Channel In A Pox

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Channel In A Pox

fart_150
So let’s say you want to buy some “Channel-In-a-Box” servers. Your network runs up to ten feeds – East, Central, Mountain, Pacific, a North regional feed (for snow tire commercials), a South regional feed (for the radial tire commercials) and three occasional feeds for those regional college games. You buy 15 Fast Allegro Real Time CIB systems – a primary for each feed and a backup for every two channels. (Remember – no single point of failure!) Of course it’s 2016 (and you want to save some $$) – so you skip the HD-SDI outputs and order the 10Gb Ethernet IP only version.

Now your vendor has configured your system with at least two of everything so that you can sleep at night. So what are the chances that all of your primary FARTs will be non-airable all at the same time? Well if your vendor promised you “six nines” of uptime over the course of course of a year I hope you have that in writing ’cause I bet you’ll only get “two nines” (3.65 days of downtime) till your vendor exorcises all the software bugs from your system!

Now I know that your old “single function” equipment had downtime too. But you were always able to patch (or route) around a bad piece of baseband equipment. But what do you do when that new banner/bug/snipe that graphics just made takes your CIB off the air?

UHD: 8 Bits vs 10

UHD: 8 Bits vs 10

Simulation of 8-bit pictureFinally realizing that more pixels alone is not enough, the UHD Alliance has come out with specs for what they call “Ultra HD Premium.” Besides HDR and a wide color gamut, the performance metrics require that the video bit depth must be 10 bit. (I assume they are talking about the luminance channel here, as most video is encoded as luminance plus color difference signals.) However if you look inside almost any broadcast/cable/satellite transmission facility, you’ll see that most are using 8-bit mezzanine formats such as XDCAM HD 50 for server storage. Why is this so bad? Imagine paying $1K or more for a 4K monitor and seeing background colors like the thumbnail above. (Or at left depending on the screen size of your device.) And no, the graphic artist did not design it that way.

While the upcoming 4K Blu-ray Disc format (which requires a new 4K Blu-ray Disc player) and some streaming services (like Netflix) will be capable of delivering Ultra HD Premium content, don’t expect any from broadcast or cable services any time soon. The future over-the-air ATSC 3.0 standard will support Ultra HD Premium services, but you’ll need some future ‘to be announced’ converter box to make it work with today’s 4K displays. Gee, it’s fun being on the bleeding edge of technology, isn’t it?

You Can’t Just Swap Cables

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You Can’t Just Swap Cables

pp5In an IP Transport plant, if you have two sources reversed (like on your monitor wall) – swapping cables probably won’t work. More than likely, you have multiple signals muxed on that fiber or GigE cable and you have to open up a routing table to straighten it all out. Yes an IP-based plant gives you less wires, less weight and likely less cost but it also gives you new headaches.

Will TR-03 Stay In Sync?

Will TR-03 Stay In Sync?

BNC-to-RJ-45 ConnectorsLast week the Video Services Forum released its draft recommendation for “elementary stream” IP media (read that as non-embeded audio). While touted by some as a low latency, low payload transport protocol with video, audio, and ancillary data being transported separately, I think it once again opens the Pandora’s Box of “out of sync” audio and video. I know that Thomas Edwards of Fox Networks said: “…when every packet is time stamped accurately, we should have better synchronization between media streams than SDI solutions could provide.” I thought that audio & video packets in MPEG-2 transport streams were time stamped as well, but that hasn’t prevented them from becoming annoyingly out of sync.

I say if you have to implement IP transport now, plan to use SMPTE ST 2022-6. (‘Cause it’s nice when audio and video arrive together.) And let’s see what actually happens when someone else actually implements TR-03 in a control room near you.

SDI vs IP: Tale of the Switch

SDI vs IP: Tale of the Switch

tapemeasureIn the continuing battle between those newfangled “I only know IP” computer type people and us ole-time TV engineers, former ABC/FOX/Olympic/ATTC engineer Jim DeFilippis warns in an opinion piece in TV Technology that we should be skeptical of claims that IP transport is better/cheaper/faster than SDI. In the first part of the article, Jim points out that if you measure the total aggregate bandwidth (TAB) of both a comparably sized HD-SDI switch and a 10 GbE IP-based switch, you might find that the SDI switch is a better value in terms of TAB, power and size.

Also, let’s say you’re a company who has been asked to build a file-based multichannel playout facility for a major international video programming distributor. You wisely connect your IP-based equipment with fiber rather than with copper. Unfortunately “… UDP/IP … is not a reliable protocol. There is no built-in mechanism to guarantee arrival in the correct order, or even arrival of the packet at all. The order of packets can be restored through sequence numbering in the RTP layer, but packet loss remains a problem.” (EBU Technical Review – 2012 Q4) You may claim to have a managed network where packet loss does not occur, but that only holds true as long as you do not approach the available bandwidth limit.

And then gremlins might just strike and your program stream might be fine along one route, while in the air path you’re droppin’ packets left and right. Just sayin’.