Hi. I'm new here (obviously), but also relatively new to the whole PVR bit...
And I've not so much as glanced at Linux in my life. lol

I recently added a Hauppauge PVR-150 to one of my WinXP systems. It was my first experience with a hardware encoder card, and despite some troubles with the install, I've been pleased with it so far.
Its seemingly low resource requirements got me to thinking though...

I have an old Dell Optiplex G1 (P2-400) and a Dimension XPS_T (P3-700), that I am considering converting into PVRs, if I can get some feedback from others who have used a similar setup.
I'm figuring that the P3-700 is enough for a Windows-based PVR (maybe), but I highly doubt the P2-400 is. So I started looking around for other options, and stumbled across KnoppMyth.

Now, I know I've seen at least one or two people in these forums that have used a 400Mhz box at some point or another...
Is there anyone still using this kind of a setup? How well does it do for watching live TV? DVDs? Watching while recording?

Also, for a neophyte like myself, just how easy is KnoppMyth to install and use?

the problem with an underpowered box like that is not the recording, but the playback. It is possible with the pvr350's that have hardware decoders as well as encoders, but your mpeg4 playback will still suck.

Others have managed to get somewhat underpowered boxes to work by using very low resolution recordings.

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Have a question search the forum and have a look at the KnoppMythWiki.

Xsecrets

I should have noted that MPEG4 playback was not really a concern for this box. I'm just wanting a basic MPEG2-only PVR for TV, and maybe also for playing regular DVDs.

Is there anything available for Linux/KnoppMyth similar to the NVidia DVD Decoder...something that will push most of the work off on the GPU rather than the CPU?

I thought I'd respond to the newbie install section of your post...

I started playing with knoppmyth a few months back, and it was the first real time I'd used linux, but I've done a lot of computing/programming work with windows.

It's a steep learning curve, but in my view well worth it. The hardest part is that nothing's where you expect it, and everything's done differently to windows

This is a great support community, and if you've got a problem they'll help you as much as they can. Also, there's a lot of information already stored here, so you may well find your question was answered last week, so go search before posting.

Mephi

linux has xvmc (X video motion compensation) which offloads the playback of mpeg2, however it is currently mostly broken, and causes frequent lockups. There is much development on it, but it is just not usable at this point.

_________________
Have a question search the forum and have a look at the KnoppMythWiki.

Xsecrets

on the linux thing - create a cheat sheet of some common commands before you start to make working on the command line easier... you should be able to copy a file, move a file, delete files and directories and edit text files using a program like nano. if you really understand windows then linux isn't overly difficult, just different.

note you can do all this from your windows desktop using putty to ssh into your myth box.

learn to dig through the forums and knoppmythwiki for info. basic questions dont always get answered on the forums.

most importantly, keep a log of what you do somewhere (i use a plain text file) with information on how you got things to work on your system. when you kill it with a bad update it makes it easier to go back and reinstall fresh.

A quick search for "unix tutorial" should turn up a link I posted within the last month or so... It's a very nice one that I have no hestitation in recommending.

heres the link... as a git linux newby... i found it helpful. most importantly for its explainations of terminology.. for example.. after reading this.. i just did a google search for guides on .. ofr example VI ..which is an essential.. but kind of different to windows txt editors.

http://www.ee.surrey.ac.uk/Teaching/Unix/

would be interested if anyone has any other quality links for linux.. cheers.

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"enter witty comment here"

Not that it is that relevant, but my external hardware mepg4 encoders take up 7.5% of a 2200 semp (amd's celeron) cpu. Scanning for commercials takes 15%, for a total utilization of just over 20%. 20% of 2200 is 440mhz... now the question is how do the MHZ between semps vs PII CPUs compare? I am going to say they are 'close enough' to give an estimation.

Your mpeg 2 cards should use more processor because there's just more bits that have to flow in mpeg 2 than 4, not to mention higher latencies because slower clocks on the busses. The bit comparisons can be taken from plextor's docs:
http://www.plextor.com/english/products/ConvertX2howmuchfitsonadisc.htm
so 1/3 more bits for mpeg2, that brings you up to 600mhz.
Of course, if you can defer commercial scanning to a 2nd pass, your numbers will fall, but at some point you'll hve to run it if at all.

All in all an XBOX is the lowest I would run a backend on (733mhz).

Now there is a point that i keep forgetting and that is MPEg2 decoder hardware is built into a lot of GPUs. to decode mpeg4, it'll take _much_ more cpu, because the mpeg2 acceleration is useless.

I hope that paints the picture a little more.

I used my old dell XPS-T500 with the Hauppauge 250 card for back-end recording and it's fine. CPU is mostly 90%+ idle. I don't do any transcoding and I don't do any automatic commerical detection. The box also supports multiple people accessing it via mythweb and an MVP myth front end w/ out problem.

Since I do all my playback on other devices, I cannot comment on how well it will do on playback, but I did try a quick experiment. I did playback on my monitor, which is running at 1024x768. Playback looked reasonable, but CPU usage ran 70%+.


Marc