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

Thu May 5 07:32:06 UTC 2005

--- Boleslaw Ciesielski <bolek-mythtv at curl.com> wrote:
> John Kondis wrote:
> > To burn to DVD, I have a script crafted after the
> > mythtv docs ala the blurb at the end of
> > http://mythtv.org/docs/mythtv-HOWTO-22.html.  This
> > involves splitting the audio and video streams
> with
> > mpeg2desc, remultiplexing them with mplex,
> creating a
> > dvd file structure with dvdauthor, and writing an
> iso
> > file system directly to DVD with growisofs.
> 
> I don't know if this will fix your problem, but with
> the current 
> mencoder you can do the DVD NAV insertion in one
> step (and skip 
> mpeg2desc and mplex altogether):
> 
> mencoder -of mpeg -mpegopts format=dvd -ovc copy
> -oac copy -o foo.mpg 
> foo.nuv
> 
> The resulting foo.mpg can be then fed directly to
> dvdauthor.

Thanks for the response, Bolek!

OK so I downloaded the latest mplayer/mencoder
(1.0pre7-3.3.3) and compiled (it took a *long* time)
and tried your suggestion on a 1-hour long recording. 
dvdauthor seemed to do its thing OK (with warnings),
and growisofs burned to the DVD no problem.

However, when played on a DVD, the resulting video
dies about half-way through, as if the video ends
around 28 minutes into the 1-hour program.  The .mpg
file from the mencoder command above is close to 2
Gigs, consistent with being 1 hour of programming, but
the DVD player (a Sony standalone unit) doesn't see
the rest of the video.  During these 28 minutes, I
don't see any a-v sync issues so it's possible that
this method of remultiplexing fixes or helps the sync
issues (it's just eyeballing, though, I am not 100%
sure).

But the "old" method of remultiplexing (mpeg2desc &
mplex) at least didn't kill half my recording (even on
the same 1-hour recording file).  It seems my choice
so far is: deal with annoying audio sync issues or
have large parts of the recordings lopped off.

FWIW, this snippet has the warnings from mencoder that
I got:

<<
PACKET SIZE: 2048 bytes
videocodec: framecopy (720x480 24bpp fourcc=10000002)
audiocodec: framecopy (format=50 chans=2 rate=48000
bits=16 bps=48000 sample-1)
Writing AVI header...
Increasing audio density to 4
AUDIO FRAME SIZE: 1152, DELTA_PTS: 2211840 (0.024)
INITIAL DELAY of 2 frames   0fps Trem:   0min   0mb 
A-V:0.037 [0:0]
Pos:2105.8s  63111f (61%) 777fps Trem:   0min 1747mb 
A-V:-0.069 [3786:384]
1 duplicate frame(s)!
Pos:2381.9s  71384f (68%) 785fps Trem:   0min 1745mb 
A-V:-0.067 [3727:384]
1 duplicate frame(s)!
Pos:2853.5s  85517f (80%) 792fps Trem:   0min 1744mb 
A-V:-0.067 [3653:384]
1 duplicate frame(s)!
Pos:3593.4s 107691f (100%) 798fps Trem:   0min 1743mb 
A-V:-0.051 [3607:383]
Writing AVI index...
>>

I'm pretty sure the 28-minute break I'm seeing on the
DVD player occurs before the 61% warning shown above.

When I run dvdauthor on the mencoder-created file, I
get *lots* of warning lines like the following:

<<
STAT: fixing VOBU at 33MB (161/7179, 2%)
WARN: audio sector out of range: -8372 (vobu #160, pts
40.140)
WARN: audio sector out of range: -8417 (vobu #161, pts
40.390)
WARN: audio sector out of range: -8445 (vobu #162, pts
40.640)
WARN: audio sector out of range: -8481 (vobu #163, pts
40.890)
WARN: audio sector out of range: -8490 (vobu #164, pts
41.141)
WARN: audio sector out of range: -8537 (vobu #165, pts
41.391)
WARN: audio sector out of range: -8577 (vobu #166, pts
41.641)
>>

But I understand these about as well as I understand
Russian.

Another interesting thing is mplayer itself sees the
entire recording of the original .nuv file, even past
the 28-minute part.  Of course, playing the video this
way on my box is slow and way out of sync since the
only graphical device on this unit is the PVR-350'
framebuffer and the mplayer I compiled doesn't seem to
support the ivtv decoder (I thought it's supposed to:
I checked .configure --help and saw no mention of
ivtv...).

ANYHOO - Does *anybody* know of a tool that can be
used to clean up the dirty .nuv files easily?  It
seems like all the PVR-x50 mpeg streams are "dirty". 
Searches on the net show lots of people with this
problem, with a great many suggesting the solution is
to load the video up on a Windows box like VideoReDo
and re-save it so that it cleans up the stream.  Does
this mean my only choice for burning recordings to DVD
is to install Windows and get some video software for
it?

Maybe there's another way to solve the problem.  It
appears that the "chapters" on the DVD re-sync
themselves for audio-video.  In other words, 4
chapters recorded with 1/2 hour programs each see much
less a-v de-sync time than a single 2 hour program. 
So chopping up a program into chapters could get me
what I'm after.  I've tried to use mpgtx to do this,
but the resulting .mpg files seem unintelligible to
mplex/mpeg2desc.  I haven't tried this with the new
mencoder commands yet.

Or, I could perhaps use mencoder to first encode into
mp4/rtgpeg (or xvid) and then re-encode it back to
mpeg2 data that the PVR-350 will play.  Does anybody
know if somethign like that will work, and where to
start to try to accomplish this?  (Again, something
command-line or scriptable.)

I'm starting to appreciate the reliability of that old
stand-by VCR.  It never fubared an entire recording
because of a transient hiccup in the input.  Eh well.