FLAC compression details

FLAC stands for Free Lossless Audio Codec which means there is no loss of quality. It is an open-source lossless compression file format that offers CD-quality audio sound at reduced file size. FLAC provides varying levels of lossless compression from 1 through to 8 which are tailored to balance file size with encoding time, but what is the best trade off? Since the video files are many orders bigger than the music ones, do we really need to worry about the end file size? Since it is more likely that they will be accessed from outside then the smaller the file the faster it will be transferred to a mobile device, but even that is less of a problem today ... that is if Vodafone is actually working at all. Storing the files uncompressed is not as much of a problem as it used to be, and my whole music collection fits on a single USB storage device so I don't even need to access via mobile broadband.

Level 0 is the original uncompressed file, while 1 to 8 take progressively longer to compress but result in ever smaller file size, with no loss of clarity over the original sound file. The default level set on my openSUSE desktop was 5. This is found in the Multimedia section of the System Settings, under Hardware. I've switched to 2 to speed up compression, but I'm not convinced I'm seeing a difference and I suspect that the limiting factor is actually reading the disk rather than the compression process. So Next test is to read as a raw .WAV file and see if that makes any difference.

OK, now I know. The basic problem is that the media of an audio CD is designed to be read at a constant ... slow ... speed, and while computer CD/DVD drives have got faster and faster, that only relates to using digital media. When an audio CD is loaded it is that which will determine the time it takes to read it. The drives I have here can manage to read the audio CD's a bit quicker but they still take time. That is at best 3 times faster than simply playing the CD normally so it's just a matter of patience. As I no longer have the vast collection of physical CD's that I used to have, I've already processed the ones I have left and they are all ripped. I'm picking up some new stuff from the charity shops for pennies, 3 disks for a pound typically in the smaller charity shops, and then I can just leave them ripping in the background.

Update - Now that is interesting. I switched over to using the windows machine to rip the CD, initially just to check what cddb data it was returning, but when running an actual rip, direct to FLAC-8 it completed the whole job in a matter of minutes! Sizes match fairly closely to the Linux FLAC rips and no way of checking if the sound quality is the same, but they sound the same. Only think I can think is that the the drive in the Lenovo box is quite old as the machine was supplied with W7 and it's got rather poor CD/DVD write performance, but it works and is a substantial save of time.