Week of the 23/10/2023 - #43
More nice demos …
Contents
tech
- Flashparty 2023
- Screen recording in Linux with ffmpeg
- More cool demos
- 4k Sound demo tool - Sointu
science
- Cellular automata to generate sequences
Flashparty 2023
This weekend was the Flashparty 25th aniversary here in Buenos Aires, 🇦🇷. There were a lot of interesting things happening. He’s a summary of the things I enjoyed.
My favorite PETSCIIs
These are my favorite entries in the PETSCII compo.
“Linking Ape” by TheRyk
“El Pombero” by Sande
“Astro” by Almighty God
“R’lyeh Gross” by Skleptold
“La Pelota No se Mancha” by Almighty God
Other nice imgaes
“Rainbow in the Dark” by Slaxx / Excess. Winner of the oldskool pixel art compo.
Mod 7
I wrote an entry for FP23 called “Mod 7”. It’s a 256 byte textmode MSDOS intro. It requires a Sound Blaster Pro and uses the OPL3 chip with 3 channels and two instruments. The music is synced with the (very simple) visuals. This has been tested in dosbox 0.74-3 and can be compiled with nasm version 2.16.x. The visuals are a version of the examples presented here:
which come from this Twitter thread:
The sourcecode is included in the ZIP and will soon add writeup in here.
- Mod 7 - Demozoo entry - 2nd place in 256b category
- YouTube video of entry - For the lazy here’s the video
- Mod 7 - Pouet entry - Pouet entry
Tools & other useful links
- Adlib tracker linux version - Used to test the audio and code instruments
- Adlib tracker documentation - the help
- Yamaha YMF262 Chip docs - PDF from Internet archive with chip docs.
- OPL2/3 documentation - Good doc on registers used in OPL chip
- NASM - The Netwide Assembler - Assemblre for x86
- NASM docs - Docuentantion
- Sound configuration options for Dosbox - Sound settings for Dosbox and Dosbox-x.
- YM3812 Part 1 – Register Basics - This is the first in a series of posts that goes very in-depth with the YM3812 (a.k.a. OPL2) Yamaha chip. Probably deserves a post for itself.
- Videos of previous article - YouTube related to previous article
- OPL3BankEditor - open source bank editor for the OPL3
Screen recording in Linux with ffmpeg
To record a video you set the video_size parameter to the width x height of the video you want to capture. Not sure how to offset so it records the current screen with offset 0,0.
ffmpeg -video_size 730x635 -framerate 25 -f x11grab -i :0.0+0+0 1.mp4
To crop the video later on you can use:
ffmpeg -i in.mp4 -filter:v "crop=720:544:0:89" out.mp4
where 720:544:0:89 are width:height:offset x:offset y.
More nice demos …
Amazing 4k demo
- Absolute Territory by Prismbeings - The demo
- The authors Twitter account
- His Github repositories
- His web
- Wackelkontakt - another awesome 4k by the same author
- WaveSabre - WaveSabre is a software synthesizer and toolchain for music for 64K intros.
Nice JS demo - TRBL - Hallmackenreuther
Pouet / DemoZoo / YouTube ▶️
Xor demo
- https://www.shadertoy.com/view/DddBWr Pouet / YouTube ▶️
Geometric Linux demo - L’enveloppe
Demozoo / Pouet / Shadertoy / YouTube ▶️
4k Sound demo tool - Sointu
A cross-architecture and cross-platform modular software synthesizer for small intros, forked from 4klang. Targetable architectures include 386, amd64, and WebAssembly; targetable platforms include Windows, Mac, Linux (and related) + browser.
Cellular automata to generate sequences
- Hiroshi Umeo - Wrote several papers on how to generate primes, and other sequences
- A construction of simple and smaller-state real-time generator for exponential sequences
- Real-Time Generation of Primes by a 1-Bit-Communication Cellular Automaton. - Fundam. Informaticae 58(2003): 421-435 (2003)
- A construction of five-state real-time Fibonacci sequence generator - “In this paper, we propose a five-state real-time generator for Fibonacci sequence and give a formal proof of the correctness of the generator. The proposed five-state Fibonacci sequence generator is optimum in generation steps, and it is realized on a smallest, known at present finite state automaton in the number of states.”. Couldn’t get this PDF.