Too Busy For Words - the PaulWay Blog

Last night at the CLUG meeting I 'ran' a MythTV 'Fixfest'. Originally I'd intended this to be a chance for everyone with a MythTV machine in Canberra to come along and smooth the rough edges - get TV guides working, upgrade to latest releases, and set up extra features, all with plenty of expert troubleshooters around to help get things working. When I did a quick poll at the 'start' of the evening and found that only a third had MythTV machines at all, and only about a third of those had brought them along, I went to my Emergency Backup Presentation, which was about storage and transcoding in MythTV.

It took me a while to work transcoding out, mainly because I didn't understand how things worked. When receiving an analogue signal, you have to run some form of compression because otherwise you'd chew up a 250GB hard disk in about two hours of recording. But with digital TV, you get MPEG2 at either 4 or 8 Mbps for standard definition picture, and probably in the 12 to 16 range for high def. So it's already compressed and just gets put into the file system as is. You still chew through 2GB or more per hour of recording, so at some point you can cut the commercials out of the programme and transcode it down to a smaller size, optionally shrinking the picture size and recompressing the audio as well. Or, if you want to move the data out of MythTV altogether - e.g. because you want to play it on a phone or an iPod - you can use nuvexport or user jobs to automatically make a smaller file with a reasonable file name (rather than something like 1001_200608251730000.nuv). But you do lose a lot of the metadata in the process since that file is no longer kept with the metadata in MythTV.

Anyway.

I hope that didn't bore the people who were just wanting a 'spotters guide to MythTV', but everyone seemed reasonably happy and after I'd finished my near-interminable rambling we ordered pizza and got back to the important task of getting machines working. Bob and George Bray from the University of Canberra had a great time getting UC's UDP Multicast streams of various satellite broadcasts playing in the ANU lab subnet, and I had the great pleasure of watching the irrepressible Tridge and a couple of other guys get my infra-red remote control working (finally). The whole process was done from first principles - find out which card is receiving the IR, which device that corresponds to, how to get lirc to read that device (in my case, with an AverMedia DVB-T 771 card, it was /dev/input/event2 and you need -H dev/input in the lirc options file to get it to read the device correctly) and finally how that plugged into MythTV (or, more correctly, how MythTV plugged into lirc). Now I have a working remote control, and I just need to set up a ~/.mythtv/lircrc file to get the remote to do something in MythTV.

I also spent some time with a few people getting them to register for the tvguide.org.au data. Unfortunately it was playing up, no doubt because we had a dozen or so machines going through NAT and appearing as a laptop upstairs. I also helped Rainer Klein get his MythTV database installed, although I kept on being distracted by other things, the chief of which was upgrading Nick's machine to Fedora Core 5 and MythTV 0.19. That was a little more hassle than we really needed

For no apparent reason, running the Fedora update process took the best part of two hours. Theories abounded but I have no really good idea why; on other machines that I've run it's been much faster. Then the ATI fglrx driver was out of date. In order to upgrade that we had to upgrade the kernel. yum upgrade threw up its hands at a lot of packages, mostly because they were ATRPMS dependencies, so I plugged in my livna and freshrpms setups, removed the worse offending packages (i.e. half of the MythTV front end, not a good sign), and upgraded. Still no upgraded kernel. Yum was firmly convinced that, indeed, there were no kernels available. Finally, at 11:30, in desperation I scp'd the current version of my work mirror. Success! Everyone - the four people who were waiting on giving me a lift, Bob who had to secure the room, others who were just masochistic, and not least Nick - breathed a bit of a sigh of relief. Then we had a bit more fun trying to get the screen configuration working, but eventually it chose the right kernel and all was well. We left at about 12:15am.

I'm really thankful to Tridge, Tom Ciolek and the other guys who got my infra-red remote working. I'm indebted to the patience of Bob and the others who waited around for this machine to work. I think there was a mutual understanding then that we couldn't just deliver Nick's machine back to him unworking and semi-catatonic and say "Sorry, don't have time now, I'll be back on Saturday, I'll get in touch." I feel that that's something that is deep in the Hacker Ethos - you can't just leave a problem unsolved, especially if someone's relying on this solution to work for their continued health and happiness (or at least domestic harmony).