Twitchy Playback

[Sakuya]

Hi. I found out that my AVI video has twitchy playback. Could this be a codec problem or is the original video supposed to be like this? I'm not sure because I forgot who made the video. Anyway, the video is fine most of the time. However in certain scenes, the character will sort of twitch when she's walking (this is a cartoon by the way). It's most noticeable in the preview at the end where entire frames would twitch. Is it an encoding problem?

I opened GSpot and it said it uses Xvid. I opened Virtualdub's File Information screen and it said the AVI uses the ffvfw MPEG-4 codec. The video is 23.976 fps. I have ffdshow set to decode: XVID, DivX 3, DivX 4, and DivX 5. I have ffvfw set to decode: XVID, DIV3.

I'm making a DVD so I'm just wondering if these twitchy problems will transfer over when I'm converting with TMPGEnc Plus.

[DJRumpy]

I can think of two possible causes.

1) The source could have been PAL, and someone converted to NTSC (23.976) by dropping 1 frame in five, instead of just slowing it down

2) The field order could be wrong. You would typically notice this on wide panning type scenes, or on scenes with a lot of motion.

[Sakuya]

I'm pretty sure the source is NTSC since I've seen a DVD in stores of it. So I'm guessing it's a DVD rip. So if the field order is wrong, how can I fix it? Most of the scenes are ok though, it's just most noticeable in the preview.

[DJRumpy]

If the video is already encoded into DivX, or XviD, then you would have to re-encode, reversing the field order. If the source files are in MPEG format, you can use PULLDOWN.EXE to reverse the field order.

[Sakuya]

The DVD rips are in AVI format, already in XviD.

[johns0]

Twitchy playback can be caused by older xvid codecs,download the newest xvid codecs.

[Sakuya]

As I said in my first post, the only codecs I have installed is ffdshow and ffvfw. And my configuration in those codecs is also listed in my first post.

[DJRumpy]

If your video is already in DivX format, the you'll have to re-encode. I don't know of an easy way to change field order for an AVI. Pick a small scene, with noticable glitches, and then re-encode using VirtualDub (assuming you want to keep it in DivX or XviD). There is a 'Field Swap' filter which should do the trick if your problem is indeed field order. Just encode a small piece and see if it resolves your issue.

If it does not, you might also give John's suggestion a try. The ffdshow and ffvfw can be poor substitues for the real thing. The codecs for this are freely available. Check the TOOLS section to the left.

When installing the DivX 5 codec, just make sure you answer NO, when prompted to install the GATOR piece. After your done with the install, you should also run Ad-Aware (http://lavasoft.element5.com/software/adaware/), It's freeware, used to clean out any spyware/adware on your PC. Quick painless, and probably something you need anyway

The DivX codec is completely free, with no spyware, and that is what I would suggest you re-encode with.

[Sakuya]

So I'm re-encoding the XviD AVI with Virtualdub and using the Field Swap filter to output to a DivX AVI? Why DivX?

[Sakuya]

It didn't work. Maybe there's no way to change it? After applying the field swap filter, the resulted AVI has lots of jaggy lines, which is even worse. Thanks for the help though. I guess it's something the creator did that caused those glitches. Hopefully, the next episode won't be like this.

[DJRumpy]

I would agree. If the field swap was even worse after the fact, then the original creator has probably dropped frames someone while encoding. A destructive encode like that cannot be fixed since the original frames are gone.