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Full Version: What does "Up-Fields" mean?
Hash, Inc. Forums > Technical Direction and Development (Learning Animation:Master) > A:M Rendering, Compositing and Special Effects > Cameras
ZPiDER
i have to start final rendering for my current animation project.
the client requested tga files at 720x576 for PAL with "Up-Fields".
does this mean "odd" or "even" fields in a:m talk?
(my guess is "odd", but i'll rather ask yall to be sure)
thanks!
ZPiDER
another related question:
is it common to give the client compressed or uncompressed TGA files?
(they will be converted to dvd + video)
Far Star Productions
You are correct it is odd field. Pal is upper field dominant and NTSC is lower field dominant. You will want to give your client the uncompressed image unless they state otherwise.
ZPiDER
thanks for the quick reply!
is there any way to make a:m render uncompressed targa files?
i'm going to use ulead media studio to convert the files, since i'll have to start rendering now, but i'll surely need this again
Sevenar
Zpider: There's no need to produce uncompressed Targa files. The compression used is an inefficient, but lossless RLE scheme. Any program that can read Targas will read both versions and produce the same output.
ZPiDER
thanks Sevenar. i know tga comression is only run length encoding, but didnt know if video cutting stations could handle this format. the compression makes a big difference in size since one of the clips is cartoony.
animaster
From: "Gareth Hardy" gareth@sentientsolutions.freeserve.co.uk
Date: 2003-10-22 00:01:27

> You are correct it is odd field. Pal is upper field
> dominant and NTSC is lower field dominant.

That doesn't sound right to me. I thought they were both lower field. (I am
happy to be corrected.)
Far Star Productions
Digital video is lower field in both NTSC and PAL.
animaster
From: "Richard Harrowell" rickh@dodo.com.au
Date: 2003-10-22 12:13:13

> From: ZPiDER : Marcel Bricman :
>
> thanks Sevenar. i know tga comression is only run length encoding,
>but didnt know if video cutting stations could handle this format.
> the compression makes a big difference in size since one of the
> clips is cartoony.

Marcel,

As far as I know, RLE compression has been an integral and non-
optional part of the Targa 1 spec since 1984. I think it would be
extremely unlikely that anyone would implement Targa file routines in
their product without RLE decoding, particularly since it only takes
a few of lines of code to implement the decoding.

However, if you are thinking of packaging the Targa files in a zip
file, you will find that the uncompressed TGA files will result in
smaller zip files then RLE Compressed TGA files.

Some typical figures for a 1MByte (uncompressed) "cartoony"-type TGA:

Uncompressed TGA: 1MByte
RLE Compressed TGA: 330KBytes

Uncompressed TGA (zipped): 100Kbytes
RLE Compressed TGA (zipped): 115Kbytes

Richard.
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animaster
From: Mark Klos mklos@bigpond.net.au
Date: 2003-10-23 04:31:07

Gareth Hardy wrote:
>
> > You are correct it is odd field. Pal is upper field
> > dominant and NTSC is lower field dominant.
>
> That doesn't sound right to me. I thought they were both lower field. (I am
> happy to be corrected.)
Field Ordering and Field Dominance are different, it seems.

Field Ordering & Field Dominance
http://tinyurl.com/rxea

Meridien-based Avid editing products (Media Composer v8 or later and
all versions of Avid Symphony) order the fields differently for NTSC
and PAL. This is to fully conform with SMPTE and EBU specifications
(more detail on this in a moment).

NTSC media is Even, or lower field first, ordered (the first spatial,
or top, field in a frame is from field 2). PAL media is Odd, or upper
field first, ordered (the first spatial, or top, field in a frame is
from field 1).
So what about field dominance?

Some programs (and previous versions of Media Composer) use the
incorrect term field dominance when referring to field ordering.
Field dominance indicates the field an editing system edits on, not
the order of the fields in a frame.

Fields, F1/F2, Interleave, Field Dominance And More
http://www.lurkertech.com/lg/dominance.html
Where Does Field Dominance Originate?
http://www.lurkertech.com/lg/dominanceorigin.html
Happy now? 8-)

-- Mark
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