For several years now, I made all my home videos with mjpegtools - mpeg2enc as an encoder, mplex as a muxer. Authoring is done with dvdauthor. Source is DV. All DVDs are without menus, with a single title and several chapters. The sound was at first MP2, long time ago, but I moved quickly to AC3 2ch 192k.
My standalone NTSC DVD player is JVC XV-N55 For a number of years, I had an annoying problem with my home-made videos: After less than a minute of playing, the image starts to stutter. This is a bit like the stutter due to panning, only continuous and much worse. It's like the player is skipping every other frame or so. It starts abruptly and it doesn't seem to stop. All fluidity of motion is lost, the movie looks like an old Charlie Chaplin thing (though the speed of the motion remains correct). The only "cure" is to stop / start the player. Also, if I author the DVD in such a way as to put a small gap between chapters (which is what I always do) instead of having seamless chapters, the stutter is "healed" when a new chapter begins, only to start again 10 ... 60 seconds later. (Well, that's something that dvdauthor does. I don't even know how to make seamless chapters with dvdauthor, if each chapter is made from a different VOB, which is what I always do.) $ cat dvdauthor.xml <dvdauthor> <vmgm /> <titleset> <titles> <pgc> <vob file="va1.vob" /> <vob file="va2.vob" /> <vob file="va3.vob" /> </pgc> </titles> </titleset> </dvdauthor> I admit that my player is finicky. However, this bug _only_ occurs with my homemade videos. I have a large library of commercial DVDs, and I rented an even larger number of DVDs all these years (definitely hundreds of discs, maybe in the thousands), and it never happened once with a commercial DVD. The bug does not occur with the software players (xine, VLC, mplayer, etc.) but I'm not surprised by that. I tried my home videos on a few other standalone players but I could not reproduce the bug - but I didn't try very hard. My oldest homemade DVDs are fine. It's only the DVDs made after a certain date (like 3 years ago or something like that) that trigger the bug. I can look at the dates on the DVDs to see which one is the oldest that has this problem, if that information could be useful. I use conservative bitrates (8000) and mplex confirms that the max bitrate is not higher than that allowed by the standard. I tend to use high-quality settings. My recent posts on the list provide examples of the typical settings that I use with mpeg2enc. The most recent mjpegtools version I tested is 1.9.0-RC2 and it still triggers the bug. Recently, I started to do experiments with HC Encoder. It's a Windows application, but works very well on Linux under WINE. It seems like it's not slower under emulation than when run natively on Win32. http://www.bitburners.com/hc-encoder/ The other components of the chain are the same (mplex, dvdauthor). But instead of mpeg2enc I use HCenc. So far I only tested one DVD made with HCenc, but surprisingly the stuttering disappeared. Just one DVD is perhaps not very relevant, but the bug never failed to appear before - it happened with every single DVD sooner or later. But not this time, when using HCenc. So it looks like mpeg2enc was the cause. I'll make another DVD soon and then I'll know for sure. But the cause is definitely one of the toolchain components, at this moment it's likely mpeg2enc. -- Florin Andrei http://florin.myip.org/ ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2008. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/ _______________________________________________ Mjpeg-users mailing list Mjpeg-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/mjpeg-users
