Authoring programs and smooth forward...

[sstavross]

Hi!

I was testing the new Womble DVD wizard and after authoring a dvd I played it from my HD with Power DVD v.5. The dvd plays fine but I noticed that when I do fast forward at 8X or 16X the movie "sticks" and I see only frames every lets say 30sec(at 16X). When I author the same movie in TDA the movie goes wonderfull smooth, I can "see "eveyrything even in 32X. Why is this? Anybody has noticed anything in other authoring programs? Or is the DVD player program problem?

[mikiem]

Guess would be the way the mpg2 was encoded. Never paid attention myself, but might be related to closed GOP etc.?

[borax]

I think it's due to missing/wrong navigation packs. You can check the vob files of both authoring applications with vobedit.

[kschang]

IMHO, it's encoding. Different amount of keyframes and all that.

[sstavross]

I think it has nothing to do with the GOP structure or the encoding as I used the same source file and these to authoring programs do not encode the movie again. Borax(hi again! what to check with vob edit? what to look for? I simple check I did, because it is a chaos of information there, show that the vob file of both the authing programms has a navigation packs every 300 video packets

[borax]

...it is a chaos of information there

I know... But unfortunately I can't tell you what to search for. If Womble also creates navigation packs all 300 video packets, you would have to dig really deep into the differences of the muxed streams. Maybe it would be easier to ask Womble directly for support. As DVD wizard costs some money, they should solve the problem anyway.

[sstavross]

As I told you I am just testing wizard, I have not bought it, so I don't know if I can ask their support... Maybe they will fix it in their next release. Anyway I am asking about this problem because I like to know more about the structure of a vod file, not because it is a real problem for me...

[borax]

Ok, if you are more interested in the matter, the next thing I would check are the timecodes (SCR/PTS+DTS/GOP) and celltimes within the vob files.
[0004] - SCR (System clock reference, incl. in each pack)
[0045] - Cell elapsed time (BCD) in nav packs only
[0017] - PES Header data details (PTS+DTS, audio packs, video packs with I-Frames)
[009a] - GOP time stamp (video packs with I-Frames only)

Some background info about this:
http://www.pxh.de/fs/svcd/DVB2SVCD/dts_pts_underflows_explanation.pdf
http://dvd.sourceforge.net/dvdinfo/index.html