Re: libiec61883 error: Failed to get channels available.

[Clemens L. <cl...@la...>]

Peter Watkins wrote:
> I'm trying to use 'dvgrab' to get video from my MiniDV camcorder
> (Canon ZR830) using an Ubuntu Natty box. It works, but I get this error:
> 
> libiec61883 error: Failed to get channels available.

Should be mostly harmless.

> Anyone know what this means?

It's from this code in src/cmp.c:

	result = iec61883_cooked_read (handle, raw1394_get_irm_id (handle), addr, 
		sizeof (quadlet_t), &buffer);
	if (result < 0)
		FAIL ("Failed to get channels available.");

I'd guess that normal programs are not allowed to access the root node
(whatever it is, probably the computer itself).  Please check the
permissions on the FireWire device nodes (/dev/fw*).

At the moment, there are udev rules to allow some users access to AV/C
devices (like your ZR830 at /dev/fw2), but not to any other FireWire
devices.  Libiec61883 tries to access the isochronous resource manager,
which is always at the root node, which gets selected somewhat randomly.
I'd guess this library needs to be changed to use the kernel's resource
management functions instead.

Without having allocated a channel, dvgrab just uses channel 63, which
works as long as two programs don't try to do this at the same time.


Regards,
Clemens