Jump to content



Sign up for a free account to remove the pop-up ads

Signing up for an account is fast and free. As a member you can join in the conversation, enter contests and remove the pop-up ads that guests get. Click here to create your free account.

Photo
- - - - -

How to switch HDMI?


This topic has been archived. This means that you cannot reply to this topic.
17 replies to this topic

#1 of 18 OFFLINE   Jeremy:::

Jeremy:::

    Auditioning



  • 12 posts
  • Join Date: Feb 24 2005

Posted February 28 2005 - 04:03 PM

I have on order an Onkyo TX-SR702 receiver and a Denon DVD-2910 DVD Player. The receiver won't accept the HDMI input from the DVD player, so should I run the DVD's HDMI directy into the TV? What am I sacrificing if I do this?

This seems like a tricky time to buy a receiver.

Thanks,

Jeremy

#2 of 18 OFFLINE   ChrisWiggles

ChrisWiggles

    Producer



  • 4,791 posts
  • Join Date: Aug 19 2002

Posted February 28 2005 - 05:06 PM

Running video directly to the display is always preferred. Running it through any kind of switcher is a compromise for convenience, all you are losing is convenience. In most cases, using a switcher won't cause any visible harm to the picture, but it will never do any good, and as such it's best to run straight to the display unless convenience issues come into play.

#3 of 18 OFFLINE   JeremyErwin

JeremyErwin

    Producer



  • 3,219 posts
  • Join Date: Feb 11 2001

Posted February 28 2005 - 05:15 PM

The HDMI output can carry multiple channels of digital audio-- so if you had a receiver that supported hdmi, you might be able to avoid a digital to analogue conversion. But the Denon can not send SACD or even CPPM protected DVD-Audio through HDMI. (see manual for details). Isn't copy protection fun?

So, you won't be missing much (except perhaps switching) if you run a hdmi cable directly between your player and the tv.

#4 of 18 OFFLINE   ChrisWiggles

ChrisWiggles

    Producer



  • 4,791 posts
  • Join Date: Aug 19 2002

Posted February 28 2005 - 05:19 PM

you make a good point, I always think video stuff first, I kinda forgot that HDMI can do audio first, in which case that could be a benefit, but he'd still need to get a whole new receiver, and there wouldn't be any sonic benefit over SPDIF.

#5 of 18 OFFLINE   Jeremy:::

Jeremy:::

    Auditioning



  • 12 posts
  • Join Date: Feb 24 2005

Posted February 28 2005 - 05:34 PM

It seems like a pain in the butt to have to get up and jack around with cables in order to switch between dvd and dish. I may just have to upgrade my receiver in a couple of years when reasonably priced models have 2-3 HDMI inputs.

Jeremy

#6 of 18 OFFLINE   Pat Frank

Pat Frank

    Stunt Coordinator



  • 176 posts
  • Join Date: Sep 05 2000

Posted March 01 2005 - 03:25 AM

If HDMI is digital, why would it be degraded by switching? Bits are bits....
"We're gonna need a bigger screen..."

#7 of 18 OFFLINE   JeremyErwin

JeremyErwin

    Producer



  • 3,219 posts
  • Join Date: Feb 11 2001

Posted March 01 2005 - 04:24 AM

After reading the manuals of various high-end dvd players, I've come to the conclusion that if you wanted a high resolution digital output for SACD/DVD-Audio, your only option is IEEE 1394/iLink/Firewire. And even then, you'd have to be especially careful to select compatible dvd players and receivers/prepros.

HDMI does, in theory, support high resolution audio (up to eight 192 KHz streams, iirc). I don't know if it supports Direct Stream Digital. But, at present, dts, ac3, and 48Khz stereo are pretty much the only audio formats carried by hdmi.

#8 of 18 OFFLINE   ChrisWiggles

ChrisWiggles

    Producer



  • 4,791 posts
  • Join Date: Aug 19 2002

Posted March 01 2005 - 04:54 AM

Quote:
If HDMI is digital, why would it be degraded by switching? Bits are bits....
It's also a lot of bits, and if they are all getting there, then you're good to go. When it comes to video, there are definitely limits on length and quality for DVI/HDMI that are visible as reported by quite a few pros. As long as all the bits are getting there you are right, but unfortunately this isn't always the case. In any case, there will never be an *improvement* in quality by using a switcher. The best you can hope for is the equivalent quality, and this is hard to achieve in the analog world. With digital, yes it's easier, but again, if there is any effects that will happen by using a switcher, they will be negative.

#9 of 18 OFFLINE   JeremyErwin

JeremyErwin

    Producer



  • 3,219 posts
  • Join Date: Feb 11 2001

Posted March 01 2005 - 05:01 AM

Does anyone know if HDCP DVI-D and HDMI use the same key exchange algorithm?

#10 of 18 OFFLINE   ChrisWiggles

ChrisWiggles

    Producer



  • 4,791 posts
  • Join Date: Aug 19 2002

Posted March 01 2005 - 05:13 AM

I believe they do, they are really kinda the same thing, except HDMI has more capability for YCbCr in addition to RGB, and audio.

#11 of 18 OFFLINE   JeremyErwin

JeremyErwin

    Producer



  • 3,219 posts
  • Join Date: Feb 11 2001

Posted March 01 2005 - 10:11 AM

It has been claimed, in reputable academic journals, that the master key for hdcp can be recovered, assuming one has access to on the order of 40 hdcp displays and some computational power. This is because the key exchange protocol used in hdcp is fundamentally flawed. The master keys themselves have not been published, yet. (iirc)

HDMI might introduce enough complications to make the cryptoanalyst's task more difficult, while retaining some backwards compatibility with DVI. The added feature (high definition digital audio) might just be a marketing promise, designed to sell yet another connector.

