Fixing aspect ratio?

[Martel]

So I've got an XviD file that refuses to display at the correct aspect ratio unless I set it manually (in VLC player and such) and won't display at the correct ratio at all under WMP. How can I fix this file? According to GSpot the ratios are: sar 4:3, par 1:1, and dar 4:3. For the file to look right I have to select 16:9 as the aspect ratio and then it's fine.

I have tried using mpeg4modifier but that doesn't seem to make any difference.

[CWR03]

So I've got an XviD file that refuses to display at the correct aspect ratio
Post a screenshot from GSpot - did you perhaps encode the file at the wrong resolution?

[EuropeanMan]

Most likely the original encode was incorrect.

[Martel]

I didn't do the encoding myself.

Assuming the encode is incorrect, what do I need to do to fix it? A full re-encode? Seems like that would be unnecessary since I can get it to display correctly just by manually setting the aspect ratio. It's like there's just some flag that needs to be changed to tell the media players what ratio to default to.

[EuropeanMan]

you need to upload that jpeg of the gspot to maxupload or something and then IMG it here...otherwise takes forever to get approval as an attachment.

we need to see the gspot eval.

plus if YOU didn't encode yourself...then there are ways to fix it...possibly. :) lets wait & see...now i am off to bed. 22.30here

[Martel]

http://maxupload.com/thumb/BEFF6B20.jpg (http://maxupload.com/img/BEFF6B20.jpg)

[EuropeanMan]

convert this .avi to mpeg format, then feed that into MeGui to adjust any cropping issues as well as proper A/R...put the size you want...that's it...also you can add additional filters should you choose to re-encode further.

[SeeMoreDigital]

Can you post two screen-shots?

The first one being an uncorrected capture of your 512x384 source. The second one being a capture, of what you think corrected image should look like.

From the two images it's possible to calculate an suitable aspect ratio signalling (PAR) value you can add to the stream to correct its shape.


Cheers

[Jay Bee]

I have tried using mpeg4modifier but that doesn't seem to make any difference.

Then the problem is likely to be with the decoder. Which decoder are you using? I think ffdshow doesn't respect the AR flags by default. It needs a setting called "overlay renderer" or something like that.

[SeeMoreDigital]

Then the problem is likely to be with the decoder. Which decoder are you using? I think ffdshow doesn't respect the AR flags by default. It needs a setting called "overlay renderer" or something like that.When you refer to GSpot, you'll see there's actually no aspect ratio signalling within the stream!

Also, I'm happy to report that the new versions of FFdshow are able to detect and respect AR flags by default now :)

[snowden]

so would i be correct in saying that the koepi's xvid decoder doesn't respect the ar either? because i'm having the same problem, no change with mpeg4modifier... :( it would be interesting if one could change the resolution flags without re-encoding..is this possible?

[SeeMoreDigital]

so would i be correct in saying that the koepi's xvid decoder doesn't respect the ar either? because i'm having the same problem, no change with mpeg4modifier... :( it would be interesting if one could change the resolution flags without re-encoding..is this possible?Provided your media players "overlay" options are set-up correctly, Keopi's MPEG-4 decoder works just fine.


Cheers

[snowden]

by overlay options are u saying that the overlay mixer won't work? because that's the setting it's on (Media Player Classic) and maybe that's why the AR isn't changing. :(

[SeeMoreDigital]

by overlay options are u saying that the overlay mixer won't work? because that's the setting it's on (Media Player Classic) and maybe that's why the AR isn't changing. :(If you are using Xvid's DSdecoder with MediaPlayer Classic, you might want to give the "VMR9 (renderless) output option a try.

Personally speaking though, I don't use Xvid or DivX's MPEG-4 DSdec filters, I use FFdshow...


Cheers

[snowden]

OK, so I tried what you suggested and it works - the AR and/or the PAR (whichever one i selected to rebuild the file with) both work. Thanks. Now I all I have to is adjust the overlay brightness because the video playback (of any video file) looks considerably brighter compared to the Overlay Mixer (now that I turned on the VMR renderless). :)