Packed bitstream, playback smoothness and audio delay

[Janzki]

I'm using XviD 1.0.3 and aim for a high-quality encode of a short clip. My B-frame settings are as follows:
Max consecutive BVOPs: 1
Quantizer ratio: 1.00
Quantizer offset: 0.00

Packed bitstream OFF
Closed GOV ON
Now when I play the encoded file it seems to get kinda jerky sometimes. I have the fourcc set to DX50 for DivX 5 compatibility reasons. With packed bitstream or without B-frames I haven't noticed any jerkiness. I was wondering if it is a good idea to leave "packed bitstream" on by default?

On a related note, I'm a little confused about the decoder delay caused by b-frames. I'm not entirely sure, but I have the feeling that the a/v sync in my encode is not 100% perfect with the above settings. If I have encoded the video and audio portions separately and join them together in VirtualDubMod, does it mean that the video will play 1 frame later than it should? Perfect sync is really really important for me.

I did search the forums for answers, but didn't find definitive answers to these questions. Excuse the n00bness. :)

[Koepi]

For DivX it's mandatory to use packed bitstream.

Also, using those quantizer/offset values will lead to quality degradation compared to a i/p-frame only encode as the bframes won't be smaller than a pframe in such situation, but the p-frames get bigger as they can't reference the bframe before them.

Using defaults (and setting to max. 1 b-frame) should be what you want.

Cheers
Koepi

[Janzki]

All right, thanks for clearing that up.