[mythtv] 'WriteAudio: buffer underrun' during playback caused by the scheduler

[Jan Kleinig]

But I'm using a quite fast machine (P4 3,2GHz in a Pundit-R case with 
1GB Ram) and don't have another system running here... Don't want to use 
X machines to have a great VCR ;) Can I do the change to the sql part 
myself? How? ;)

And why is it poosible that sql takes away CPU power from playback while 
playback has realtime priority? I thought that this is the point to give 
a proccess realtime priority...

Thanks!

Mark Buechler schrieb:
> What's happening is mysql is taking more CPU/IO during the scheduling 
> process which takes CPU/IO away from playback/recording. I've had 
> trouble with this from time to time due to another issue but a 
> temporary solution would be to put your database on another (maybe 
> faster) system. Another might be to change the sql in the scheduling 
> thread to use a loop and the LIMIT clause to attemt to tone it down a 
> bit.
>
> - Mark.
>
> On 9/9/06, *Brian C. Huffman* <bhuffman at graze.net 
> <mailto:bhuffman at graze.net>> wrote:
>
>     I'm getting similar problems during playback.  I don't think it's
>     caused
>     by the scheduler though...I'm seeing it on playing videos that
>     have been
>     ripped from DVD.  I'm about to open a ticket.
>
>     -b
>
>     On Sat, 2006-09-09 at 17:21 +0200, Jan Kleinig wrote:
>     > Hi,
>     >
>     > I'm still having those problems :(
>     >
>     > I am using Knoppmyth R5C7 with mythtv svn 11084 and the
>     ac3-patch 0.20
>     > written by Mark Spieth.
>     >
>     > I'm using the EIT Scanner because tvtoday doesn't support that many
>     > channels and I hate hunting for a new script when they change the
>     > layout of there homepage...
>     >
>     > The problem is, that every time when the scheduler 'reschedules', I
>     > get audio problems in the recording or LiveTV I watch.
>     >
>     > The backend log says:
>     >
>     > 2006-09-09 17:11:26.371 EITScanner: Added 10 EIT Events
>     > 2006-09-09 17:11:26.375 Reschedule requested for id -1.
>     > 2006-09-09 17:11:28.878 Scheduled 36 items in 2.5 = 1.19 match +
>     1.31
>     > place
>     >
>     > At the same time, the playback stumbles and the audio is gone in
>     most
>     > of the cases. Sometimes, the audio comes back to live again after
>     > about 3 seconds... The frontend tells me this:
>     >
>     > 2006-09-09 17:10:48.608 TV: Attempting to change from None to
>     > WatchingPreRecorded
>     > 2006-09-09 17:10:48.627 libavformat type mpegts
>     > 0: start_time: 2615.887 duration: 539.622
>     > 1: start_time: 2615.963 duration: 539.611
>     > 2: start_time: 2615.896 duration: 539.616
>     > stream: start_time: 29065.414 duration: 5996.522 bitrate=2668 kb/s
>     > 2006-09-09 17:10:48.635 AFD: Opened codec 0x8bc9330, id(MPEG2VIDEO)
>     > type(Video)
>     > 2006-09-09 17:10:48.635 AFD: Setting maxchannels to 6, -1
>     > 2006-09-09 17:10:48.635 AVFD: codec MP3 has 2 channels
>     > 2006-09-09 17:10:48.635 AFD: Opened codec 0x8b52c10, id(MP3)
>     > type(Audio)
>     > 2006-09-09 17:10:48.826 Opening audio device 'default'. ch 2 sr
>     48000
>     > 2006-09-09 17:10:48.826 Opening ALSA audio device 'default'.
>     > 2006-09-09 17:10:49.005 VideoOutputXv: XvMCTex: Init failed
>     > 2006-09-09 17:10:49.005 VideoOutputXv: XVideo Adaptor Name: 'ATI
>     > Radeon Video Overlay'
>     > 2006-09-09 17:10:49.398 TV: Changing from None to
>     WatchingPreRecorded
>     > 2006-09-09 17:10:49.399 Using realtime priority.
>     > 2006-09-09 17:10:49.430 Video timing method: USleep with busy wait
>     > 2006-09-09 17:11:26.752 WriteAudio: buffer underrun
>     > 2006-09-09 17:11:27.247 WriteAudio: buffer underrun
>     > 2006-09-09 17:11: 27.521 WriteAudio: buffer underrun
>     > 2006-09-09 17:11:27.776 WriteAudio: buffer underrun
>     > 2006-09-09 17:11:28.339 WriteAudio: buffer underrun
>     >
>     > You see, at 17:11:26.375 the rescheduling is getting startet and at
>     > that time, the error occures...
>     >
>     > Does anybody have an idea what to do?
>     >
>     > Thanks!
>     > _______________________________________________
>     > mythtv-dev mailing list
>     > mythtv-dev at mythtv.org <mailto:mythtv-dev at mythtv.org>
>     > http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
>
>     _______________________________________________
>     mythtv-dev mailing list
>     mythtv-dev at mythtv.org <mailto:mythtv-dev at mythtv.org>
>     http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
>
>
> ------------------------------------------------------------------------
>
> _______________________________________________
> mythtv-dev mailing list
> mythtv-dev at mythtv.org
> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-dev
>   
-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://mythtv.org/pipermail/mythtv-dev/attachments/20060910/7616b0bd/attachment.htm