Why is XVCD sometimes jerky?

[Tomas]

Hi,

i've got 2 DVD players:
Silva Schneider 5500S : DVD, CDR,RW, VCD, XVCD, SVCD, XSVCD
JVC TH-A9R: DVD, CDR,RW, VCD, XVCD

i make xVCD with TMPGEnc 2.50, MPEG1, 720x576, 2-passVBR(min 0, avg 1850, max 3000kbit). And multiplex with TMPGEnc as VCD-Nonstandard

JVC this play very jerky(video+audio) every one second, Silva Schneider too.

if i remultiplex it with bbMpeg as VCD, muxrate-0, VBR, Video buffer about 70kB (not to be underflows). JVC play this good wholemovie, but SilvaSchneider sometimes (i think when hi-motion is present) is Jerky.
When i multiplex it in bbMpeg as SVCD then Silva Sneider play it without jerky. But JVC doesn't play SVCDs.

I think that problem could be in very high maximal bitrate. Could it be?
Please help how to create VCD, that i can play in both players.

Thanks.

PS: please try my bitrate calculator: http://www.tomzavodny.cz/projekty_en.php?page=program_avivcdbitcalc

[wildcatfan]

several things.... first your dvd player just may not like off spec material and secondly the 3000 max bitrate may be too high. Try lowering the max to about 2500 and see if that helps (maybe even a little lower). If its just a dual speed drive that is about the max it can handle bitrate wise.

[Tomas]

I don't think that it is only doublespeed. because i can play SVCD 2-pass VBR AVG 3000kbit and max 5000kbit, without any problem. Problem seems to be only in VCD high bitrate multiplexing. I am sure that it is bad multiplexing.

So my question is:

Can XVCD have higher bitrate than 2520kbit?

Thanks for your answer

[RoopeT]

Can XVCD have higher bitrate than 2520kbit?

The rule is that there's no rule. In principle, you can make an XVCD @ 10 Mbps, but I'm sure you won't find a player that accepts it. (XVCD just means non-standard VCD)

[Tomas]

Hmm. I found that my player (Schneider) plays XVCD in 5000kbit/s without any problem, but problem is that i have to multiplex it with bbMpeg as VCD, VBR-on, MuxRate-0, video buffer-46KB. It reports many buffer underflows, but it works without any problem. When I use bigger video buffer as about 64KB it is sometimes jerky and when i use 128KB buffer it is jerky every one second. I dont undestand this. Because bbmpeg's help says, that i have to use videobufffer size minimal as big as VBV and in my case VBV are bigger then 46KB. I will try this XVCD with JVC-TH A9R, and i think it will be jerky. I'll try it next week