video bandwidth question - various cable types

[mitt]

Coax cable can carry HD video and audio, uses 1 conductor, and costs pennies per foot. 

Why do video components like dvd players, xbox, & htpcs use hdmi or dvi or component cables that cost dollars per foot, and are much more complex with up to 8 conductors?

mitt

[NAKID]

http://www.amazon.com/HDMI-Cable-2M-6-Feet/dp/B0002L5R78/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1238029197&sr=8-1

<$0.19 per foot....


I have these for my cable box to receiver, PS3 to receiver and receiver to LCD. They work great (which for HDMI means they work at all)...

[superjohn]

Because the signal over the coaxial cable (or phone line if you have FIOS or U-verse) is compressing the living shit out of your HD audio video before transmitting it and in some cases it's even buffered on top of that.

HDMI et al is uncompressed or minimally compressed audio/video from the player to your system.

[mitt]

http://www.amazon.com/HDMI-Cable-2M-6-Feet/dp/B0002L5R78/ref=pd_bbs_sr_1?ie=UTF8&s=electronics&qid=1238029197&sr=8-1

<$0.19 per foot....


I have these for my cable box to receiver, PS3 to receiver and receiver to LCD. They work great (which for HDMI means they work at all)...

not complaining about prices - more of an engineerd question.

[mitt]

Because the signal over the coaxial cable (or phone line if you have FIOS or U-verse) is compressing the living shit out of your HD audio video before transmitting it and in some cases it's even buffered on top of that.

HDMI et al is uncompressed or minimally compressed audio/video from the player to your system.

That is what I understand, but it seems like a waste to transmit uncompressed data until the last moment it is needed.  Imagine a rack of video components with only coax cables going to your TV.

And if the coax cable signal is so efficient, why isn't it uses as the format for dvd's and streaming.

It boggles my mind that you can receive off air, 1080i off $10 rabbit ears with coax cable, while a $40 480p dvd players needs at a $10 cable to feed data to the TV.


mitt

[DoubleEagle]

Cable TV has to be constantly amplified the further it gets from the source until it reaches you.

Each time it is Amplified it adds  "noise " which gives an inferior end product to what can be pulled out of the air with an Antenna.    Dolph     

[redxblack]

HDMI also has architecture in the format to keep you from dubbing signals in-line. It's needlessly complex because the manufacturers do not trust you (or me).

[il d00d]

It is possible to use coax to transmit HD signaling to a display, it just isn't the cable of choice for the manufacturers.  Depending on who you talk to, DVI and especially HDMI was a standard pushed by the entertainment industry as a way to control content.
But the difference between the signal to your cable box, and the signal to your TV is your set top box is getting a compressed movie (a data file), the set top box is sending signals (instructions) on how to display it. 
It would be the same if you were streaming a show from Hulu to your PC - you are getting a stream of data in some video format over the internet,- let's say you connection to your provider was ethernet to your modem, and fiber to your provider.  Your PC gets this video info and decodes it.  Then, the DVI connection from your video card on your PC to your monitor transmits display info in the form of RGB, clocking, etc.  It would not be impossible to transmit RGB over ethernet, they just have not invented a display and an video card with ethernet connections.

[NAKID]

not complaining about prices - more of an engineerd question.

Well, going by those questions, it's clearly not an engineering question, it's all about greed. Obviously they can still sell those wires at that price and make a profit. It's other companies that charge more, saying their product is superior when in reality, HDMI is digital. It either works or it doesn't...