TV cards: hardware/software decoder/encoder?

[enco]

Hey,

I've been reading a couple posts on the forums about hardware and software encoding and decoding on analog TV cards recently, but I need some confirmation as to what's used for what.
From what I've read so far, I understand that hardware encoding is used primarily for recording and timeshifting, whereas decoding is used for watching live TV, is that correct?
However, in one thread I read that MP actually can't make use of hardware decoders because time shifting wouldn't be possible otherwise - is this true?

I'm currently using an old analog WinTV PCI card (both software de- and encoding) on my rather slow HTPC (Athlon 1200 plus non-DirectX9 graphics card), and watching live TV with it is impossible (CPU at 100% and a framerate of about 1 fps).
I don't care much about timeshifting (though it would be nice to have), my primary concern is watching live TV.
So, would a TV card with hardware decoder help or should I try a DirectX9 graphics card first or will I actually need both?
Any thoughts on this?

Thanks a lot in advance...