[mythtv-users] mythtranscode interlace issues with 0.25 after upgrade

[Andrew Lynch]

Hi

I am a user of Mythbuntu with a pair of PVR-250's.  Recently I upgraded to 12.04 (MythTV 0.25) and am having some issues.  I record regular NTSC analog cable to MPEG2 via ivtv from the PVR-250's.

In particular, when I specify an MPEG2 recording to be transcoded to MPEG4 I get horrible combing and it looks like the interlace is broken.  Sort of like the vertical resolution is cut in half.  

If I set the transcoding profile to "pass through" then the video looks fine but of course is still its native MPEG2 and not MPEG4.  I searched quite a bit for a solution to the problem but I am not sure what's wrong.  This message on MythTV-users sounds a lot like the symptoms I am seeing:

http://www.mythtv.org/pipermail/mythtv-users/2012-May/333230.html

(see paragraph #2)

One person later in the thread above suggested deinterlacing the MPEG2 file before transcoding.  I don't know how to do that though.  I tried various deinterlace settings on playback to no effect.  I confirmed on another computer that the transcoded file itself has the interlace artifacts so it is not a playback issue AFAIK.

Does anyone recognise this problem and know how to fix it?  I am sorry if this is a FAQ but I could little information on the problem so I may be looking for the wrong thing.  Please help!

Thanks and have a nice day!

Andrew Lynch