[mythtv-users] Lossless Transcode 0.25

[Scott and Nicole Harris]

>>> Actually, I have discovered something a little disconcerting. After 
>>> watching some shows that I transcoded with 0.25 last night and tonight (some 
>>> of them recorded with 0.25 and some on 0.24), there are flashes of vertical 
>>> purple lines on the screen approximately every minute and at every 
>>> commercial transition that was removed. The same issues are not present 
>>> on the recordings before they have been transcoded. I tested playback on 5 
>>> different frontends, different recordings, etc and it's pretty consistent; 
>>> anything transcoded with 0.25 in the last two days has vertical purple line 
>>> flashes every minute or so; everything else is fine.
>>> It sounds a lot like this http://code.mythtv.org/trac/ticket/10110 except 
>>> these are lossless transcodes. Also, the same issue here 
>>> http://www.gossamer-threads.com/lists/mythtv/users/495911?do=post_view_threaded#495911 
>>> indicates that an ffmpeg update fixed it for him to the point that the 
>>> affected recording were no longer affected, indicating it was a playback 
>>> issue. 4 of my frontends are Mythbuntu 11.10 fresh installs and one is a 
>>> pretty old 10.04 install that has never displayed this behavior before these 
>>> 0.25 transcodes.
>> When reading through ticket #10110, it concludes with "Closing at reporter request. >> As an aside, this was likely due to the Debian external libmpeg2 insanity.". >>I am not entirely sure what the Debian external libmpeg2 insanity is, or what I can >>try to do to resolve this? It's pretty bad, it is affecting every single transcode I >>do to the point that I probably won't be able to do any transcodes other than to >>try to test the result of possible resolutions.

>The "debian insanity" were patches made to the source of the packages 
>they were distributing, that caused them to be linked to external 
>decoder libraries, rather than the ones internally used by MythTV. That 
>is the only way updating external libraries MythTV should not be 
>depending on would make any difference.

>Does this issue show up on all of your frontends or just the one? Does 
>this issue show up on players other than mythfrontend/mythavtest? What 
>hardware are you experiencing this on? Grab a copy of mkvtoolnix, 
>mp4box, or tsmuxer, multiplex the video into one of those containers, 
>and see if the problem persists.
It is present on all my frontends (5 of them).  I haven't tried viewing the files with other players, I'lltry VLC tonight when I get home.  I'm also going to bring it over to a Windows box to see if it's present there as well on VLC/Windows.
I wonder if it's a Mythbuntu 10.04 / 11.10 thing.  My SBE used to do all my transcoding and it's on 10.04(I haven't been able to upgrade this machine past 10.04 because of some bug in their installer),but I've moved it back to the MBE which is running a fresh 11.10.
As far as the other suggestion, it's a bit above my paygrade, so I'll have to look into how to dothat.  Do you mean multiplex one of the "bad" recordings?
The hardware is varied on the frontends. Pentium Dual Core / 4GB ram / Intel Graphics, Core 2 Dual / 6GB ram / NVidia 8400 GS,AMD 4600 X2 / 4GB ram / NVidia 220GT, AMD Athalon 3200 / 2GB ram / NVidia 430GT with the COre 2 DUo being the MBE where the transcoding is happening.