[mythtv-users] MythArchive and MPEG4 recording truncated

[Rod Smith]

On Thursday 25 October 2007 12:48:39 kanetse at gmail.com wrote:
> Last night, I recorded a TV news program from 1750 to 1900.  The show
> is normally scheduled to start from 1800 to 1900, but I start
> recording 10 minutes early just to grab the previous news segment.
> This recording was made with an ATI TV Wonder PCI, which is a
> bttv-based software capture card.
>
> Then, I attempted to use MythArchive to create a DVD iso for later
> burning.  However, after MythArchive generated the .iso file, it was
> only 200MB and it only contained the first 6-7 minutes of the
> recording.
>
> Can anyone help with me this problem?  I've never used MythArchive at
> all until now.
>
> I'm using 0.20.2 (from atrpms) on Fedora 7.

I've run into similar problems from time to time. I suggest you first check 
your MythArchive log files (in the logs subdirectory of the main MythArchive 
directory, wherever that happens to be on your system). When this has 
happened to me, I've seen some error messages to the effect that there was a 
bitrate problem, I believe in the mplex program, followed by several errors, 
then a message that there were too many errors (dropped frames, IIRC) and so 
the program (mplex, I believe) was exiting. Unfortunately, I don't happen to 
have any samples of these error messages saved, so I can't be more precise 
about what to look for. The result is a truncated file in the dvd/VIDEO_TS 
directory and a short recording.

I don't fully understand the cause, but I do know that some additional 
transcoding can usually work around it. I do this with a custom transcoding 
script I've written that uses mencoder, but in principle doing it with MythTV 
GUI-driven transcoding options should also work. Unfortunately, any way you 
do it, the transcoding will take some time, it's not guaranteed to work, and 
even if it does work, it'll result in some degradation in quality. If you use 
MythTV's GUI, you'll also lose the original file (unless it's set to keep the 
original), so if you know how to do so, I recommend you back it up first, 
just in case this procedure doesn't work.

Sadly, making a DVD using MythTV is like building a house of cards; there are 
a lot of things that can go wrong and create a mess. I'm sure the situation 
will improve with time, but for now MythArchive requires a lot of attention. 
(The other big problem area, in my experience, is audio/video sync, 
particularly when the original source file is in MPEG-4 format rather than 
MPEG-2 format.)

-- 
Rod Smith
http://www.rodsbooks.com