What Are The Differences In Lines Of Resolution Between Broadcasted And Recorded Video Sources?

Power is down all around me but mine is still up more or less. When charlie came near by my powerline went down so I think when they repaired it they strengthened it. The storms is just hanging to the east and I'm waiting for it to hit and I'm hoping it will get down graded. I'm not checking spelling don't have time. Be back later.

 

A bit rushed but considering how many times my power has been out today, I'm lucky to have finished anything.

First let me start by conceding that non HD Digital TV is capable of 480i by 480p lines of resolution which is the limit of standard TV, and provided these capabilities are in use, it’s as good as one can expect outside of HDTV.

To access DTV’s resolution the TV/PC tuner, must be connected through a high quality connector such as component connectors for optimum quality or S-Video connectors which are still almost as good but limited to 400 lines of resolution. Super VHS is also capable of 400 lines, so if we’re comparing DTV cable against VHS quality, then SVHS can’t be excluded and Donald’s original allegation still stands.


Like Vurbal, I was unable to discover the actual picture quality produced by DTV (and it does seem to be a well guarded secret) and so I’m still conceding to its maximum potential. Because it is an on air captured signal it is as are all such signals, subject to the defects that standard radio is such as bad weather and atmospheric conditions. It‘s reasonable to assume that the ultimate quality of such a transmission will therefore vary in quality (I verified this while surfing for info) based on location and other environmental conditions.

This however was not the substance of Donald’s statement regarding picture quality which was in regards to a recording made on an ATI all in wonder tuner. Even if this tuner or any other equivalent capture device was connected to a DTV signal it would still be limited by its design and have to be connected by either an S-Video or component input to realize anything better than an antenna pickup, a composite patch, or a standard RF cable connection.

Although PC tuners have the software capability to reproduce 720 by 480 lines, unless it has HD capabilities it’s only capable of receiving 330 lines by antenna with an optimal transmission and reception. But rarely are antennas optimal and at their very best they produce about a 24% line increase over VHS quality (yes I did the math).

I don’t recall anyone stating that all SDTV captures were no better, only that they are in general no better than VHS and in all my statements I gave them a slightly better to marginal superiority over VHS. I only included S-VHS because Vurbal included DTV. I think that I’ve proved that it depends on which VHS format and cable format we’re referring too. If we can leap from standard cable to DTV while still maintaining that cable is cable then it’s only fair that we do the same and make a leap to S-VHS and maintain that VHS is still just VHS.


All this and still shorter than Vurbal.


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Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." Sherlock Holmes (by Sir Arthur Conan Doyle, 1859-1930)[/small]

 

He's alive!

Good morning Sophocles. Are things slowing down at all.
It still looks like your covered by the storm.

Your post would indicate that you believe that in general a TV signal capture would yield little improvement over a VCR tape.
I would agree.

 

I'm fine but the winds still blowing and it's causing the branches of a tree to blow against the power line in my neighbors yard. It sonds like a fireworks display and sparks are flying everywhere. I called the power company but they're too busy with more important issues.

 

Don't try to fix the tree yourself.
Not that you would but some people around here have done so with dire consequences. Just keep an eye out for fires.
I don't want you to loose your house.

 

@Vurbal

Things are fine but I'll be glad when it's over.

I only included S-VHS in my response because you included DTV but neither were really a part of the original debate.

I’ve done lots of captures of home movies (about 30 or so) and numerous recordings of Star Trek and other TV shows. I have a Hauppauge Win PVR 350 which has a hardware encoder and a WinFast pro XP 2000.

S-Video input allows for a separation of the Chrominance and Luminance and thus results in a better picture quality, a component connection is very close to that of an RGB connection in that two of the lines carry the chrominance and 1 the luminance (providing I remember correctly}. If you are taking a signal from a DTV receiver, in order to get the quality the signal has to be fed by either S-Video or component to benefit from it. A composite or and RF connection fully optimized, will only be slightly better than a standard VHS HQ signal. In other words, you can't make a racing horse out of a jackass. The same principle with ripping a CD to MP3 128K, you can encode it to 196K or even to wav 1410 but it can’t put back what was taken out.

