[MEncoder-users] [BUG] a-v sync problems with pullup, softskip (only on some DVDs)

[Phil Ehrens]

Corey, would you mind if I copied your description of these
"classes" to the transcode wiki for inclusion into a document
detailing the vagaries of NTSC dvd and TV formats?

Corey Hickey wrote:
> Phil Ehrens wrote:
> >
> >I just wanted to step in here and say that if this is a
> >U.S. release dvd, these things typically change frame rate
> >at strange times and for no apparent reason. Hardware players,
> >mplayer, and mencoder seem to be able to deal with this
> >in all the cases I have seen, but maybe some filter or
> >plugin is incompatible with the "handling"? Just an idea.
> >
> 
> Yes, it is a U.S. NTSC DVD. I know what you mean about changing 
> framerates; usually it's really changing from soft-telecine (actually 
> 24000/1001 fps progressive) to hard-telecine (30000/1001 fps).
> 
> From what I've seen, there are several types of DVDs that do this.
> 
> Class 1: TV-show DVDs that have a canned intro spliced in.
> Example: Buffy the Vampire Slayer season 1 (and later?).
> The actual content of these titles is soft-telecine, but the intro (with 
> the opening credits, scenes from past episodes, etc.) is hard-telecine.
> 
> Class 2: TV-show DVDs with brief hard-telecine at scene changes.
> Example: Sex in the City season 1 (and later?).
> My hypothesis is that this is a result of broken DVD-mastering software. 
> Perhaps the scenes are stored separately before mastering and the 
> telecine occurs where files are "spliced" together. Now that I think 
> about it, the hard-telecine might actually be at chapter divisions; I 
> never bothered to look closely.
> 
> Class 3: TV-show DVDs with random, frequent telecine changes.
> Example: Some Twilight Zone episodes I saw a long time ago.
> These were really annoying to look at: every couple seconds the video 
> would toggle from hard-telecine to soft-telecine, with no apparent 
> regularity or correspondence to anything I could see.
> 
> Class 4: Cinematic DVDs with very occasional brief hard-telecine.
> Example: The Lord of the Rings extended version.
> This is probably similar to "Class 2", but very infrequent (only a few 
> times in the whole movie). Definitely not chapter boundaries.
> 
> Class 5: Cinematic DVDs that switch from soft- to hard- once.
> Example: Polluck
> Polluck is the only movie I've ever seen that does this. It's 
> soft-telecine until somewhere in the middle, where it switches to 
> hard-telecine for the remainder.
> 
> ...there's probably more, but these are the ones I've come across.
> 
> 
> In any case, Rich wrote the pullup filter, so he'll be able to figure 
> out what's wrong.
> 
> -Corey
> 
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