DivX to DVD video stutters

[Spydertech]

Before anyone says it, yes I did search. (Here and a couple of other forums). So far, my search hasn't turned up much.

Here is the problem. The movie and audio are in synch, but the video is choppy (jerky, stutters, etc.) at times. It seems to be occur at regular intervals. It isn't terrible, just annoying. I don't know what I could have set wrong at this point. Seeing as the encoding is taking approximately 16 hours at a time, I was wondering if anyone could shed some light on this.

Using VirtualDub, I stripped the audio from the .avi, I converted it to AC3 using BeSweet. I set up TMPEnc to convert the avi to a ES(video only) .m2v. I used MPEG-2, 720x480, 1:1(VGA), 23.97 (internal 29.97), 2 pass VBR 4000 average, 6000 max, 1200 min., NTSC, 3:2 pulldown, 9bits, High quality.
On the Advanced page: Non-interlaced, bottom-field first, 1:1 VGA, full-screen (keep aspect ratio).
Everything else left as default.

The info I have from VirtualDub on the movie is 640x272, 23.976fps, DivX 5.03 decoder.

Oh, the playback is the same on a stand-alone and pc. (also, the .m2v without sound is the same, so I'm pretty sure the encoding is the culprit)

Any info would be greatly appreciated.

Spydertech

[Epi]

Spydertech

The reason your getting the stuttering is that your selecting bottom-field first. Even though the file is progressive you should always choose top-field first, that should fix the problem.

-if not-

Another reason you getting the stuttering is the fact that most MPEG4 codecs (DivX, XviD, Quicktime, etc.) say they are 23.976 fps but sometimes the encoder changes the fps during the encoding, to optimize the bitrate that is assigned to the video. For example during a high motion scene the encoder might drop frames to keep up the quality, this is especially true when those losers on KaZaa use low bit rates to encode thier videos to share.

Hope this helps.

-Epi

[Spydertech]

I am re-encoding the movie now, following your suggestion.

So, I guess that a divx video can use a variable frame rate and still look OK when played back?

This one is over 1.4 gig long in divx 5.02. The vid looks great, but that stuttering (video only) just irritates me

Spydertech

[Spydertech]

Just a little FYI.

I solved the problem (and learned a whole bunch along the way).

The problem seems to be the pc I was using to do the encodes.
(P4 1.7, 1gig ram, via chipset). I redid the encodes on a P4 2.4b, 768meg ram, Intel 845 chipset, and everything worked like a charm.

Spydertech