lmms/plugins/StereoEnhancer/StereoEnhancer.cpp

/*
 * StereoEnhancer.cpp - stereo-enhancer-effect-plugin
 *
 * Copyright (c) 2006-2014 Tobias Doerffel <tobydox/at/users.sourceforge.net>
 *
 * This file is part of LMMS - https://lmms.io
 *
 * 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 (see COPYING); if not, write to the
 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301 USA.
 *
 */


#include "StereoEnhancer.h"

#include "embed.h"
#include "plugin_export.h"

namespace lmms
{


extern "C"
{

Plugin::Descriptor PLUGIN_EXPORT stereoenhancer_plugin_descriptor =
{
	LMMS_STRINGIFY( PLUGIN_NAME ),
	"StereoEnhancer Effect",
	QT_TRANSLATE_NOOP( "PluginBrowser",
				"Plugin for enhancing stereo separation of a stereo input file" ),
	"Lou Herard <lherard/at/gmail.com>",
	0x0100,
	Plugin::Type::Effect,
	new PluginPixmapLoader("logo"),
	nullptr,
	nullptr,
} ;

}



StereoEnhancerEffect::StereoEnhancerEffect(
			Model * _parent,
			const Descriptor::SubPluginFeatures::Key * _key ) :
	Effect( &stereoenhancer_plugin_descriptor, _parent, _key ),
	m_seFX( DspEffectLibrary::StereoEnhancer( 0.0f ) ),
	m_delayBuffer( new sampleFrame[DEFAULT_BUFFER_SIZE] ),
	m_currFrame( 0 ),
	m_bbControls( this )
{
	// TODO:  Make m_delayBuffer customizable?
	clearMyBuffer();
}




StereoEnhancerEffect::~StereoEnhancerEffect()
{
	if( m_delayBuffer )
	{
		delete [] m_delayBuffer;
	}

	m_currFrame = 0;
}




bool StereoEnhancerEffect::processAudioBuffer( sampleFrame * _buf,
							const fpp_t _frames )
{

	// This appears to be used for determining whether or not to continue processing
	// audio with this effect
	double out_sum = 0.0;

	if( !isEnabled() || !isRunning() )
	{
		return( false );
	}

	const float d = dryLevel();
	const float w = wetLevel();

	for( fpp_t f = 0; f < _frames; ++f )
	{

		// copy samples into the delay buffer
		m_delayBuffer[m_currFrame][0] = _buf[f][0];
		m_delayBuffer[m_currFrame][1] = _buf[f][1];

		// Get the width knob value from the Stereo Enhancer effect
		float width = m_seFX.wideCoeff();

		// Calculate the correct sample frame for processing
		int frameIndex = m_currFrame - width;

		if( frameIndex < 0 )
		{
			// e.g. difference = -10, frameIndex = DBS - 10
			frameIndex += DEFAULT_BUFFER_SIZE;
		}

		//sample_t s[2] = { _buf[f][0], _buf[f][1] };	//Vanilla
		auto s = std::array{_buf[f][0], m_delayBuffer[frameIndex][1]};	//Chocolate

		m_seFX.nextSample( s[0], s[1] );

		_buf[f][0] = d * _buf[f][0] + w * s[0];
		_buf[f][1] = d * _buf[f][1] + w * s[1];
		out_sum += _buf[f][0]*_buf[f][0] + _buf[f][1]*_buf[f][1];

		// Update currFrame
		m_currFrame += 1;
		m_currFrame %= DEFAULT_BUFFER_SIZE;
	}

	checkGate( out_sum / _frames );
	if( !isRunning() )
	{
		clearMyBuffer();
	}

	return( isRunning() );
}




void StereoEnhancerEffect::clearMyBuffer()
{
	for (int i = 0; i < DEFAULT_BUFFER_SIZE; i++)
	{
		m_delayBuffer[i][0] = 0.0f;
		m_delayBuffer[i][1] = 0.0f;
	}

	m_currFrame = 0;
}





extern "C"
{

// necessary for getting instance out of shared lib
PLUGIN_EXPORT Plugin * lmms_plugin_main( Model * _parent, void * _data )
{
	return( new StereoEnhancerEffect( _parent,
		static_cast<const Plugin::Descriptor::SubPluginFeatures::Key *>(
								_data ) ) );
}

}


} // namespace lmms