# Reliable video playback recomendations?



## Parisii (Jul 22, 2013)

Hi, this is pretty simple stuff but I need a second opinion as my group's real video guy just quit. Thank you for the patience.

We have lost our tape player(with the video guy) so we're making a simple computer playback system. The whole show is basically one video so we need something that's SUPER RELIABLE, and stutter free. Our current idea is the best computer we can buy(cheap) runnings a simple linux system with VLC, the show file, and nothing else.

Is this a good idea?

The setup is very simple the player goes directly to one projector (or stack) and that's it; no switching or recording.
We render are own stuff in 1080p 60fps but we can lower it to 720p if we can't afford a good enough computer. The files can also be changed as they/re custom too at the moment I think they are .AVI but we'll use what ever is the most efficient if someone has a better idea.

How powerful of a computer do you think we would need? Separate graphics? Should we use a windows OS?

I also had a question about cabling HDMI dies at about 15' and we hoping to have the player at the tech table. Does anyone know a cheap way to get FHD a few hundred feet? 

Anyone have an idea that isn't a computer? Like a cheap digital sign player?

Thank you all very much for any advice.


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## dbaxter (Jul 22, 2013)

If you're thinking of cheap computers, you'll be looking at something other than Apple. I would check out sites like Computer parts, Laptop computers, Desktop computers, Computer Hardware - Geeks.com or TechBargains: Best Deals, Dell Coupons, Cheap Laptops, Computer Sales to find something refurbished. Obviously, a free Linux is less expensive than Windows 7, but does limit your software options. For ease of control, you may also want to get an additional video card to drive the projector, keeping the built-in video for your monitor. It will relieve the motherboard of some processing duties as well.
To go over 100 ft. with video is another challenge. You will need to consider converters to go from video to Ethernet and back or perhaps one of the newer wireless distribution systems. I think you'll find that the issue is not so much 1080p vs. 720p itself but what resolution that translates to. These units will give you an idea of what to expect: Tripp-Lite
Don't get upset at losing some resolution, depending on the surface you are projecting on, your audience will likely not be able to distinguish between 1920x1080 and 1280x920 at a distance of 30 ft.
Hope this gets you started.


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## museav (Jul 22, 2013)

Parisii said:


> We have lost our tape player(with the video guy) so we're making a simple computer playback system. The whole show is basically one video so we need something that's SUPER RELIABLE, and stutter free. Our current idea is the best computer we can buy(cheap) runnings a simple linux system with VLC, the show file, and nothing else.
> 
> Is this a good idea?
> 
> ...


What native resolution is the projector? Not much point to running the video at a higher resolution than what the projector can actually display.


Parisii said:


> I also had a question about cabling HDMI dies at about 15' and we hoping to have the player at the tech table. Does anyone know a cheap way to get FHD a few hundred feet?


The HDMI standard is 15' but there are plenty of people running it much further with good quality cabling. However, transmitting 1080p60 signals a "few hundred feet" is past direct HDMI cabling and pushing most HDMI-over-UTP/STP and even HDMI-over-Ethernet options (at least without an intermediate switch) to where ymay be getting into HDMI-over-fiber territory. You might want to verify the distance required but be sure it represents a practical path to run the relate cabling and not just the direct point-to-point path.


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## llburg (Jul 22, 2013)

What about converting to SDI and back? Long distance runs and the cable itself is probably cheaper than fiber.


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## cpf (Jul 22, 2013)

It may be easier to leave the player next to the projector, and remote-control it from another computer over your LAN (or if you like to live on the edge, WiFi). Could use something VNC (free) or Remote Desktop Connection (free with certain versions of Windows) to make the connection. Just make sure your player has 2 video outputs and your control connection is to the screen without the video.


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## Parisii (Jul 22, 2013)

> What native resolution is the projector? Not much point to running the video at a higher resolution than what the projector can actually display.


