[AG-TECH] System freezes sending video on Linux w/ IVC-200 capture card

Christoph Willing c.willing at uq.edu.au
Sun Mar 29 18:00:33 CDT 2009

On 26/03/2009, at 4:58 PM, Christoph Willing wrote:

> On 26/03/2009, at 3:34 AM, Andrew Ford wrote:
>> Hi,
>> For a while now we've been seeing hard freezes (ie, trying to kill  
>> the X server does nothing) on one of our Linux machines when it  
>> tries to send video via an IVC-200 cap card. It tends to occur more  
>> frequently when the load is heavier - attempting to send 2 or more  
>> 720x480 mpeg4 or h.264 streams causes it to freeze within 5-10  
>> minutes, 4 h.261 videos make it freeze in about half an hour, and 2  
>> 261 videos makes it last about 2 days. dmesg and /var/log/messages  
>> don't give any clues. Other types of load don't seem to cause  
>> freezes, and I ran memtest86 overnight with no errors. Originally  
>> the machine was Ubuntu 8.04 64-bit, then 8.10 64-bit, then 8.10 32- 
>> bit, and the problem was seen in all 3. In all cases it was running  
>> the UQ-provided AG 3.2beta with the stock VideoProducer services. I  
>> know there was a bttv driver deadlock issue in kernels pre-2.6.24,  
>> but this is running kernel 2.6.27 so that shouldn't be the problem.
>> Also when sending video on that machine occasionally the stream  
>> would start to flicker, flashing an old frame alternating with the  
>> current output of the camera. Has anyone seen either of these  
>> issues before?
> Andrew,
> I just installed a 32bit Ubuntu 8.10 on the UQVislab node's video  
> capture machine. I've been running 2x mpeg4 streams and an h261  
> stream for over two hours. I just powered the machine down to  
> confirm it is actually an IVC-200G card (it is). After the restart,  
> I've now configured it to run with 3x mpeg4 streams. These are full  
> PAL streams 704x576. Its been running for nearly 10 minutes now -  
> will leave it running overnight (in the APAG lobby, if you want to  
> check on them) and report back. Based on the previous successful 2  
> hour test, I think this 3 large streams test will be OK too.


We've now had this setup (32bit Ubuntu 8.10 with IVC-200G streaming 3x  
mpeg4 streams @ 704x576) running continuously for over three days now  
without any discernible problem. That result suggests a hardware issue  
with your capture card (or even the machine itself).


> You could try reseating the card - maybe some dust or contact  
> oxidation is creating some bad effect? Do you have any similar  
> capture cards lying around you could temporarily replace the IVC  
> with? That may indicate whether you have a card fault or machine/OS  
> fault.
> chris
> Christoph Willing                       +61 7 3365 8316
> QCIF Access Grid Manager
> University of Queensland

Christoph Willing                       +61 7 3365 8316
QCIF Access Grid Manager
University of Queensland

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