[mythtv] 3 problems with mytharchive (2 solved - patch provided)

Paul Harrison mythtv at dsl.pipex.com
Thu Feb 21 23:19:59 UTC 2008

Guillaume Laurès wrote:
> Hello,
> Since december I quite heavily use the mytharchive to burn
> on DVDs shows recorded with my DVB-T cards.
> The mythburn.py script is really a clever thing, but I had 3 problems
> with it.
> 1- Some channels broadcast one 5.1 (ac3) soundtrack as well as various
> 2.0 (mp2). By setting 2 preferred languages in the DB, and with the
> magic in mytharchive, I got DVDs with french language in both 5.1 and
> 2.0 soundtracks, which is enough for me (don't need other languages).
> However my DVD reader doesn't like mp2 soundtracks, so the 2.0 track
> was not readable. Hence the idea to use the "force ac3 re-encoding"
> setting. But this had the side effect to remove the 5.1 ac3 soundtrack
> from the DVD.
> It turned out that mythburn.py did extract 5.1 and 2.0 sound from the
> recording, but while re-encodig the 2.0 in ac3, it was overwriting the
> already-in-ac3 5.1 soundtrack.
This does look like a bug. I'll take a look at this one.

> 2- When just burned, the DVDs work fine in the player. Some days
> after, it takes several minutes for the player to detect the discs,
> sometime they even get ejected. Go figure. I noticed mythburn.py used
> an unknown growisofs option: -dvd-video. I couldn't find this option
> in the growisofs man page, but I found one similar: -dvd-compat. Now
> the progress.log file often ends with "Input/output error" but the dvd
> plays fine. Even when cold ;-). May be the media I'm using is badly
> handled by my burner ?

No the -dvd-video parameter is actually passed on to mkisofs by
growisofs so is correct. Current svn does also add the -dvd-compat
parameter as well so this is already fixed in trunk.

> Also, is -use-the-force-luke a joke ? I couldn't found it documented
> anywhere.

:-) No it's a genuine parameter it just isn't documented although the
man page does mention its existence it just doesn't give any details.
Google for it and you should find some references to its uses.

> 3- This is the one I couldn't fix. For a few weeks now (mean after an
> update),  I can't get 5.1 sound on the DVDs anymore. I looked at
> progress.log and tracked down this to mytharchivehelper. It sounds
> like it is buggy at checking the soundtracks from recorded files:

Someone else has reported having problems similar to this and I have a
sample file that I can reproduce the problem but so far I haven't had
much time to look into it properly. I do know it's the optimizations we
add to our copy of  libavformat that is causing it because ffplay has no
problems finding all the streams. Probably related to ticket #2797.

> 4- I just realized that after encoding the recordings to remove the
> ads (I use lossless encoding) they seem to lost the language tag (this
> is another, untouched recording):

I think this has already been fixed in mythtranscode.

> Anyway, thanks for your unvaluable software !
> GoM

Paul H.

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