The Newsroom

BBC World News | 30th October 2017 Onwards

(October 2017)

This site closed in March 2021 and is now a read-only archive
CO
commseng
It's becoming far less common and practical.
The cost of bringing everything in and out of jackfields is high, and requires a lot of space.
It is much easier to rely on a matrix, which allows flexibility, and also replaces distribution amplifiers, plus can be remotely controlled.

The technology has moved on hugely.
An example - when I worked in the BBC's main London Switching Centre for Video circuits, it was based on a 25 x 25 way matrix.
It was driven by buttons on a desk, which switched relays, which had associated audio circuits through it, and that in turn drove a solid state BBC designed video matrix.
It took up around 4 bays, maybe more, plus another bay for the jackfields (video and audio).
It was replaced at the end of the 1980s with a 64 x 64 matrix which could be remotely controlled.
That was far smaller, and bought about the closure of the area as it could now be controlled from TVC.

Now a scanner would be built with a large matrix over 1000 sources and1000 destinations and it would be one bay.
Even so, with 4K it is now easier to use IP rather than a discrete video matrix!
MA
Markymark


Now a scanner would be built with a large matrix over 1000 sources and1000 destinations and it would be one bay.
Even so, with 4K it is now easier to use IP rather than a discrete video matrix!


Yes, 12 G SDI is non starter for anything beyond a few metres of cable, so you're forced to use Quad Link or 2SI 3G SDI which of course multiplies everything by 4. So a router that's say is 512 sq becomes over 2000 sq for the equivalent at 4k !

IP is the way forward....
GE
thegeek Founding member
NTT or Ateme encoders are used for many fixed IP paths AIUI.

BT still use a fair bit of Ericsson kit to send MPEG transport streams around their MPLS network. We've been using NTT for a while for HEVC (over satellite) and it's pretty solid kit.


IP is the way forward....

I'm quite excited and also a little nervous about our wonderful IP future. I think it's mainly the transition period that worries me. Our nice HD studio facility felt pretty future-proof when we built it five years ago!
MA
Markymark


IP is the way forward....

I'm quite excited and also a little nervous about our wonderful IP future. I think it's mainly the transition period that worries me. Our nice HD studio facility felt pretty future-proof when we built it five years ago!


One of my regrets was that I was born about 15 years too late. I'd have loved to have been around
working in the industry late 60s/early 70s in the pioneering days of colour. Perhaps with IP I was born about 15 years too early Sad
CO
commseng
Digits. That was our hill to climb. Now SD SDI is old hat. MPEG coding, DVB-T DVB-S all in the past too.
But it was fun getting it all to work!
MA
Markymark
Digits. That was our hill to climb. Now SD SDI is old hat. MPEG coding, DVB-T DVB-S all in the past too.
But it was fun getting it all to work!


Yes Cool I remember in 1990 modifying a monitor to accept a SDI input, and marvelling at the interface. That said, still had to struggle on with those orange parallel digital converter dongles that hung off the rear panels of Quantel kit for a couple more years
EL
elmarko
Sorry, CNG?

Edit: Cellular, doh.
JW
JamesWorldNews
Wow! I’m impressed by the technical brilliance displayed in this thread.
NG
noggin Founding member
It's becoming far less common and practical.
The cost of bringing everything in and out of jackfields is high, and requires a lot of space.
It is much easier to rely on a matrix, which allows flexibility, and also replaces distribution amplifiers, plus can be remotely controlled.


Yes - particularly in OB trucks.

In some studios you will often still find mixer inputs for core sources (cameras, dedicated outside sources, EVS replay etc.) hardwired and not going via a router - for resilience purposes. The mixer will then have 'Assign lines' which are router destinations (sometimes fed via synchronisers if the sources are likely to be non-sync) for getting other ad hoc sources present on the router onto the mixer.
NG
noggin Founding member


Now a scanner would be built with a large matrix over 1000 sources and1000 destinations and it would be one bay.
Even so, with 4K it is now easier to use IP rather than a discrete video matrix!


Yes, 12 G SDI is non starter for anything beyond a few metres of cable, so you're forced to use Quad Link or 2SI 3G SDI which of course multiplies everything by 4. So a router that's say is 512 sq becomes over 2000 sq for the equivalent at 4k !

IP is the way forward....


And with 2022-6/7 IP you still have Quad3G or 2SI don't you - as 2022-6/7 is effectively 3G-over-IP.

That's one reason 2110 is looking to be the way forward for IP stuff longer term (though it is more complex as it doesn't use embedded audio and has more complex timing stuff)
MA
Markymark


Now a scanner would be built with a large matrix over 1000 sources and1000 destinations and it would be one bay.
Even so, with 4K it is now easier to use IP rather than a discrete video matrix!


Yes, 12 G SDI is non starter for anything beyond a few metres of cable, so you're forced to use Quad Link or 2SI 3G SDI which of course multiplies everything by 4. So a router that's say is 512 sq becomes over 2000 sq for the equivalent at 4k !

IP is the way forward....


And with 2022-6/7 IP you still have Quad3G or 2SI don't you - as 2022-6/7 is effectively 3G-over-IP.



Yes, though arguably easier to ‘throw’ the signal around as a 10Gb link in the IP domain, through enterprise switches, than as baseband SDI. Of course you need a bit of light compression ( defacto TICO) to get from 12 gigs down to 10. Though SAM ( aka Snell/Probel, now absorbed into GV/Belden) did just manage with 50Hz UHD to get it into a 10 Gb channel by cutting out all the anc data, but that didn’t quite work for those pesky 60 Hz formats 😬That said minimum 25Gig links are the future.

That's one reason 2110 is looking to be the way forward for IP stuff longer term (though it is more complex as it doesn't use embedded audio and has more complex timing stuff)


Yes, the Pandora’s box of PTP !
TE
Technologist
PTP /SMPTE ST 2059 in SMPTE 2110 is no worse than the sub nanosecond timing in analogue....
and the advantage for studio centres of having different flows is well worth having ...
As is the ability to handle things like BBC news most used formal 1080*1920 ..

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