[GEM-dev] Re: Gem and video capture

Ivica Ico Bukvic ico.bukvic at gmail.com
Fri Mar 17 09:56:28 CET 2006


Aarrgh... I just had one of those moments: after 10 hours of frustration,
you are about to give up and then have that last-second "this may seem
stupid, but let's try it anyhow" idea--and it works! DOH!

When I looked at the gem code, it seems that Gem also looks for the
/dev/dv1394 node as a fallback option. Well, on my computer, even though the
dv1394 driver is loaded, the /dev/dv1394 node is missing. Apparently the
node type depends on the format being captured (something like 171,32 for
NTSC and 171,34 doe PAL), so Ubuntu never created one (I am not even sure if
it should have generated it in the first place). So, I go and first start
messing with /dev/MAKEDEV dv1394 and computer tells me it does not know how
to make it... Then I try the brute-force way of simply doing:

mknod /dev/dv1394 c 171 32
chown root:video /dev/dv1394
chmod 660 /dev/dv1394

And... What Happen? We got signal! Main screen turn on!... (sorry, it's 4am
and I feel a bit geeky :-)

Now, if I could only figure out my other problem... BTW, does anyone know
who/what is responsible for generating the dv1394 node? This may be a useful
piece of info to the Ubuntu maintainers... Oh well, off to bed...

Thanks to all Pd/Gem/externals devs for the wonderful software!

Best wishes,

Ico



On 3/17/06, Ivica Ico Bukvic <ico.bukvic at gmail.com> wrote:
>
> Greetings all,
>
> I have just started messing with the video in on my Linux laptop and have
> encountered some problems with Gem:
>
> *The OS is Ubuntu Hoary, Pd 0.38, and Gem 0.90.
>
> *I am using ADVC-100 ieee1394 interface which allows me to connect any
> S-Video device to my laptop. The device works fine with Kino (dvgrab).
>
> *My /dev folder includes /dev/raw1394 and /dev/video1394/0
>
> *All of the stuff is installed TTBOMK properly.
>
> *When using Gem, I cannot get the video to work as I do not have v4l
> devices available (/dev/video0) with this device, and the ieee1394 devices
> Gem looks for under /dev/ieee1394/dv/host<x>/<y>/in which obviously fails on
> my system. The exact error in the terminal is:
> /dev/ieee1394/dv/host0/PAL/in: No such file or directory
>
> *I tried linking /dev/raw1394 to /dev/video0 (I am not sure as to what is
> the difference between the two, so this may have been stupid--nonetheless I
> tried it just to cover all possibilities) and then using
> ../gem/examples/04.video/00.SimpleVideo.pd tutorial generates one complaint:
> get capabilities: Invalid argument and I get no video. All permissions
> should be properly set on the devices/links (root:video 660).
>
> *I tried using latest vloopback driver (0.97) and when I modprobe it, I
> get /dev/video0 and /dev/video1 devices (81,0). However, connecting to them
> yields following in PD:
>
> video4linux
> ieee1394 for linux
> Direct Rendering enabled!
> GEM: Start rendering
> pix_videoNEW: starting transfer
> cap: name Video loopback 0 input type 0 channels 1 maxw 0 maxh 0 minw 20
> minh 20
> picture: brightness 32768 depth 32768 palette 0
> channel 0 name Composite1 type 2 flags 0
> setting to channel 0
> buffer size -1397530602, frames 2, offset 0 -698765301
> wanted format is 0x1908
> setting cmcapture to 0x0    5
> now trying standard palette 0
> closing video
> pix_texture: not using client storage
>
> In addition, the terminal also spits out: VIDIOCMCAPTURE: Invalid argument
>
> *I tried using dc1394_vloopback  with various settings including:
> dc1394_vloopback --video1394=/dev/video1394/0 --vloopback=/dev/video0
> but that simply tells me "no cameras found :(" no matter what settings I
> try (I also made sure that the vloopback driver was unloaded).
>
> I am not aware of any other way to bridge ieee1394 feed and v4l, nor am I
> sure as to how to force pix_video to use different ieee1394 source (not sure
> whether this even works with the advc-100).
>
> *I tried accessing Gem CVS to see if there were any changes since the 0.90,
> but the CVS seems to be inaccessible:
> cvs -z3 -d:pserver:anonymous at cvs.gem.iem.at:/cvsroot/pd-gem login
> Logging in to :pserver:anonymous at cvs.gem.iem.at:2401/cvsroot/pd-gem
> CVS password:
> cvs [login aborted]: unrecognized auth response from cvs.gem.iem.at: M -!-
> Project map lookup failed ()
>
> So, I have pretty much run out of ideas and I was hoping that someone
> might be able to help me out with this one, namely:
>
> 1) Is there a way to use my ADVC-100 to stream video to PD/Gem?
> 2) If there is no native way to do that is there a way to use vloopback or
> some similar method to channel its feed into the v4l format?
> 3) any other ideas/suggestion (other than spending money and buying myself
> a new <whatever> :-)
>
> I would greatly appreciate assistance in this matter!
>
> Best wishes,
>
> Ico
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.puredata.info/pipermail/gem-dev/attachments/20060317/cbb516b4/attachment.htm>


More information about the GEM-dev mailing list