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

[D Richard Felker III]

On Wed, Mar 16, 2005 at 10:28:07PM -0800, RC wrote:
> On Wed, 16 Mar 2005 23:34:37 -0500
> D Richard Felker III <dalias at aerifal.cx> wrote:
> 
> > Nope, it means pullup is failing to get enough good frames to output.
> > This means either it's deficient in finding them, or the input file is
> > horribly broken.
> 
> You're ignoring the obvious possibility that the source could have
> duplicate frames, which I find to be common.

No, you're ignoring the obvious fact that I've run this file through
pullup and read the verbose logs.

In any case, pullup does NOT remove duplicate frames; this isn't its
job. All it does is identify sequences of two or three consecutive
fields which it believes came from a common progressive frame. If
pullup sees 4 consecutive fields that all happened to come from the
same frame (a genuine "duplicate"), it will output two frames, each
using two of the fields, and mencoder will NOT do its "duplicate
frame" thing. When you see duplicate frames using pullup, it always
means that there were some unmatchable fields, caused either by bad
splices at scene-changes or very bad content that pullup could not
find a sane way to field-match.

Rich