Jerky Playback... Not a TFF/BFF issue though!

[n1ck0s]

I though I had everything figured out... :(

Im backing up "Meet Joe Black" which is a rather long movie (>2:40). Somewhere at the end of the movie (around 2:30) the playback becomes jerky! Its not that obvious, but its there. Motion is not smooth at all.

At first I thought that it was my fault, because I was using my computer while CCE encoded the last part of the movie (I woke up in the morning and CCE hadn't finished yet, so I minimized it and start working). But when I checked the .mpv file playback was fine.

After searching a little bit I saw that jerky playback can happen because of TFF/BFF wrong settings. But this can't be the issue because a) Its PAL and most likely Progressive (I don't know how to determine this yet), b) jerky plaback occurs only after a certain point, c) I'm testing w/ PowerDVD, and PC monitors dont care about TFF/BFF right?

What could it be then? Scenarist multiplexing fault?

tia,
</n1ck0s>

P.S. I don't have a standalone to do further tests

UPDATE: Even more confused... If I open the last .vob file w/ PowerDVD, playback is smooth! But I don't think is a PowerDVD issue 'cause the the jerky playback always follws the same pattern (its not random). Could it be something in the IFO file?

[idbirch2]

It sounds like the last couple of minutes are interlaced. You wouldn't be able to tell this from watching on the PC though it would only show up once you've burnt it and tried watching it on the TV. I know how to deal with interlaced material but not when its part of an existing, progressive PGC. Sounds like you may have to do something funky like the dreaded 'Demux by VobID'.

[n1ck0s]

Originally posted by idbirch2
It sounds like the last couple of minutes are interlaced. You wouldn't be able to tell this from watching on the PC though it would only show up once you've burnt it and tried watching it on the TV. I know how to deal with interlaced material but not when its part of an existing, progressive PGC. Sounds like you may have to do something funky like the dreaded 'Demux by VobID'.

Is this possible? Only a portion of the movie being Interlaced? Anyway you must have just missed the update I wrote for a couple of minutes. As I say above, If I double click on the last .vob file (it opens w/ PowerDVD) the playback is just fine. I am about to delete this project from the hd (I don't realy care to spend any more time on this one), but I maybe be doing something wrong to all or some of my movies. I'm concerned about not being able to watch my movie backups WHEN I'll finally buy a deck player.

[Paced]

Originally posted by n1ck0s
Is this possible? Only a portion of the movie being Interlaced?

I believe it is possible if the DVD needs to be demuxed by vobid (someone correct me if I'm wrong). I've had a situation where approximately 5 minutes before the movie ended, it was interlaced, as were the credits. But, to double check, I suggest you download "BitrateView", and load some of your .m2v files into it. It will give you information on whether the stream is interlaced or not (it will also give you the appropriate field order for encoding). If it turns out to be interlaced, I suggest you leave/encode it as interlaced - motion will be as smooth as the original.

[Trahald]

@n1ck

definately possible.. when making the dvd, if the authors decide not to use the origional film footage on the dvd on certain sections (maybe to edit out things they didnt notice until after the theatrical release..) and they use interlace output .. they just splice it in with the progressive.. this will play fine on a standalone.. but will make backing up a pain. remember although we see it as a continous pgc.. doesnt mean the studio didnt put it together in segments. to deal with it as a whole you end up having to run deinterlace over the whole thing (decomb will leave progressive parts as progressive and deinterlace the interlaced parts). or you can use vob id (or who knows.. could be at cell level for that dvd) and handle each segment separately if you want to keep the interlaced parts interlaced .

happens on pal and ntsc flicks

[n1ck0s]

Thank you all for this info...

But I don't think this is the case w/ my problem though. I was just asking out of curiosity :).

As I wrote earlier:
UPDATE: Even more confused... If I open the last .vob file w/ PowerDVD, playback is smooth! But I don't think is a PowerDVD issue 'cause the jerky playback always follows the same pattern (its not random). Could it be something in the IFO file?
Thx in advance.
</n1ck0s>

[n1ck0s]

After some more reading...

Could it be "field shifted progressive" after a certain point, because of editing? If yes, is there a way to encounter that?