#12 of 18 OFFLINE   AaronMan

AaronMan

    Second Unit



  • 286 posts
  • Join Date: Jan 20 2003
  • Real Name:Aaron

Posted March 01 2005 - 05:22 PM

What happened to IEEE 1394 firewire? I thought everything was heading that direction. I guess its used mostly with computers.

#13 of 18 OFFLINE   Pat Frank

Pat Frank

    Stunt Coordinator



  • 176 posts
  • Join Date: Sep 05 2000

Posted March 02 2005 - 03:48 AM

Quote:
As long as all the bits are getting there you are right, but unfortunately this isn't always the case.

But most data transmission in the digital world is handled on a lossless basis via the use of a simple process of packet acknowledgement and retransmission.

Is this not the case with HDMI?

Thanks to digital technology, I can transmit data without loss of information clear around the world using the Internet. Why should there be data loss in a digital transmission between my DVD player and my HDTV, just because a switch has been introduced? No, that's analog thinking. If a switch causes picture degradation in HDMI transmission, surely there has to be another factor involved.
"We're gonna need a bigger screen..."

#14 of 18 OFFLINE   ChrisWiggles

ChrisWiggles

    Producer



  • 4,791 posts
  • Join Date: Aug 19 2002

Posted March 02 2005 - 05:08 AM

The video guys I trust are very clear that some cheapie longer length DVI or HDMI cables introduce gilmmery artifacts to the picture, so that's my take on it.

#15 of 18 OFFLINE   David_Rivshin

David_Rivshin

    Second Unit



  • 352 posts
  • Join Date: Dec 13 2001

Posted March 03 2005 - 09:02 AM

Quote:
But most data transmission in the digital world is handled on a lossless basis via the use of a simple process of packet acknowledgement and retransmission.

Is this not the case with HDMI?
I would be quite surprised if HDMI had any form retry mechanism for video or audio data transfer. With real-time data there is rarely any point to retransmitting, because by the time you've retransmitted you're already past the point in time where you needed the data. With video and audio it's generally accepted that a small amount of data loss is acceptable from a users point of view, as they will rarely notice it. Another example would be most action oriented multiplayer games, were if player position data is not received in time (or at all) it is interpolated by the client until such time as a new value is received. This is why (non-guaranteed) UDP is often used in preference to (guaranteed) TCP. Of course if your data loss rate is too high you get very bad results.

The "shimmering" often noted is probably the result of losing some (alot of) video data, and the display having to make up some value to fill in the hole. If you lose one pixel every few seconds you'd probably never notice at a high enough resolution. Lose a few hundred pixels per frame and now it's unwatchable. In any event, it's not a very gradual loss of quality as with analog. If your cabling or switching is hurting you, you should know it almost immediately.

Disclaimer: I have no engineering knowledge of HDMI, so take my comments with a grain of salt. It's just educated guessing on my part at this point.

-- Dave

#16 of 18 OFFLINE   John Garcia

John Garcia

    Executive Producer



  • 11,552 posts
  • Join Date: Jun 24 1999
  • Real Name:John
  • LocationNorCal

Posted March 03 2005 - 09:22 AM

Do you have a fixed pixel display? If using a CRT display, you may not see a considerable improvement via HDMI. In either case, I'd say leave the HD box on HDMI and use component for the 2910.
HT: Emotiva UMC-200, Emotiva XPA-3, Carnegie Acoustics CSB-1s + CSC-1, GR Research A/V-1s, Epik Empire, Oppo BDP-105, PS4, PS3,URC R-50, APC-H10, Panamax 5100 Bluejeans Cable
System Two: Marantz PM7200, Pioneer FS52s, Panasonic BD79
(stolen) : Marantz SR-8300, GR Research A/V-2s, Sony SCD-222ES SACD, Panasonic BD-65, PS3 60G (250G)

Everybody is a genius, but if you judge a fish by its ability to climb a tree, it’ll spend its whole life believing that it is stupid.” – Albert Einstein

 


#17 of 18 OFFLINE   Jeremy:::

Jeremy:::

    Auditioning



  • 12 posts
  • Join Date: Feb 24 2005

Posted March 03 2005 - 10:24 AM

I don't have an HD Box. I was thinking of running the DVD-2910's HDMI output to the RPTV and running component from Dish Network (SD) to the RPTV.

#18 of 18 OFFLINE   John Garcia

John Garcia

    Executive Producer



  • 11,552 posts
  • Join Date: Jun 24 1999
  • Real Name:John
  • LocationNorCal

Posted March 03 2005 - 11:25 AM

If you don't have an HD box, then that's definitely what I would do.
HT: Emotiva UMC-200, Emotiva XPA-3, Carnegie Acoustics CSB-1s + CSC-1, GR Research A/V-1s, Epik Empire, Oppo BDP-105, PS4, PS3,URC R-50, APC-H10, Panamax 5100 Bluejeans Cable
System Two: Marantz PM7200, Pioneer FS52s, Panasonic BD79
(stolen) : Marantz SR-8300, GR Research A/V-2s, Sony SCD-222ES SACD, Panasonic BD-65, PS3 60G (250G)

Everybody is a genius, but if you judge a fish by its ability to climb a tree, it’ll spend its whole life believing that it is stupid.” – Albert Einstein

 






Forum Nav Content I Follow