_X_X_X_X_X_[small]

Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." Sherlock Holmes (by Sir Arthur Conan Doyle, 1859-1930)[/small]

 

Vurbal,
I have no doubt that your experiences yeilded the poorer results from VHS but you are taking the worst of the video tape world and comparing to the best available tv signal.

If you had the best source on the best video tape against CBS over rabbit ears then you can get different results.

My only contention was that the average tv signal over the air I don't believe is any better than VCR quality, extreme cases not withstanding.
I'm not saying VHS is better than TV. Just tv is not that great overall.

 

Vurbal

good luck with your PC.


I don't think there's any point in continuing the debate and I'm definitely not in the mood to count chrominance pixels in a given line. The difference is largely due to the lack of the actual lines themselves. All I’m saying is that the signal will be no better than its source regardless of the recording capacity or capabilities of your capture card. If your capture card is connected to your DTV receiver by either S-Video or component then you are able to record a high quality picture but if it’s connected by a composite or RF cable then the input will be seriously downgraded.

 

My experience matches yours.

 

I also agree with that but then I've only captured from Hi8 and Betmax. I still have two SuperBeta hifis which I treasure. You will remeber that I conceded that standard cable produced a marginally better picture than VHS.

jdobbs

Seems I was lucky since I'm still able to get online. In the county I live in(Hillsborough), 66% of the population lost power, so I'm among the fortunte 34%. I'll still give those battery backups a consideration.
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Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." Sherlock Holmes (by Sir Arthur Conan Doyle, 1859-1930)[/small]

 

Well I could debate the "marginally" -- but this horse is as dead as it gets.

Glad you kept the power up... still getting rain? I listen to the news and start thinking of Bill Cosby: "Noah... how long can you tread water?"

 

jdobbs

Let me second that.

What's odd is that my neighbor's lost their power lines in fact two of them are in my back yard right nest to my pool.

I like Bill Cosby too and the joke was well placed. I've been sleeping in 3 hour spurts since Friday so that I can keep an eye on my family. I'm not as lucid as I'd like to be but outside the continued rain things are good.

I've made my wife a little nervous because to kill time in the "wee hours of the morning" I decided to check out Ebay. I'm bidding on a copy of Adobe Premier Pro 1.5.
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Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." Sherlock Holmes (by Sir Arthur Conan Doyle, 1859-1930)[/small]

 

My understanding is one line of tv signal is analog with no discete countable pieces of information like a digitital signal. Although I imagine you can attempt to segment the analog lines into the pixels on a screen. But this could hardly be considered effective resolution.
The Chroma you describe while it is possible to modify the quality or the picture to some degree is reletively limited in effect.

It has been some time since my studies in this area but the color aspect of the tv signal has always been more of an afterthought and very limited in scope until the higher definition standards came out.
Even when NTSC was created it was considered limited and subject to change as technology permitted.

I haven't kept up on all the advances so I can't keep up with all the ins and outs of our discussion but other than HDtv I know of no real quality improvements to the tv signal since color was added to the signal.
_X_X_X_X_X_[small]Donald

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That's why a broadcast signal is measured in "horizontal lines of resolution" -- because there truly are no pixels in an analog signal. Of course a standard CRT based TV does have the equivalent of pixels in phosphor dots.

Horizontal lines of resolution lets you know how many side-by-side black-and-white lines can be distinguished as such before they dissolve into gray mush.

 

Hey guys!

My thoughts are that this thread should be used for the off topic discussions we sometimes pollute an on topic thread with. I think we need a place to share ideas and blow off steam. It should have been started in "Safety Zone," but I see no reason why that's important. Sometimes the off topic discussions can teach us as much, if not more than the strict and Narrow right on topic threads can.

 

Signal to noise ratio determines the differnce in lower quality formats. If digital has less noise and fewer artifacts during transmission than the others, then it will at least benefit from that, even if the overall piture quality has been downgraded.

You keep talking about pixels but as jdobbs stated they're really no clearly defined pixels just illuminated phosphors affected by three color guns (RBG). Unless of course they're LCD or some similar screen reproduction where the actual pixels are illuminated.


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Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth." Sherlock Holmes (by Sir Arthur Conan Doyle, 1859-1930)[/small]