video-to-oscilloscope

a set of simple tools to turn a video into 2-channel audio ready to be "displayed" on an oscilloscope in xy mode

Requirements:

Setup:

1. create a conda env

1. activate the env

1. install the requiremnts

Usage:

1. If you have just a single file you can skip this. If you have multiple files and don't wan to use a video editor, you can quickly slam them together into one file. put the videos into a directory somewhere cd to it make a list of files ls -1>list.txt use vi to put a 'file ' at the start of each line %s /^/file /g use ffmpeg to concatenate the files into one file ffmpeg -f concat -safe 0 -i list.txt -c copy my_video.mp4
2. If you want the video to be in a certain ratio e.g. 1:1 you can quickly fix it ffmpeg ~/Movies/my_orig_video.m4v -filter_complex "[0:v]crop=w='min(iw\,ih)':h='min(iw\,ih)',scale=720:720,setsar=1" my_square_video.mp4

1. Run the extraction script. It uses ffmpeg edgedetect filter to reduce the video to outlines/edges, and then it breaks it up in to individual .png files for further processing. ./extract.sh my_video.mp4 etc...
2. Run the vectorizing script. ./vectorize.sh It takes a while. It doesn't display anything while running.
3. Convert the svg files into an audio file. python svg_to_audio.py "frames/*_opt.svg" --sample-rate 192000 --fps 30 Use the highest samplerate you can. There are cheap $20 USB-C adapters which can do 192KHz, Cubilux, as an example, makes one. You can edit the script to change the output resolution. 720x720 is fine, I think going beyond 1024x1024 is pointless, given the limited samplerate you can use.
4. Combine the wav files into a single file ./cat-wavs.sh
5. Watching the result On mac there's a free program called "Oscilloscope" which will let you see the file the way it would look on an oscilloscope. You can use your computer sound card, headphone output, or a USB dongle to play the audio into an oscilloscope. You can buy a 3.5mm stereo to 2x BNC breakout cable, which makes things much easier.

tips for creating better output

• choose video files with an uncluttered background
• if you use AI i2v to make your video, avoid black outlines - edgedetect will create double lines if the outlines aren't really thin, and this wastes drawing bandwidth
• gen your AI videos with a black background
• you can play with the edgedetect filter parameters used by ffmpeg in extract.sh edgedetect=high=0.5:low=0.8
• keep it simple - even at 192KHz the beam is moving pretty slow compared to arcade stuff, where it might me in the MHz range

finally