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dvgrab:

Posted: Thu Jan 29, 2015 6:00 pm
by peter_b
[PROBLEM]
Using dvgrab for capturing DV over firewire from a "Sony HVR-M35E" replayer, I got the following error message:
Found AV/C device with GUID 0x0800460103f215cd
libiec61883 error: Failed to get channels available.
Turning on OpenDML to support large file size.
Waiting for DV...
Capture Started
[...]
[SOLUTION]
Thanks to a thread on the Linux IEEE1394 mailing list, I checked the access rights for "/dev/fw0" - the root device of my firewire adapter.
Quoting Peter Watkins on that list:
I'm not familier with Firewire internals, but this is what I've gathered from what you guys've told me:
The Isochronous Resource Manager (IRM) is a node (a device or the computer itself) on the Firewire bus that allocates resources.

Channels are one of those resources. dvgrab needs a channel on which to communicate with my ZR830.

It attempts to request a channel by talking directly with the IRM, which is the root node (my computer) in my case. However the default permissions in Ubuntu Natty don't allow direct communication with the root node. dvgrab fails to get a free channel so it picks channel 63, hoping that channel 63 is free.
I've done the following on /dev/fw0:

Code: Select all

$ chown root:video /dev/fw0
$ chmod 660 /dev/fw0
Now, the error message is gone.

TODO: Update udev rules to make these permissions permanent.