[mythtv-users] Re: DVD recording sync issues with PVR 350

[John Kondis]

For the curious: I've attached a simple script which
can be used to write pvr-x50 generated .nuv files to
DVD.  (Use at your own risk.)  It uses ProjectX
through its command-line interface to demultiplex the
audio and video.  Then it recombines using mplex and
authors using dvdauthor.  It finally burns using
growisofs.  In the intervening time, it takes up a
bunch of space (~2x the files being burned) because
ProjectX won't output to pipes.

It can requantize the video portion (if you have
transcode/tcrequant installed) if you use the option
-r<N>, where N is the requantization factor.  Also, if
you use the option -d, it will only create the file
structure and not burn to DVD.  Under normal
circumstances, it cleans up all its own temp files,
but it may leave some (potentiall big) files in the
directory dvd.tempdir.  Check and delete if you have
to.

Note also that ProjectX won't run as command-line
unless it "thinks" there is an available X device. 
Plus, you have to run ProjectX at least once through
the GUI so that you can accept the license agreement.

Certain options, like the device file representing
your DVD burner, are settable within the script
itself.  You also have to set the ProjectX binary and
X.ini files within the script.  I'm just being lazy.

I've been using this script and it seems to run well
for me.  One problem is ProjectX sometimes chokes on
the input files for no apparent reason, at least when
doing audio re-syncing.  I have one file where it
chokes bigtime (though myth can still play it through
the 350's decoder) and another where it chokes at the
end of the audio file when doing re-syncing.  In the
latter instance, the burned DVD still worked fine, but
in the former, it failed to even create the .mp2 audio
file, so mplex and dvdauthor then choke.

When ProjectX chokes on these files, it gives an error
message like:

<<
audio frames: wri/pre/skip/ins/add 74780/0/0/0/14  @
00:29:54.720 done..
===> new File: ./dvd.tempdir/stream1.mp2
stopped...
java.lang.NullPointerException
        at X$PIDdemux.close(X.java:12968)
        at X$WORK.vdrparse(X.java:6852)
        at X$WORK.working(X.java:5586)
        at X$WORK.run(X.java:5297)
>>

(Just in case any of you java and mpeg gurus wanted to
try to find why ProjectX is choking...)

Having said all that, it's a shame that other tools
won't demultiplex the PVR x50 mpeg's properly.  The
result is, this script is a bit clunky and doesn't
always work, but at least it keeps the sync right when
it works.

--- Mario Limonciello <mario.mailing at gmail.com> wrote:
> Somewhere amist this discussion about ProjectX,
> someone had mentioned
> little documentation about it.
> 
> 
>
http://www.doom9.org/index.html?/DigiTV/projectx-fullguide.htm
> 
> That seems to be a pretty useful guide for it, for
> the curious.
> _______________________________________________
> mythtv-users mailing list
> mythtv-users at mythtv.org
>
http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
> 
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