[mythtv] mythrecode

Michael Pedersen michael.j.pedersen at verizon.net
Mon May 19 13:17:40 EDT 2003

Hash: SHA1

| michael, i just wanted to start off a little thread about the mythrecode
| you mentioned.  what are your plans for this that wouldn't be achieved
| by enhancing mythtranscode, and providing a ui inside mythtv for
| scheduling recoding of recordings for archiving/whatever purposes?
| i see what i'm working on with getting mythtranscode to eventually allow
| me to do just that.  right now it would only do rtjpeg or mpeg-4, but as
| new encoding schemes become available they could get added in.  i think
| that there might need to be some work on improving the base classes for
| encoding/decoding (i'd really like to be able to easily extract the
| un-decoded data), but someone (issac probably) has done a lot of work to
| make re-encoding nice and simple, and i'm initially at least, trying to
| leverage that.

I am utilizing the parts that I can, but mythrecode is being built for a
specific purpose related to mythmkmovie. Basically, not all files built
my mythtv will work with mencoder, even with the mythtv patch (my most
common failure is an error stating that "Static sprites are not
supported"). As a result, some shows that I wish to archive can not be

So, my solution? Link against libmyth, and put in a new wrapper which
uses the NuppelVideoPlayer to decode all frames. After that, I'm going
to feed the decoded frames directly into mencoder (by way of a pipe) as
an uncompressed AVI file (and for that, I'm going to use libavcodec).

Basically, I'm not rewriting any code. Just doing more glue work (as
I've already done with mythmkmovie).

And, as I noted elsewhere, I've gotten much faster results on retrieving
file length (and that's just so far). My machine is no slouch, but
running this command:

mencoder -ovc copy -oac copy -o /dev/null mythtvnuvfile

still takes 10 seconds for a half hour show, 20 for a one hour, etc. My
current code efforts have allowed me to retrieve the same information in
less than 0.25 seconds on both my p2/300 laptop and my 1.3Ghz desktop.

Oh, and for the major question: Why use this, instead of the transcoder?
I want to produce an output divx file, suitable for archiving off. I
want it to be viewable on Linux, Windows, and Mac. I do NOT want to
leave shows in the MythTV recordings list indefinitely, since that just
gets annoying (especially since, just so far, I've got about 50 shows
archived off). I want to reduce filesizes, and I want to remove the

And, honestly, I don't want to get in you guys way. The work being done
by everybody is fantastic, and I dearly love MythTV. I don't watch live
tv anymore because of it. I just record everything, watch what I want
when I want, and save off the shows I really care about. All because of
the work you guys have already done. I just hope you guys can enjoy some
small amount of what I've done.
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