For some reason, I have, by far, the worst issues with any DVDs from Universal Studios when it comes to playback. I have no idea how they author their DVDs, but they obviously do it different from everyone else, since it’s always just a little bit off. Even different episodes on the same disc will have different issues, so it’s always a moving target.
I just got Buck Rogers: The Complete Series in the mail today, and at the same time I was playing around with ripping other stuff, notably Murder, She Wrote and The Incredible Hulk … all from Universal. For some reason though, the audio delay was way off on these all of a sudden. Now, I already have mplayer set a default delay of -.1 ms for my Matroska videos. I have no idea why I always have to do that — they play perfectly in sync when they are in the original VOB format, so I’m guessing that something in mkvmerge is throwing it off. It doesn’t really bother me, because it’s consistent so I can account for it. Oh, and for the record, it’s not just TV shows, it’s everything, including movies.
So I normally have a short delay, but suddenly I was getting wildly varied A/V sync issues. On an Incredible Hulk episode, it was actually off by +.300 ms, and on a Murder, She Wrote, it was off by -.400, and then on the first Buck Rogers episode / movie, it was -.500.
At first, I thought it was because I had been playing around with my video filters. For deinterlacing in mplayer, I normally use the softskip, pullup combination, but I recently started looking at different ones. I settled on yadif (yet another deinterlacing filter), since it works on the very few exclusions that the other one doesn’t. So I tinkered with my settings back and forth, and nothing was really changing. At the same time, I was testing a DVD rip from an independent film as well, as it’s delay was oddly at -.400, and I’d *never* had issues with movies before … or at least that I can recall.
It dawned on me after a bit of poking around with different versions and filters that all my sources were pretty questionable to start with. Anything from Universal Studios always seems cheap, to put it simply. Anytime I’ve had a disc that I couldn’t rip, it’s usually been from them. I know there are some episodes of Knight Rider that will freeze up my older DVD drives if I try to rip them. And I’ll take a look at the disc and the disc quality just seems questionable. Plus, I know that they have had in the past replacement offers for people who bought some of their DVDs. That’s not entirely uncommon though, as it has happened with other studios as well.
Once I realized that testing a movie from an independent filmmaker probably wasn’t the best idea for a control group, I went back to all my original, new settings, and tried something that had consistenly just had the normal delay (7th Heaven, in this case), and it worked fine. So, it was just their disc, again.
I have no idea what the problem is, or why the sync is off so badly in some cases. It’s really not a big deal to work around, since I just have keys mapped on my universal remote to adjust for audio delay, so once you start something up it just takes right off.
Right now I’m playing around with ffmpeg, just for fun, re-encoding it from the source VOB to another VOB file with the same codec settings, just to see what happens when I remux it into a Matroska video. One thing I love about ffmpeg, is that it seems to just correct a lot of crappy encoding issues from the source, even if I just use no options at all. It’s great. I probably won’t resort to re-encoding anything just to account for a small delay, but I am curious to see if I can figure out where the source of the error really lies. Interesting stuff.
Well, the ffmpeg finished while I was writing this, and the results are pretty nice. I just re-encoded it back to the same source settings, wrapped it in MKV, and the audio sync is dead on, without my configured delays. Pretty nice.
Here’s what I did:
ffmpeg -i 801._The_List_of_Yuri_Lermentov.vob -ab 192kb -acodec ac3 -sameq ffmpeg.vob
mkvmerge ffmpeg.vob -o ffmpeg.mkv
You can use ffmpeg to mux to MKV directly, but I’ve had issues with it, especially with AC3 for some reason.