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

[Nick]

On 5/6/05, John Kondis <jkondis at yahoo.com> wrote:
> 
> --- "Michael T. Dean" <mtdean at thirdcontact.com> wrote:
> [...]
> > So, as suggested by Nick in this thread, I tried
> > Project X.  I just
> > opened the video and demux'ed with default settings.
> >  It threw away a
> > ton of broken video (11.278 seconds total!  Started
> > at 2:05:55.422 and
> > ended at 2:05:44.144).  Afterwards, I could open the
> > video in Avidemux2,
> > specify an external MPEG audio stream, and the
> > recording was in sync.
> 
> You and Nick rock.

After having used Project X for a long time now, and reading of these
problems, I had a hunch it was the deumxing of the streams initially
that may be causing the sync issues. After all, remuxing cannot add
back what is not present in the demuxed streams, and so if the sync is
not fixed at this stage, I can't see the remuxing magically sorting it
out.

> So now I have done the same thing.  Figuring out
> ProjectX wasn't as easy as I thought since most of the
> docs are in Dutch.  In any case, I installed it,
> compiled, ran it (requires a GUI, at least the first
> time), opened a .nuv file with "Add..." and clicked on
> "demux" with default options.  And off it went.
> 
> Actually, on my Duron 1.6 (not the actual mythbox,
> just my general purpose server) it didn't take long to
> process at all - just a few minutes.  The nice touch
> is at the end, where it says "Synchronizing audio with
> video..." or something.

On my 2.4G system, demuxing takes only a few minutes - if its >30
minutes there could either be significant errors, non standard
settings in ProjectX, or lots of other disk activity occuring at the
same time.

> 
> The output is demultiplexed audio and video streams
> (.mp2 and .mpv), so I fed these directly into
> 
> mplex -f 8 -V -o $MPGFIFO <.mp2> <.mpv> &
> 
> where $MPGFIFO is a FIFO I made with mkfifo.  Then I
> ran
> 
> dvdauthor -o <temp_dvd_directory> -f $MPGFIFO
> 
> and
> 
> dvdauthor -o <temp_dvd_directory> -T
> 
> and finally used growisofs to burn to DVD.  I played
> the DVD and...
> 
> It works great!  No sync problems or anything.

Excellent

> 
> So now onto how to do this in command line: It turns
> out ProjectX has a CLI (command line interface).  It's
> a little tricky to figure out, but this now works
> great for me:
> 
> java -jar <compiled_projectX_file> -c
> <projectX_ini_file> -n <output_stream_basename> -o
> <dir_to_put_streams> <input_nuv_file>
> 
> The "X.ini" file that it needs was, for me, in the
> original src directory where I compiled ProjectX.  A
> couple of notes: first, it apparently requires you to
> run it as GUI at least the first time so that you can
> click on "accept" for the license agreement.  (It's
> GPLed but author expressly forbids commercial use???
> WTF?)  Also, when I ssh'ed into my box without "-X",
> projectX failed to start, apparently because it needs
> to feel like it's accessing an X server even when it
> isn't going to use one.  (Go figure.)  So if you don't
> have an X display defined it may not work from the
> command line.

Haven't played much with the CLI yet as my video processing is not
done on my myth box, but this may now soon change if a suitable
demux/edit/remux combo is found.

> 
> > HTH.
> 
> It did, but I'm not sure I owe you the beer, since you
> didn't tell me about the commandline interface.  ;)
> Next project: to scriptify this whole mess.

That'd be a nice feature!

Cheers,
Nick