About the TV series "ER"...

[obiwan71]

I've tried to capture two episodes and have a question. The series has not been released on DVD, but those who may have tried to capture it may know the answer. :)
So, there is my question...is it progressive or interlaced? I've applied different filters (using Decomb) but can't really figure out if the source is video - really interlaced, or film, that is, progressive. :confused:

[droolian01]

Hi there.
I havent captured ER but have captured a lot of american tv programs here in the uk and have experienced similar problems to yourself.
In the strictest meaning of the terms your captures consist of 2 interlaced fields per frame and so can never be called 'progressive'. But what is more important is the type of source that the tv company used to transmit this video data stream to you. Another imporant point to consider is that the us uses ntsc 30fps whereas france uses 25fps (as does the rest of europe uk included).

Apparently most us tv shows are originally shot using FILM (the real celluloid 24 fps progressive stuff) and are then telecinied (24fps progressive to 30 fps interlaced) for transmission to the us home viewers. If your tv company got the same film stock as used in the us they could transmit this at 25fps (by slightly speeding it up) and you could use telecide(post=false)(see below for an explanation!) to recover the original progessive frames perfectly. My experience is that tv companies rarely do this.

What usually happens afaik is that the tv companies must get hold of video tape of the 30 fps ntsc version (used to transmit to the us viewers) and do a 'dirty' conversion to 25 fps - dirty becouse it becomes impossible to recover the original prgressive frames. You can check this in your ER caps by using:

avisource("ERCAPTURE.avi")
separatefields()
selecteven()

Check this in virtualdub, you will see that some of the individual fields that have been separated out are blurs of two fields (not just motion blur). If this is the case then you could use telecide() as by default it does some post processing to get rid of any odd interlacing that gets though the field matching. If you saw no blured fields when stepping though the frames then your source is capable of being recovered 'progressively' and i would suggest using telecide(post=false) as no post processing should be required.

The only time i find i can use telecide(post=false) is with domestically produced tv or sometimes for captures of films from tv.

Sorry if this is obvious to you, and sorry for the long post

Good luck

p.s. i've done lots of tv caps but am stil trying to perfect deinterlacing/ivtc these american tv episodes myself (buffy, enterprise, 24, 6 feet under)

[droolian01]

p.p.s.

If you lived in the us you would never have this problem as you would be able to properly ivtc ER. I wonder if american capturers have similar problems with uk/european tv shows?

[obiwan71]

Well...what a nice post this is!

In fact, "ER" is likely to be shot on film. I've found some information on the IMDB:
http://us.imdb.com/Technical?0108757

Plus, I noticed that some portions of the captures were truly progressive streams, whereas others were "interlaced"...rather telecined, to be precise. It may sound surprising, but it happens at times.

When applying "Telecide()" or "FieldDeinterlace()", and even when disabling postprocessing in the first case, I've got similar results, except the few combing artefacts left if I disable postprocessing.

As for films, they are sometimes telecined, sometimes not. The stream may be a truly progressive one (just like video on DVD). Thus it is very easy to capture it through my capture card (DC10+) and encode it without using any deinterlacing filter at all (the source is digital satellite, which provides excellent quality - especially the TV channel "Canal+"). And if the stream has been telecined, I use Decomb and its "Telecide" feature that works great. Then encoding takes a little more time, of course...

[theReal]

I don't really understand what can be ivtc'ed when your capture is 25fps interlaced. Is the result still 25fps, or do you decimate it to 24? If it is still 25fps, then what is the benefit of telecide() over a normal deinterlacer?

[droolian01]

Hi there.

Telecide() does not perform an ivtc operation on its own, its main role is that of field matching - in order to provide progressive frames. A movie that is captured in a pal country can be EXACTLY recovered as it was (i.e. 24 fps progressive). Movies are usually just speeded up from 24fps to 25 fps then transmited interlaced. Telecide will just match those fields back up again (but it is very clever in that it can accomodate field switching etc..) at a frame rate of 25fps progressive. You could if you wanted to change the frame rate to 24fps if you, but i know of no one who can be bothered to shrink the audio and remux: simply not worth bothering.

So there you have it - telecide is perfect for these sources as EVERY frame is recovered perfectly PROGRESSIVE (only 1/25 faster than the original film).

See :http://www.doom9.org/decomb.htm

Thanks

[theReal]

I have checked the guide for telecide() recently, but I didn't really get the difference between what telecide() does compared to a deinterlacer like Smartdeinterlace (or Fielddeinterlace, to stick with the Decomb package).

I think I got it now: telecide recovers progressive frames by taking the correct two fields and putting them back together while a deinterlacer looks for combing artefacts and blends or interpolates in the combed areas but leaves the rest of the picture as it is.
Is that right?

I've only started to learn about telecining two weeks ago when I got a few DVD's from Malaysia which were telecined but not encoded as FILM. I think I have to try telecide() for my tv captures in the future.

[neuron2]

@theReal

Yes, that is right.

[obiwan71]

theReal: Yes...try and see "Telecide" for yourself. You'll be amazed by it, since it does a wonderful job. I've used it for a month or two, and I only wish I had the idea of using it before. I thought IVTC was just related to DVD and NTSC. Well...I should have thought about this telecining process before!
This "Telecide" filter is the appropriate filter, the one I needed to "deinterlace" my captures. :)

[obiwan71]

By the way...I was wondering:
How do you pronounce the word "telecine"? :confused:

[theReal]

I guess it is pronounced /'telesain/

(I can't use IPA* symbols here, but luckily I didn't need any special characters)

*International Phonetic Alphabet: http://www2.arts.gla.ac.uk/IPA/fullchart.html

[obiwan71]

Thanks for the link. ;)

I perfectly know what the IPA is...In fact I am an English graduate. :D
But "telecine" is a technical term. It is the kind of word you don't find easily in a basic dictionary.

[obiwan71]

I've just found that:
http://www.infoplease.com/ipd/A0688556.html

[theReal]

;) This is typical - Americans don't use the international phonetic symbols but use their own ;)

As far as I can see I wasn't wrong - except the second "e" should be upside down (=Schwa)