Comments

Marco. wrote on 1/2/2006, 11:26 AM
I'm still not sure if uncompressed video actually is supposed to be upper field first. If not modifying the "vegas profiles.ini"-file will help.

Marco
GaryKleiner wrote on 1/2/2006, 11:31 AM
I am not seeing any change in the field order on the rendered clip.

Gary
Marco. wrote on 1/2/2006, 12:53 PM
In former times we discussed if this might be a kind of bug which only occurs in real PAL surroundings where not only PAL is the render format but where the Windows configuration is set to European local settings.

Gary are you in a NTSC surrounding and did you render to NTSC and Kalevi are you in a PAL surrounding and did you render to PAL?

If so maybe that's it. I can state the behavior Kalevi speaks about using PAL settings. Having lower field first DV video in the timeline and rendering it to a new track to uncompressed AVI it results in an upper field first video if I wouldn't use the modified version of the vegas_profiles.ini-file.

Marco
Kalevi wrote on 1/3/2006, 11:16 AM
Yes, I am working in PAL-environment, so the problem seems to be familiar to you. Nice to know that I am not alone whith this. What is this "modified version of the vegas_profiles.ini-file". How can I do the fix or get fixed file?
Marco. wrote on 1/3/2006, 11:43 AM
I'm not sure if this is really a fix for you because I'm not sure about uncompressed PAL video. Should it be upper or lower field first? Anyway - even if I tell Vegas to render it lower field first it will be recognized as upper field first so I asume there MUST something be going wrong.

O.k. - to modify that .ini-file take a look in the Vegas program folder. There is a file called "Vegas profiles.ini". Backup this file than open a copy of it and search the line:

"Key2=0, "None", 720, 576, 25.0, 0
Attributes2="Upper First", 1.0925925925, "Undefined", 1"

Edit it to:

"Key2=0, "None", 720, 576, 25.0, 0
Attributes2="Lower First", 1.0925925925, "Undefined", 1"

Now save this one as your "Vegas profiles.ini".

Restart Vegas and you'll see your uncompressed avis are handled as lower field first now.

Marco
RBartlett wrote on 1/4/2006, 3:33 AM
Although this dates back to when the SDI standards were being formalised (no not the Ronald Reagan SDI):

The convention (take that to mean what you want) for uncompressed PAL files is based on a broadcasting convention - which is that field order is upper-field-first.

DV25 is always lower-field-first irrespective of the TV standard it is aiming to serve.

NTSC uncompressed is upper-field-first when in the 480 line representation, whereas it is lower-field-first in the 486 line representation.

I don't know if there is a bug in any version of Vegas in dealing with setting or transcoding the field order based on DV, progressive, media-in-need-of-swap-but-correctly-identified-in-header or media-in-need-of-swap-but-incorrectly-identified-in-header. So many things to test and for the main, this isn't a regular issue once you have an established workflow.

Some codec option can have overriding settings that'll supply fields in a different order to the header statements in the media file. However, generally uncompressed AVIs (be they RGB or YUV based) are null codecs that don't really do a lot of memory/space/time oriented processing.

Sometimes you need to review what upper-field-first means from the broadcasting and CRT derived scanning perspective.