upper field to lower field question?

TeeJay wrote on 9/18/2008, 5:34 PM

I am working in PAL HDV which is Upper Field but when i render it out as a DVD compliant SD file should i keep the fields Upper or change it to Lower? I don't really understand this stuff enough to know whether selecting opposite fields has a negative impact on the quality of my output...

Cheers

Comments

JohnnyRoy wrote on 9/18/2008, 6:47 PM

The important thing is that you identify the media as the proper field order. So changing an upper field first file to lower will cause problems because changing the flag doesn't really change the media. However, rendering your upper field HDV to lower field DVD will look fine because it is being rendered and Vegas will take care of flipping the field order properly. So keep your project as HDV and just select a DVD render template and let Vegas worry about the field order.

~jr

TheHappyFriar wrote on 9/18/2008, 6:52 PM

i've never noticed a difference between selecting upper or lower field first. As long as the fields for whatever you're editing are all the same it should be ok. it's when you mix fields that things get messed up. The reason it doesn't matter what field order you choose is because most (all????) DVD players auto-correct. So it would reverse the order if it needs to be.

TeeJay wrote on 9/18/2008, 7:48 PM

Thanks guys! Looks as though i'm on the right track then...

T

John_Cline wrote on 9/18/2008, 8:16 PM

MPEG2 files, unlike .AVI files, have a flag in the header to tell the decoder the field order with which the video is encoded. You can encode MPEG2 as either upper or lower as long as you tell the encoder the correct field order of the source file that you are compressing.