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Don't waste your money on high end digital cables - Page 4

post #46 of 53
Quote:
Originally Posted by gritzcolin View Post
Yes and he is absolutely right. Over the air pbs 1080i is going to look better than a 1080p blu-ray or hd-dvd because it is uncompressed (or nearly) the bandwidth each station has is unreal. Now goin through cable or satellite the BRD or HDDVD is gonna win cause the compression is usually lower.
What?! I am very very sure over the air it is still using a lossy encoding scheme. Plus, it is 1080i, half of the picture information is missing.

Some research turned up this:
Quote:
In the US, HD is broadcast over the air in a 6MHz wide channel at
between 19-20 Mbps (3 bits/symbol). However, that 20 Mbps stream can
be divvied up in lots of ways: 1 really HD channel, 5 SD channels, 2
SD channels plus a medium rate HD channel...

Compressed digital video that is intended for further editing is also
compressed differently, because the "broadcast" compressions tend to
have unsuitable artifacts in the editing process. Squeezing a raw
data rate of >1 Gbps down into 20 Mbps or so always entails some
compromises, and the broadcast compressions are designed to allow
inexpensive decoders (and expensive encoders..you'll be making
millions of decoders and dozens of encoders) and for artifacts that
are visually unobjectionable to an end user.
So unless he was talking about editing video before it's encoded he is lying.
post #47 of 53
Thread Starter 
Quote:
Originally Posted by Dr. Strangelove View Post
So... you are telling me that your 1080 interlaced picture using (probably) Mpeg 2 compression with bit-rates spec'd for transmission is better than a H.264/VC-1 non-interlaced picture stored on a disc with high bit-rates?

Aside from uncompressed, master print, or studio HD transfer, I highly doubt anything looks better than what comes out of my HD-DVD drive. Btw, I thought they used SDI cable in the broadcast industry? HDMI is a connect for consumer electronics.
Allow me to clarify some more.

The HD signal I look at at work is a direct feed from the SDI output of the CCU's (Camera control units) It runs at 4:2:2 color sampling (not sure about the bit-rate). It is routed through a SDI video switcher, so the signal path goes - CCU->Switcher->Sony HD LCD monitor.

FYI "SDI" is a digital video standard, typically transmitted through standard digital coax cable.

HD-DVD is compressed. Actually I was just at Fry's with my brother and we stopped to look at one of those Blu-Ray demo displays and the amount of compression artifacts in the picture was very obvious.
post #48 of 53
Thread Starter 
Quote:
Originally Posted by Dr. Strangelove View Post
What?! I am very very sure over the air it is still using a lossy encoding scheme. Plus, it is 1080i, half of the picture information is missing.
1080i does not mean half of the picture data is missing. It simply means all 1080 lines are not simultaneously displayed. Odd scan lines - Even Scan lines - Odd scan lines....etc. One frame of 1080p contains 1080 scanlines. One field of 1080i contains 540 (I think) It takes two interlaced fields to make up one frame.

And yes, the HD signal you can pick up off the air with a TV antenna is superior to what the cable company or DirecTV delivers.
post #49 of 53
Quote:
Originally Posted by simpleworld View Post
1080i does not mean half of the picture data is missing. It simply means all 1080 lines are not simultaneously displayed. Odd scan lines - Even Scan lines - Odd scan lines....etc. One frame of 1080p contains 1080 scanlines. One field of 1080i contains 540 (I think) It takes two interlaced fields to make up one frame.
I know what interlaced is, but I was under the impression that when use in the context of broadcast, a field was dropped.

Quote:
Originally Posted by simpleworld View Post
FYI "SDI" is a digital video standard, typically transmitted through standard digital coax cable.
Mmhm, I know (which is why it's preferred over HDMI).

Quote:
Originally Posted by simpleworld View Post
HD-DVD is compressed. Actually I was just at Fry's with my brother and we stopped to look at one of those Blu-Ray demo displays and the amount of compression artifacts in the picture was very obvious.
I realise that (Hence the mentioning VC-1 and H.264).

Actually, some Blu-Ray discs use the Mpeg 2 codec, which when compared to H.264 and VC1 does not look as good.
post #50 of 53
Thread Starter 
Quote:
Originally Posted by Dr. Strangelove View Post
I know what interlaced is, but I was under the impression that when use in the context of broadcast, a field was dropped.
Nothing is dropped.

Interlaced = Fields displayed sequentially
Progressive = Fields displayed simultaneously
post #51 of 53
I've been listening the the audiofile view on cables for decades and it just makes me laugh. How many people have been taken for a ride by manufacturers for how many years?

Here are the simple facts with regard to digital audio cable: Provided the cable is of decent quality and can pass digital audio without dropping bits of data and incurring excessive error correction there is not and cannot be a difference from one cable to another, end of story!! The digital audio cable is just transmitting a series of 0s and 1s. Eventually this data is passed through a digital to analogue converter (DAC). Provided the DAC can tell the difference between a 0 and a 1, the actual quality of the 0 or 1 is completely irrelevant to and has no effect whatsoever on the audio quality output by the DAC. If there are people who can tell a difference, it's them that require a neurologist, not you needing new cable. Last time, there is not and cannot be a difference!

Analogue cable: All the commercial recording studios I've ever worked or been in around the world use high quality cable, usually from Klotz or Van Damme, it usually costs around 4 dollars a meter (or less!). If someone is trying to convince you to buy fantasitc cable for substantially more than this, laugh at them! If it's good enough for the multi-million dollar systems in Abbey Road and the Hit Factory, it's certainly good enough for your home!!

Gold connectors look pretty. If you want to spend the money for it to look pretty, go for it but if you think it's going to sound better, forget it. Again, I've never seen gold connectors used in any commercial studio, the connectors of choice for the professional are made by Neutrik and should, for example, cost about 3 dollars for an XLR.

Gregorio
post #52 of 53
what is 1 and what is 0? is 1 really 1.95v, 1.89v, or 1.76v? and is 0 0.2v, 0.1563v, 0.3v or some other value? Does 1 stay the same over time or does it drift around and overshoots, and undershoots, and rings?

Does that look like digital or analog?

think about it.
post #53 of 53
Quote:
Originally Posted by chesebert View Post
what is 1 and what is 0? is 1 really 1.95v, 1.89v, or 1.76v? and is 0 0.2v, 0.1563v, 0.3v or some other value? Does 1 stay the same over time or does it drift around and overshoots, and undershoots, and rings?

Does that look like digital or analog?

think about it.
It doesn't matter if it overshoots, undershoots or whatever, provided it can still be identified as a 1 or a 0. Therefore, 0s or 1s can have a whole range of identifiable values. For example, it makes no difference whatsoever to audio quality whether it's 0.7 or 1.4, because the value will be interpreted as a 1. Furthermore, it doesn't even matter if the odd bit of data can't be interpreted as a 0 or a 1, as error correction is usually pretty perfect until it has to extrapolate too many errors and then it usually falls over and the DAC plays all 16bits set to 1 (digital distortion).

Therefore, even relatively serious signal degredation can have absolutely no effect whatsoever on the audio quality output by the DAC. In other words, any reasonable (and even the vast majority of cheap) quality digital cable is going to perform identically to the most expensive cable on the planet when you measure the output of the DAC. In fact, this feature of digital audio is the whole reason why digital audio was invented in the first place!

Gregorio
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