HDMI protocol.

Anyone understand HDMI protocol and can explain it? Here's the problem.

Want to be able to view the HD PVR on the TV in the kitchen as well as on the TV beside it.

Have an HDMI splitter amp - active - for the job. 1 input, two outputs.

If I plug the outputs of the splitter into HDMI 1 on both TVs, the set in the kitchen sort of sees the signal and tries to connect, but doesn't and says 'no signal'.

If I plug the splitter output into HDMI 2 on the kitchen set it now works.

So far, so good.

Except that if I bring the PVR out of standby so it selects itself on the main TV, it selects HDMI 2. While being plugged into HDMI 1. So you have to select HDMI 1 manually.

No deal breaker - just annoying.

So it would seem the kitchen set is telling things the signal is on HDMI 2

- even when on standby.

I've tried every possible combination of powering things down fully, and switching on in different sequences. To no avail. The HDMI splitter is powered down when not in use. And have swapped its outputs over.

Reply to
Dave Plowman (News)
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The source reads the capability of the display, and sends a signal which matches it. If your two displays have different capabilities, I'm not sure this will work. It might work if you plug in the lower spec display first, and hope the signal format is also acceptable to the higher spec display.

Reply to
Andrew Gabriel

They are both full HD sets, and seem to both display HD at the same time happily. Or SD, if the PVR has recorded that.

Reply to
Dave Plowman (News)

When all else fails, use analogue. I always convert to UHF with a modulator, that way I can view anything anywhere in the house. For local use, composite works well.

Reply to
Capitol

Words fail me.

Reply to
Dave Plowman (News)

Perhaps its got something to do with the protection against using it to record on other devices that gets it all muddled up. Having tried to figure it out for a friend, I gave up in the end. Another case of improving things worse. Brian

Reply to
Brian-Gaff

And we all thought Scart was Weird being designed by the French. Who d3esigned hdmi?

Brian

Reply to
Brian-Gaff

I did have RGB SCART doing the same thing with the old TVs and old PVR, using a home made RGB DA. But SCART won't do HD.

Reply to
Dave Plowman (News)

It may be reliable, but is akin to listening to quality music down the telephone.

Reply to
Fredxxx

Can you even buy a UHF modulator for DTTV?

And composite video never has been as good as RGB or component.

But audio isn't a good comparison. Analogue audio can be just as good as digital as regards routing round the house. Provided it is done correctly.

Reply to
Dave Plowman (News)

I think the comparisons between analogue audio of FM and HD digital audio and that of AM radio or telephone analogue audio is quite good.

Reply to
Fredxxx

There are various levels of HD. Can you check what the HD format is when one TV is connected or when both are connected?

HDMI, DVI and even the 15pin VESA/VGA connector have a DDC (Display Data Channel) which is an I2C variant. It is really only designed to communicate between a single Source and a single Sink. Therefore any passive splitting of this channel is going to be hit and miss, and depends on which sink spills its beans first, or most likely last.

I'm wondering when you switch to HDMI2 on the kitchen set, if this restarts the conversation to the Source. If you switch back again to HDMI1 on the kitchen set, does it still display the picture?

Reply to
Fredxxx

Both 1080p

But it's not a passive splitter. It's active - so probably best called a DA

I do have a VGA DA too. Very expensive it was in its day. And that would only work at basic VGA.

But this HDMI unit happily works at any display rate the PVR is chucking out - as to both TVs.

Re-plugging to HDMI 1 with the system running gives the same result - the kitchen TV says 'connecting', then 'no signal' While it's doing this the output to the main set from the PVR (or DA) is blanked, then comes back when it says 'no signal'

Reply to
Dave Plowman (News)

AM radio wasn't even mentioned.

And even I wouldn't agree that the difference between decent composite video and good digital is anywhere near the difference between decent audio and telephone quality.

Reply to
Dave Plowman (News)

I guess that depends on your eyesight and the viewing angle vs your hearing ability.

I have to wear glasses to appreciate HD over composite video, but the difference is quite stunning. Similarly the 3kHz bandwidth with a compander on my telephone doesn't compare with an FM broadcast.

YMMV

Reply to
Fredxxx

What frequenc(y/ies)? If you set the source to a lower standard, does the same happen?

I appreciate the high-speed serial links will be repeated to both sets of differential signalling pairs; but the DDC pins are more esoteric due to their bi-directional nature. They can sometimes be simply wire-or'd together.

Shame you can't simply disconnect the DDC pins and let the kitchen set piggy back the other!

What happens to the other set's picture? Does that picture change during plugging in HDMI1 on the kitchen set. (I presume that might be awkward as the sets are in different rooms!)

Reply to
Fredxxx

The film industry to reduce piracy. HDMI gives considerable digital distortions as it is encoding and decoding the signal. It is another example of lack of bandwidth produces a crap result. As most TV/film signals now are heavily degraded in bandwidth terms (& colour/brightness range) HD is not really worthwhile. There are numerous analysis on the web written by people who are expert on film technology which highlight the shortcomings of digital systems. As I can recall the days of being easily able to resolve a 6MHz bar on a TV, I know how standards have dropped.

Reply to
Capitol

Bandwidth on phone systems is normally not much better than

2.4KHz. Colour bandwidth was limited to 3.4MHz as I recall on the PAL system. I haven't looked to see how poor the digital bandwidth is.
Reply to
Capitol

I've already said both follow the output of the PVR when showing SD or HD. And it doesn't upscale.

Reply to
Dave Plowman (News)

Many analogue TVs wouldn't either. The sub carrier filter removed everything above it.

Reply to
Dave Plowman (News)

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