mirror of
https://github.com/portapack-mayhem/mayhem-firmware.git
synced 2024-12-13 19:54:39 +00:00
91 lines
2.4 KiB
C++
91 lines
2.4 KiB
C++
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/*
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* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
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* Copyright (C) 2016 Furrtek
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*
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* This file is part of PortaPack.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2, or (at your option)
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* any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; see the file COPYING. If not, write to
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* the Free Software Foundation, Inc., 51 Franklin Street,
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* Boston, MA 02110-1301, USA.
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*/
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#include "proc_rds.hpp"
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#include "portapack_shared_memory.hpp"
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#include "sine_table.hpp"
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#include <cstdint>
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void RDSProcessor::execute(const buffer_c8_t& buffer) {
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for (size_t i = 0; i<buffer.count; i++) {
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//Sample generation 2.28M/10=228kHz
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if(s >= 9) {
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s = 0;
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if(sample_count >= SAMPLES_PER_BIT) {
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cur_bit = (shared_memory.rdsdata[(bit_pos / 26) & 15]>>(25-(bit_pos % 26))) & 1;
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prev_output = cur_output;
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cur_output = prev_output ^ cur_bit;
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int32_t *src = waveform_biphase;
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int idx = in_sample_index;
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for(int j=0; j<FILTER_SIZE; j++) {
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val = (*src++);
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if (cur_output) val = -val;
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sample_buffer[idx++] += val;
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if (idx >= SAMPLE_BUFFER_SIZE) idx = 0;
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}
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in_sample_index += SAMPLES_PER_BIT;
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if (in_sample_index >= SAMPLE_BUFFER_SIZE) in_sample_index -= SAMPLE_BUFFER_SIZE;
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bit_pos++;
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sample_count = 0;
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}
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sample = sample_buffer[out_sample_index];
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sample_buffer[out_sample_index] = 0;
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out_sample_index++;
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if (out_sample_index >= SAMPLE_BUFFER_SIZE) out_sample_index = 0;
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//AM @ 228k/4=57kHz
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switch (mphase) {
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case 0:
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case 2: sample = 0; break;
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case 1: break;
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case 3: sample = -sample; break;
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}
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mphase++;
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if (mphase >= 4) mphase = 0;
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sample_count++;
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} else {
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s++;
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}
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//FM
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frq = (sample>>16) * 386760;
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phase = (phase + frq);
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sphase = phase + (256<<16);
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//re = sintab[(sphase & 0x03FF0000)>>16];
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//im = sintab[(phase & 0x03FF0000)>>16];
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buffer.p[i] = {(int8_t)re,(int8_t)im};
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}
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}
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