HDMI cable behind wall?

[sfav8r]

Distance past 15' the signal degrades, and unless you are paying a premium for the cable you risk it not sync'ing, or the equipment deciding what the max data will go through it.

I noticed on the site you referenced they have HDMI cables up to 100' long. That seems a bit optimistic :grin:

 

[danickstr]

an hdmi end will fit through 1" flex. don't use two cat 5's, that will involve a balun set and they can be problematic.

check smurf 1" i think that will work too. just buy a hdmi or try it at store with a scrap. but I know they fit in 1" flex.

do not use component if AV guy spec'ced hdmi. no comparison. this is not a tough run.


btw it looks like a toilet goes in right under the tv..

 

[e57]

I noticed on the site you referenced they have HDMI cables up to 100' long. That seems a bit optimistic :grin:

I did not see any on the site I referanced (I don't think they sell their own product other than through a vendor. And they make 'baluns' It might be counter-intuitive for them to sell cables...) - but there are others who do. Most cables anywhere near that length would be with active boosters either with them or sold seperately. Doubtfull you would get any usable signal at that length otherwise. And the one I referanced makes 'Baluns' which is just another name for a convertor that swaps one signal or transmission format for another then back to the original on the other side. In this case over twisted pairs up to 150'...

There are others who claim 300' plus on cat-5 or fiber optic lines or combination of both up to a 1/4 mile.
http://www.gefen.com/kvm/cables/hdextenders.jsp#hdmi1000

http://www.gefen.com/kvm/product.jsp?prod_id=4504

 

[LarryFine]

I haven't read the entire thread, so I apologize if I repeat anyone else's contributions. In no particular order:

I have run a 50' HDMI cable that worked perfectly. Digital signals will work perfectly until they simply stop.

An analog signal loses signal voltage along a cable, whereas a digital signal loses nothing until it falls off.

There is nothing wrong with component (analog) video; it's just as hi-def as digital video (HDMI and DVI) is.

A balun is for changing between balanced (twisted pair) and unbalanced (shielded single conductor) cabling.

 

[danickstr]

Larry I have a point to consider. With most signals traveling (arriving) as digital, to convert them to analog just to use component and then convert them back to digital at the end of the run is making a copy of a copy. I have seen analog conversion engines introduce color issues of many sorts, and we would be putting the quality of the picture at the mercy of the conversion engines at either end, and usually the cable boxes are not known for their excellence in components. Keeping it digital until the TV presents it is going to make for the most true picture. The audio is a non issue for the most part, since most monitors' audio will not be used.

 

[stickboy1375]

I just dont get the hype with HDMI, maybe i'm missing something, but I thought it was only for HD-DVD and some up convert dvd players? I just dont get it:-?

 

[LarryFine]

Dan, I must confess that I come from the analog side of the tracks, as my HT uses a CRT projector. I only have to convert component to RGB-HV with a transcoder.

I also dislike the fact that the available resolution (and other parameters and DRM issues) can be controlled by the studios via digital connections.

I have DVD players that up-convert via the component outputs, which I'm sure you know has not been available for several years. I also have laser discs and players, analog video all.

I actually have no digital-video cabling in my system at all.


(Remember the good ol' days when 'analog' was spelled 'analogue', 'disk' was spelled 'disc', and 'cassette' was spelled '8-track'? :wink

 

[cadpoint]

Cool

Cool

Back to OP
Why is this silver connection stopped and started in mid air?
Why isn't this run to interface with the house Goodies on the right?

I don't know anything about anything electronic much less the high end stuff, to make a call. But, as usuall have learned alot about something for nothing, thanks...

 

[e57]

I have run a 50' HDMI cable that worked perfectly. Digital signals will work perfectly until they simply stop.

~

A balun is for changing between balanced (twisted pair) and unbalanced (shielded single conductor) cabling.

First off - lucky you on 50' HDMI is real time, and will not resend data packets from what I understand of the format - so if it misses from signal strength it will compensate by changing resolution. After showing a few sparkles of blank pixle like spots.

And yes - in the true sense of the word that is what a balun would be.

