HydrogenAudio

CD-R and Audio Hardware => CD Hardware/Software => Topic started by: vilsen on 2018-06-19 16:11:29

Title: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: vilsen on 2018-06-19 16:11:29
Hi, this is my first post here.

Being in the process of finally ripping my CD's with pre-emphasis, I have some questions.

In the wiki - http://wiki.hydrogenaud.io/index.php?title=Pre-emphasis - the following is stated:

"WaveEmph, SoX, and all of the foobar2000 plug-ins have been tested and produce nearly identical output. The differences are minuscule and inaudible."

In the same wiki it is also stated that "cddeemph (Windows) - processes multiple WAV files with audiophile quality filter."

I tend to interpret these quotes as if WaveEmph, SoX and foobar2000 are good enough for de-emphasizing, but also that cddemph is slightly better than the others based on the expression "audiophile quality filter". Is this true or am I just reading too much into those words?

Also, reading from the russian download link for cddemph it seems that it uses dithering after the 16-bit filter, or alternately 64 bit-floating point raw pcm at the output for further Noise Shaping and conversion to 16 bit (Adobe Audition seems to be recommended by the cddeemph developer for the latter task).

Is cddeemph unique in using these techniques, or does SoX / Foobar2000 also use them or similar techniques? I can't find any info on this on the SoX site or in the manual.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: DVDdoug on 2018-06-19 16:42:38
I really wouldn't worry about it unless "something doesn't sound right".   There is no mathematically perfect analog or digital filter/EQ...  There is no "bit perfect" filter.  But, they can be darn-good and audibly perfect.   I'd use whatever is convenient for you.  And if  one or two rips don't sound right, maybe the pre-emphasis flag is wrong and they don't really need de-emphasis, or maybe they need a little EQ to fix 'em up.

I assume these are older masters so the pre-emphasis was probably an analog filter.   There's a good chance that the de-emphasis filter on your CD player is also analog.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: magicgoose on 2018-06-19 16:45:51
For playback it doesn't matter as you'll be unable to hear any difference. 
SoX and foobar2000 plugin don't force conversion to 16 bits at any step, it's up to you to choose (and foobar2000 can apply noise-shaped dithering when converting to 16 bits) 

But for archival it's better to just keep the original. Any kind of *filtering* is irreversible loss of data (because computers don't work with infinite precision numbers, etc.) There are only so much things that are possible to do with audio without losing precision (integer multiplication, integer addition) and they are rarely needed and most regular wave editors can't do this (easily) anyway.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: Rollin on 2018-06-19 17:18:30
WavEmph, SoX and foobar2000 are good enough for de-emphasizing, but also that cddemph is slightly better than the others based on the expression "audiophile quality filter". Is this true or am I just reading too much into those words?
Expression "audiophile quality filter" is meaningless. Actually, any expression with words "audiophile quality" is meaningless.
Also, reading from the russian download link for cddemph it seems that it uses dithering after the 16-bit filter, or alternately 64 bit-floating point raw pcm at the output for further Noise Shaping and conversion to 16 bit (Adobe Audition seems to be recommended by the cddeemph developer for the latter task).
Is cddeemph unique in using these techniques, or does SoX / Foobar2000 also use them or similar techniques? I can't find any info on this on the SoX site or in the manual.
In SoX and foobar2000 you also can do dithering and noise-shaping. In fb2k it is called simply  "Dither", but actually it is dithering+noise shaping. SoX do dithering by default if output is 16 bit, but you can disable it or select different kinds of noise-shaping.
fb2k and SoX do processing in 32 bit floating point. Author of cddeemp claims that it uses 80 bit floating point for processing.

Here is comparison between de-emphasis by foo_dsp_effect (no dithering) (green) and cddemph (red):
Spoiler (click to show/hide)
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: Rollin on 2018-06-19 18:21:44
SoX (no dither) (green), foo_dsp_effect (no dither) (yellow), cddemph (red)
Spoiler (click to show/hide)
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: vilsen on 2018-06-19 20:27:00
Thank you all very much for your input.

My CD's with PE are mostly from the 80's to early 90's but I also have some recent ones which are classical. But maybe they are from older masters.

