vdr cutting rocks

Oct 1, 2005 / 0 comments

In the continue theme of things software I've been using for a while can do, but I only just discovered, I give you editing of recordings under VDR. I use VDR as my PVR; taking a raw MPEG2 DVB stream and saving it without any conversion seems the right way to do things to me. And the interface may be simple, but that's good. However it's annoying to end up with lots of adverts on things I'm planning on keeping around; takes up unnecessary disk space for starters. So I finally put the effort into learning about setting cutting marks while watching playback. Hit 0, it makes a mark. Do it again, it makes another and decides the video between these two is what you want. Do this for all of the program and hit 2 and then it stitches all the bits you want together and ditches the rest. Result. You can even fine step the marks with 4 and 6. I've halved the amount of disk space my South Park collection is taking up. Result.

Netgear DG834G hackery

Sep 28, 2005 / 0 comments

I have a rather weird network setup at home. Partly due to having both a sensible ADSL connection from Black Cat and an NTL cable modem as backup, partly because I have native IPv6 (over the ADSL). I used to just use a normal PC with a USB Speedtouch plugged into it, but a while back I managed to get an ASUS WL-500g setup to do the job (it has USB for a flash drive / webcam, but this got the Speedtouch plugged into it). It does the job, but is somewhat hacked up. Plus I think the USB ADSL modem adds extra latency and can sometimes be dodgy.

So, when I discovered that the Netgear DG834G had source available for all the important bits (wireless, ADSL, ethernet) I was intrigued. I already know a bunch of people who have this router and are happy with it, so the knowledge that it was more hackable than the average ADSL router made it very appealing. As it happened quinophex (who seems to becoming my hardware pimp) had a spare one, so we did a deal and he brought it round today.

After checking it actually worked and could connect to my ADSL line it was time to open it. The screws are hidden underneath the little white feet and appear to be torx style, but I had a normal flathead that did the job (I should really get myself a larger set of screwdrivers). At first I couldn't spot any headers, but then I saw JP603 half hidden under a sticker with the MAC address on it. Ta da. 4 holes, one obviously ground, one looked non connected, 2 had tracks leading away from them.

I found a piece of veroboard in my toolbox and realised I'd put off building my MAX232 level shifter for too long. After much too long (but no burnt hair) I'd soldered up the simple circuit and was ready to try it out with my Linksys WMA11B. Using Andrew Wild's excellent serial port instructions I had an adapted device to test with. Hooked it all up and it didn't work. Bah, think I. My soldering sucks. No, serial ports suck. ttyS0 has decided not to play nice on my desktop machine. One USB serial port adaptor later and I can see the Linksys boot. Yay!

So, onto the Netgear. A bit of prodding (and dodgy soldering) later and I have a console. Yay! I can see ADAM2 and I can see the kernel boot and get a busybox login. Rock. Now I just need to work on getting a better firmware installed that can handle what my Asus is doing at present.

GPS doesn't love me

Sep 26, 2005 / 0 comments

I finally got the loan of quinophex's Magellan 315. So I went on a wander with it, to see how it faired. (The advantage of a handheld device is that it's self contained, so I can go for a walk with it easily rather than having to bring the USB device and a laptop with me.) However I'm still getting the same offsets compared to the Landsat pictures when I compare on OSM or osm-editor locally. I've set my datum to WGS84, which I understand is the default for GPS. I've made sure the GPS can see a reasonable number of satellites (5 locks is good, right? With an extra couple of marginals?). I was walking, so it's not at any great speed. And yet, as with my USB device, the track is slightly down and to the left.

I'm planning on going on a drive with both devices hooked up to the laptop so I can compare the data from each at the same point in time, but does anyone have any idea why I might be having these problems? Take a look at a screenshot of osm-editor (579KB, 1280x1024) to see what I mean; the track at the bottom is clearly shifted downwards from where the dark line of the road is.

Northern Ireland

Sep 21, 2005 / 0 comments

The English don't really seem to understand Northern Ireland (maybe the rest of the world doesn't either, but I don't get exposed to them as much). I was born in Northern Ireland and lived there until I went to university in England. I still go back there several times a year as my family live there.

The first indication I remember that something was wrong was when I tried to buy car insurance for the first time. I was living in England (car insurance in Northern Ireland is more expensive, and most of the online options won't cover it; I understand this is because injury claims are [or possibly used to be] awarded by jury there, as opposed to by a judge on the mainland. Juries apparently are likely to award more.), and when I was asked if I'd lived in the UK all my life I said yes. Except they knew about me being from Northern Ireland or something (I'd probably asked about being covered for driving back there) and claimed that it wasn't part of the UK. And when I said that yes it was they fell back to "but it hasn't always been". Er, yes, it has. For as long as Northern Ireland has existed as an entity distinct from the rest of Ireland it's been part of the UK. And it's been part of the UK since 1801 anyway. Long before I was born thankyouverymuch.

Since then there have been minor incidents; for example the Post Office clerk not being sure if it cost more to send things to Northern Ireland (she got corrected by one of her coworkers though, and I know that sometimes they won't guarantee delivery times so I forgive her that).

Today I get asked by a friend if Northern Ireland is part of the UK phone network. WTF? Yes. It is. It's part of the UK. No, really. I'll say that again so it sinks in. Northern Ireland is part of the UK. BT are the monopoly telephone provider there. 3, O2, Orange, T-Mobile and Vodafone all provide service there. You don't need a magically different mobile phone contract (the person in question was particularly interested in short codes) if you live in NI rather than mainland UK. Gah. What are these people taught?

(I didn't confuse the issue when explaining to my friend about NI being part of the UK by saying that some call charges do differ; last I investigated ringing Ireland from Northern Ireland with a BT line was the same price as ringing the rest of the UK. Equally it was cheaper to ring NI from Ireland than to ring the rest of the UK. My information is several years old now as I tend to just use my mobile when I'm back there. There's also the oddity about dual citizenship; anyone born in NI has the right to Irish citizenship as well if the choose. Oh, and while I'm ranting, why is the adjective for someone from the UK "British"? Britain doesn't cover all of the UK. I wasn't born in Britain yet I'm British. Can't I be UKish or something?)

A solution for Debian mirroring?

Sep 20, 2005 / 0 comments

Recently security.debian.org has been having some problems with maxing out its connection due to an X update. This reminded me of a conversation I had at DebConf5 about the feasibility of a Debian anycast instance. This was originally under the guise of ftp.debian.org, but there's no reason it wouldn't work nicely for security.debian.org as well.

The idea is that Debian would obtain a /24 of PI (or something unlikely to get filtered anyway; I think anything smaller wouldn't work) and their own AS. They'd then host instances of f.d.o/s.d.o around the world with ISPs that would route this AS for them. This would mean that big sponsors able to provide global routes would still be able to do so, but smaller sponsors (like Black Cat) would still be able to help out by announcing the route to their peers.

You'd need the servers involved to all be reliable push mirrors, so that they're as close to being in sync as possible. And I'm not sure how well TCP works over anycast; assuming stable routing I can't see why it'd be a problem (does the Akamai service work this way?). Certainly it seems to be quite common for major DNS servers these days. But it could end up with quite a few decent local mirrors with no work required on the part of the users to take advantage of them. Am I insane?

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