I'm trying to use a firewire capture box with pix_video. Here's my setup:

OS: Ubuntu 8.04
Pd: 0.40.3-extended
capture device: "Hollywood Dazzle"

I can capture using Kino or dvgrab. Coriander can't see the device. Modprobing a variety of different modules, I can get /dev/video1394/0, /dev/dv1394/0, or /dev/raw1394.

In Pd, I've tried setting the device to all of those. When I open the gem window, I just get this error:

get capabilities: Invalid argument

and the window is just white.

I read through an older thread on gem-dev and tried chris clepper's texture mode suggestion, but it didn't change anything.

http://markmail.org/message/56bf6xow2x5eznud

I can't tell if the "get capabilities" error is a death error or just a warning.

thanks in advance,

--Ben

Hi.

Did you find a solution for this problem? I have a similar situation on Debian.

When I send a [driver 1( message and then [device /dev/video1394/0( to pix_video i get :

initializing: Inappropriate ioctl for device

If I send [driver 0( message I get

get capabilities: Inappropriate ioctl for device

This happens with unibrain's fire-i firewire board camera which works under coriander no problem. I use it with openFrameworks also. It doesn't work with dvgrab. http://www.unibrain.com/Products/VisionImg/Fire_i_BC.htm

A sony minidv firewire camera does work with pix_video however.

Since my Debian system is a mess I downloaded a pure:dyne's leek and potato to test the camera and had the same results.

Does anyone have any idea how to fix this? I've searched the mail archives and every resource I could think of. I'm new to linux so maybe I'm missing some basic stuff. Any help would be greatly appreciated.

thanks

ciao.

No, I haven't solved it yet That's a drag that it doesn't work with the UniBrain camera, I was going to go and get one of those. I tried to join the GEM dev mailing list but accidentally joined one for a different software environment, also called GEM (which is also really cool, incidentally). I'm going to try and join the real one and/or hack at the source a bit. This should totally be fixable.

So I also tried out pix_video with the built-in iSight on my Macbook Pro, running Kubuntu. It didn't work either. I wrote up a little test program to capture and display webcam video, that works fine; so there's something peculiar either to how you use pix_video or something that needs tweaking inside it ...

Finally got around to learning how to compile and hack on GEM, and I've made some progress on this. Here's what I did.

First, I didn't get the whole deal about the colorspace, so was trying to use RGB with my iSight, which is wrong. "colorspace YUV" was the first step. I got it this far:

v4l2: changed size from 64x64 to 320x240
v4l2: GEM: pix_video: Opened video connection 0xB

However, I kept getting this error:

VIDIOC_DQBUF: stopping capture thread!: Resource temporarily unavailable

Looking through the source for pix_videoNEW, I found where this was happening.

In videoV4L2.cpp, videoV4L2::capturing()

 if (-1 == xioctl (m_tvfd, VIDIOC_DQBUF, &buf)) {
      switch (errno) {
      case EAGAIN:          
        perror("VIDIOC_DQBUF: stopping capture thread!");
        goto stop_capturethread;
      case EIO:
        /* Could ignore EIO, see spec. */
        /* fall through */
      default:
        perror ("VIDIOC_DQBUF");
      }
    }

I don't know what an "EAGAIN" error is. Maybe it means "You should try again!", instead of giving up and closing.

so I took it out, and now I get video in my gem window! yay! it's slow and still has a lot of errors streaming out all the time, but it works!

Edit: ok, that is what EAGAIN means:
"By default VIDIOC_DQBUF blocks when no buffer is in the outgoing queue. When the O_NONBLOCK flag was given to the open() function, VIDIOC_DQBUF returns immediately with an EAGAIN error code when no buffer is available."

http://v4l2spec.bytesex.org/spec/r12878.htm

So it just means a capture buffer isn't filled yet, rather than a total failure. The investigation continues...