From 00992c1e68444a8123ffc89a971751cecf7287ed Mon Sep 17 00:00:00 2001 From: Filippos Karapetis Date: Wed, 21 Aug 2013 03:41:30 +0300 Subject: MT-32: Sync with the latest changes in munt --- audio/softsynth/mt32/DelayReverb.cpp | 142 ----------------------------------- 1 file changed, 142 deletions(-) delete mode 100644 audio/softsynth/mt32/DelayReverb.cpp (limited to 'audio/softsynth/mt32/DelayReverb.cpp') diff --git a/audio/softsynth/mt32/DelayReverb.cpp b/audio/softsynth/mt32/DelayReverb.cpp deleted file mode 100644 index d80c98acbc..0000000000 --- a/audio/softsynth/mt32/DelayReverb.cpp +++ /dev/null @@ -1,142 +0,0 @@ -/* Copyright (C) 2003, 2004, 2005, 2006, 2008, 2009 Dean Beeler, Jerome Fisher - * Copyright (C) 2011, 2012, 2013 Dean Beeler, Jerome Fisher, Sergey V. Mikayev - * - * This program is free software: you can redistribute it and/or modify - * it under the terms of the GNU Lesser General Public License as published by - * the Free Software Foundation, either version 2.1 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 Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public License - * along with this program. If not, see . - */ - -//#include -//#include -#include "mt32emu.h" -#include "DelayReverb.h" - -namespace MT32Emu { - -// CONFIRMED: The values below are found via analysis of digital samples and tracing reverb RAM address / data lines. Checked with all time and level combinations. -// Obviously: -// rightDelay = (leftDelay - 2) * 2 + 2 -// echoDelay = rightDelay - 1 -// Leaving these separate in case it's useful for work on other reverb modes... -static const Bit32u REVERB_TIMINGS[8][3]= { - // {leftDelay, rightDelay, feedbackDelay} - {402, 802, 801}, - {626, 1250, 1249}, - {962, 1922, 1921}, - {1490, 2978, 2977}, - {2258, 4514, 4513}, - {3474, 6946, 6945}, - {5282, 10562, 10561}, - {8002, 16002, 16001} -}; - -// Reverb amp is found as dryAmp * wetAmp -static const Bit32u REVERB_AMP[8] = {0x20*0x18, 0x50*0x18, 0x50*0x28, 0x50*0x40, 0x50*0x60, 0x50*0x80, 0x50*0xA8, 0x50*0xF8}; -static const Bit32u REVERB_FEEDBACK67 = 0x60; -static const Bit32u REVERB_FEEDBACK = 0x68; -static const float LPF_VALUE = 0x68 / 256.0f; - -static const Bit32u BUFFER_SIZE = 16384; - -DelayReverb::DelayReverb() { - buf = NULL; - setParameters(0, 0); -} - -DelayReverb::~DelayReverb() { - delete[] buf; -} - -void DelayReverb::open() { - if (buf == NULL) { - delete[] buf; - - buf = new float[BUFFER_SIZE]; - - recalcParameters(); - - // mute buffer - bufIx = 0; - if (buf != NULL) { - for (unsigned int i = 0; i < BUFFER_SIZE; i++) { - buf[i] = 0.0f; - } - } - } -} - -void DelayReverb::close() { - delete[] buf; - buf = NULL; -} - -// This method will always trigger a flush of the buffer -void DelayReverb::setParameters(Bit8u newTime, Bit8u newLevel) { - time = newTime; - level = newLevel; - recalcParameters(); -} - -void DelayReverb::recalcParameters() { - // Number of samples between impulse and eventual appearance on the left channel - delayLeft = REVERB_TIMINGS[time][0]; - // Number of samples between impulse and eventual appearance on the right channel - delayRight = REVERB_TIMINGS[time][1]; - // Number of samples between a response and that response feeding back/echoing - delayFeedback = REVERB_TIMINGS[time][2]; - - if (level < 3 || time < 6) { - feedback = REVERB_FEEDBACK / 256.0f; - } else { - feedback = REVERB_FEEDBACK67 / 256.0f; - } - - // Overall output amp - amp = (level == 0 && time == 0) ? 0.0f : REVERB_AMP[level] / 65536.0f; -} - -void DelayReverb::process(const float *inLeft, const float *inRight, float *outLeft, float *outRight, unsigned long numSamples) { - if (buf == NULL) return; - - for (unsigned int sampleIx = 0; sampleIx < numSamples; sampleIx++) { - // The ring buffer write index moves backwards; reads are all done with positive offsets. - Bit32u bufIxPrev = (bufIx + 1) % BUFFER_SIZE; - Bit32u bufIxLeft = (bufIx + delayLeft) % BUFFER_SIZE; - Bit32u bufIxRight = (bufIx + delayRight) % BUFFER_SIZE; - Bit32u bufIxFeedback = (bufIx + delayFeedback) % BUFFER_SIZE; - - // Attenuated input samples and feedback response are directly added to the current ring buffer location - float lpfIn = amp * (inLeft[sampleIx] + inRight[sampleIx]) + feedback * buf[bufIxFeedback]; - - // Single-pole IIR filter found on real devices - buf[bufIx] = buf[bufIxPrev] * LPF_VALUE - lpfIn; - - outLeft[sampleIx] = buf[bufIxLeft]; - outRight[sampleIx] = buf[bufIxRight]; - - bufIx = (BUFFER_SIZE + bufIx - 1) % BUFFER_SIZE; - } -} - -bool DelayReverb::isActive() const { - if (buf == NULL) return false; - - float *b = buf; - float max = 0.001f; - for (Bit32u i = 0; i < BUFFER_SIZE; i++) { - if ((*b < -max) || (*b > max)) return true; - b++; - } - return false; -} - -} -- cgit v1.2.3