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CD-ROM Speed

PostPosted: Sat Apr 12, 2003 12:14 pm
by Tux
Are there any ways to increase the speed my CD player runs at in linux other than hdparm?
My reason for asking this is that in Linux, when ripping CD's in grip it averages about 4x.
The hardware is capable of much more than that and I have seen it doing in the 20's in windows (ick)
Maybe I just need to configure cdparanoia?
So, any suggestions?

PostPosted: Sat Apr 12, 2003 12:22 pm
by Linux Frank
I use xcdroast, and when you do a root setup configuration you can adjust the speed the read and write functions perform at. So it will try to work at those speeds if the hardware will let it, of course you can damage your hardware if it is not capable.

PostPosted: Sat Apr 12, 2003 12:36 pm
by Tux
No no, what I mean is when it rips the CD to .wav's before mp3/ogg encoding.

PostPosted: Sat Apr 12, 2003 1:04 pm
by Linux Frank
Yeah when a CD is ripped to the hardrive the single biggest limiting factor is the read speed, which you will have to configure somewhere. The encoding of the ripped data into a .wav is a system resource issue, and is only dependant on the CD speed whilst it is waiting to rip more data (you should make sure you have none of the polling options selected in grip). The rip will fill up your buffer (say 2MB) then encode that, then rip the next 2MB, then encode. The speed at which the CD spins would not alter this, in fact it may cause problems as it might skip data, the CD slows down to read the data from the CD acurately enough. So the maximum speed is the maximum read speed of the CDrom.

The read speed can be limited by inaccurate configuration in your CD ripping program (paranoia, roast, toast, cdrecord), or by having a driver installed that limits your CDrom performance - such as a generic type driver because your CDrom is not supported. The CDrom controls the speed it spins at when reading - you only want to be trying to mess with that when you know exactly what you are doing.

Edit : actually also see what your buffer limit is set to in your ripping software, and trying altering it, that might help.

PostPosted: Sun Apr 13, 2003 8:46 pm
by Void Main
It might also be that your hard drive is not running optimally and can not write as fast as the CD can be read. Check your hard drive speeds by running "# hdparm -tT /dev/hda" (if /dev/hda is drive you write your WAV files to). If you run "# hdparm /dev/hda" it will tell you your current settings and "# hdparm -I /dev/hda" will give you a lot of information about your drive.

PostPosted: Mon Apr 14, 2003 4:44 am
by Tux
Hard drive is set up fine too! This is turning into a bit of a mystery :)

PostPosted: Fri May 23, 2003 12:45 am
by Engineer
Forgive my ignorance and bringing up this old topic, haven't been here in a while, but what are the benefits of ripping to .wav before going to .ogg, .mp3, etc. I assume the same principle applies when making CDs as well? Or is it ok to just burn from .mp3/.ogg?

TIA

Dj

PostPosted: Fri May 23, 2003 2:50 am
by Calum
you mean to burn audio CDs from mp3s or oggs?
well the fact is that audio CDs contain uncompressed digital audio sampled at 44,100 Hz and so do wavs (largely) so it makes sense to go from wavs to CDs since the conversion would have to be made anyway, and there's less distance to go if the files are more or less in the same state already as they are going to be on the CD.

The real reason for converting to wav files before you burn onto a CD is to make sure you get less errors. Decompressing takes longer than just reading a file, and all that extra memory use and decompression time might well enable your CD writer's buffer to run dry and result in another shiny beermat.

Those of us with a celeron 700 and 128 MB of RAM have a bit of a grasp of the reasons for giving the CD writer as easy a time as possible! :)

PostPosted: Fri May 23, 2003 3:06 pm
by Engineer
Thanks for the reply

Dj