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livetrax/libs/ardour/resampled_source.cc

146 lines
3.5 KiB
C++

/*
Copyright (C) 2007 Paul Davis
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 "pbd/error.h"
#include "ardour/resampled_source.h"
#include "pbd/failed_constructor.h"
#include "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, framecnt_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;
}
framecnt_t
ResampledImportableSource::read (Sample* output, framecnt_t nframes)
{
int err;
/* If the input buffer is empty, refill it. */
if (src_data.input_frames == 0) {
src_data.input_frames = source->read (input, blocksize);
/* The last read will not be a full buffer, so set end_of_input. */
if ((framecnt_t) src_data.input_frames < blocksize) {
src_data.end_of_input = true;
}
src_data.input_frames /= source->channels();
src_data.data_in = input;
}
src_data.data_out = output;
if (!src_data.end_of_input) {
src_data.output_frames = nframes / source->channels();
} else {
src_data.output_frames = std::min ((framecnt_t) src_data.input_frames, nframes / source->channels());
}
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 (framepos_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;
}
framepos_t
ResampledImportableSource::natural_position () const
{
return source->natural_position() * ratio ();
}