 

[dezwitinc]

Just for info, Arlington has a new rough in box that is recessed specifically for flat screens that allows all cabling to be hidden directly behind the TV.
Catalog#TVB613.
http://www.aifittings.com/whnew98.htm
It is deep enough that everything can plug in and the TV can still be flat against the wall.
A very handy product.
Unfortunately they don't have it on their website yet.
TV Box(TM) for LCD/Plasma TVs

TV Box(TM) for LCD/Plasma TVs

For New and Old Work - Organizes Power Outlets and Audio/Video/Data Connections - Easy Installation

 

[nvpowerdoc]

HDMI Standards

HDMI Standards

To quote "http://www.hdmi.org/learningcenter/faq.aspx":

"HDMI supports standard, enhanced, or high-definition video, plus multi-channel digital audio on a single cable. It transmits all ATSC HDTV standards and supports 8-channel, 192kHz, uncompressed digital audio and all currently-available compressed formats (such as Dolby Digital and DTS), HDMI 1.3 adds additional support for new lossless digital audio formats Dolby? TrueHD and DTS-HD Master Audio™ with bandwidth to spare to accommodate future enhancements and requirements."


One of the greatest advantages of Digital signals over Analog signals with regards to transmissions over long distances and losses due to those distances is the ability of CRC error checking. If all the 1's and 0's don't arrive the way they were sent, Cyclical Redundancy Coding embedded in data sent allows the receiver to "re-formulate" the original content. This is the TRUE BEAUTY of digital signals.

It is expected that Blu-ray HD content playback devices (DVD players that have 1080p or i output capability) will require a direct HDMI interface with a video display monitor (to maintain high resolution HD content). The main reason for this requirement is to thwart video piracy. How true this will remain will probably be driven by Sony (as they seem to drive a lot of these standards).

In terms of reproduction (of the source content), HDMI allows for the greatest control of how a signal can be sent and received, and those companies that chose to comply with HDMI must sign license agreements to use such. Once the signal has been converted to analog, the user is only able to make a 2nd generation copy (the TV Monitor is "Same Generation" as LCD and Plasma screens, which are digital right up to the moment the pixal color is derived at the screen matrix).

Sorry much of this is quite off-topic for an NEC forum, but the wrong information / mis-understanding of information was swirling in earlier posts.

 

[jerm]

offtopic

offtopic

probably be driven by Sony

Sony is pushing bluray because they (in a roundabout way) designed it and are on [can you say running] the BDA. They're about the only manu to be pushing it.

I'm sure it will take off and replace Every Other Format Known To Man, just like their previous ventures, BetaMax and MiniDisc. You do have a BetaMax player and a MiniDisc player, right?

We now return you to your regularly scheduled NEC forum.

 

[brantmacga]

Just for info, Arlington has a new rough in box that is recessed specifically for flat screens that allows all cabling to be hidden directly behind the TV.
Catalog#TVB613.
http://www.aifittings.com/whnew98.htm
It is deep enough that everything can plug in and the TV can still be flat against the wall.
A very handy product.
Unfortunately they don't have it on their website yet.
TV Box(TM) for LCD/Plasma TVs

TV Box(TM) for LCD/Plasma TVs

For New and Old Work - Organizes Power Outlets and Audio/Video/Data Connections - Easy Installation

leviton has one too that's been out for a couple of years. but its a square box w/ cut-outs for o/w boxes to be attached on three of the four sides. the arlington box has 4; one more never hurts.

 

[stickboy1375]

I'm sure it will take off and replace Every Other Format Known To Man, just like their previous ventures, BetaMax and MiniDisc. You do have a BetaMax player and a MiniDisc player, right?

At the time Betamax was a higher quailty product, you can thank the adult industry for using VHS over Beta...

 

[jerm]

At the time Betamax was a higher quailty product,

BetaSP is certainly better than VHS (there are a lot of broadcasters out there using it-- all the ones in the US who haven't paid for their HD upgrade yet...), so Beta as a format had a reasonable chance to succeed in the marketplace. BetaMax isn't BetaSP and is only marginally better than VHS-- but I'll give you that it is better. In any case, they priced themselves out of the marketplace. Regardless (or IRregardless, if you prefer!) Sony has proven that it doesn't know how to handle new tech, even if it may be superior for the time being.

 

[brantmacga]

did you guys know there is actually a d-vhs format? HD content and 5.1 surround on vhs, and 1080i resolution. i think it was jvc that put it out about 10 years ago. its the only way to record encrypted HD content.

 

[Rampage_Rick]

To quote "http://www.hdmi.org/learningcenter/faq.aspx":

One of the greatest advantages of Digital signals over Analog signals with regards to transmissions over long distances and losses due to those distances is the ability of CRC error checking. If all the 1's and 0's don't arrive the way they were sent, Cyclical Redundancy Coding embedded in data sent allows the receiver to "re-formulate" the original content. This is the TRUE BEAUTY of digital signals.

Sorry much of this is quite off-topic for an NEC forum, but the wrong information / mis-understanding of information was swirling in earlier posts.

