.has_flag(ProcessContext<float>::EndOfInput)) {
samplecnt_t bs = _size / n_channels;
_latency = _limiter.get_latency ();
while (_latency > 0) {
memset (_buf, 0, _size * sizeof (float));
samplecnt_t ns = _latency > bs ? bs : _latency;
_limiter.process (ns, _buf, _buf);
//stats (ns);
ProcessContext<float> ctx_out (ctx, _buf, ns * n_channels);
if (_latency == ns) {
ctx_out.set_flag (ProcessContext<float>::EndOfInput);
} else {
ctx_out.remove_flag (ProcessContext<float>::EndOfInput);
}
this->output (ctx_out);
_latency -= ns;
}
}
}
} // namespace