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

Video reproduction comes in so many different packages today because of the many different ways in which it's transmitted or accessed. We all remember the days of early TV broadcasts which have been largely replaced by cable TV. The debate between which is better Betamax or VHS (Vertical Helical Scan, later changed to Video Home System) ultimately resulted in the lower quality of the two, VHS being adopted.

Broadcasted TV signals still remain and later on some even carried HD signals. As time progressed along came DVD playback, Digital cable, and High Definition TV. The debate here is in regards to their quality and lines of resolution. This thread is meant to be one of loose discussion as long as everyone plays nice.

 

I didn't mean to create a problem. It was just my opinion that a tv show off the airwaves not being DVD quality did not require DVDrebuilder.
The video capture and vcr resolution stuff just kinda got overblown.

 

And you were correct. If it turns out that there was some incorrect information then the record should be set straight. The difference between a debate and an argument is that in one we argue for ignorance and in the other we either teach or learn from our mistakes. I felt that jdobbs was cut short in his last answer and I think that he should be heard.

 

Here is a quote from the "bible" (FAQ):

"Everyone gets confused by the term "lines of horizontal resolution," also known as LoHR or TVL. It's a carryover from analog video, it's poorly understood, and it's inconsistently measured and reported by manufacturers, but we're stuck with it until all video is digital and we can simply report resolution in pixels.

Technically, lines of horizontal resolution refers to visually resolvable vertical lines per picture height. In other words, it's measured by counting the number of vertical black and white lines that can be distinguished an area that is as wide as the picture is high. The idea is to make the measurement independent of the aspect ratio. Lines of horizontal resolution applies both to television displays and to signal formats such as that produced by a DVD player. Most TVs have ludicrously high numbers listed for their horizontal resolution.

Since DVD has 720 horizontal pixels (on both NTSC and PAL discs), the horizontal resolution can be calculated by dividing 720 by 1.33 (from the 4:3 aspect ratio) to get 540 lines. On a 1.78 (16:9) display, you get 405 lines. In practice, most DVD players provide about 500 lines instead of 540 because of filtering and low-quality digital-to-analog converters. VHS has about 230 (172 widescreen) lines, broadcast TV has about 330 (248 widescreen), and laserdisc has about 425 (318 widescreen).

Don't confuse lines of horizontal resolution (resolution along the x axis) with scan lines (resolution along the y axis). DVD produces exactly 480 scan lines of active picture for NTSC and 576 for PAL. The NTSC standard has 525 total scan lines, but only 480 to 483 or so are visible. (The extra lines contain sync pulses and other information, such as the Closed Captions that are encoded into line 21). PAL has 625 total scan lines, but only about 576 to 580 are visible. Since all video formats (DVD, VHS, LD, broadcast, and so on) have the same number of scan lines, it's the horizontal resolution that makes the big difference in picture quality."

and here is a couple very good references:

http://members.aol.com/ajaynejr/vidres.htm
http://www.petesvideo.com/vidformats.htm

 

I certainly don't wish to oppose Vurbal or jdobbs on any technical point. I would assuredly lose.
It was more of a general observation and opinion than technical infomation.
_X_X_X_X_X_[small]Donald

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Sorry, I didn't mean to sound like a jerk... I'm an engineer and can sometimes get wrapped up in details.

It's a well known fact that engineers shouldn't be allowed into any social setting.

 

Your way cool with me. Any serious information is always welcome.

My parents and brother are electrical engineers.
I an automotive technician and get the same way when people blather about what they think is right on cars.
_X_X_X_X_X_[small]Donald

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jdobbs

No apology is necessary I appreciate your input on everything and besides I'm sitting here waiting for a storm and I can use any distraction to take my mind off it. I was an AV consultant for almost 20 years but certainly not an engineer. Have you followed the debate on the link below?

http://forums.afterdawn.com/thread_view.cfm/98032
_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]

 

So you went for A/V consultant to teaching? Interesting.

I taught part time at the college level for a couple of years and really enjoyed it, and (like some of the others here) my wife is a teacher (7-8th grade Language Arts).

As for Frances -- I've been watching it on TV... looks like it's going to be a real soaker.

 

jdobbs

Actually I went from a rock muscian, to AV consultant, to recording studio engineer (a very loose definiton of the term engineer), and then to teaching. Keeps my wife off balance. LOL

Forgot something, I also have a degree in Social Work. (BSW)
_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]

 

Does anyone remember the Beta versus VHS debate? Why did Beta loose against an inferior format? Is this an example of how things can go wrong because of format politics? Is there a superior format out there now that is facing the same fate as the Betamax?

 

Yep. Betamax was much better. But sometimes it doesn't matter. It's kind of like comparing CCE output to DVD Shrink -- people will argue about quality even when it is intuitively obvious to the casual observer. The VHS crowd swore by it.

The MAC is a vastly superior computer to the PC, but I don't own one because it has already lost the battle.

It's all in the marketing.

 

Gasp Arrrgh. Mac is superior! Which Mac. The old non multi tasking slow ones. Or the newer Unix compatible freebsd Morphs. I do want a dual proc unit but can't afford one.
I had Apples and Macs early on but like you said. They lost miserably. I would have liked to see them go the non proprietary route.
_X_X_X_X_X_[small]Donald

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Sorry
I'm just mad Apple screwed up a good thing.
I didn't care about the Beta Vhs war. Beta cost too much at the time anyway.

 

Apple did something that took IBM clones some time to do, make a stable PC. They're still doing pretty good considering the support that IBM clones have received.

 

I must say that DOS was no match for the Mac when it came out, but DOS had stability. Windows took a little longer to get it.

It's like Linux. People who like Linux or Apple swear by the stability but when I have used them side by side I don't see it.

I have some powerbooks that still give me fits if you try to do anything out of the ordinary. Like load a driver for a wireless card if you can find one.
Lucent seems to be the only reasonable cost alternative out there.

 

Donald

Is it just me or shouldn't Vurbal have made his way here by now with one of his mini-novels?

 

We may be to far off topic.

I do so enjoy his writing.

Do you mean like a specific history of Beta and VHS or evolution of the Mac and PC.
_X_X_X_X_X_[small]Donald

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Yea, he does love to get his facts together.

Read my intro!

we can bring all of our off topic discussions here and be on topic by being off topic. LOL

 

I can tell you that the Mac' GUI interface was way ahead of Micro$oft. But I saw that writing on the wall and concentrated on PCs... good thing too.