DAR problem

[-Murali-]

Video is encoded by cropping top and bottom....but forgot to set DAR 2.35:1...now the video is encoded and its AR is 16:9....so if i change the AR in mkvmerge will it affect the quality??

please help...:(

[TheSkiller]

No, changing the DAR does not affect picture quality (it's just a flag).
I always advise people not to use DAR because it's (rather) messy, use PAR instead. Just set the correct PAR for your video and it will always be fine even if you crop asymmetrically.
But — I'm not sure though — as far as I know MKV supports DAR only.

[-Murali-]

k...actually its encoded at that 1920 X 1080 resolution...so if i change does it affect??

[TheSkiller]

Yes, if you crop your 1920x1080 picture then the DAR changes (if you crop symmetrically/even it doesn't, of course). But your video seems to be square pixel anyway, so there should be no need to set any DAR or PAR.