View Full Version : HDMI distribution over CatX to nmultiple displays


HWL
12-07-08, 01:58 PM
I need a PROVEN solution to my commercial installation problem and I prefer the solution to take advantage of today's digital technology.

I have HDMI sources (camera video with audio, PC, HD players, etc.) I need to distribute to multiple display devices in COMMERCIAL buildings (5 - 50 displays). The video information is not being (re)recorded, just displayed. The video signal is generated on-site and is therefore assumed not protected by DRM nor does it involve any other copyright infringement legalities. It is possible that we would in the future need to include a BluRay type DVD source though, as well as PC's and video servers.

Our attempts to do this has been by inputting our "raw" (camera for example) HDMI source into various brands of HDMI distribution amps and/or conversion to UTP "boxes", converting into a Cat/UTP transport, and DISTANCE delivering (50'-300') throughout a building. However, using this method, when over three displays are connected and turned on, the system goes dark. I assume this is due to HDCP keys rejecting the multiple flows (thanks Hollywood).

An HDMI to YUV conversion is obviously analog...but may be all there is...and if the gear is HDCP compliant the issues may persist.

Any PROVEN system architectures are appreciated.

NOTE: Proven means the supplier/manufacturer has actually done the system design and proofed it - I have encountered several who have NOT and they have been surprised at their equipment failure! Embarrassing and expensive….

Thank you

FiberOpticDude
12-09-08, 04:11 PM
HWL,

Sorry, HDMI over CAT5 + 300ft = trouble. The issue is that the uncompressed bandwidth of HDMI makes transmission over CAT5 very difficult. At the highest data-rates, anything over 120ft isn't very likely even with the absolute best equalization and Clock and Data Recovery. There are the issues of loss, crosstalk, and skew. If the HDMI signals were compressed via JPEG2000 or something similar, then 300ft over CAT5 should be possible but I don't know of anyone doing that.

The only solution I can think of is to convert to analog and use either Extron or Magenta Research CAT5 Matrix switches.