Tag Archives: obs

Quick previewing negatives using OBS

I’m using a camlink to connect a Nikon camera to my PC, but you could use your webcam also for this trick.

Now i can activate the full screen projector in OBS to preview and sort the negatives on a big screen. (right click on you preview screen)

When connecting a camera to OBS you initially have a “negative” image.

Below trick inverts your image, after that you can use your camera controls or OBS colour correction filter to adjust.

I’m using gimp to invert the LUT png image, but most image editors can invert an image.

A LUTs is a LookUp Table. Color presets/filters for adjusting the image.

Hardcore method .. command line

convert input.png -channel RGB -negate invert.png

Streaming, recording, videocall and more

I use a bunch of different tools to create video’s or stream stuff.
Below is some info about those tools.


  • Kdenlive – Linear video editor (Adding text, transitions, etc)
  • VLC media player – For example to embed video in OBS
  • OBS – Opensource Broadcast software, i use this also to record my screen – You can use this as a virtual webcam, so you can fool around with the image.
  • Audacity – For editing audio
  • QPrompt – Teleprompter

For OBS i made a shortcut/macro keyboard thingy. Based on an arduino pro mini. (Which can connect to a computer acting like a HID, for example a keyboard or mouse)
I use this one to emulate keystrokes which i’ve configured in OBS to do:

  • Switch to scene 1
  • Switch to scene 2
  • Transition from scene to scene
  • Start streaming
  • Start recording
  • Mute
  • [empty] – sometimes used as “start virtual webcam”
  • Slow transition
  • Blank screen
  • Display overlay text

(Originally i planned to do this with a Nextion Display)

Mobile Phone holder, like a third hand

Sometimes a Nikon on a tripod is better.

I don’t have a dedicated webcam for my battlestation. So i mainly use a Actioncam (4k) which can be connected via USB. Or i use a Nikon together with the Camlink.

So i record using my mobile, webcam, screen record
Edit using Audacity and Kdenlive.

When recording with OBS i use MP4 as a container, this is a no-brainer to embed in websites. Use mkv when recording long shots, or when connections can break. (A mp4 will be corrupted)

ffmpeg -i streamrecord.mkv -codec copy putinmp4container.mp4

I’ve played around with StreamFX which gives you some nice extra tools.
(There are loads of plugins to download)
Using websockets is on my todolist.

A little OBS trick without green screen

StreamFX example

Working on a blender animation.
Realtime screen grab, which gets 3D placed in a scene.

Blender transparent animation for logo

First test to make a personalised logo for myself to use embedded on movies or in OBS streams.

Created a simple animation in Blender.

We need to export in RGBA (A for aplha), One of the supported video codex you can use is : Quicktime – QT rle.
Select this one, and make sure it’s RGBA and not RGB

Now i can use the exported video file in OBS for streaming.
I made the animation i a way that it can be looped.
(Don’t forget to set this option in OBS.)

Also useable in Kdenlive editor as watermark.

Using OSB to record screens

While you can use screencapture to record virtual machines, to real machines it is a different story.

Virtual machines running locally or remote can be accessed with spice/vnc or rdesktop.
So you have a window displaying the remote screen, which you can capture using window capture.

There are also emulators which you can window-capture. But i want the real thing when available. Emulators give a too crisp screen output. And you want to have the real SID chip sound.

Hardware capturing:

I’ve got two capturing usb sticks:

Camlink 4K for hdmi capturing (Which i use mainly for my nikon)

Basetech BR116 RCA and S-Video capture (NTSC 720 x 480 , 30 FPS/PAL 720 x 576 , 25 FPS)

Devices and recording:

  • C64 – Use Basetech, and the DIN to RCA cable
  • Vic-20 – same as above
  • Raspberry – Use a HDMI and Camlink
  • Amiga – I use the basetech and grab the composite signal from the Scart connector, another solution is to use a A520 Modulator, which has Composite out. (There are schematics on the internet to connect hdmi to your amiga)
Amiga A520 Modulator

The 520 Modulator connects to the amiga using a DB23 connector, and a Y cable for the 2 rca audio jacks.
It outputs a composite video signal, and RF modulated signal to connect to a old Tube/Crt monitor

When recording video from those screens, i configure my OBS file format to MP4. This makes it easier to embed into websites. Only downside on writing to MP4 instead of mkv is the fact that the file probably isn’t recoverable when something crashes.

