Cat 6 and HDMI

[ekmdgrf]

The world has yet to catch up. A couple of years ago I ran some HDMI cables from the media area to my projector and the scant faceplates available were amazingly poorly thought out. In the end I ran standard HDMI cables, got some keystone faceplates with blanking plates and some right-angled HDMI gender changers. Cut a hole in the blank and plastiwelded the gender changer into the hole. Actually worked and I even managed to get it inside a 25mm backbox*. Do like the idea of running it over Cat6 with a punchdown faceplate though.

* Don't think you'd want to be doing this if you were installing them for a living though

 

[ban-all-sheds]

Buy some bulk HDMI cable and use these?

http://www.cie-group.com/shop/conne...20/conec2-modular-faceplates-50mm-range_1018/

 

[Lectrician]

The world has yet to catch up. A couple of years ago I ran some HDMI cables from the media area to my projector and the scant faceplates available were amazingly poorly thought out. In the end I ran standard HDMI cables, got some keystone faceplates with blanking plates and some right-angled HDMI gender changers. Cut a hole in the blank and plastiwelded the gender changer into the hole. Actually worked and I even managed to get it inside a 25mm backbox*. Do like the idea of running it over Cat6 with a punchdown faceplate though.

* Don't think you'd want to be doing this if you were installing them for a living though

We have installed VGA and HDMI cables for projectors in the past, and have found some of the angled modules to prevent higher sync rates, causing some laptops to refuse to work unless you change settings - something you don't expect staff or visiting reps to have to do. Much prefer the active powered converts with cat6. Foolproof.

 

[SimonH2]

Why are digital modulators so expensive ?

Have you thought about what they have to do ?
Step one: Encode the incoming video stream into a compressed stream (IIRC this is a Program Stream in DVB parlance). IIRC UK Freeview uses H264 for SD channels, something newer and better for HD channels.
Step two: Combine multiple compressed streams (PSs) into one multiplexed Transport Stream (TS)
Step three: RF modulate the TS onto a UHF carrier. This isn't a simple modulation - there are thousands of subcarriers, each of which carries a relatively low data rate.

For a "private" system, the choice of PS coding scheme and modulation scheme is somewhat flexible as long as you stick to what your receivers (TVs) can handle. But there aren't all that many choices and none of them are "trivial" ! The video compression/coding in step one is computationally intensive - jsut try doing a transcode (conversion from one format to another) on your PC and see how much CPU power it takes to get some idea.

So complicated silicon that is only used in "pro" applications. So unlike "domestic" equipment, it's not expected to amortise the development costs over many millions of units - so each unit carries a higher value in amortised development costs, and also probably costs more to built as there's less incentive to optimise manufacturing costs for low quantity/production rate.

http://en.wikipedia.org/wiki/DVB-T
http://en.wikipedia.org/wiki/DVB-T2

 

[Lectrician]

It's good **** though

The HDMI inputs being available as HD TV channels.

We had two analogue composite inputs and two HDMI. it was cheaper to replace the composite sources with HDMI than get two modulators (we could only source ones with either composite or HDMI, not a mix.

 

[SimonH2]

There's also kit out there to carry HDMI over coax - designed specifically for pub/hotel type installations where replacing the existing coax would be prohibitively expensive and/or disruptive.

 

[Lectrician]

There's also kit out there to carry HDMI over coax - designed specifically for pub/hotel type installations where replacing the existing coax would be prohibitively expensive and/or disruptive.

Doesn't give you the choice at each TV though.

 

[Monkeh]

IIRC UK Freeview uses H264 for SD channels, something newer and better for HD channels.

Boring old archaic MPEG2 for SD, I'm afraid. MPEG-4 AVC (... H264) for HD.

 

[SimonH2]

Ah yes, I remembered that later in the evening - when I was busy cleaning up the transcoded MP4s I've watched