[mythtv] "Transcoding" PVR-[23]50 output

[Russ Southern]

(Posted to MythTV-Dev since I'm testing against latest CVS)

Greetings,

Sorry for the interminable post - trying to cover all the bases.

Summary: I want to re-encode/transcode MPEG files, using MythTV's cut list.

I've been working in vain the last few days to concoct a commercial-cutting,
re-encoding solution for PVR-250 MPEG files.  Looking for opinions before I
go off the deep end...

Problem Statement:

I just tried mythtranscode from last night's CVS.  It ran about 1.5 hours on
the ~4GB PVR-250 file, producing ~100MB of output that is not recognized by
mplayer.  Rumor had it the new mythtranscode might handle these files...

The MPEG files output from the Hauppauge cards use VBR, and mencoder cannot
handle skipping in VBR encoded files.  The transcode package shows more
promise (since it just bites the bullet and deals in frames, scanning its
way to each cutpoint), but I have, as yet, been unable to find a working
combination of input and output codecs to satisfy transcode and mplayer.

Disclaimer: transcode segfaults/floating point exceptions on certain of
these combinations, so I may just have onsistently faulty transcode builds.

So, mencoder can create files but not cut them well.  transcode can cut on a
specific frame boundary (very nice for use with MythTV), but seems unable to
manipulate files for me.

Discussion:

Some folks on the ivtv-devel list suggested a couple packages for mpeg
stream-editing, but they either would not compile (not very newbie-friendly
- my goal is to release something easy-to-use), or are GUI-only (not
scriptable).

mythmkmovie depends on mencoder's ability to skip correctly.  My intent is
to add a command-line argument to mkmovie, replacing the makesegments and
makemovie subs with special-case code to handle MPEG files.  (If I can find
a usable approach, that is)

I have, at some point in the proceedings, created an mpeg4 file, with
correct audio and commercials cut.  I did it by first using mencoder to
reencode the file to some format or the other, then using mencoder/transcode
to cut commercials.  Two reencodes is not ideal, of course.

Question:

Am I missing something obvious, here?  I do not have a plain capture card,
so have no idea how mythtranscode is supposed to behave.  Has anyone else
had success with the new mythtranscode on MPEG files?

Russ