Audio capturing :

When capturing your movie don’t forget to add a audio source to your OBS sources.
Use Audio input capture, or you can use Audio output capture when sound is playing by your system.

Demo a friend made using a demomaker (Music starts half way)

Flightsim on a Amiga (See more on flightsims)
C64 Hellraiser (part 1) no de-comb/de-interlace filter

Note: check your output/cables

RTMP / RTSP / HLS Streaming video

UPDATE: 20220906 – Started testing with steaming VR/360 also

RTMP stands for Realtime Messaging Protocol
RTSP stands for Realtime Streaming Protocol
HLS is a HTTP Live Streaming method

I needed a way to stream semi-realtime video to a website.
There are multiple use cases.

  • Streaming a boardgame online
  • Showing my desktop, while i was working on projects.
  • Watched (streamed) Curse of Oak Island with some friends while being in a Jitsi meeting at the same time together.

In all cases i used OBS to stream to the website.

Prepare the stream server:

Install nginx, with the rtmp module

wget http://nginx.org/download/nginx-1.9.7.tar.gz
wget https://github.com/arut/nginx-rtmp-module/archive/master.zip
tar -xvf nginx-1.9.7.tar.gz
unzip master.zip
cd nginx-1.9.7
./configure --add-module=../nginx-rtmp-module-master/
make && make install
mkdir -p /HLS/live/test # live is the stream name, test is the pass key
chown -R {nginx user} /HLS

create a config file

worker_processes  1;
error_log  logs/error.log debug;
events {
worker_connections  1024;
rtmp {
server {
listen 1935;
allow play all;

application live {
allow play all;
live on;
record all;
record_path /video_recordings;
record_unique on;
hls on;
hls_nested on;
hls_path /HLS/live;
hls_fragment 10s;


application vod {
play /video_recordings;

http {
include       mime.types;
default_type  application/octet-stream;

server {
listen 80;
server_name www.fash.nu;
add_header Access-Control-Allow-Origin *;

location /live {
types {
application/vnd.apple.mpegurl m3u8;
alias /HLS/live;
add_header Cache-Control no-cache;

location /mobile {
types {
application/vnd.apple.mpegurl m3u8;
alias /HLS/mobile;
add_header Cache-Control no-cache;

location / {
root   html;
index  index.html index.htm;

You need a webpage containing the embedded player

<!-- HTML -->
<video id='hls-example'  class="video-js vjs-default-skin" width="400" height="300" controls>
<source type="application/x-mpegURL" src="http://www.fash.nu:8080/live/test/index.m3u8">

<!-- JS code -->
<!-- If you'd like to support IE8 (for Video.js versions prior to v7) -->
<script src="https://vjs.zencdn.net/ie8/ie8-version/videojs-ie8.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/videojs-contrib-hls/5.14.1/videojs-contrib-hls.js"></script>
<script src="https://vjs.zencdn.net/7.2.3/video.js"></script>

var player = videojs('hls-example');

Run the server part:

/usr/local/nginx/sbin/nginx -c /root/stream.conf

Now you can connect OBS to the streaming server

Open the webpage and enjoy!

2nd webcam showed card details. Also text boxes appeared who’s turn it was.

UPDATE: 20220906 – Started testing with steaming VR/360 also

When attending the MCH2022 talk about streaming 360 video, i made a mental note to try this with my Vuze cam, using current setup and the one suggested in the talk : https://www.youtube.com/watch?v=460vo1O5pC4

To check : EGJS

Vuze Android App