640x272 xVid source - jitter problems - any suggestions?

[kintwerp]

I have an avi source file which VirtualDub reports as:

Video Stream:
Frame Size 640x272, 23.976 fps (41708ms)
# of frames 99663(1:09:16)
Decompressor Xvid MPEG-4 Codec
Key Frames 979
Min/avg/max/tot key frame size 1900/17839/61553(17056K)
Min/avg/max/tot delta frame size 96/4853/39966(467758K)

The audio is fine, I can deal with that np (lol, after my last request for help!!)

The problem I'm having is that the source is excellent quality (superb in fact) but all my efforts so far to convert to DVD format give a jerky - jittery result. The higher the bitrate, the better the result but the jitter just will not go away. I am using tmpgenc(latest ver)

Any ideas all ??? To narrow the problem down, I tested with lsx mpg encoder to mpg2 but with no resizing - flawless result. So I think the problem lies with the resizing. Is this why people frameserve ?

Any help really appreciated folks. If any experienced peeps would be kind enough to briefly outline what they would do with this format of avi to make it dvd compliant mpeg then I could conclude that it isnt just me fumbling around in ignorance that is the problem!

TIA all,

Kinny.

[bugster]

Just to be sure, have you successfully converted 23.97fps avis before? It may have nothing to do with the fact that it is Xvid.

If you are converting to PAL at 25fps this will cause jitter in the output mpeg. Encode to NTSC with the following changes from the standard template:

Encode Mode 3:2 pulldown whne playback
Framerate 23.97fps (internally 29.97fps)

Hope this helps

[Nelson37]

A flaw in your analysis - you had success using a completely different encoder, without resizing, and conclude that the resizing is therefore the problem?

Try using the SAME encoder, without resizing - THAT would tell you if resizing is the problem. CHANGE ONE VARIABLE AT A TIME WHEN TROUBLESHOOTING, OR YOU WILL LEARN NOTHING.

My guess would be field order, but other than that you did in fact resize (what settings?) and used TMPGENC (what settings?), and are converting to DVD format (which one?), I have very little info to analyze.

[DJRumpy]

Resizing will not cause jitter. Changing the frame rate, as well as the wrong field order will. If this is a standard internet DVD Rip type of DivX, then you should be using Bottom Field first (B) in your TMPGenc settings. I use CCE, so adding pulldown flags is always done with PULLDOWN.EXE. You should be using this setting in TMPGenc on the Advanced TAB. This assumes your movie is going to remain NTSC, and not PAL. If you didn't use this option, then use PULLDOWN.EXE to add these flags. This will tell your player to telecine the movie back to 29.97 frames per second during playback (your source file actaully remains 23.976).

It is possible, that your MPEG may not have the pulldown flag, and your DVD player is actually attempting to play it back at 23.976 frames per second (mine will do this as well). Examine your final MPEG with MPEG PROPERTIES (see the tools section on the left), to determine the properties of your output MPEG. If it has the pulldown flags, it will be reported as 29.97 fps. Also make sure you check the resolution, and audio to ensure it's in spec.

[legalthugs]

DJRumpy We Meet Again. What about PAL SVCD To NTSC DVD Same Problem With That. Any Suggestions?

[DJRumpy]

Sorry lethalthugs, I've been away a while on vacation...

PAL to SVCD conversions are generally pretty easy once you get the hang of them. Make sure your not just dropping a frame. Instead, you slow down your video by one frame per second from 25 fps to 23.976 frames per second. The audio is seperated BEFORE you do this. use BeSweet and the PAL to FILM option to resample your audio to the correct length.

Use AVISyth for this, and the AssumeFPS command. Example:
AssumeFPS(23.976,False)

The False paramter is to sync the audio or not. Since your doing the audio seperately, you don't need to sync it here (it would be a little slow and low sounding if you did).