Hacker News Reader

Comment by szvsw | Hacker News Reader

Congrats on delivering this fun project! I do a lot of work with synchronizing media content across devices so it’s always fun to see the solutions people come up with. You probably came across them in your research, but the industry standard way of creating a synced video wall like this is with BrightSign media players. The total cost for purchasing them and the screens would for 20 displays could easily end up in the 10s of thousands, so big kudos to you guys for finding a way to make this work with recycled devices.

If you are ever interested in working on some mediasync-related codebases hit me up! We hire devs to do freelance contracts fairly often.

View on HN

Thank you!

I didn’t get the chance to mention them in the blog post, but yes we checked out the price tags on the commercial solutions :) It’s crazy! I’ve always wondered how much of the cost is hardware vs software… and I would imagine professional digital signage is also designed for reliability longevity and all that.

Reliability is a big part of it - but they are not really all that expensive for what you get IMO, especially in an enterprise context. A BrightSign is effectively a very sandboxed Linux box (you can SSH into them!) which has extremely reliable video and audio output, plus a huge amount of customizability, networking, scripting etc - plus various fleet provisioning/management software that goes with it. In terms of $/minute, the amount you pay ends up being vanishingly small IMO.

Your main “cheap” alternative to a BrightSign is a Raspberry Pi, which is definitely cheaper, but has its own host of issues to deal with.

Is the separate box thing because of commercial display realities? Certainly at trade shows and the like I mostly see people just plug a usb stick into the smart tv from wal-mart and play their sizzle reel off of that.

Is there some incentive to not just bake a small arm computer into each display?

I entirely work with museums, where there are lots and lots of considerations in re: rendering device. The considerations for eg a commercial display are a little different, but I don’t have experience with working with those sorts of clients, so my answer is from the perspective of the media art context.

Having a separate box is just good separation of concerns - you can hook it up to whatever kind of projector you like (one projector might cost as much as $100k!), or you might need to use an analog display device (eg a CRT monitor) which certainly won’t have any USB/SD compatibility, in which case you will need some sort of hardware to convert signals appropriately. The separation of concerns just gives you much more flexibility.

Additionally, as mentioned before, you can network the boxes, which lets you do things like creating multi-channel synchronized video art installations.

Most BrightSigns also have GPIO pins on them, so I’ve even done things where I’ve synchronized kinetic art to the video playback.

You can write entire custom applications for your brightsigns (or plugins to the BrightAuthor configuration engine) - it’s just its own self contained platform, so there are a lot of benefits to having it be agnostic to the display.

I operate a digital signage company based around the Pi. Curious what problems you run into. SD cards?

The deprecation of OMXPlayer has been problematic for one, since I rely on some custom applications which need to be able to have some fairly precise/low latency requirements between when you tell it to start playing vs when the playback actually starts, etc. I haven’t found a suitable mechanism which meets our reqs on a Pi for controlling/playing videos yet since that deprecation.

The lack of a regular HDMI output is mildly annoying but not really a problem. Audio configuration is sometimes problematic, usually not…

If a client wants to use their own Pis, getting them provisioned with our software isn’t always the easiest if the customer is techno-phobic (though that’s partly on us - RPi usage is relatively infrequent for our customers so we haven’t put the time/energy into docs and into baking an image etc).

I love Pi’s, but they just that extra bit more finicky than BrightSigns which are hyper optimized for our use case and prevalent in our customers’ equipment rooms already.

> The deprecation of OMXPlayer has been problematic for one, since I rely on some custom applications which need to be able to have some fairly precise/low latency requirements between when you tell it to start playing vs when the playback actually starts, etc. I haven’t found a suitable mechanism which meets our reqs on a Pi for controlling/playing videos yet since that deprecation.

Yeah. The Pi3 -> Pi4/5 jump was quite a massive change in how things work. I've been writing my own playback engine for 10 years now and that one was quite challenging. Precise playback start is something my software supports: You control everything in Lua and can, for example, preload a video and then start it based on either internal logic or based on an external trigger. Up to the Pi3, my software also supports dynamically adjusting the HDMI clock, so the vsyncs of multiple displays are synchronized. Customers have been using that for almost 10 years for video wall playback.

If you go with the hosted version of the software, provisioning is as simple as extracting a single 60MB zip file to an empty SD card and placing that into the Pi. If needed you can even use the API to preconfigure that ZIP file to include settings like WiFi.

Sounds great! I think I’ve actually stumbled across info-Beamer before. We use pretty much the exact same approach in re: configurable zip deployment for BrightSigns.

It would be great to chat some time!

I’ll shoot you an email.

By the way, you can use Chromebooks and -boxes for digital signage (and kiosk) as well if you manage them with Google Cloud.

Why waste old chromebooks for fun when you could donate them to the 3rd world schools for children? Thinkpads 11e are still proper hardware, I own one. Just install the latest Lubuntu and donate to people in need rather than disposing them. It's sad that huge number of the 1st world hardware is being thrown away rather than upcycle and serve the poor people in the 3rd world.

Getting laptops to third world countries is a real challenge. Customs agents see the computers, unaware of their age or value, and they get held, go missing until they are bribed, or just outright stollen.

Where I previously worked, we had a server room with over a hundred laptops, many late intel MacBook pros much better than the computers coworkers in India were using, but we just could not get them there from the US. The best we could do is ask coworkers traveling to visit the India team if they were willing to carry an additional laptop through customs. But a work laptop, personal laptop, and now a second "personal" laptop, even just three devices, would sometimes cause them a headache. If the logistics were easier, I am sure more of what you are proposing would happen.

Laptops valued under Rs 50,000 are exempt from duty in India. Laptops between Rs. 50,000 and Rs. 70,000 come under 10% duty. Laptops over Rs 70,000 come under 18% + 18% GST. This is a lot.

However, if your laptop meets these criteria, you can forgo paying duties:

- it is used or opened with signs of wear or tear,

- it has an older invoice (3+ years) showing purchase outside India,

- it has repair or warranty documents from previous use abroad.

Reply on news.ycombinator.com