Simon Rumble’s blog

Michael Fox has commented on the reasonable UPnP client in the PS3 and its interactions with MythTV, and I think he's helped me work out why I've been having some problems. It seems Myth is recording in different formats, for what reason I don't know. So when MythTV offers them over UPnP, some of them play and others just don't.

For example the output from file:

1010_20090217175500.mpg: MPEG transport stream data
1020_20090216233000.mpg: data
1020_20090217172200.mpg: data
1020_20090217190000.mpg: data
1020_20090217192700.mpg: data
1020_20090217212700.mpg: MPEG transport stream data
1020_20090217223000.mpg: TeX font metric data (\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377\377

Dunno about the TeX font metric data, but there's some that are MPEG and others that are just "data". On that first item (identified as MPEG TS by file), mplayer reports:

VIDEO MPEG2(pid=512) AUDIO MPA(pid=650) NO SUBS (yet)!  PROGRAM N. 1
VIDEO:  MPEG2  720x576  (aspect 3)  25.000 fps  9000.0 kbps (1125.0 kbyte/s)

The second one is reported as

VIDEO MPEG2(pid=2314) AUDIO A52(pid=2315) NO SUBS (yet)!  PROGRAM N. 1
VIDEO:  MPEG2  1280x720  (aspect 3)  50.000 fps  9600.0 kbps (1200.0 kbyte/s)

So the first file is MPEG2, 576i with MPEG audio. The second is MPEG2, 720p with A/52 (AC-3) audio. Trouble is, the next one that file identified as MPEG TS is also 720p MPEG2 video with A/52 audio.

Is the problem, perhaps, just that MythTV is a bit sloppy about writing MPEG TS to the disk and just writes whatever crap is coming down the aerial, regardless of whether it's a valid MPEG header? I seem to recall a rather obscure option in the MythTV settings to wait until some kind of start thing ("Wait for SEQ"?). Will try that out tonight.

A couple of questions, dear lazyweb. Can anyone suggest some better tools to analyse these files? And how do I match these programmes up with their equivalent recordings in MythTV, so I can see if it's perhaps a specific tuner or channel that's causing problems?

After my recent hardware woes, I've had a little more success getting MythTV back up and running. I bought another cheap Dell workstation to act as my new Myth server. After a little fiddling, it's up and running just fine, with three tuners and so far 600 gigs of SATA drives (to be upgraded to 1.6TB tonight when I buy another SATA interface card). It's also hosting SqueezeCenter which drives all my Squeezeboxen for music around the house.

Previously I had a fanless, diskless front-end in the lounge room, using a Via EPIA board with video decompression done on its video chips. This worked fine and was beautifully silent, but doesn't support high definition, and I now have a high definition telly. The telly came with a "free" (really $300) Playstation 3, but the MythTV client on PS3 is being held up by Sony blocking hardware access to the video decoding hardware in third-party operating systems. That's a real shame.

What I've discovered is that the PS3 is a very powerful UPnP client, and MythTV makes its recordings available over that protocol. So the PS3 is able to play back 1080i recordings taken over the air without any problem.

Downsides of doing it this way are that you lose some functionality. The UI is just a list of recordings, without the cool context you get in the Mythfrontend. You can't delete recordings, you can't schedule (though I suppose the PS3 web browser pointed at Mythweb will do that) and features like commercial skipping aren't supported. UPnP effectively treats the MythTV server as a file share of video files. Hopefully at some point in the future the PS3 will natively run a Myth frontend, but for now this works pretty well.

I'm also sharing out my music and other video files from the server using the MediaTomb UPnP server. It's quite flexible, and explicitely supports PS3. A nice feature of it is you can transcode anything on-the-fly for cases where a media type isn't supported. For example, PS3 doesn't support OGG, FLAC or Matroska. So you can set up a rule in MediaTomb to transcode these into something the PS3 does support. Quite neat!

Following advice from Graeme and Grant, I bought and tried out an ordinary ATX PSU to solve my PSU problem but unfortunately it hasn't worked out. It fits in reasonably well, with three of the screws able to go in, and only a small gap, but it's not got what I need.

The IBM system has two additional "AUX" power connectors, with eight and ten pins each. But standard ATX PSUs only have a single AUX connector, with only four pins.

Fortunately Adelong Computers have a 7 day return policy, so I can take the PSU back in on Monday. I'll take the IBM PSU in with me and see what they can suggest.

Got home this afternoon and tried to turn my desktop machine on, and got nothing. Looking up the diagnostic lights the Dell manual says "System board failure has occurred." Not good!

