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Posted By: shaned HDMI - 07/25/05 03:17 PM
Hello. I was wondering someone could explain to me the value of HDMI? If you run HDMI from your STB to your TV, you then have to run a line to your amp for processing. Isn't just another obstacle for the music/sound?
Same with HDMI from a DVD player to the TV. Isn't it always better to run as direct as possible?
I certainly can understand DVI, but not HDMI. Unless you do not have a receiver, what would be the value of combining the video and audio? And then having to route it again?
Or, if you ran it to your receiver you would then have to send your video to your TV?
I really don't understand the value. Could someone be kind enough to explain it?
Thank you!

Shane D
Posted By: ratpack Re: HDMI - 07/25/05 03:22 PM
Here is an article on HDMI which may answer some of your questions;

HDMI

I think that the bottom line is that HDMI is supposed to be a high speed, multi-channel, link for both video and audio signals.

Hope that this helps.
Posted By: shaned Re: HDMI - 07/25/05 04:06 PM
Thanks for the link Rat. I certainly see the value for video, much as with DVI. However, unless there is a separate line to go direct to the receiver, won't the TV resending the signal compromise audio quality? Doesn't it have to by virtue of being a filter?

Still don't really get the whole value for home theatre, unless there is a direct audio line.

Shane D (trying not to appear TOO dense)
Posted By: Ajax Re: HDMI - 07/25/05 05:57 PM
I think the advantage will come when we start to see receivers that can handle HDMI video/audio switching.

Assuming your TV, and all your sources are HDMI capable, it will only take one cable, each, from your DVD and Cable/Sat box to the receiver, and another from your receiver to your TV for both audio and video As it is now, we must run separate audio and video cables to and from the above mentioned equipment.

If you wish to send all your video directly to the TV, bypassing the receiver, this advantage will be negated, as you'll still be running separate video cables from each source to the TV or a switch, and separate audio cables to the receiver.
Posted By: ratpack Re: HDMI - 07/25/05 06:48 PM
Well, I have a little different "spin" on the situation. I think that all the HDMI inputs need to go to the HDTV first, not the HT receiver. Why? The easiest place to fix/ compensate/ adjust the lip sync/ video delay problems that we are starting to see with HDTVs is in the TV itself. The HDTV "knows" how long it is going to take to upconvert or whatever, and can lock the audio to the video frame to frame. Let the TV do all of its magic and then send the audio over to the receiver through either a HDMI or optical cable. Long term, probably better to do it with a HDMI cable.
Posted By: INANE Re: HDMI - 07/25/05 08:57 PM
In reply to:


Well, I have a little different "spin" on the situation. I think that all the HDMI inputs need to go to the HDTV first, not the HT receiver. Why? The easiest place to fix/ compensate/ adjust the lip sync/ video delay problems that we are starting to see with HDTVs is in the TV itself. The HDTV "knows" how long it is going to take to upconvert or whatever, and can lock the audio to the video frame to frame. Let the TV do all of its magic and then send the audio over to the receiver through either a HDMI or optical cable. Long term, probably better to do it with a HDMI cable.




I'd agree except I don't want my TV (HD) doing any of the conversions, which is why I've gone the route of doing everything in a HTPC, send the audio to the AVR and video to the TV.

So no HDMI doesn't get me much, cept I'd love to see the industry settle down with one nice connector/cable so the price will drop. There is no real reason to have DVI since HDMI is bascially the video portion of DVI with audio added (even if I'm not using it, one standard cable). Now if computer manufactures would switch to HDMI (not likely anytime soon).

Plus its a nice small cable with a nice small connector.
Posted By: shaned Re: HDMI - 07/25/05 09:15 PM
So, you don't think that there is any audio degradation by feeding through the TV and back out to the receiver?

I just have a hard time believing that going through a "filter" will not have some impact. I must be wrong I guess because HDMI seems to be the future.

Shane D
Posted By: hashts Re: HDMI - 07/25/05 09:33 PM
Well if the entire signal is in digital format then passing through any number of hops/filters should have no effect on the signal itself. Now analog on the other hand might be prone to interference passing through devices but digital makes it much easier to transfer the signal.
Posted By: ratpack Re: HDMI - 07/26/05 03:03 AM
Why do you think that the audio will go through a "filter?"

What you really want is the audio to be "locked" to the video, frame to frame, so there is no noticable delay between the audio and video.
Posted By: shaned Re: HDMI - 07/26/05 03:08 PM
My take is that you are sending the signal to a TV. It is then resent to the receiver. Don't you think that there would be at least some degradation of the signal? Or would it be so miniscule that nobody could notice a difference?

Shane D
Posted By: shaned Re: HDMI - 07/26/05 03:16 PM
So, being a digital signal, it will not degrade? If that is true, then it makes sense. Does the TV have to have any certain capabilities to ensure function, or is the signal just passed on without any processing?

Shane D
Posted By: Ken.C Re: HDMI - 07/26/05 03:31 PM
Lord knows, if we can make computer cables and switches and such that don't have any trouble passing a digital signal, a TV shouldn't be a problem, not with 12 feet of cable or so. As for your second question, dunno. I would think that it would pass through without processing, but since nothing is really doing this yet (to my knowledge) your guess is as good as mine.
Posted By: hashts Re: HDMI - 07/26/05 08:20 PM
I'm 99% sure that the tv in no way should ever modify the digital signal. If it did, then it would require decoding/encoding chips. I haven't heard of any TVs which actually decodes signals.

I think this is quite analogous to most (not all) dvd players that simply pass along the DTS/Dolby Digital signal. The receivers do the actual processing of the signals, but some high-end dvd players (denon) perform the decoding themselves.
Posted By: ratpack Re: HDMI - 07/27/05 03:28 AM
The new HD TVs have lots and lots of processing. You want to lock the audio stream to the video stream, frame to frame, so that you don't get the dreaded lip sync.

A digital signal should exhibit little if any degradation going through the TV to the audio receiver.
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