Whatever prog I decide to use for de-emphasizing, I will also keep the original, ripped files for archiving.

Thanks for the info on the prog's features. It seems there aren't any major differences in what they can do for this purpose, except maybe the 32 vs 80 bit floating point but I don't think it makes much of a difference for de-emphazising 16-bit files. And the graphs from Rollin shows no significant differences.

Just for clarification, are the cddeemph graphs with dithering and the rest without dithering? In that case dithering doesn't make much of a difference either.

I've also been doing some very limited testing myself today and so far I have not been able to hear any differences between the resulting files from the progs. I haven't been able to download cddeemph though, which is why I am curious if it can actually be any better than the others. From the replies from you all and the graphs I reckon there isn't much of a difference.

Expression "audiophile quality filter" is meaningless. Actually, any expression with words "audiophile quality" is meaningless.

I agree, if I had seen this quote on the developer's site I had considered it marketing. But seen in the wiki here at Hydrogenaudio it made me wonder if it had been purposely put there because cddeemph has the edge over the other progs.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: lvqcl on 2018-06-19 20:49:41
But seen in the wiki here at Hydrogenaudio it made me wonder if it had been purposely put there because cddeemph has the edge over the other progs.

Probably was just copied from this program's decsription.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: vilsen on 2018-06-20 10:33:10
Probably was just copied from this program's decsription.

Yes, probably. But it's misleading enough that it shouldn't be in the wiki imo.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: Rollin on 2018-06-20 10:55:16
But it's misleading enough that it shouldn't be in the wiki imo.
Most probably developer of cddeemph himself added this text to wiki. And... it is not there anymore  :)
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: Rollin on 2018-06-20 11:01:36
Just for clarification, are the cddeemph graphs with dithering and the rest without dithering?
cdddemph graphs  are with default settings - 16 bit input, 16 bit output (anyway there is no way to change settings). I would say that i see no symptoms of dithering there.

I haven't been able to download cddeemph
I uploaded it to dropbox - https://www.dropbox.com/s/i8v0tybxgz975ep/cddeemph.zip?dl=1 (https://www.dropbox.com/s/i8v0tybxgz975ep/cddeemph.zip?dl=1)
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: vilsen on 2018-06-20 17:55:17
Most probably developer of cddeemph himself added this text to wiki. And... it is not there anymore  :)
Someone must be reading this thread, haha...
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: vilsen on 2018-06-20 17:57:46
I uploaded it to dropbox
Thank you! Now I can compare it with the other progs in a few days to see which I prefer.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: Porcus on 2018-06-26 13:15:35
Being in the process of finally ripping my CD's with pre-emphasis

... keep the original. Then you can retro-verify with AccurateRip and all that sort of stuff.

And especially if you actually use foobar2000 - then the de-emphasis can be applied on-the-fly using a suitable component and a PRE_EMPHASIS or PRE-EMPHASIS tag.
I have to admit that the only reason I use foo_deemph by @lvqcl ,  https://hydrogenaud.io/index.php/topic,99394.0.html , is that I started using it five years ago and it works satisfactory.
Title: Re: CD's with pre-emphasis: Cddeemph vs SoX vs Foobar2000
Post by: vilsen on 2018-06-28 12:48:32
Being in the process of finally ripping my CD's with pre-emphasis

... keep the original. Then you can retro-verify with AccurateRip and all that sort of stuff.

And especially if you actually use foobar2000 - then the de-emphasis can be applied on-the-fly using a suitable component and a PRE_EMPHASIS or PRE-EMPHASIS tag.
I have to admit that the only reason I use foo_deemph by @lvqcl ,  https://hydrogenaud.io/index.php/topic,99394.0.html , is that I started using it five years ago and it works satisfactory.


I'm keeping the untouched rips as a backup, in case I need them in the future. No big decision either, since hard disks are cheap these days. As for the physical CD's, I'm afraid they'll go in the trash can...

I need a one-time solution of de-emphasizing since I play my music on various players, so on-the-fly is not practical for me.

I've been busy with other stuff for a week so I haven't yet decided what I'll use. But since there seems to be no audible differences in the de-emphasized files between the programs, it's only a matter of which method one finds the most convenient, as pointed out in the thread.