Month: April 2007

That was with an open source driver – another reason why NVidia has better linux support, there is an open source driver that’s good enough for most purposes. I then downloaded the proprietary driver and installed that and everything was then working.

Tested it with Myth and live TV playback is smooth. Not only was the aspect ratio correct but it actually detected the resolution of my LCD TV automatically.

Now the onboard video card isn’t as fancy as the one I removed. In particular

• it only has a VGA connection – the other one had DVI (with VGA adapter) and S-Video. But my TV has a VGA in so that’s no problem.
• it only has one screen – the other one is dual. This has come in slightly useful as I can connect to my TV and a monitor. So that if/when it generates a resolution/refresh rate the TV can’t handle the monitor can. But this is a minor point. If I need to debug a problem with a different video mode, I can just plug in the monitor.
• it uses main memory for its video memory. That’s ok, I’m probably over-spec’d for memory anyway.

In general the on-board card doesn’t have as much ‘oomph’ as the ATI one but that’s still more than enough for watch TV. Maybe if I was using HD it might need it – but I’m not.

My experience generally with Myth is that you don’t need as highly spec’d a box as all that. My old machine would probably have been fine and that was 5 years old. Buying a new machine has primarily got me a bigger hard disk and quieter machine. The processor doesn’t break a sweat and I rarely use all the 2Gb memory.

So now I’m thinking I’ll sell the ATI card on ebay. It’ll be perfect for some gamer on Windows.

But if I looked at it purely in terms of money I wouldn’t be building a myth box, I’d be sticking with my PVR or buying another. I justify it on the basis that it’s a project and therefore fun. But days and days of trying to get one thing working is not fun.

It’s interesting. I was at M’s the other night for a meal. Afterwards I offered to look at her laptop, which wasn’t connecting to the internet. I spent probably 90mins-2hours and in the end fixed it. But there was a point where I was about to give up. I actually enjoyed tinkering but I think another 30 minutes and it would have stopped being fun.

So do I buy a card or not? I think I’ll give myself a couple of hours tonight and if I can’t get it working, maybe make an order.

From the point of view of what the MythTV box can do, definitely. It can do the usual stuff that a PVR can do – pause and rewind live tv, record something and watch the beginning whilst it’s still recording the end. However where it comes into its own is on finding stuff to record. You can search for stuff, so unlike my commercial PVR, I don’t have to manually trawl through the program guide to find stuff. If there are multiple showings of the same show, it can record the one which doesn’t conflict with other stuff I want to record. All in all it’s pretty cool and so definitely worth it.

 

And yet… I have now ordered a box for phase 3. Phase 3 was supposed to mean buying the pieces and building a custom box, but it turned out expensive. I couldn’t get it in under £400. Which isn’t a lot, but for a PVR it is. I can buy one like mine for £150. It has a smaller hard drive and no cool search features but still. So instead of trying to build one, I bought a PC from Dell Outlet. Dell Outlet is where you can buy returned PCs at a discount. You can get some pretty good bargains. So I ordered one. Which means if I could have lived with the smaller disc space until it arrives, I could’ve saved myself a day and a half of effort. Effort which will in some ways be repeated once I have to set up the new machine.

 

So was it really worth it? Yes – because what else would I be doing other than slobbing around actually watching these programs I’m recording! Heh.

 

Of course the next problem is whether I can easily transfer the recordings to the new PC. But that’s next weekend’s problem…

(P.S. the observant amongst you will have noticed that today’s tuesday therefore yesterday wasn’t sunday. I wrote this yesterday but am only posting it now. Because of no internet access at home.

P.P.S. Did I mention I have no internet access at home???)

 

So this weekend was all about adding another 60Gb drive. In order to do that however I needed to have a version of Linux that had something called logical volumes. It’s a feature that allows you to present two or more disk partitions as if they were one unit. Which means I could add an extra disk and have it look as if I had one big disk.

 

Unfortunately Suse 9.3 didn’t appear to have this feature. It might have been possible to add it by downloading the necessary software but I don’t have the internet at home yet (recall the stuff with the phone – not sorted yet, not quite). Also it’d just be easier to just install a version that had it all integrated and working. So the plan was

 

• Back up data from PC including existing recordings and all the settings needed to put MythTV back the same way.
• install the new disk
• install a version of Linux that has logical volume support (Fedora Core 6)
• set up a small partition for the OS, and use the rest of both disks to set up a logical volume to be used for the recordings
• compile a new kernel – the TV card needs a later one than comes with FC6
• install the various software that MythTV needs.
• recover the data from the back up
• install MythTV and configure it
• recover the MythTV settings – this involves restoring a MySQL database backup

 

And go!

 

Simple right? Well a couple of hours on Saturday night had the backup and the new disk and OS installed. Yesterday was a slow process of re-installing software. It took 75 minutes to compile the kernel and an hour to compile MythTV – the later I ended up doing twice. About an hour to restore the backed up data. So how come it took around 12 hours to get a working system?

 

The problem was that MySQL database. Even though it was a brand new installation and I could connect using the MySQL client, MythTV itself wouldn’t connect to the database. The socket, a file MySQL uses for connections was configured to be in one place, but MythTV was convinced it was in another. I couldn’t understand this. It was a clean compile of MythTV and an installation of MySQL from the FC6 disks. It couldn’t be pointing to the wrong place. I checked the MySQL config file and that was pointing to /tmp, but every time I ran MythTV is was pointing to /var/lib/mysql. And I couldn’t find where this was set. I grep’d the entire source tree of MythTV and couldn’t find it. How could that be?

