[linux-dvb] Re: problems with more than one dvbs-card

[Klaus Schmidinger <Klaus.Schmidinger@cadsoft.de>]

apieper@gmx.net wrote:
> 
> -------- Original Message --------
> Subject: [linux-dvb] Re: problems with more than one dvbs-card (10-Jun-2001 23:20)
> From:    Klaus.Schmidinger@cadsoft.de
> To:      linux-dvb@linuxtv.org
> 
> > apieper@gmx.net wrote:
> > >
> > > Hi,
> > >
> > > since i installed a second dvbs-card in my vdr-pc
> > > i got some problems.
> > >
> > > My VDR-PC: Pentium 166 / Intel Chipset (FX?)/ RAM 128MB
> > > VDR 0.72 / Driver 0.82 / Mandrake with kernel 2.2.17
> > > 2 Hauppauge DVBs-Cards, 'old' Version, 80GB Maxtor
> > >
> > > Problem 1:
> > > Often (60%-70%) if i record with both cards and one
> > > recording stops vdr is unloaded and my pc reboots
> > > (the pc is installed to reboot if vdr stops).
> > >
> > > Problem 2:
> > > I get messages in the log regarding buffer overflow, example:
> > >
> > > Jun  8 20:16:10 VDR vdr[854]: record /mnt/video/vdr.00/Tagesschau/2001-06-
> > > 08.19.59.10.04.rec
> > > Jun  8 20:16:10 VDR vdr[854]: recording to '/mnt/video/vdr.00/Tagesschau/
> > > 2001-06-08.19.59.10.04.rec/002.vdr'
> > > Jun  8 20:16:11 VDR vdr[2088]: output thread started (pid=2088)
> > > Jun  8 20:16:11 VDR vdr[2089]: input thread started (pid=2089)
> > > Jun  8 20:16:43 VDR vdr[2089]: buffer usage: 76%
> > > Jun  8 20:16:43 VDR last message repeated 5 times
> > > Jun  8 20:16:43 VDR vdr[2089]: buffer usage: 77%
> > > Jun  8 20:16:43 VDR last message repeated 7 times
> > > Jun  8 20:16:44 VDR vdr[2089]: buffer usage: 78%
> > > Jun  8 20:16:44 VDR last message repeated 6 times
> > > [...]
> > > Jun  8 20:16:52 VDR vdr[2089]: buffer usage: 97%
> > > Jun  8 20:16:52 VDR last message repeated 6 times
> > > Jun  8 20:16:52 VDR vdr[2089]: buffer usage: 98%
> > > Jun  8 20:16:53 VDR last message repeated 7 times
> > > Jun  8 20:16:53 VDR vdr[2089]: buffer usage: 99%
> > > Jun  8 20:16:53 VDR last message repeated 6 times
> > > Jun  8 20:16:53 VDR vdr[2089]: buffer usage: 100%
> > > Jun  8 20:17:04 VDR vdr[854]: buffer stats: 1048575 (100%) used
> > > Jun  8 20:17:04 VDR vdr[854]: timer 3 stop
> > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> > >
> > > In this example vdr stops here and the pc resets.
> >
> > Aren't there any further messages in the log file?
> > I don't see why VDR would see any need to exit here?!
> 
> Jun  8 20:16:02 VDR kernel: record buffer full
> Jun  8 20:16:06 VDR last message repeated 69 times
> Jun  8 20:16:07 VDR vdr[854]: confirm: Aufzeichnung beenden?
> Jun  8 20:16:07 VDR kernel: record buffer full
> Jun  8 20:16:07 VDR last message repeated 12 times
> Jun  8 20:16:07 VDR vdr[854]: confirmed
> Jun  8 20:16:08 VDR kernel: record buffer full
> Jun  8 20:16:09 VDR last message repeated 36 times
> Jun  8 20:16:10 VDR vdr[854]: buffer stats: 1048575 (100%) used
> Jun  8 20:16:10 VDR vdr[854]: timer 9 stop
> Jun  8 20:16:10 VDR vdr[854]: deleting timer 9
> Jun  8 20:16:10 VDR kernel: record buffer full
> Jun  8 20:16:10 VDR last message repeated 5 times
> Jun  8 20:16:10 VDR vdr[854]: stopping recording on DVB device 1 due to higher priority
> Jun  8 20:16:10 VDR vdr[854]: timer 3 start
> Jun  8 20:16:10 VDR vdr[854]: switching to channel 1
> 
> This are the messages before the ones i sent with
> my last mail.

What about messages _after_ those? Isn't there anything _after_ the

  Jun  8 20:17:04 VDR vdr[854]: timer 3 stop

message??

> Why are there so many messages re-
> garding the buffer, arent 128MB enough for VDR ?

VDR uses a 1MB buffer for its recording function. If that buffer overflows,
something bad must have happened.

> After more tests i can say that the reboots after
> one recording stops (if i record with both cards)
> will occur in ~20-30%.
> 
> > > Sometimes i get such buffer-usage messages but
> > > vdr is running without problems.
> > >
> > > Even with only one dvbs-card i got such messages,
> > > but this never produced such effect.
> > >
> > > Problem 3:
> > > Picture distortions (blocks).
> > > If i record with both cards sometimes i get distorted recordings
> > > with blocks in it. Until now i only got this when i recorded
> > > Pro7 and Sat1 together, i tested few other combinations (will
> > > test more next days) but there where no problems (e.g. ARD and RTL).
> > > With Sat1 and Pro7 i can reproduce the errors, the recordings
> > > are almost unusable.
> > >
> > > I guess i have a bottleneck somewhere, how can i
> > > change this ? (faster processor, more ram ?)
> >
> > Are you sure you have DMA activated for your disk?
> >
> >    video:/home/kls # hdparm /dev/hda
> >
> >    /dev/hda:
> >     multcount    = 16 (on)
> >     I/O support  =  0 (default 16-bit)
> >     unmaskirq    =  0 (off)
> >     using_dma    =  1 (on)       <=====================
> >     keepsettings =  0 (off)
> >     nowerr       =  0 (off)
> >     readonly     =  0 (off)
> >     readahead    =  8 (on)
> >     geometry     = 4560/255/63, sectors = 73261440, start = 0
> 
> DMA is activated. For example if i transform recordings
> with pes2av_pes the throughput is much higher than 2
> simultaneously recordings should acquire (should be ~1MB/sec ?).
> 
> I only wonder that this errors only seems to occur (as of
> now i only tested some channel-combinations) if i record
> Sat1 and Pro7 together.
> 
> > Otherwise you could try using a faster processor.
> 
> So you mean faster processor is better than more ram ?

VDR doesn't use too much RAM for buffering, so more RAM won't
change anything.

Klaus
-- 
_______________________________________________________________

Klaus Schmidinger                       Phone: +49-8635-6989-10
CadSoft Computer GmbH                   Fax:   +49-8635-6989-40
Hofmark 2                               Email:   kls@cadsoft.de
D-84568 Pleiskirchen, Germany           URL:     www.cadsoft.de
_______________________________________________________________


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