Why use 50i/60i wrapper?

F

Framerate

Well-known member
Hi -I've been getting my head around the whole fps thing (or trying to, anyway)

As I understand it, the standard GH1 shoots at 25p (PAL) or 60p (NTSC) - and then pops it into a 50i or 60i 'wrapper'

Why? - what's the reasoning behind this?.

Further, since my AVCHD player reports the fps as 25 (PAL), without the native 25p hack checked, is there any point in actually using the native 25p option?

I'm assuming that Neo2 also sees into the 50i wrapper, and treats the files as 25p - so, again, is there any need to record using native 25p if the NLE software already knows it to be 25p in actual fact?

Sorry if this seems a newbie question (well, it is!) but I'd appreciate any advice on this subject.
 
it is wrapped in 50i 60i to be able to be played directly from camera into a tv because it is a consumer camera. that is my understanding.

if you are shooting PAL you don't really need to use native, just drop it into a 25p timeline.
 
It doesn't play. Not sure about new hdtv's, but the old CRT jobbers can only handle interlaced -- something to do with how fast the cathode ray can fire, or something like that. Instead of showing one frame, the screen would display two fields back to back (each made up of half the horizontal rows of pixels.) In the regular old interface, like on tv or VHS tapes, the fields would have been captured sequentially (so you wouldn't have any real frames to put back together.) With this style of interlace, both fields are captured at the same time, giving a proper frame.

Feel free to correct me if I've misspoken, I'm drawing on what I remember from school.
 
I'm drawing on what I remember from school.
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If I drew on what I remember from school, I'd be questioning the need for colour! Ah, those simpler black-and-white days...
 
pomoville said:
It doesn't play. Not sure about new hdtv's, but the old CRT jobbers can only handle interlaced
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I have an old crt tv. Apparently it handles well 25 progressive (de-interlaced) footage issued from fcp through a wdtv device. So I don't get it.
 
My limited understanding for the logic behind it is twofold:

1) Compatibility with older interlaced equipment

2) Puts less demand on the transmission of information thu the camera's system onto the storage device.

Still...it's a primitive throwback and a pain to work with.
 
kostas said:
I have an old crt tv. Apparently it handles well 25 progressive (de-interlaced) footage issued from fcp through a wdtv device. So I don't get it.
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your wdtv is probably making it work or your tv can handle it. as a consumer camera it should be able to play on almost any tv straight from the camera, stops people calling in asking why their 1080 footage ain't playing on so and so tv? i still think its because it was because it was designed to be a consumer camera.
 
Ozpeter said:
If I drew on what I remember from school, I'd be questioning the need for colour! Ah, those simpler black-and-white days...
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Oh, yes, indeed - that's my problem, I'm getting old and I'm becoming simple ;)

Increasingly, I find that every new piece of information stored in my brain displaces something that was there previously.

Thus, I might master bit-rates, for example - but, then, knowledge about interlaced and progressive scan modes has to be stored and....whoops....out goes the bit rate info.

It's a bit like placing a hundred tins of beans on an open shelf designed to accommodate only 50 tins ;) - you keep taking them out of the box and pushing the line along as you add them - but at the other end the tins are falling on the floor....

I was born in the early 50's - when the only home entertainment choice was whether to put a new needle in your mono Dansette record player, or not.

Ahhhhhhh - remember EP's?


All this is faffing about with the GH1 is just my way of trying to avoid finally taking my place at the staring window, btw ;)
 
Chris Light said:
i was born in the mid-70s. there was a gas crisis. stop complaining.
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Mid-70's? - my eldest son was born in '75....aghhhhhhh, I'm so olllllllllld.

And I'm going to complain! - because, [1] I'm British, and that's what we do best, and [2] I'm stuck in cold northern Britain, while you're driving around Santa Catalina in a golf buggy, having fun and romance, and endless sunshine!

(Wonderful vid, btw)

So, in summary - I'm old, I'm cold, and I still don't understand why they put 25p into a 50i wrapper -;)
 
Age has nothing to do with anything. If you can still take off your pants without needing to sit down you're doing okay.
 
It appears to me it would be more difficult to take off your pants sitting down... where is that in the menu settings?
 
Blackout said:
It appears to me it would be more difficult to take off your pants sitting down... where is that in the menu settings?
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It's under compression settings - depending on how tight the waistband gets ;)

They range from 'low compression', to, "Oi! - that button that flew off your pants nearly took my eye out!"
 
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