Cropping black bars causes wrong aspect ratio

[yankeee80]

Hello all,

I think my problem has a very simply solution, but I haven't been able to find it anywhere.

I crop the black bars (using null-transform filter) which are encoded in some (mpg) videos and then save the result as an XVID video.

I get this info from AVICodec:
Original video file: 320x240 (4:3) mpg
Processed video file:320x188 (16:9) xvid

When comparing the two videos the processed one is too low, causing people in it to look fat.

When superimposing the processed video (the red rectangle)on to the original one it's easy to see that the processed video is too low

http://professorthailand.com/untitled.JPG

[CWR03]

Your source video is probably not 16:9 cropped. Since your 16:9 overlay doesn't cover all the video area, if you're cropping only the black bars and creating 16:9 output you're causing the "squish." It looks like your final video should be 320x224.

[yankeee80]

Thanks for your prompt reply, much appreciated!

this happens to every video I try to crop the black bars from, so I'm obviously doing something wrong.

1) How do I prevent the processed video from getting a 16:9 aspect ratio?

2) do I need to appy any more filters in virtualdub?

kind regards
Eric

[CWR03]

Filters aren't the problem. It's caused by your cropping and setting the wrong AR output.

What exactly is your process that produces an incorrectly cropped and resized video?

[yankeee80]

Hi,

open video
add filter "null transform"
crop the bars
set audio comp. to Mp3
set video comp. to XVid (fourCC:xvid, bitrate ~1,200)
compress

[mgh]

load defaults in the xvid codec and then check the encode

[Ghitulescu]

1) How do I prevent the processed video from getting a 16:9 aspect ratio?

Leave it as it is, or be happy with 16:9.