[mythtv] [PATCH] Partial fix for mythtranscode segfault

Geoffrey Hausheer ou401cru02 at sneakemail.com
Tue Dec 2 09:52:10 EST 2003


On Mon, 01 Dec 2003 20:35:58 -0500, "Andrew Mahone andrewmahone-at-eml.cc
|mythtv/1.0-Allow|" <685xhmkpgi0t at sneakemail.com> said:
> Geoffrey Hausheer wrote:
> > As always, I'll be happy to take a look at it if you can provide me with
> > the original video, and the other info I need (cutlist, and transcoder
> > settings).  I haven't seen any such corruption, but I don't normally
> > transcode from mpeg4->mpeg4, and very rarely use cutlists, so I normally
> > need examples to debug issues with configurations different from my own.
> 
> I haven't been having any problems with segfaults, and I guess I should 
> have figured that this wouldn't apply to me.
> 
> I don't have anything available right now, but I can record something to 
> test with.  What's the easiest way to get the cutlist and transcoder 
> settings out of the database?  Also, I remember seeing an option to save 
> the original after a transcode, but I can't seem to find it now.  If I 
> can't keep the original that way, I'll just copy it before the 
> transcode.  I'll try to make the samples as small as possible, so that 
> it won't take you days to get them off of my computer (cable modem, 
> rather low capped upstream).
> -- 
The option is from the 'setup' program I believe.  Under General Options.
 Or just change the 'SaveTranscode' value in the settings table through
mysql

Anyhow, I mightbe able to save you the trouble.  First off, are you doing
commercial cuts before transcoding?  If so, this is causing the problem. 
The transcoder was never designed to do what you are doing (though it
shouldn't be too hard to support).  When converting mpeg4->mpeg4 and the
commerical-cut code is on, it assumes you want to prune out the
commercials without re-encoding the whole file.  So you'll end up with a
hodge-podge of different frame types around the commercial cuts, that are
likely to screw up your video.
A crude hack would be to comment out line 2935 in NuppelVideoPlayer.cpp
(the line which says 'decoder->SetRawVideoState(true);').  If that fixes
your problem, I'll try to think of a way to control that option better. 
Note that if you're not in 'raw' mode, it will take a long time to
transcode the file, since it needs to reencdoe every frame.

.Geoff


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