[mythtv-users] Transcode or Nuvexport issue from mpg (mpeg) to avi

[Peter Schachte]

> I just wish that the
> default transcode from using the backend wouldn't change the databased aspect
> ratio

I'm not sure what you mean.  nuvexport produces an .avi file; I don't
think it *writes* anything to the database.

> Oddly, I've had a few recent MPG's that have exhibited the same length
> behaviour, Myth believes them to be 45 mins long, but they play for over an
> hour.  I've not tried to transcode them, but it is odd.  Is the length of the
> clip be taken from a value other then the recording time?

Interesting.  What myth version are you using?  Where do your .mpg
files come from?  When I was using 0.18, and even an SVN version from
a month or two before 0.19 was released, to record from DVB-T, I got
quite a few recordings with this flaw.  Happily, it hasn't happened
since I upgraded to 0.19.  Unfortunately, when I did mythcommflag
--rebuild, it made the problem much worse -- two hour recordings would
claimed to be a few minutes long.  The odd thing was, the program
would play fine, and half way through the program, myth would think I
was half way through the few minute running time.  I looked in the
database, and found that rather than having a record for frames 25,
50, 75, etc, as other non-defective recordings do, it had a record for
frames 1, 2, 3, etc.  And rather than having a max frame number of a
~180000 it had a max of more like 7200.  So it seems like it was
counting seconds as frames, or something like that.

A dev list message
(http://www.gossamer-threads.com/lists/mythtv/dev/170636#170636)
suggested a small patch (attached).  I found that after upgrading to
0.19, and with that patch, mythcommflag --rebuild did fix this
problem, which allowed me to edit out commercials and then nuvexport
the recording.  After that, though, the recordings always showed a
short end time, and IIRC, mythcommflag --video didn't fix it properly.
So I used the patch to salvage my old recordings, and then removed the
patch so mythcommflag could repair the new .avi files.

> How are you using 'mythcommflag --video' as mentioned in your last post?

I run it after most nuvexport runs to fix the recording length.

-- 
Peter Schachte              Everything that is really great and inspiring is
schachte at cs.mu.OZ.AU        created by the individual who can labour in
www.cs.mu.oz.au/~schachte/  freedom.
Phone: +61 3 8344 1338          -- Albert Einstein 
-------------- next part --------------
--- /usr/src/mythtv/mythtv/libs/libmythtv/avformatdecoder.cpp	2006-04-02 17:48:49.000000000 +1000
+++ /home/mythtv/mythbuilder/avformatdecoder.cpp	2006-04-03 16:42:47.000000000 +1000
@@ -796,7 +796,9 @@
         keyframedist          positionMapType  
-        if (!strcmp(fmt->name, "avi"))
+// PDS:  commented out as recommended in
+//       http://www.gossamer-threads.com/lists/mythtv/dev/170636#170636
+//        if (!strcmp(fmt->name, "avi"))
         {
             // avi keyframes are too irregular
             keyframedist