Evidently whomever wrote that FAQ has a less than complete understanding of digital error detection/correction.

Firstly, a Cyclic Redundancy Check (CRC) doesn't allow the receiver to "re-formulate the original content". A CRC is only useful to tell you if the data has become corrupted along the way. It's even written there as "CRC error checking." If I sent you the numbers 3, 8, 17, 22, 55 I could also tell you that they should add up to 105. If they don't then some part of the message must have been garbled.

Error correction is possible for digital signals, the easiest method being parity bits. HDMI does in fact use parity bits at the physical layer to minimize TMDS transmission errors. Very similar to the method used between your hard drive and motherboard. (especially SCSI) However this error correction is minimal at best, which is why digital usually works or doesn't. It can correct a bit here and there, but once you reach a certain threshold it just hopeless.

Digital signals prone to data corruption employ more complicated error correction, and generally speaking more space is consumed by the error correction data. Lets take DishNetwork/ExpressVu for example, which average 20-30% error correction overhead:

Each transponder on an Echostar satellite uses a standard Symbol Rate of 20 MS/sec, which works out to 40 Mbit/sec using QPSK (8PSK used for HD uses an SR of 21.5 MS/sec which works out to 64.5 Mbits/sec)

So... given a raw data stream of 40 Mbits/sec, we subtract all the bandwidth required for Forward Error Correction. Originally they used an FEC of 3/4 (meaning 3/4 of the bandwidth was usuable) but in the quest to cram more channels in the available bandwidth, they've lowered the FEC to 5/6 and ExpressVu even had the balls to drop it to 7/8. (and people up here wonder why they have rain fade)

Next we have to subtract the bandwidth required for 188:204 Reed-Solomon error correction, so subtract 16/204.

Of that original 40 Mbit/sec we are left with...
27.647 Mbit/sec per transponder (FEC 3/4 SR 20.00 QPSK)
30.719 Mbit/sec per transponder (FEC 5/6 SR 20.00 QPSK)
32.255 Mbit/sec per transponder (FEC 7/8 SR 20.00 QPSK)

and of the 64.5 Mbit/sec we have:
39.637 Mbit/sec per transponder (FEC 2/3 SR 21.50 8PSK)

Now HDMI v1.3 is pumping 3400 Mbit/sec through each of three color channels. Do you think they want to waste 20-40% of their bandwidth on error correction?


What's the Matter with HDMI?

 

[nvpowerdoc]

Evidently whomever wrote that FAQ has a less than complete understanding of digital error detection/correction.]

Thanks for missing the point and killing the thread! Error detection and correction exists in practically every application of digital signal transmission. My example of CRC error correction was used merely as a term most people are familiar with (even though, true, it is not what is used with HDMI). That wasn't the point.

The point of the entire thread has been about why everyone has to deal with the HDMI (connector and wiring) standard. Blu-ray and the HDMI interface standard is being backed by proprietors of DRM (digital rights management). If you want to playback your blu-ray disk at its highest resolution, then you'll need an HDMI compatible monitor (LCD / PLasma screen, or whatever you want to call it). HD doesn't require this, but Blu-ray does - and there are many more companies jumping on the HDMI band-wagon (just this week Warner Brother's decided to back blu-ray). Disney is another big name. In other words, try to find a recording device with an HDMI "IN". The purpose of the HDMI cable is to secure a dialogue between the source and the display which is required for decrypting the copy-protected material. If the HDCP information isn't transmitted, the device won't deliver a signal. Various cables have been tested, and it has been shown that if the signal voltage level drops to 0.32 to 0.29Volts (from 1.0V), then in fact you will lose your signal.

As you mention, error correction methods such as QPSK coupled with traditional Reed Solomon and Viterbi codes have been used for over 20 years (in DBS). And as you mention, other modulation schemes such as 8PSK, 16QAM and 32QAM have also increased signal transmission efficiency, further enabling transmission of the HD format. Again, this wasn't the point of this thread.

 

[Rampage_Rick]

My apologies...

However, don't get me started on DRM

 

[dbuckley]

and there are many more companies jumping on the HDMI band-wagon ... The purpose of the HDMI cable is to secure a dialogue between the source and the display which is required for decrypting the copy-protected material. If the HDCP information isn't transmitted, the device won't deliver a signal.

Yep, Microsoft are on the bandwagon big time, which impacts all the convesionist devices. As are some of the satellite broadcasters. Whereas HDMI won't (at the mo) deliver a better signal then separate coaxes, in the not to distant future that will change.

Expect to see more HDMI.