Use custom path for video encoder devices?

[touchstone]

I am attempting to switch from running Sage on Vista to OpenSuSE 11.2 (I know Ubuntu/Debian distributions are recommended, but the reason for my shift is to consolidate onto an existing server).

My question is: How can I tell Sage to use a specific video device path for my three HD-PVRs? Each HD-PVR is assigned to a /dev/video0 to /dev/video2 block device. The order of the videoN assignments changes between boots. I have read about setting udev persistent mapping rules., but these devices are created very early in the process when usbfs runs -- before the root volume is mounted. The /dev/videoN devices already exist when udev runs.

There are static symlinks created in /dev/v4l/by-id/usb-AMBA_Hauppauge_HD_PVR_<SerialNumber> referring to the appropriate /dev/videoN device. I would like to have Sage use the /dev/v4l/by-id symlinks rather than the /dev/videoN devices. Is there a way to do this?

[drewg]

Originally Posted by touchstone

There are static symlinks created in /dev/v4l/by-id/usb-AMBA_Hauppauge_HD_PVR_<SerialNumber> referring to the appropriate /dev/videoN device. I would like to have Sage use the /dev/v4l/by-id symlinks rather than the /dev/videoN devices. Is there a way to do this?

Sage sees only the patterns that it looks for (/dev/videoN, /dev/dvb/adapterN). Before I figured out udev, I had a shell script that would run before startsage that would just make a new symlink for each device back to whatever random device name that udev gave it. So adapter10 would point to one udev-created /dev/dvb/adapterN, adapter11 would point to the next, etc. I then told sage to use the /dev/dvb/adaptor{10..12} links, rather than the randomly created /dev/dvb/adapter{0..2} native directories.

Drew

[bcjenkins]

with udev you could manage this with the serial numbers.

[jpwegas]

Originally Posted by touchstone

Each HD-PVR is assigned to a /dev/video0 to /dev/video2 block device. The order of the videoN assignments changes between boots. I have read about setting udev persistent mapping rules., but these devices are created very early in the process when usbfs runs -- before the root volume is mounted. The /dev/videoN devices already exist when udev runs.

Don't worry about what devices exist when udev runs - it's job is to remap everything anyway.

I have 3x PVR-500s (multiple videoN devices), as well as a pcHDTV 5500 and DVico FusionHDTV 5 Lite (each shows up as a dummy videoN device, which I use udev to suppress, and an adapterN device). Because I need to match each videoN device to the correct IR tuner, I needed persistent naming for each physical device.

As bcjenkins mentions, use serial numbers in your rules if possible. They are the easiest way to uniquely identify a card. Some of my cards do not have them and I had to identify them by the PCI slot they were in.

I took me a while to figure out the rules I needed, but now everything always show up in the same place.

Be sure you have the command "udevtest" (my distro didn't install it my default, IIRC), it's really handy to try things out without rebooting. Sometimes it's output is a little confusing, but it reduces how many times you have to reboot as you're testing your rules.

--John