Pat Farrell Wrote: > Max.spicer wrote: > >I'm just getting towards the end of the horrible task of ripping all > my > >music from CD to flac. I did all of this without any normalisation, > but > >I'm beginning to wonder if this was a mistake. What exactly does the > >normalisation process do? > > Normalization is ensuring that the maximum value of the digital signal > is as high as allowed by the format. (This is normally called 0 dB > full > scale) > > For example, if your song never got louder than -3 dBFS, > you could 'normalize' it by adding 3 dB to each value > to make sure that it is full scale. (Actually, you multiple all values > by 2, which is how you make something 3 dB louder) > > Many extraction utilities will tell you the highest signal encountered > during the extract (aka rip, but that usually means extract and > compress). > > > Can it be done "post-rip" by a Linux tool (my server runs Debian )? > > Sure, you can, there are other posts that tell you how to do it. > > >Do you lose quality by doing this? > > Yes, you lose quality. And the point of using a lossless > compression such as FLAC is that you can recreate the > original signal, bit for bit, if you want to. > If you normalize it, or do any other signal processing (compress, EQ, > etc.) then you no longer can restore it to the original. > This flies in the face of why you would want to use FLAC in > the first place. > > (Of course, you could keep both the un-messed with version and > the normalized/EQ/compressed version for only twice the disk space, > and then you would not lose anything in the original.) > > The specifics on what you lose tend to get complicated. > As a minimum, you lose the dithering that the mastering house > did on the original recording. > > If you are doing critical listening, I'd strongly suggest > that you not touch the original data. If it is for background > music, I'd make a second copy with a lossy compression > and do signal compression, and EQ for "loudness contour" > while you are at it. > > You can automate it all with a couple of shell scripts. > > > -- > Pat > http://www.pfarrell.com/music/slimserver/slimsoftware.html
I have started ripping my CDs to FLAC for use with my squeezebox and am using dbpowerAMP. However, I have had the volume normalisation turned on!! I presume this means: 1) I have been altering the data itself (not just the metadata) 2) The FLAC files are not strictly lossless so I cannot get back to the original WAV. Can anyone confirm the above 2 comments please? I am thinking I'll need to start the rip process again using ReplayGain....ouch! Jimmy -- jimmy ------------------------------------------------------------------------ jimmy's Profile: http://forums.slimdevices.com/member.php?userid=616 View this thread: http://forums.slimdevices.com/showthread.php?t=13583 _______________________________________________ ripping mailing list [email protected] http://lists.slimdevices.com/lists/listinfo/ripping