 

In the end I had to grep my entire hard drive to find it. I realised that I’d copied the MySQL config as part of my backup. That was the one that pointed to /tmp. The default one that came with Fedora pointed to /var/lib/mysql. But it’s a config setting so it should be changeable right? Well MythTV uses a programming system called QT and QT has a MySQL plugin library. So it seems that MythTV calls MySQL through this library rather than directly. Fair enough – but it’s this library that’s pointing to /var/lib/mysql. As far as I can tell it’s hard-coded i.e. there’s no way to tell the QT to look elsewhere. This seems daft to me. So daft that I hope I’m wrong, that it can be configured. But so far I’ve not found a way.

 

Anyway I just reset the MySQL config file to point to /var/lib/mysql and everything worked. Hoo-(finally)-ray!

Then it hit me one day that I already had 90% of what I needed. I had a Linux box with a TV card that worked. So enter the big idea – a phased approach.

 

Phase 0 – Do the research. Figure out exactly what software I need.

 

Phase 1 – Install the software on my existing machine.

 

Phase 2 – replace my aging analogue TV card with a freeview capable one.

 

Phase 3 – buy the parts and build a custom box for a really good Mythtv box.

 

Phase 0 I kind of did though I could have done more. My main goal in phase 0 was that I knew I’d probably be installing over a weekend and that, as we know, at present means no internet access. Which means I didn’t want to be stuck half-way through but have that one tantalising problem left to solve, or one missing prerequisite program. On that score I succeeded phase 0.

Phase 1 was what I had done last time I blogged about MythTV. It showed the possibilities of the software. But the quality of the picture, and the size of the recordings made it nothing more than a proof-of-concept.

 

Phase 2 came last weekend when I spent £60 on a Hauppage Nova T 500 card. I’ll pause a moment to say how good this card is. It contains not one but two Freeview tuners – which for the price is very good value. It’s well supported under Linux. True, I had to compile a new kernel but that was straightforward and whilst it took time, it was no three-day marathon. Within a few hours of installing the card I was using it to watch TV using some very basic tools. Once I’d re-configured the MythTV software I had something which was actually useable as a PVR. And I did use it. I started recording whole programs, not just ‘tests’.

 

The reason it was so useable was because the Nova T card resolved the two problems with the older card. First since it is Freeview and Freeview channels are natively mpeg2 streams, the file sizes are inherently smaller. (with analogue cards you typically re-encode the files to make them smaller, but with my old PC the CPU was too slow to do that and do, well, anything else). Second, since it’s digital, if the channel tunes at all it’s as good as it going to be. The other fact is that because it’s actually two tuners then it’s actually useful because you can record two channels at once, or watch one and record another.

 

So that was last weekend. More on this weekend in part 3.

Although I had the software to do timed recordings, to make my computer a PVR, I never did that as it meant leaving the computer on all the time and the software wasn’t that reliable. So I mostly used it to record programs and make VCDs and SVCDs, and later DVDs. By the time I wrote about changing to Linux and nearly changing back, I had been doing this for a while and doing it quite a lot. (I still have nearly two series of West Wing and various movies on S/VCD).

 

One day my computer (running Windows XP) started behaving strangely. I recall I rebooted it once and it got worse. I rebooted a second time and it wouldn’t boot at all. This was obviously some form of malware – virus, whatever. But my computer had a firewall, up-to-date anti-virus and all the latest security fixes. I know that’s no guarantee but it angered me that I could do everything right and still have my system unusable. So I decided to switch.

 

I didn’t do it straight away, impulsively, as I am prone to do sometimes. I used my internet connection at work to find out something – could I use Linux to do all the things I did under Windows? Well I already knew I could do things like web browsing and email. I could do the odd bit of word-processing. The big question was whether I could use my TV card. Could I a) watch and record programs under Linux and b) do all the conversion, editing and manipulation needed to generate DVDs etc? Under Windows I’d amassed an impressive array of (mostly free) programs for manipulating audio and video. After brief googling I found that others were doing it with the same TV card as me and that there were similar programs available – which must mean it’s possible.

 

So I booted my computer using a Linux ‘live cd’ (i.e. running from the cd without using the hard drive). Using that I was able to back up data from my hard drive. Then I installed SuSE 9.3 from a cover disc from some magazine. That was the easy part. Finding and compiling the programs to replace my Windows tools was only moderately harder. (Mplayer is great and will nearly always compile, it’s whether it compiles with all the various formats supported that’s the trick. Still mostly that’s just a time investment – you try to compile, it fails, you figure out there’s a library you need, you find it, install it, re-compile – lather, rinse, repeat.)

The hard part was getting the TV card to work. Although I had done my (minimal) research before switching, I’d found that the instructions I’d found didn’t work. It took me three days of it almost working but not, of reboots, of compiling kernels and kernel modules, of figuring out why said modules wouldn’t load, to finally get it working. It took another couple to get all the channels tuned in and figuring how to record.  It was during this  time that I almost went back to Windows.

 

Oh dear. As usual what was meant to be a bit of background has taken over. I feel a part 2 coming on…