TMPGEnc: Aspect Ratio vs Source Aspect Ratio?
 

Okay I got a few questions for you guys:

1. What do I put for "Aspect Ratio" in the "Video Stream Setting"

2. What do I put for "Source Aspect Ratio" in "Video Source Setting"

1/ the A/R of the video you want to obtain (4/3 or 16/9).
2/ the A/R of the source you are encoding (1:1, 4/3 or 16/9, eventually choose the lines with "704x..." if the source is a DVD).

Quite simple actually.

Anyway, these settings are used when you want TMPGENC to do the resize. If you are using an avisynth script, with the resize computed by paranoia, then you just need to select the correct value for 1/. The other one won't be used at all.
In case you don't now, "16:9" for the video obtained is equivalent to say "anamorphic". So select "16:9" if you asked to paranoia to compute the resize for an anomrphic result.

Hmm.... Kind of makes sense. So if I have a widescreen movie and I want to keep the aspect ratio, I'll just put 16:9 in both boxes?

If your source is also 16/9, yes. As I said the secnd box must reflect the A/R of the source. But anyway I never used tmpgenc to do the resize, so as mentionned above, the second box is useless to me.

Also, as I don't want to tell you wrong things, I would suggest to make some test on a 1 min video. You just have 4 cases to test :) (4/3-16/9 for source and 4/3-16/9 for target).