Problems with saving PAL files to .AVI format

[christopheramos]

My video files are in .MPEG format. I load them into VirtualDub to use a filter or two on them, then save them to .AVI format.

The problem is, when I play back the video in Windows Media Player, the video width has been squeezed inward, but the height looks the same. The result is a funky looking video that's much taller than it is wide.

I am losing my aspect ratio because saving PAL in .AVI format causes a loss of "flags."

Does anybody know how to fix this problem ????

Thanks!!!!!
Chris

[celtic_druid]

Well you either need to resize or set the PAR the same as the source. Setting the PAR is possible with XviD and x264, also should be possible, at least after encoding with other MPEG-4/AVC codecs.

If you use XviD, I would recommend a current build, since a bug with resizing was fixed. Previous builds won't resize correctly on playback if you use bframes that aren't packed.

[Graham Meredith]

Chris,

Yes. This is normal, when playing an avi in windows media player. The issue is that the mpeg you loaded into virtual dub had half-height resolution, which is 352x576, or you loaded a filter into VD that outputted an avi at that resolution.

When playing back an avi, media player will play it exactly as the dimensions of the clip are. But when it plays an MPG of a clip at that resolution, it senses that it is one of several compliant DVD resolutions, and re-stretches it back for normal playback (as does a DVD player, also). 352x576 is one of the compliant res specs for DVD's, and has the advantage of being a smaller file, and so able to fit a longer movie onto a disc, at the expense of some resolution, as compared to 704x576 (or 720x576) full resolution.

If you are outputting it as an avi, with the intention of converting it to an mpg for burning to a DVD, don't worry about how it looks as an avi, just encode it to mpg, and it will play fine in media player, and also on a DVD player. If you want to use the avi directly for viewing, eg. on your computer, then you'll need to use a VD resize filter to output it at the correct res you want (704 or 720x576)

Cheers,

Graham

[christopheramos]

If you are outputting it as an avi, with the intention of converting it to an mpg for burning to a DVD, don't worry about how it looks as an avi, just encode it to mpg, and it will play fine in media player, and also on a DVD player. If you want to use the avi directly for viewing, eg. on your computer, then you'll need to use a VD resize filter to output it at the correct res you want (704 or 720x576)

Okay, so if I save my .MPEG in .AVI format through VirtualDub, then encode it back to an .MPEG using Cinema Craft Encoder, the resulting file should be okay??

[celtic_druid]

Sure, as long as you set the AR correctly in CCE. Waste of time converting an mpg to avi then to mpg though. Better to just frameserve.

[christopheramos]

Yeah, I'm thinking it might be a waste of time too. But, I need to run my .MPEGs through VirtualDub in order to clean them up with a couple of filters.

The problem is, VirtualDub saves the files in .AVI format, and that's why I have to covert from .AVI back to .MPEG.

Unless someone knows a better way. I'd love to hear any suggestions though!!!!

Thanks!!!!

P.S.
I know nothing at all about frame serving. Where can I learn about that?

[celtic_druid]

Probably some guides here. I would suggest AVISynth over VDub though.

[Graham Meredith]

Definitely frameserve using Vdub, just as celtic_druid said! You will mimimise the loss from processing by skipping the avi step altogether. You'll also save yourself a heap of HD space. You only need Vdub and TMPGEnc (or any other mpg encoder that will accept framserve handles from Vdub). If you want more filters than what Vdub offers, use Avisynth in between the 2, but without it, they work fine.

Check out the guide:

http://www.virtualdub.org/docs_frameserver

Cheers, Graham