portapack-mayhem/firmware/baseband-tx/proc_xylos.cpp

/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2016 Furrtek
 * 
 * This file is part of PortaPack.
 *
 * 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, 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 the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 51 Franklin Street,
 * Boston, MA 02110-1301, USA.
 */

#include "proc_xylos.hpp"

#include "dsp_iir_config.hpp"
#include "audio_output.hpp"

#include "portapack_shared_memory.hpp"
#include "sine_table.hpp"

#include <cstdint>

void XylosProcessor::execute(const buffer_c8_t& buffer) {
	
	// This is called at 1536000/2048 = 750Hz
	
	// ai = 0;
	
	for (size_t i = 0; i<buffer.count; i++) {
		
		// Sample generation rate: 1536000/10 = 153kHz
		if (s >= (5-1)) {
			s = 0;
			
			if (silence) {
				if (sample_count >= SILENCE) {
					silence = false;
					sample_count = CCIR_TONELENGTH;
				} else {
					sample_count++;
				}
			} else {
				if (sample_count >= CCIR_TONELENGTH) {
					if (shared_memory.transmit_done == false) {
						message.n = byte_pos;	// Inform UI about progress (just as eye candy)
						shared_memory.application_queue.push(message);
						digit = shared_memory.xylosdata[byte_pos++];
					}
						
					if (digit == 0xFF) {
						message.n = 25;	// End of message code
						shared_memory.transmit_done = true;
						shared_memory.application_queue.push(message);
					}
					
					sample_count = 0;
				} else {
					sample_count++;
				}
				
				aphase += ccir_phases[digit];
			}
		} else {
			s++;
		}
		
		if (silence) {
			re = 0;
			im = 0;
		} else {
			sample = (sine_table_f32[(aphase & 0x03FF0000)>>18]*127); // 255 here before :D
			
			// Audio preview sample generation: 1536000/48000 = 32
			/*if (as >= 31) {
				as = 0;
				audio[ai++] = sample * 128;
			} else {
				as++;
			}*/
				
			//FM
			frq = sample * 1000;	// 500 was here
			
			phase = (phase + frq);
			sphase = phase + (256<<16);

			re = (sine_table_f32[(sphase & 0x03FF0000)>>18]*15);
			im = (sine_table_f32[(phase & 0x03FF0000)>>18]*15);
		}
		
		buffer.p[i] = {(int8_t)re,(int8_t)im};
	}
	
	//audio_output.write(audio_buffer);
}