[mythtv] [PATCH] Partial fix for mythtranscode segfault

Geoffrey Hausheer ou401cru02 at sneakemail.com
Tue Dec 2 13:58:23 EST 2003


On Tue, 2 Dec 2003 10:56:22 -0500, "Dooferlad" said:
> Just thought I would doom myself and start posting :-)
> 
> Could the transcoder find the key frame previous to the commercial cut
> start and the key frame following the cut end and re-encode between them?
> I am no mpeg4 expert, but to my simple mind it sounds like it should
> work. The rest of the video can be a direct stream copy. In fact you
> could insert a keyframe at the point where the commercial cut starts
> and just encode until the key frame following the commercial cut, if that
> sort of thing is possible.
It already does this in the case of mpeg4->mpeg4 encoding (which i svery
likely why Kenneth was seeing problems).  the problem is it is not
trivial to determine what setting were used during the initial mpeg4
encoding, and if the transcoding settings don't match the original mpeg4
settings, you may run into some issues.  In any case, we don't reencode
from key-frame to keyframe.  instead we create a new key-frame at the
cutpoint, do some adjusting of the key-frame index, and encode to the
next key-frame.  It has worked fine for me at least for the past 6 months
or so since I wrote it.

> 
> I think I will go back to hiding under a rock before people start
> throwing things at me.
No need.  most people don't throw things here.

> 
> By way of introduction I have finally got around to getting a PVR350 to
> put in my Shuttle box so I should have video out under Linux. I put
> Mandrake on it but it failed to set up my Radion 9000 AIW correctly
> for X so I will have to try another distro. I am a Debian nut at
> heart so I will probably go with that unless I get told not to.
I run Debian, as do many others on this list.  I've not had any issue
with either Matt's .debs or building via CVS.  Of course the lockdown of
the servers bit me with not having an updated xmltv, but it wasn't too
hard to deal with.

.Geoff


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