Ross Monroe
Student and Creative Technologist
download.jpg

Red Bull Pi Wall

 

Project:

CRT Video Wall

Client:

Red Bull Music

Agency:

Very Suspicious Projects

Location:

Seattle, WA

Roles:

Hardware Development

Hardware Design

Software Design

Installation

IMG_2891.jpeg
 

Overview:

For a partnered event between Red Bull Music and Toe Jam, I was brought on to create a video wall made out of old school tube tvs that acted as a unified big screen up on stage capable of playing any kind of video content and logos.

This event was a rap concert style party where parts of the venue were transformed to replicate rooms of a home to bring the house party feel to one of Seattles most well known venues, the Showbox Market. The stage resembled a living room with chairs and a couch on one side and the large array of tv’s on the other.

The wall of tvs consisted of 14 televisions 10’ wide and 6’ tall that received video from a central computer that could be changed live during the event.

Development:

After learning about the idea to use multiple televisions to create a wall display, I looked into a program I had learned about from a friend called Pi Wall. This software allows a video to be split up between multiple displays using miniature linux computers called Raspberry Pi’s. 

This software allows you to output to as many displays as you want, but you do have to have a Raspberry Pi for each display, plus one more Raspberry Pi that acted as a master to send the video signal to all of the slaves.

To start, I made a test bench out of small 8” LCD monitors and 5 Raspberry Pi’s to output a video to an array of 2 by 2 displays. After getting it running I quickly realized the main limitation of this software was that it was developed to play a video file from the master Pi, but I needed to send live video.

IMG_1986.jpeg
Screen Shot 2019-01-19 at 4.59.10 PM.png

Looking into the software I was able to see that the video player that acted as the backbone for Pi Wall allows you to send a video stream over ethernet using the Real Time Streaming Protocol (RTSP). I searched forever to find a simple RTSP server but no simple options really exist beside one that required using Touchdesigner.

Touchdesigner is an expansive visual programming software that gives you the building blocks to integrate external hardware and software into one project where all of the data can be manipulated however you like. It is really such an insane piece of software that I wish I knew more about. Thankfully creating a simple RTSP server was actually incredibly easy.

IMG_2851.jpeg

Once I set this up, I used VLC to play the RTSP server over the network on the master pi to make sure the server was functioning properly. I then had to read through a lot of documentation to help form one line of code that allowed Pi Wall to receive the RSTP stream and redistribute it out to all of the Pi’s. It took about a day of searching to get this working.

Now with the video stream working from Touchdesigner I needed to integrate a live video mixing software called Resolume Arena.

Arena is a layer based live video mixing software that has the ability to manipulate all of the media you input using live effects and can be controlled through midi. To combine these two pieces of software I used spout, a video routing application for windows. This tool allows a video signal to be sent out of one program (Arena), and be used as an input on another (Touchdesigner). 

The final chain to make all of this working consisted of:

Resolume Arena -> (Spout) -> Touchdesigner -> (RTSP stream) -> Pi Wall -> (UDP stream) -> 14 Raspberry Pi’s -> (Composite Video) -> TV

The last step necessary to make the video output properly to the TV’s was creating the master settings file that consisted of the physical size of each tv screen, and where each tv was located according to an origin. This allowed the video to line up properly and proportionally between each tv.

Screen Shot 2019-01-19 at 5.24.08 PM.png
Screen Shot 2019-01-19 at 5.16.23 PM.png
pi-wall pixel map.png
IMG_2860.jpeg

Once all of this was completed I hooked up all of the tvs to test. The first attempt was close but my measurements had been off and I was testing inside of a storage unit so I ended up getting this finalized day of show.

For the hardware, I put together a portable rack mount that contained a 24-port switch, power conditioner, 3 10 port usb charging hubs, and 3D printed rack mounts to hold all of the Raspberry Pis. This allowed the entire system to be portable and protect it during transport to the event.

IMG_2135.jpeg

Execution:

With the software finalized and the tv’s all working, I was able to stack all of the tv’s using a kitchen table and small shelving unit along with some supports I made and ratchet straps to keep everything stable throughout the show.

Setting up all of the tv’s turned out to be very easy but I realized I wanted to add some more functionality for the show besides using everything as a unified display. Using Resolume I was able to create a custom output that allowed me to switch between a unified screen or output the same video to every single tv or any combination of the two.

full display trim.gif

This was all controlled during the show with an APC 40 midi controller allowing me to use faders to transition between the display options and video content. Thankfully the venue had hardline ethernet cables run to the stage so I was able to run the system from the sound booth in front of house where I could easily see everything throughout the show.

Results:

During the event I did have one Raspberry Pi freeze, but I was able to remotely re-start the software using terminal from my laptop and within ten seconds everything was back to normal.

Besides that minor issue, the system was able to run without any major problems throughout the entire 5 hours of the show. Red Bull Music was incredibly impressed with how the wall turned out and I had many of the venue staff coming up to learn more about how everything functioned because they had never seen anything like it.

trim close up.gif
trim hype.gif

Overall, the system was able to successfully stream live video with a half second to one second delay and now the portable Pi Wall box can be adapted and re-deployed to run any style of displays with up to 23 total in its current configuration but can be expanded with a larger switch.


If you are interested in learning more about this project feel free to send me an email!