el_processor.h

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/*
Copyright (C) 2007 Christian Kothe

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.
*/

#ifndef EL_PROCESSOR_H
#define EL_PROCESSOR_H

// the Free Surround decoder
class fsurround_decoder {
public:
        // create an instance of the decoder
        //  blocksize is fixed over the lifetime of this object for performance reasons
        fsurround_decoder(unsigned blocksize=8192);
        // destructor
        ~fsurround_decoder();
        
    float ** getInputBuffers();
    float ** getOutputBuffers();

        // decode a chunk of stereo sound, has to contain exactly blocksize samples
        //  center_width [0..1] distributes the center information towards the front left/right channels, 1=full distribution, 0=no distribution
        //  dimension [0..1] moves the soundfield backwards, 0=front, 1=side
        //  adaption_rate [0..1] determines how fast the steering gets adapted, 1=instantaneous, 0.1 = very slow adaption
        //void decode(float *input[2], float *output[6], float center_width=1, float dimension=0, float adaption_rate=1);       
        void decode(float center_width=1, float dimension=0, float adaption_rate=1);    
        
        // flush the internal buffers
        void flush();

        // --- advanced configuration ---

        // override the surround coefficients
        //  a is the coefficient of left rear in left total, b is the coefficient of left rear in right total; the same is true for right.
        void surround_coefficients(float a, float b);

        // set the phase shifting mode for decoding
        // 0 = (+0ﾰ,+0ﾰ)   - music mode
        // 1 = (+0ﾰ,+180ﾰ) - PowerDVD compatibility
        // 2 = (+180ﾰ,+0ﾰ) - BeSweet compatibility
        // 3 = (-90ﾰ,+90ﾰ) - This seems to work. I just don't know why.
        void phase_mode(unsigned mode);

        // override the steering mode
        //  false = simple non-linear steering (old)
        //  true  = advanced linear steering (new)
        void steering_mode(bool mode);

        // set front/rear stereo separation
        //  1.0 is default, 0.0 is mono
        void separation(float front,float rear);

    // set samplerate for lfe filter
    void sample_rate(unsigned int samplerate);

private:
        class decoder_impl *impl; // private implementation (details hidden)
};


#endif

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