[mythtv-users] One HDMI question from (Hijacked): HDMI sound issues

[Raymond Wagner]

On Aug 28, 2013, at 10:56, Stephen Worthington <stephen_agent at jsw.gen.nz> wrote:

> On Wed, 28 Aug 2013 06:44:31 -0400, you wrote:
> 
>> On Aug 28, 2013, at 4:37, Stephen Worthington <stephen_agent at jsw.gen.nz> wrote:
> 
>>> HDMI signals were never supposed to work over long distances - that
>>> was never part of their design.  If you want a really long HDMI cable,
>>> it will need one or more regenerators in the cable (and power for them
>>> to work from), or it will need to convert the HDMI signal to something
>>> else (eg ethernet) that will travel over a longer distance, and then
>>> be reconverted to HDMI at the other end.
>> 
>> That's not Ethernet, it's still HDMI. All they're doing is discarding the grounds, and retransmitting the remaining lines at much higher power levels over the 16 (much thicker) conductors of two CAT6 cables.
> 
> Is that how those cables do it?  In which case, they are selling
> products with false descriptions (something that is illegal under New
> Zealand's Fair Trading Act).  Something described as "HDMI over
> ethernet" should be using ethernet signaling and protocols.  So those
> cables should be described as "HDMI over dual CAT6".  If the power
> levels they are using are dangerous to real ethernet devices, that
> sounds like a recipe for killing ethernet devices that get plugged
> into the wrong RJ-45 socket.

If they were ethernet, they would be running 1Gbit, and have insufficient bandwidth in the pair to handle HDMI, or would be running 10Gbit, either be limited to short ranges or require higher grade wiring, and would only need one wire.