Grand Guide Pedestrian

Let me tell about a pet project I did recently.

It’s name is "Grand Guide Pedestrian". It’s a virtual interactive experience where a player controls another human, a hero, who walks in the city like it’s a GTA game. No gunfire, no car thefts, no other crimes, though.

Look at the demo:

And here is the data flow:

A hero streams a video from his camera to the restreamer, who then streams it back to a player. A player controls a hero with "classical" WASD controls. Keypresses are just sent to the server via websocket, where they are listened by the hero controller app.

Thus, the prototype consists of:

  • Video restreamer

  • Websocket server

  • Hero’s mobile app

  • Player’s SPA

It took me 27 days to finish from the first lines of code to the first walk in the city. But actually I’ve spent only two or three nights coding the server and configuring the video restreamer. It took a lot time to find a friend who could help me with the player’s SPA. And I’ve spent a week drawing a poster, which was absolutely optionaly, but gave me a lot of fun in the process. Look at this poster!

Finally, I’ve spent a night trying to invent an over-the-shoulder camera rig. I’ve made one a few years ago, but back at those days I had a lot of tools and space to work in, but theese days I have only a Leatherman Rev™ tool. So, I’ve made it out of my absolutely fantastic camera tripod (I like it because it already survived three modification and still functional), a karabiner and a few laces. Well, I didn’t get the "GTA view", it’s more like in PUBG.

Hero’s mobile app is written in Flutter, because I know some Flutter and I could make this simple app without any help.

Server uses Kotlin, just because it’s the best language in the whole world.

Video restreamer is SRS. I just took the first working solution.

My friend Alex created the player’s SPA with React. I’m very happy he did it.

Finally, I used Face 2 Sticker Telegram bot to finish some of the poster bits.

The biggest challenge is video restreaming. It’s too complex and requires computing resources. Currently SRS gives a three second delay on a perfect Internet connection. 4G in the city is twice as slow: five to ten seconds.

It’s absolutely impossible to achieve the interactivity with this delay. I’ve read some articles in the Internet and it seems like HTML5 video is just not as good as RTMP was when Flash was alive. Now I look at YouTube at a different angle. Believe me: it’s ten second delay during a stream is fu##ing great result, a combinations of top-notch engineers and hardware.

The second challenge are websockets. They lose connection, deny to reconnect and drop messages constantly.

That’s it. The code is available here.

Thank you for your attention and have a great day!

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