On Wed, 2005-09-07 at 19:56 -0700, Steven M. Schultz wrote: > There are several other likely candidates for where the problem lies. > Sure mpeg2enc could have an issue - BUT if mplex says the .m2v is > OK, and if DVD Studio Pro says the file is OK and if it plays in > all but one player - the the player is suspect and not the tool chain.
Well, it could be a brief bitrate spike or something like that. mplex would not complain, yet the stream would be non-compliant. > Interesting you mention JVC - that's the only player I ever had a > problem with too. Claimed to be able to play VCDs but it did such > a poor job it was replaced with a different brand. I guess I was lucky, mine plays everything I throw at it (including old SVCDs made years ago with mjpegtools). > Other problem areas could be: 1) the authoring software dvdauthor > > scenes when there's a lot of motion, the image stutters. The parameters > > are normal, 8000kbps, q=6, etc. > > That sounds very much like the player is struggling to pull the data > off the recordable media reliably. You say "when there's a lot of > motion" and that's precisely when the bitrate would be up at the > 8000 (or slightly more) -exactly where one would expect issues with > reliable reading of data. > > Try 7500 for those movies - you probably won't see the difference but > the disc might be more widely playable. But some older mjpegtools versions never had this issue, even at 8500, while the current "stable" one has issues at lower bitrates. Looks like a regression to me. > Commercial DVDs don't have the problem because they're stamped out of > more reflective material. Um... I'm not sure how to put it, since we're discussing in a public forum, but you'll figure out anyway... Let me just say that you'll have to trust me when I say that I tested material generated with commercial software on the same cheap DVD-Rs and the problem never occurs. > Two days before release is not the time to raise the issue of > some players having problems with recordable media with high bitrates. > I've said it numerous times - high bitrates with recordable media > have portability problems. Nothing the encoder can do about that. Not high bitrates generated by commercial tools. Those go right up to 9800 and have no issues with the same "recordable media" on my rig. > Where have you been all thru the period leading up to RC1, the rather > lengthy RC1 and then RC2 releases? In a couple days 1.8.0 will be > out (hopefully) and you can begin testing towards 1.8.1 - 7 or 8 months > or so should be sufficient time :-) <sigh> mjpegtools is unique among the open source projects I'm following closely, with regard to the extremely low frequency of releases. Often, a bug is fixed only in CVS and it sits there idle. Meanwhile, most users use packages, but package repositories only follow "stable" releases (rpm.livna.org is an exception since it also tracks release candidates), so they still use buggy software. Plus, sparse releases means low feedback for the developers. Everybody loses. Too bad, since it's the best open source MPEG2 encoder I'm aware of. -- Florin Andrei http://florin.myip.org/ ------------------------------------------------------- SF.Net email is Sponsored by the Better Software Conference & EXPO September 19-22, 2005 * San Francisco, CA * Development Lifecycle Practices Agile & Plan-Driven Development * Managing Projects & Teams * Testing & QA Security * Process Improvement & Measurement * http://www.sqe.com/bsce5sf _______________________________________________ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
