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ZM and other app using the same video device

Posted: Sun Nov 30, 2003 8:33 pm
by loop
I'd like to have ZM running and recording /dev/video0 on my RH9 but still be able to run GnomeMeeting using the same video device which ZM is recording. I'd need somehow to duplicate /dev/video0, because the other app (GnomeMeeting) says that /dev/video0 is in use.
I think I've seen somewhere such solution but I can't find it anymore.

Best regards,
Darko

Re: ZM and other app using the same video device

Posted: Mon Dec 01, 2003 12:32 am
by rdmelin
Hi Darko,
You might checkout this "http://motion.sourceforge.net/vloopback/index.html"
It works with "motion", it may work with ZoneMinder. Also check the motion mailing list archive for some recent info on this.
"http://www.frogtown.com/pipermail/motion/"
Hope this helps

Ross

Re: ZM and other app using the same video device

Posted: Mon Dec 01, 2003 10:21 pm
by loop
Thank you Ross,
I'vre tried to make it work but I can't compile vloopback 0.91 or older on my RH9 2.4.20-8 linux. I don't know linux so good that I could solve the problem alone: Here's the result of the make:

Darko


[root@omnibox vloopback-0.91]# make
cc -D__KERNEL__ -DMODULE -DCONFIG_PROC_FS -DCONFIG_VIDEO_PROC_FS -Wall -Wstrict-prototypes -O2 -fomit-frame-pointer -fno-strict-aliasing -pipe -fno-strength-reduce -march=i686 -falign-loops=2 -falign-jumps=2 -falign-functions=2 -I/usr/src/linux/drivers/usb -I/usr/src/linux/include -c -o vloopback.o vloopback.c
vloopback.c: In function `uvirt_to_kva':
vloopback.c:172: warning: implicit declaration of function `pte_offset'
vloopback.c:172: warning: assignment makes pointer from integer without a cast
vloopback.c: In function `vloopback_mmap':
vloopback.c:503: warning: passing arg 1 of `remap_page_range' makes pointer from integer without a cast
vloopback.c:503: incompatible type for argument 4 of `remap_page_range'
vloopback.c:503: too few arguments to function `remap_page_range'
vloopback.c: At top level:
vloopback.c:878: warning: initialization from incompatible pointer type
make: *** [vloopback.o] Error 1

vloopback

Posted: Fri Jun 10, 2005 9:23 pm
by lgmoltrasio
Is there some workaround about that?? I need to do something like that. 2 programs accesing the same device....

Thanks

Posted: Fri Jun 10, 2005 10:40 pm
by zoneminder
I _think_ V4L2 (Video 4 Linux v2) allows multiple concurrent access to video devices whereas V4L (v1) doesn't. I could be wrong though.

Phil

Posted: Sat Jun 11, 2005 3:23 am
by lgmoltrasio
Ok, Phil. I will try,

thanks.