Re: transcoding dvd - how long should it take?

[Anton]

Ha!
Finally got me on something I know about and I'm way down the queue on answers... Transcoding is a fickle beast and there are many lists out there devoted to squeezing the best performance out of your box. Mplayer is a good one but the traffic is huge - 1.5x this list - which requires lots of block deletes. the transcode one has very little traffic and I don't know how many answers you will get. Firstly if you are at all concerned about speed then you should move to mencoder (part of mplayer). As far as I can tell (from my tests, and reading on the net) it is 1.2-1.5x faster with similar options and the same codecs. There is not the beautiful dvd::rip gui that transcode has (only the much less funky acidrip) but I don't think that will concern you very much, being a bit of a guru (shameless grease...:-)! 
Now on to your particular situation. The thing about encoding and speed is, as is often the case, it depends. The thing you need to realise is that there are at least 5-10 variables that affect greatly the speed of your transcodes. Firstly, of course is processor speed. With my duron 700 I was getting about 12-15 fps and with my athlon 2000xp (1600 ish mhz) I'm getting 30-40 fps (with xvid using vidomi under windows). However, I am usually not so concerned with getting the most out of my rips and usually just go with a set of default values - the quick ones. Using mencoder I have got mid to late 50's fps, again using the fastest options. The next factor is format. Some reason the tools out there seem to work a lot better with PAL than NTFS. People are constantly complaining about not getting good rips from NTFS - probably cos of the stupid framerates and non-easily-divideable nasties I read about but forget what are (excuse that last sentence). The other thing with NTFS is interlacing - you tend to get much more interlacing on NTFS, though in general interlacing is going out of fashion. You still get it lots with tv though, so if you are transcoding tv then you will have to deal with that (I have never done that - don't watch tv!). Deinterlacing KILLS your speed. Particularly with transcode - I was getting something like 8fps deinterlacing with transcode - needless to say I didn't let that one run to completion! The thing is that you get horrible artefacts (usually) if you don't deinterlace an interlaced source when you transcode. The next big block of speed-affecting factors are the codecs. Of the open-source lavc (or is it ffmpeg, I can't quite get that) and xvid are the most famous, and probably the best. People argue over which is fastest and best - the mplayer people seem to think that lavc is best, but I have heard some truly amazing things about xvid 1.0 which should be coming out any day now (hurrah!) - in tandem with mplayer/encoder 1.0, it should be an unbeatable combo. In any case, under linux these two seem to outperform divx (3, 4 or 5) and the other lesser known ones. www.doom9.org is the place to start for codec comparisons, and more generally transcode stuff, though beware that the transocde community is heaps bigger in windoze and most stuff on the net is doze oriented. The next big block of speed factors are the filters. Deinterlacing is done via a filter and other filters can have similarly disastrous effects on speed. In order to save bits it is usually recommended that you crop off the edges, as very sharp lines take up lots of bits, and chopping off the extremities isn't usually that noticeable. You need to keep in mind, however, that the final size (after cropping) often needs to be a multiple of 16 or similar. Xvid requires it, and it destroys the speed in some other codecs if it's not. This is another filter. There are also filters and options that you play around with to get the best quality. For example if you are trancoding a particularly dark movie (eg a vampire one or something, not meaning the humour :-))  then for best quality you will need a quite different set of options to one that has mostly light scenes, if you want to get the best quality. There are some options, at least with mencoder, that try to get the best quality and search through the available possibilities and use the best one for each frame, but this also can destroy the speed.
Also, NEVER leave your screensaver on. This will reduce the speed by up to 50%. Watching other movies at the same time seems to be ok, and will also reduce the speed by about a half, but you are using the machine at the same time. AFAIK, nice has no effects whatsoever, apart from the fact that the encode will interfere less with your other operations - it will not make it any faster, as it has no effect on how many operations your cpu can perform, and be assured transcoding uses all your free ones! (seems to have much more of an effect on other operations in windoze though, as linux simply has a better ??$%^?? scheduling system (?)). 
I haven't experimented with slave-encoding yet as I am just trying to set up a network now... but things look quite interesting - can't give you any advice though.
So as you can see there is lots to take into consideration. I would expect on an athlon 1133 (is that 1300xp, or 1100?, or however they put it?) you would get at /least /20fps, using only speed-neutral filters. You may even get 30 on a gentle widescreen (fewer pixels per frame) PAL. On the duron 800 (with xvid on doze) it took 6-8 hrs to encode so we just left it overnight. The thing is that if you can be stuffed with the hassle you can set up a schedule (via a script in linux with mplayer, and maybe gui with transcode - not too sure) and get two or three (or more) to encode in the background (here nice is probably useful) while you do other stuff, go to work, sleep, the supermarket, sauna, go tramping...(a bit carried away there, sorry!). The transcoding world is big and varied. Unfortunately if you want good speed /and/ good quality then there is a major time investment that usually needs to be made.
Cheers
Anton