 -museav

Our venues rent the projector(s) for us, so we get it match it to the video, we want 1080p because it's the best off the shelf system. But every vertical pixel counts, (unlike in most other applications I know) we would do QHD or custom if we had the money. That's why we're loth to settle for 720p but we've done it in the past, the highest resolution the computer can handle is our favorite. 1200 and other less common resolutions are a possibility but I don't think the animators want to deal with them at the moment and if we go too much vertical we'd need to blend two projectors for the correct viewing width and that's not happening right now. So yeah 1080.

Great ideas about cable runs, probably just end up moving tech or having a stagehand/PA behind the stage to press go on the player. At least until we can buy a DVI-fiber line to keep the audio snake and foh DMX company. My main concern is building a reliable player.

One of the video guys at my real job says that VLC on linux might have trouble playing at a true because of an Xorg issue, does anyone know if this is a real problem or how I would go about fixing/researching it. I've used Linux and open source software for a while now but their forums are still very intimidating to a lowly wrench spinner like myself. 

Does anyone know a way to test signal outputs/quality without just looking at the projector? fps, hertz, frame drops, lag, etc. Are there any file formats that are easier to decode/process. I might just be paranoid at this point.

THANK YOU, I'm quite desperate.


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## cpf (Jul 23, 2013)

It's a trade off between file size and CPU usage. If you have a RAID array of SSDs, you can get away with a relatively uncompressed file that will not tax the CPU. If you're working with a 5400RPM laptop hard drive, you'll need a more compressed file format so that the disk can keep up. I'd say that pretty much any computer you can buy these days would easily be able to handle your video needs, you just might need to tweak the way you encode your videos a bit. 

I've ran HD video off of memory keys using a 6-year-old $700 laptop without any trouble, so don't worry about spending a lot. My main concern with *nix would be finding proper drivers for the graphics chipset: most modern GPUs have built-in facilities for decoding common video formats (taking the load off the CPU), but only if the drivers you're using support it.


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## museav (Jul 23, 2013)

llburg said:


> What about converting to SDI and back? Long distance runs and the cable itself is probably cheaper than fiber.


I've encountered a number of problems with HDMI>HD-SDI and HD-SDI>HDMI conversions relating to HDCP or mismatched frame rates, resolution or color space, however those experiences involved integrating with other devices and not just converting for transmission. Something as simple as a computer or other source device outputting 1080p60 and/or RGB color space with the HD-SDI devices that in some cases may be limited to supporting 1080p59.94 and YUV color space are easy to overlook until they bite you, then you really start paying attention to such details.


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## metti (Jul 25, 2013)

I think you may be over thinking this a bit. A few years ago getting reliable linear playback of a single 1080p stream might have been difficult but given the current state of technology it really is an extremely common practice in theatrical projections. I have worked on very large systems for live performance and installations that are easily getting dual 1080p or WUXGA streams out of a mid-spec Mac Mini with rock solid reliability day in and day out. The biggest thing is to make sure you are playing from an internal 7200RPM drive or SSD or if you can't do that than an external via FW800, Thunderbolt, or USB 3.0 would be acceptable but sub-optimal. Beyond that, you should be good as long as you use reasonably reliable playback software and you set the computer to always stay awake, turn off all power-saving features, and uninstall or disable any unnecessary software. I tend to be wary of using software for live performance playback that isn't designed specifically for that because its too easy for a stray mouse cursors or transport bars to appear on a projector output. I would look at Qlab 2 (not yet 3 for stability reasons) and a mid-end Mac Mini. This is a pretty proven solution for theatre projections.

In terms of extending your signal, HDBase-T HDMI over Cat6 extenders are pretty readily available for around $200 and will get you up to around 300' of run with decent quality Cat6 cable. Longer than that and converting to SDI is a possibility but DVI over fiber systems have come down in price so it probably wouldn't be all that much more to do fiber and that's definitely the preferred professional solution. Given that you're in varying venues with rented projectors it might be worth exploring whether the shop providing the projector can also provide suitable signal distribution to accompany it. That would mean you could get the right gear (Cat6, fiber, etc) for any given venue without having to purchase whatever would be needed for the longest possible run you will ever encounter.


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