[mythtv-users] jumping frames, out of order, and frontend segfaults

[Jason Joines]

On Mon, 14 May 2007, Jason Joines wrote:

> Date: Mon, 14 May 2007 11:30:04 -0500 (CDT)
> From: Jason Joines <jason at joines.org>
> Reply-To: Discussion about mythtv <mythtv-users at mythtv.org>
> To: mythtv-users at mythtv.org
> Subject: [mythtv-users] jumping frames, out of order, and frontend segfaults
>
>     I'm using mythtv 0.20-0.2 with a Hauppauge PVR 150 on Kubuntu 6.10
> with an AMD AM2 3000+ cpu and 1 GB ram.
>
>     Recently I noticed the picture seemed jumpy during playback.  I
> eventually realized that what was happening was future frames were being
> shown out of order.  For example, if a person was about to nod there head,
> you would see a flash of where there head was about to me, a moment later
> they would move there head there.
>
>     It's been getting worse and yesterday the frontend crashed for the
> first time.  I got a couple of errors in my system log such as this:
>
> May 13 18:52:08 myth kernel: [1923098.337467] mythfrontend[20651]:
> segfault at 00002aaab4cf9250 rip 00002b419792fb90 rsp 0000000044881a60
> error 4
> May 13 20:38:47 myth kernel: [1929491.029774] mythfrontend[21294]:
> segfault at 00002aaaafdd7b00 rip 00002b17cd87b270 rsp 000000004307eed8
> error 6
>
>     There are a lot of errors in the backend log like this:
> [mpeg2video @ 0x2b288497cfd0]end mismatch left=584 DEFA9
> [mpeg2video @ 0x2b288497cfd0]Warning MVs not available
> [mpeg2video @ 0x2b288497cfd0]ac-tex damaged at 43 29
> [mpeg2video @ 0x2b288497cfd0]Warning MVs not available
> [mpeg2video @ 0x2b288497cfd0]ac-tex damaged at 24 29
> [mpeg2video @ 0x2b288497cfd0]invalid cbp at 0 8
> [mpeg2video @ 0x2b288497cfd0]Warning MVs not available
> [mpeg2video @ 0x2b288497cfd0]00 motion_type at 4 29
> [mpeg2video @ 0x2b288497cfd0]ac-tex damaged at 30 21
> [mpeg2video @ 0x2b288497cfd0]Warning MVs not available
> [mpeg2video @ 0x2b288497cfd0]invalid mb type in I Frame at 44 29
> [mpeg2video @ 0x2b288497cfd0]Warning MVs not available
> [mpeg2video @ 0x2b288497cfd0]ac-tex damaged at 44 16
>
>     Another symptom has cropped up related to being out of order.  Several
> times I've got near the end of a recording and realized I'd fast forwarded
> past the last scene.  I rewound to a spot I knew was before the scene, say
> 27:50 and watched to the end but didn't see it, just a commercial.  Then I
> rewound again and saw a different commercial at the same time index.  This
> has happened several times.
>     It has even jumped forward a few times during the rewind.
>
>     A few days ago, I thought the problem might be related to load and
> commercial flagging.  I disabled auto commercial flagging in the frontend
> setup and disabled auto skip of the commercials since they weren't being
> flagged.
>     However, last night it was still flagging commercials.  Thinking
> backend might need to be restarted before the change took affect, I
> restarted it this morning.  However, the it kept showing commercial flags
> in the queue.
>     I manually killed the mythcommflag job and the load started dropping
> dramatically.  Then it popped up again and I had to manually kill it
> again.
>     How do you disable commercial flagging?  Any other ideas as to what
> could be causing the frame ordering issues?
>
>
> Jason Joines
> ================================
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> mythtv-users at mythtv.org
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      Well I finally got commercial flagging disabled by a few backend 
setting changes ( but haven't got it to stop queuing them ).  That didn't 
help the problem though.
      I did a test via "cat /dev/video0 > /tmp/test.mpg".  That also had 
jumpiness.  I also played it with MPlayer and Kaffeine and both of them 
also had problems although they acted differently.  However, I think this 
shows the problem is not with Myth.

      I rebooted the box and did another test.  It was fine.  All the stuff 
Myth has recorded since then has been fine.  The box had been up a long 
time.  I guess there must be a problem with the ivtv driver and/or 
firmware that manifests itself when it's been loaded a long time.  I'm 
using module 0.7.0-2 and firmware 0.20061007.  Hope upgrading those will 
help.


Jason
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