Aspect Ratio problem?

[iradic]

hi... i have read a lot about ar and i thought i understand it - how wrong i was...

this is my wrong thought:
movie with pixel-ar 4:3 cropped and encoded with pixel-at 4:3 would be the same as original without cropped area when played back...

this is what i get:
movie cropped to 340x236 and encoded with xvid rc3, pixel-ar custom 4:3
playback (mp4):
ffdshow: 314:236 - this is picture aspect ratio 4:3, right?
3ivx: 1360(340*4):708(236*3) - this is 1.92:1
mplayer: Movie-Aspect is 1.92:1 340x236->454x236

is this width/height mod4 problem?
i can figure out how to set this right (depending on player/decoder) but can someone give me some explanation?

thanks

[Stux]

The main thing is you're confusing PAR with DAR

a Pixel Aspect Ratio of 4:3 will most likely not get you a Display Aspect Ratio of 4:3, unless you had the same number of pixels horizontally and vertically... say, 480x480 (ie SVCD)

See http://www.3ivx.com/support/par.html

In 3ivx you should select either the NTSC or PAL 4:3 PAR presets depending on your source (NTSC or PAL).

PAR is a more powerful concept than DAR because cropping does not matter, you will get the right result no matter what cropping was performed (as long as you haven't performed any scaling, because when you scale, all bets are off)

[iradic]

now i figured out where i was wrong...

i was using wrong numbers... custom par 4:3 is wrong!!!
i should use par PAL 4:3...

stupid me!

thanks for help stux