[MPlayer-advusers] terminology misunderstanding: pulldown vs telecine

[Andrew Savchenko]

Hello all!

I can't clarify difference between "pulldown" and "telecine" 
concepts currently. I'm in the middle of translation of 
encoding-guide.xml (into Russian), where the problem of 
distinguishing this terms was encountered. So, I'm relying on your 
help.

Sorry if it is wrong mail list, but previously I was edified that 
adv-users is more acceptable place for questions which not clearly 
belongs to the other topics and which are not users meanwhile. I 
haven't send this to documentation or translation ML, 'cause it 
seems to be not a question about documentation improvement, but 
rather about my misunderstanding of some points in it.

It is the first extract from encoding-guide.xml:
---
Whenever a movie is prepared
for display on television (including DVD), it is converted to a
field-based format.
The various methods by which this can be done are collectively
referred to as "pulldown", of which the infamous NTSC
"3:2 telecine" is one variety.
---

From this I can conclude that telecine technique is a subset of 
pulldown methods.

But further in the text there is an opposite statement:
---
Because NTSC is 30000/1001 fps, some processing must be done to 
this 24 fps video to make it run at the correct NTSC framerate. 
The process is called 3:2 pulldown, commonly referred to as 
telecine (because pulldown is often applied during the telecine  
process), and, naively described, it works by slowing the film 
down to  24000/1001 fps, and repeating every fourth frame.
---

Still here I'm bit confused. In the first statement pulldown is a 
common name for telecine methods, and the telecine seems as subset 
of the pulldown. In the second statement it is almost vice versa.

Are they (telecine and pulldown terms) synonyms? If they are why 
they are used in different ways across documentation? If they 
aren't then either it is a typo, or I completely misunderstood 
something.

Of cause, I also looked up via wikipedia 
(http://en.wikipedia.org/wiki/Telecine and 
http://en.wikipedia.org/wiki/Pulldown), but similar unclearness is 
there: pulldown is refered as a part of telecine technique but 
telecine is refered to pulldown 8-/.

And there is another trouble dependent on previous. How to 
understand this:
---
On the other hand, TV series are usually only interlaced, not 
telecined.
--
??

Of cause, telecined video is a video in field-based format, that's 
why it is interlaced (and not progressive) by definition. But how 
video can be interlaced and not telecined simultaneously? 
From the context of previous text (in encoding-guide.xml) I can 
conclude that this sentece is about video being interlaced without 
framerate change, IOW each frame was just transformed into two 
field with odd and even lines alternately. Am I right?

But if telecine and pulldown refers to the same process, the last 
quotation seems to be senceless, since pulldown is always applied 
in order to make interlaced video from progressive.

Please, explain me clearly these incomprehensible concepts and 
difference between them.

Thanks for your help.
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