Roger Allen rogerallen

TLDR: if you've got a bunch of delays in series, for example all-pass filters in a reverb, put them all in a single big buffer and let them crawl over each other for a perf win!

recently I was fiddling around with my hobby reverb code, in preparation for porting it onto a smaller/slower CPU. I'd implemented a loop-of-allpass filters type reverb, just like everybody else, and indeed, I basically had the classic 'OOP'ish abstraction of an 'allpass' struct that was, say, 313 samples long, and... did an allpass. on its own little float buffer[313]. (well, short integer, not float, but thats not relevant) I'll write out the code in a moment.

but then I was browsing the internet one night, as you do, and stumbled on this old post by Sean Costello of Valhalla DSP fame - noting the sad passing of Alesis founder and general all-round DSP legend, Keith Barr. https://valhalladsp.com/2010/08/25/rip-keith-barr/

It's worth a read just for his wonderful anecdote about the birth of the midiverb - which spawned the thou

In this article, I will share some of my experience on installing NVIDIA driver and CUDA on Linux OS. Here I mainly use Ubuntu as example. Comments for CentOS/Fedora are also provided as much as I can.

	;; Roger's Simple .emacs

	;; ----------------------------------------------------------------------
	;; global variables & settings
	(setq auto-save-default t
	auto-save-interval 1000
	delete-auto-save-files nil
	make-backup-files nil
	require-final-newline t
	compile-command "make -k "

	#include <stdio.h>

	/*
	* Calculates what Ada Lovelace labeled "B7", which today we would call the 8th
	* Bernoulli number.
	*/
	int main(int argc, char* argv[])
	{
	// ------------------------------------------------------------------------
	// Data

	/data/backup/$TODAY#!/bin/bash -e

	read -r YESTERDAY TODAY <<<$(
	python3 -c '
	import datetime
	def day_to_slot(n):
	return bin(n)[::-1].index("1")
	n = datetime.date.today().toordinal()
	print(day_to_slot(n - 1))
	print(day_to_slot(n))

	#! /bin/bash
	#
	# -SCOPE
	# This script will replace the shared library files lwjgl.so and libopenal.so
	# contained in the minecraft lwjgl *natives-linux.jar with those in a specified
	# directory and update the associated sha1sum.
	# The purpose of this is to enable playing of "standard" minecraft
	# on non x86 / i386 chipsets running linux. Eg. ARM.
	#
	# -IMPORTANT

	#
	# Himawari-8 Downloader
	#
	#
	#
	# This script will scrape the latest image from the Himawari-8 satellite, recombining the tiled image,
	# converting it to a JPG which is saved in My Pictures\Himawari\ and then set as the desktop background.
	#
	# http://himawari8.nict.go.jp/himawari8-image.htm
	#

	# EPIC Daily “Blue Marble” API

	The API URL is: http://epic.gsfc.nasa.gov/api/images.php

	This gets you a list of the latest day’s images & metadata.

	OR

	http://epic.gsfc.nasa.gov/api/images.php?date=YYYY-M-D&w=X&e=Y

	(defmacro deftrack

	"Defines an instrument with frequency, duration, volume, position and wet pre-defined.
	NB: these variables will shadow any instances in a wider scope.

	(deftrack simple [vibrato 3]
	(* (saw frequency) (sin-osc vibrato)) ; Signal
	(adsr)) ; Envelope

	(simple :frequency 440 :position -1 :wet 1)

	#!/bin/bash

	# This script will copy the newly compiled lwjgl.so and libopenal.so
	# from the specified directory into the correct minecraft jar file.
	# It will then compute and update the correct sha1sum.
	#
	# First Arguement (Required):
	# Path to the directory containing:
	# lwjgl.so and libopenal.so
	#

Roger Allen rogerallen

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