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Discussion Starter · #1 ·
What is the difference of progressive and 3:2 pulldown? My Philips 30PW850H has an option for normal signals to be either progressive or 1050i and some other tv's i've seen have a 3:2 pulldown and was wondering if it was any different than what my set has?


I know I have been asking alot of questions lately, but I have a limited time to decide whether or not to keep this set.


Thanks

Ryan
 

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Progressive is a video format where the entire frame is sent at once, compared to interlaced which sends a frame out as two fields, odd and even. There is more than one way to create a progressive frame from the two interlaced fields. One method is 3:2 pulldown for FILM-based sources since the interlaced fields from a film source were created in a known pattern (3:2 cadence) - so the process can be reversed to recreate the original frames. For video material (not filmed source) however this is not possible and other methods have to be used. So progressive format does not equal 3:2 pulldown, if your equipment supports 3:2 pulldown you will get better quality for film-based sources however.
 

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Discussion Starter · #3 ·
So if a DVD player has progressive but does not say anything about 3:2 pulldown then it uses some other method?


Since most DVD's are of film based material, would it be better to use a dvd player with progressive or a tv that has a progressive mode?


Also, a tv that has 3:2 pulldown, how does it know that it is getting a film based material?


Thanks

Ryan
 

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Ryan,


A progressive tv with reverse 3-2 pulldown can accept a 480i (film based) signal from a regular DVD player and converti it to 480p. Or it can accept 480p directly from a progressive DVD player.


All progressive players have reverse 3-2 pulldown built in which converts 480i to 480p and then sends that to the tv.


It is generally accepted that it is better for the player to do it rather than the tv as the player does it before the D/A conversion.


There are tons of websites that give very detailed descriptions on "reverse 3-2 pulldown"


Just do a search and you'll find some great resources......


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The de-interlacers in TVs usually do not match the capabilities of the best ones in DVD players, particularly the ones with the Faroudja chip.
 

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The Philips TVs typically look better in the 1050i mode. I don't THINK their progressive has reverse 3:2 pulldown, but have not been able to confirm. I'd also suggest a progressive DVD player.
 

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Quote:
Originally posted by ThumperBoy
Progressive is a video format where the entire frame is sent at once, compared to interlaced which sends a frame out as two fields, odd and even. There is more than one way to create a progressive frame from the two interlaced fields. One method is 3:2 pulldown for FILM-based sources since the interlaced fields from a film source were created in a known pattern (3:2 cadence) - so the process can be reversed to recreate the original frames. For video material (not filmed source) however this is not possible and other methods have to be used. So progressive format does not equal 3:2 pulldown, if your equipment supports 3:2 pulldown you will get better quality for film-based sources however.
Actually.... the more important aspect of this topic is the acquisition of the image, versus the read-out of the image data. Progressive images can be output as either P or i, whereas interlaced captured images can never be output as true progressive. only through processing "tricks" can interlace be presented in a progressive format.


... 3:2 pulldown (in fact it is 2:3 pulldown) is used to simply match the 24 frame rate of film to the 30 frame rate of NTSC television. Film is progressively scanned.. and then seperated into fields and then some of the fields are repeated in order to increase the frames from 24-30. Reverse pulldown, simply ignores the duplicated frames. Reverse pulldown is not necessarily progressive.. it could be interlaced.
 

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Quote:
Originally posted by oryan_dunn
So if a DVD player has progressive but does not say anything about 3:2 pulldown then it uses some other method?


Since most DVD's are of film based material, would it be better to use a dvd player with progressive or a tv that has a progressive mode?


Also, a tv that has 3:2 pulldown, how does it know that it is getting a film based material?


Thanks

Ryan
A bit (or maybe flag) in the MPEG2 stream indicates repeated frames. The decoder then can decide what to do.


Not sure if it ever really happens, but supposedly when any encoder detects pulldown, even in an interlace master, it sends the stream as 24 frame in order to conserve bandwidth.
 
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