Re: [libdc] Muliple Cameras Silent with 2.0.0-rc9 and Later

[David C T. <dc...@jp...>]

Irv,
I have not had a problem with libdc1394-2.0.2 (using lib1394raw 1.3) and 
multiple cameras. I have 4 ptgrey Scorpions and 1 Pixelink PL-B742F 
cameras. The four scorpions are on their own bus and the pixelink on its 
own bus (i.e. I have 2 physical pcie 1394a cards).
Have you tried playing around with the packet size? I have noticed that 
when you have multiple cameras on a single bus the bandwidth negotiation 
gets tricky. Playing with the packet size gives you more control, but in 
reality is itself a bit of a black magic, but I have patiently managed 
to find values that work. Be sure to query the 
dc1394_format7_get_packet_parameters and make a note of the max and unit 
values. Use these numbers as a basis for your search. Also check out 
this article for more information on the packet size. 
http://www.ptgrey.com/support/downloads/documents/TAN2007001_Exceeding_Bandwidth_Limitations_with_FMT7.pdf 

If you are still having issues. Post some sample code of what you are 
trying to do as well as what cameras you are running ( I have access to 
just about every ptgrey camera in my lab).
Good luck,
David Trotz

Irv Elshoff wrote:
> Greetings,
>
> I've been using LibDC1394-2.0.0-rc7 for a while now.  Keeping up with 
> newer versions was difficult because of minor but frequent API changes 
> on the way to the official 2.0.0 release.  I've recently given 2.0.2 a 
> try, but encountered a problem with multiple cameras that I've been able 
> to localize to between rc7 and rc9 (I can't compile rc8 because of a 
> problem in basler.c).
>
> The problem is that whenever more than one camera is physically 
> connected to the system, no camera delivers images through the LibDC API 
> (dc1394_capture_dequeue) after rc7.
>
> There have been other reports of muliple camera problems on the mailing 
> list.  I've read them, tried things, and have come to the conclusion 
> that this may be something different.
>
> Most salient fact is that just connecting a second IIDC 1.3 camera to 
> the bus breaks things in rc9, but not in rc7. I have a test program that 
> picks one came, starts iso transmission, and waits for the first image.  
> Works fine in rc7, but swap rc7 out for rc9 and no frames are delivered.
>
> My systems are running CentOS 4.6 and 5.1.  I've tried kernels from 
> 2.6.18.8 up to 2.6.25.6, all with 1394 support (not standard in CentOS) 
> custom compiled.
>
> I am NOT using Juju.  Tried it, but had major problems compiling with 
> LibDC1394 and LibRaw1394 versions.  At this point Juju is not an option 
> as far as I'm concerned.  I'd appreciate it if responders do not 
> recommend or refer to Juju. Comparisons are probably meaningless. (But 
> hey, who knows...)
>
> I've tried LibRaw1394 1.2 and 1.3, but don't see any difference. 
> (Obviously recompiling everything in between.)
>
> I'm using Point Grey cameras with or without hubs.  I've tried a laptop 
> with various VIA and Agere CardBus interfaces and several desktop PC's 
> with TI and VIA OCHI PCI-32 controllers.  I've tried manually allocating 
> iso channels as suggested in a earlier post about problems with multiple 
> cameras.  All to no avail.
>
> It all boils down to LibDC1394-2.0.0-rc7 works but LibDC1394-2.0.0-rc9 
> and later does not.  It's very reproducable.  How can I help?
>
> Cheers,
>     Irv.
>