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livetrax/libs/ardour/resampled_source.cc

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4.1 KiB
C++

/*
* Copyright (C) 2007-2017 Paul Davis <paul@linuxaudiosystems.com>
* Copyright (C) 2008-2011 David Robillard <d@drobilla.net>
* Copyright (C) 2010 Carl Hetherington <carl@carlh.net>
* Copyright (C) 2013-2016 John Emmas <john@creativepost.co.uk>
* Copyright (C) 2015-2016 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 "pbd/error.h"
#include "ardour/resampled_source.h"
#include "pbd/failed_constructor.h"
#include "pbd/i18n.h"
using namespace ARDOUR;
using namespace PBD;
#ifdef PLATFORM_WINDOWS
const uint32_t ResampledImportableSource::blocksize = 524288U;
#else
const uint32_t ResampledImportableSource::blocksize = 16384U;
#endif
ResampledImportableSource::ResampledImportableSource (boost::shared_ptr<ImportableSource> src, samplecnt_t rate, SrcQuality srcq)
: source (src)
, _src_state (0)
{
_src_type = SRC_SINC_BEST_QUALITY;
switch (srcq) {
case SrcBest:
_src_type = SRC_SINC_BEST_QUALITY;
break;
case SrcGood:
_src_type = SRC_SINC_MEDIUM_QUALITY;
break;
case SrcQuick:
_src_type = SRC_SINC_FASTEST;
break;
case SrcFast:
_src_type = SRC_ZERO_ORDER_HOLD;
break;
case SrcFastest:
_src_type = SRC_LINEAR;
break;
}
_input = new float[blocksize];
seek (0);
_src_data.src_ratio = ((float) rate) / source->samplerate();
}
ResampledImportableSource::~ResampledImportableSource ()
{
_src_state = src_delete (_src_state) ;
delete [] _input;
}
samplecnt_t
ResampledImportableSource::read (Sample* output, samplecnt_t nframes)
{
int err;
size_t bs = floor ((float)(blocksize / source->channels())) * source->channels();
/* If the input buffer is empty, refill it. */
if (_src_data.input_frames == 0) {
_src_data.input_frames = source->read (_input, bs);
/* The last read will not be a full buffer, so set end_of_input. */
if ((size_t) _src_data.input_frames < bs) {
_end_of_input = true;
}
_src_data.input_frames /= source->channels();
_src_data.data_in = _input;
}
_src_data.data_out = output;
_src_data.output_frames = nframes / source->channels();
if (_end_of_input && _src_data.input_frames * _src_data.src_ratio <= _src_data.output_frames) {
/* only set src_data.end_of_input for the last cycle.
*
* The flag only affects writing out remaining data in the
* internal buffer of src_state.
* SRC is not aware of data bufered here in _src_data.input
* which needs to be processed first.
*/
_src_data.end_of_input = true;
}
if ((err = src_process (_src_state, &_src_data))) {
error << string_compose(_("Import: %1"), src_strerror (err)) << endmsg ;
return 0 ;
}
/* Terminate if at end */
if (_src_data.end_of_input && _src_data.output_frames_gen == 0) {
return 0;
}
_src_data.data_in += _src_data.input_frames_used * source->channels();
_src_data.input_frames -= _src_data.input_frames_used ;
return _src_data.output_frames_gen * source->channels();
}
void
ResampledImportableSource::seek (samplepos_t pos)
{
source->seek (pos);
/* and reset things so that we start from scratch with the conversion */
if (_src_state) {
src_delete (_src_state);
}
int err;
if ((_src_state = src_new (_src_type, source->channels(), &err)) == 0) {
error << string_compose(_("Import: src_new() failed : %1"), src_strerror (err)) << endmsg ;
throw failed_constructor ();
}
_src_data.input_frames = 0;
_src_data.data_in = _input;
_src_data.end_of_input = 0;
_end_of_input = false;
}
samplepos_t
ResampledImportableSource::natural_position () const
{
return source->natural_position() * ratio ();
}