So the power supply on my MythTV server died last weekend with a bang. I'm hoping it didn't take all the other hardware with it, but first I need to get a replacement PSU in there. One nice thing about IBM hardware is the extensive documentation which tells me the power supply is Field Replaceable Unit (FRU) 24R2555 or 24P6820. All well and good, except the places selling these things online either don't ship to Australia or insist on maximum-cost couriers like UPS or Fedex, so a US$20 part ends up costing well over US$100. An eBay seller in the UK changed his mind and cancelled the sale after discovering postage was going to be £60 rather than the £25.90 he'd quoted me.

So can anyone, perhaps someone who knows their way around the bowels of IBM documentation better than me, tell me if this power supply follows some kind of standard I can source somewhere other than official Big Blue? It doesn't follow the same form factor

While common software applications require that you disable the privilege escalation functions, Windows will never solve its security issues. The concept of running as a low-privilege user, while using temporary escalation of privileges when necessary, is absolutely essential to software security. *nix has, of course, had this forever.

Our laptop had some problems with heat in the recent spate of Summer temperatures. I pulled it apart and gave it a vacuum. Sure enough, lots of dust and a fair few dead cockroaches. To prevent a recurrence, I bought one of those "laptop cooler" products which prop the laptop up and blow air up and over it.

Problem is, the one I bought had little blue "bling" LEDs and really loud fans. The LEDs make me feel like one of those pindicks from the suburbs with a Honda Civic that goes Uuntz Uuntz Uuntz, with a spoiler and an exhaust pipe that leaves you in no doubt where my own anatomy is deficient. The fans were just annoying. Any time I was using the laptop late at night, it annoyed me: bright lights that really wasn't needed, and a bit of a low roar from the fans.

So I snipped off the wires leading to the LEDs, which solved that problem. And I put a little variable resistor into the path of the fans, so I can control the speed. I used a 50K logarithmic pot, and now think I should have used a lower value or a linear. Still, works fine.

So now no bling lights, and the fans are dialed down to not make much noise but still move plenty of air. All for the price of a variable resistor, which was about $2.50.

Google Reader has a pretty good idea of what I read, so WTF is it doing suggesting a V8 Supercars feed to me? Hopefully it'll learn the error of its ways when I click "No thanks".

The major record labels seem to have finally worked out that downloads are the future, that DRM will never work and that people will pay for high-quality music downloads. I've recently been buying a fair chunk of music. The independent labels are pretty good: Matador, Arts&Crafts and Warp are excellent. The majors have a way to go yet.

At issue is that they've wasted years now making legal downloads so painful that users have learnt how to use pirate sources. The pirate sources are quite easy to use, and the quality can be quite good. So the majors need to learn to make it trivially easy to buy legally, and give people exactly what they want.

Yesterday I bought the Empire of the Sun album from the EMI/7digital site musichead. It's mostly okay: 320kbps mp3, which is acceptable. The metadata seems mostly intact, though Squeezecenter doesn't quite cope with x/x track numbers. The biggest problem was the download process. I had to download every track individually and rename them in my preferred nn.trackname convention. I prefer the files to list in the right order in an alphanumeric sort, and this wasn't provided.

What they should do is provide the option of downloading a zip file of the entire album. There should also be the option of defining the naming format of the tracks, with a selection of various options available.

Ideally, I'd like to be able to download FLAC versions of the files. I'd even be willing to pay a small amount more for this!

Still, they're making progress. Even better, the "Alternative/Indie" category doesn't feature Coldplay. That's progress!

I've been intrigued since upgrading to the latest Ubuntu release where NetworkManager has a shiny new "Mobile Broadband" tab. This is something I've wanted to get working for a long time. I don't want a built-in 3G unit, or one of those USB dongle things, and I don't want an expensive monthly plan. All I want is to use my existing 3G phone to connect to the Internet occasionally.

The new "Mobile Broadband" tab, however, requires that you have already set up the appropriate serial connection over Bluetooth with your phone. There are command-line ways of doing this, but I wanted to see if I could do it in a GUI. Hunting around I found this excellent description of how to do it with Blueman and NetworkManager. I tried it out last night and it works a treat!

Blueman seems to be a decent Bluetooth tool for Linux, at last. For far too long we've had really poor Bluetooth tools, and now we have a rather sensible, and most importantly fairly comprehensive, front-end to it.

Now with the combination of a tiny Bluetooth USB adaptor, an Eee 900 and my mobile phone, I'll be able to connect from anywhere. Yay!