Issue 23: Video Issues with DVD NTSC mpeg-2
Status:  Fixed
Owner:
Closed:  Apr 2009
Reported by smacdiarmid, Nov 7, 2008
What steps will reproduce the problem?
1. Download a show using the format DVD NTSC mpeg-2
2.
3.

What is the expected output? What do you see instead?
The resulting video bounces up and down slightly.  This occurs when playing back the video with 
VLC and playing the video on my TiVo via TiVoGoBack.  The bouncing makes movement in the 
video seem a little choppy and is almost enough to make you feel motion sickness.

What version of the product are you using? On what operating system?
1.3.1 OS X 10.5.5

Please provide any additional information below.



Nov 7, 2008
Project Member #1 yoav.yer...@gmail.com
Sounds like an issue with the encoding options to mencoder. Possibly an issue with
interlacing.. I don't know.

   If you have any opinions on 'good options for mencoder' to stop this wobble, I'll
be happy to include them.  Next version should make it easier to change options on
the fly if you want to try out some and see if it helps.
Status: Accepted
Owner: yoav.yerushalmi
Labels: -Priority-Medium Priority-Low
Nov 7, 2008
#2 smacdiarmid
I would actually prefer just to use the no conversion mode, but I really like the commercial removal step.  Is it 
possible to simply cut the commercials out and splice the pieces together without converting?  That would be the 
best option for me, because I like the quality and reliability of the no conversion option.

Nov 7, 2008
Project Member #3 yoav.yer...@gmail.com
Hmm..  There is an option to mencoder to 'passthrough' the video and audio.  So the
only question is if you can use passthrough AND an edit list to cut out commercials..

  Guess I'll try it here and see...

Nov 7, 2008
Project Member #4 yoav.yer...@gmail.com
Ok so I'll let you test it out  :)

  Open up your iTiVo.  go to the prefs option, 'advanced'.  Check the 'update with
beta software' button.

  Then choose (from the top menu)  iTiVo... Check for Update...

   It should download 1.4b1, which has a new download option named mpeg-2
(re-encode).  Tell me if it works for you (it seems to work on the SDTV show I had,
but seemed to have audio issues with the HDTV show I tried after....

 (note.. my plan is to replace these menu download choices with a more configurable
thing anyways.. but since you seem to need this feature.. not too much work.. :)
Nov 7, 2008
#5 smacdiarmid
I just tested it on a 30 minute SD TV show.  Everything works great except the audio is a few seconds out of sync 
with the video.  I love this feature though.  Do you think you will be able to get the audio and video to sync?

I am trying it on a HD TV show as I am writing this.  I will let you know how it turns out, but my guess is that it 
will have the same issue.  Thanks for all these great new features, and the speed at which you respond to 
concerns!

Nov 7, 2008
#6 smacdiarmid
Additional information:

The audio sync problems on the SD TV show seems to come and go.  It was out of sync until after where the first 
commercial would have been, and then corrected itself.  It then got out of sync again over the next few minutes, 
and after the next commercial it was back in sync.  Don't know if that helps trouble shoot, but I thought I would 
mention it.
Nov 7, 2008
#7 smacdiarmid
Same audio sync issue with the HD show.  On this show the audio was synced for about the first half of the 
show, but after that it was a few seconds off.
Nov 7, 2008
Project Member #8 yoav.yer...@gmail.com
Well, it's really knee-deep into the 'mencoder' territory at this point.
  I made a last-ditch change, tell me if it works (download it from

  http://yoav.org/iTiVo/iTiVo-1.4b1.zip

and try it out.  it uses one additional flag.
Nov 7, 2008
#9 smacdiarmid
It still has audio sync problems.  If you have any other things that you can try, I would be happy to test them.
Nov 9, 2008
Project Member #10 yoav.yer...@gmail.com
Well, I don't have any useful ideas, BUT!
  If you upgrade to 1.4b2 (it's a beta.. things will probably be broken).  It now
lets you control the flags under the 'advances prefs'.  (So far, only mencoder is
supported though).

  So if you want to look around on google for things related to
mencoder/mpeg2/wobbling and see if there are any suggestions, you can try whatever
flags you see out there.  Simply add them under 'advanced'.  IF you find something
useful to fixing it, I can add it back to the code. (also keep in mind that changing
download format will reset those flags back to their old values)

Apr 13, 2009
Project Member #11 yoav.yer...@gmail.com
so, this will be on a case-by-case thing, but if you can 'guess' how delayed the
audio is, under advanced prefs other options, add

 ' -delay 0.5'

or whatever delay in seconds you want to induce between the video and audio.  This
should help you re-sync the two (although I'm guessing since the sync differs by
show, you'd need to do it on a case-by-case basis.

  Another option is to try a different encoder (like ffmpeg) since each one has
different 'issues' and you may find that it works better for you.

  Marking this as 'fixed' since this is about as useful an answer I can give.  Part
of the black magic of re-encoding data sources is that it can get pretty sucky.
Status: Fixed