[mythtv] [PATCH] Partial fix for mythtranscode segfault

Geoffrey Hausheer ou401cru02 at sneakemail.com
Mon Dec 1 17:59:22 EST 2003


On Mon, 01 Dec 2003 14:30:54 -0800, "Geoffrey Hausheer " said:
> I have tracked down the mythtranscode segfault to a problem in the
> avdecoder fast-forward code.  Specifically, after a fast-forward, under
> certain conditions, the timecode gets set to '0' which really hoses up
> the encoder.
> 
> I haven't yet figured out where the problem is yet, but I will work on
> that next.  For the time-being, the following patch shoul gaurantee
> monotonically increasing timecodes, and prevent the segfault.
> 

Okay, I knoiw why the timecode doesn't get updated, but noto what to do
about it.

effectively, when doing a fast-forward, we can jump directly to the video
frame in question (via the recordedmarkup table).
Depending on the jump, in getFrame() pkt->pts may contain AV_NOPTS_VALUE
(i.e. we haven't seen a sync frame...or so i assume).  Since we cleared
lastvpts during the fast-forward, we now have no timecode.

The best option I can think of is to not clear lastvpts on a
fast-forward, but that may cause some other issues, and i'm not familliar
enough with the code to know what they are.  Can someone pick this up and
run with it?  If not, the patch I posted will work fine for the
transcoder, but I'm not sure what the ramifications would be to other
video consumers.

.Geoff


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