How to add a Chat-Overlay

I will explain how to add a chat overlay using the window capture abilty of OBS, as well as using a plugin for mIRC or the logfiles of Hexchat. If you prefer a video version, check this link.

• mIRC or Hexchat with a Plugin or using the Logfile

First of all you of course need a running instance of either Hexchat or mIRC connected to your desired chat channel. In this tutorial I will use the Twitch.tv chat as an example. You can find several tutorials for this on the Internet but for mIRC I can recommend this plugin. It allows you to enter your Name/Password combination for Twitch and connect to the chat right away. One other nice feature is the ability to output only the last X lines of chat to a textfile, so you dont have to load the whole logfile. And another nice feature is a little overview window, which can be especially handy for users with only one monitor. It allows you to show a small transparent window on top of your applications/games so you can see what your viewers are writing to you. A normal screen-region/window capture or game capture will not capture this window, so it will only be shown to you. (of course this wont work on a two-pc setup)

Now after you configured your desired program you only have to select the correct text-file in your Streaming application. In OBS you select "Use text from file" and and link it either to the plugin output or your hexchat logfile. Configure the text to your liking and you will get a result similar to this:

If you are going to use the logs produced by Hexchat for example, you want to make sure that color codes are stripped and probably also timestamps should be removed. OBS offers an option to wrap the text to a "Custom Extent" and keep use Scroll Mode. This will always show the newest lines of the textfile while you can easily cut off the upper parts which are not needed. Place a picture behind it to create a chat box as seen in my example.

• Window capture of a chat window

This way of adding an overlay gives you quite some more options as the above one. If you are going to use the Twitch popout chat you can style its appearance using a browser plugin and a little script. In my example I used the plugin called "Stylish" for Google Chrome with the Twitch.tv Black Theme from userstyles.org. On the other hand if you choose to use mIRC or Hexchat you can change every color to your liking and use different themes or just change the font.

With Windows-Aero active (transparent taskbar, etc) you can capture "hidden" windows like they would be on top of your screen. The windows must NOT be minimized. Minimized windows do not receive updates. If you have to disable Windows-Aero you might run into problems capturing a hidden window that is currently in the background as overlapping windows might get captured. So lets assume you have Aero activated and can capture the window. In OBS you would use Add -> Window Capture and select the corresponding window name in the dropdown. You could also set a sub-region or just crop your capture to just show the area you want.

In my example I used a simple background picture to give the whole chat a box and some style. Of course to see the background behind the text you will have to use the Color Key or Chroma Key features of OBS or XSplit to remove the background colors. The rest is up to you.