Jittery playback on SVCD from AVI file

[jexnet]

Hello,

First off, I apologize for not consulting the FAQs and guides prior to posting this, but I'm having a very hard time articulating what the problem is-- so I've decided to make a post concerning it.

I've converted an AVI (DiVX, video 132kbs, 23frames/sec) to an SVCD using AVI2SVCD's default settings. Here's the problem I'm having.

The playback is smooth when there are only minor changes from frame to frame (e.g., when a character is speaking but the background remains constant). however, when there are major changes from frame to frame, the motion jogs - it's not smooth. For example, when the camera moved around a scene and the whole display is changing, the problem occurs.

i'm guessing that something could be improved during compression, rather than a frame-rate problem.

does anyone have any suggestions?

Thank you!

Dustin

[Nick]

Do you live in a PAL area and is this problem on your standalone? If so I think the framerate is more likely the problem. I'm guessing the actual framerate is 23.997 fps (NTSC). If you live in a PAL area (25 fps) although your DVD player will play NTSC the difference in the framerate does cause some minor differences and every couple of seconds you get a very small jump, for example if the camera pans left to right across a scene over a period of, say, 10 seconds, you will get a handful of very slight jerks.

I may or may not be correctly understanding your problem but if I am then there is a workaround.

The only way around this is to check the NTSC2PAL box on the conversion tab. This speeds up the video to 25FPS, eliminating the problem. The audio will also be speeded up slightly to resynch but the increase in pitch is normally pretty much imperceptible.

Open your movie file and find a passage (a minute or so) of film where the problem is bad. Note the time it starts. Launch VirtualDub (doom9.org downloads page) and open your avi in it. Now select and cut out (using selection start, selection end and delete selection from the Edit menu) from the start of the movie to the start of the passage. Then do the same from the end of the passage to the end of the movie. This should only leave you with 1 min of avi. Now select Direct Stream Copy in the Video menu, and save your avi with a different filename.

Do a quick (CBR) encode of the resulting file and burn it on a CDRW. See if it solves the problem. All in it should take no more than half an hour's testing.