Some jerkiness in TMPGEnc encoded DVD

[Mr Henderson]

I have encoded a 10-minute home-made animation from AVI to DVD (PAL). It mostly runs perfectly, except for some short, very jerky sections where there's sudden, fast overall movement in the original video. Encoded using TMPGEnc, 2-pass, max. bitrate = 9.35Mbps, average = 8.85Mbps, min. = 2Mbps. GOP structure 1xI-frame, 5xP-frame, 2xB-frame. Authored using DVD-Lab. I have looked at the bitrate using Bitrate Viewer (shareware version) and the jerkiness doesn't seem to correspond to bitrate peaks. Any ideas on how to get it all running smoothly?

[ZippyP.]

Was your source file PAL?

[Mr Henderson]

Yes - 25fps, 720x576.

[Abond]

Field order?

[Mr Henderson]

Definitely correct - I know what reversed field order looks like.

[Abond]

I think they are interlaced. Have you encode them as interlaced?

[guns1inger]

Watched on a TV or your PC ?
If it was your PC, using what software ?

[Mr Henderson]

Yes, encoded as interlaced. And the problem is there on both PC and TV. PC software is the ATI DVD player. But I'm very keen that the DVD should play well on as many players as possible, as I will be sending it out to other people - so just improving playback on my system isn't really the point.

[Nelson37]

You may be exceeding the max bitrate. Try reducing it somewhat.

[Mr Henderson]

Hmmm... neither the Bitrate Viewer programme nor the error detection in DVD-Lab show excess bitrate. However, you could be right - seems to me both programmes might miss very short bitrate spikes. Will try, though one or two sections will probably show a bit of noise.

[Abond]

Maybe try to author it for testing only in muxman. It will throw a warning if there is something wrong with the bitrate.
What else it could be is probably VBV buffer size, but if you used DVD template in TMPG, this should be OK.

[Mr Henderson]

I hadn't come across Muxman - thanks, I'll give it a try.
VBV buffer size is set to 0 (automatic).

[Abond]

Maybe it is worth to set it at 224 - thus I think you will force it for all the cases (scenes).

[Mr Henderson]

Right, I'll try that too.

Off to lunch now....

[Mr Henderson]

...After experimenting with Muxman I have found that the problem appears to arise when authoring with DVD Lab. (This is a great pity as [a] I paid good money for DVD Lab and [b] I have been going around recommending it to all and sundry.) Even using a Muxman .vob in DVD Lab causes the same problem. I will experiment further.

[Mr Henderson]

Better round off this thread by posting my solution.

I said that using a Muxman .vob file in DVD-lab didn't solve the problem. I was wrong. In the end I used Muxman to multiplex the audio and video into one file and imported the resulting .vobs into DVD-lab. You get 3 options when you do this. I used the default (middle) option: 'Use it directly without demultiplexing'. (There might be times to use the 3rd option, but you certainly don't want the 1st.) You can then proceed as normal.

Works perfectly, but it's silly that a paid-for programme can't mux as well as freeware.