Jeff’s Place

Just a quick update on the DirectTV2PC application I started fiddling with a few days ago, since I’ve now managed to get things working.

The application seems to work pretty well, even on my laptop that is supposed too under-powered according to their system requirements list. Video is a little glitchy, especially HD content, but I can see that my laptop’s cpu (dual-core 1.2ghz ULV Intel U7600 processor) is pretty much pegged so that’s probably the cause. I’m also using the wireless adapter on my laptop instead of a wired connection but that doesn’t appear to be the problem. It took some poking around but there is a way to point the dtv2pc app at a different DVR – it’s in the “Menu->Settings” menu, you can pick which “server” to connect to. It shows them by receiver ID, which isn’t terribly friendly, so you have to make a mental note of which is which, and you have to use the up/down arrow keys to pick the dvr, the mouse doesn’t make the selection. Switching DVR’s causes the dtv2pc app to load the program list from the new dvr and off you go.

I tried using the app from a remote network, with a vpn connection back to my home network, but the dtv2pc app fails to find the dvr’s. I fired up wireshark to see if I could tell why, and discovered that at startup the app multicasts for the dvr’s, so since that multicast traffic doesn’t get forwarded over the vpn link it’ll never be able to see the dvrs. That is probably a solvable problem with some network hacking but it’s not something the casual user could manage, and I probably won’t bother but it may be possible to get this thing to work remotely ala slingbox if you’re willing to invest some time to get multicast forwarding over vpn to work. I did find that when switching back and forth that at some point one of my dvr’s started reporting that it had no recordings, although it correctly showed only 6% of space available. Again with wireshark, I found the dvr was returning an error when the dtv2pc app requested the program list. I figured I’d probably have to reboot the DVR but it eventually fixed itself, although I don’t know how long that took, it was just working the next morning when I looked at it again. Everything on the DVR itself was working fine, it was just the remote dtv2pc app that didn’t get a program list.

By the way, it looks like the app uses http conversations with the dvr to get it’s program lists and other data. It might be interesting to spend some time sniffing to see what info might be available, I could see maybe writing a script to track which shows get recorded and put the data on a server somewhere. Anyway, that’s all for now, more later when I have time to dig into this more.