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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: Chris K on January 23, 2004, 05:07:58 PM

Title: upsampling for post-processing??
Post by: Chris K on January 23, 2004, 05:07:58 PM
a taper pal of mine, that is not on ts.com (yet), says that he sometimes upsamples his d7 dat tapes from 16bit to 24bit in order to add post processing compression, normailzing, etc.

he says that it allows for a smoother transition from the raw data to the bounced data

he then down samples back to 16 bit for cd burning, shn and flac distribution

does this make sense?

anyone else do this?
Title: Re:upsampling for post-processing??
Post by: Sean Gallemore on January 23, 2004, 05:16:41 PM
your description makes since
Title: Re:upsampling for post-processing??
Post by: Chanher on January 23, 2004, 05:22:30 PM
I "upsample" to 32-bit in CEP whenever I do something extraordinary.  For example I've finally gotten around to converting some of my very first tapes and almost half have significant clipping.  so I convert to 32-bit, run clip restoration, then back to 16-bit.

nice name btw
Title: Re:upsampling for post-processing??
Post by: Chris K on January 23, 2004, 05:28:08 PM
what i am wondering is, will the higher bit rate make an audible difference assuming you do the same post processing in 16bit?

what are the advantages?

this is quite new to me, and i find it very interesting!



Title: Re:upsampling for post-processing??
Post by: Sean Gallemore on January 23, 2004, 05:36:35 PM
a lot of people will record in 24bit and 48ktz when possible, even if the end result will be a CD (16/44.1).  Maybe it allows for more percision ???

my take is that you can't get more from less.  16 > 24 > 16 in my limited knowledge wouldn't make it better.  A horrible comparison is using mp3s, going 128 > 192.  You just can't get the data that isn't there.  However, maybe the smooting out theory is right......fuck I dunno, I'll shut up
Title: Re:upsampling for post-processing??
Post by: scb on January 23, 2004, 06:25:02 PM
first: it's not upsampling.  bit rate change has nothing to do with changing the number of samples

more bits = more precise numbers.  doing calculations in the 24 bit realm allows for more precision
Title: Re:upsampling for post-processing??
Post by: Craig T on January 23, 2004, 07:02:30 PM
doing any kind of editing in 16bit, especially DSP (eq, etc), kills the quality.  take identical copies of a recording, DSP one in 16bit.  the other covert to 32bit-float (or 24bit) then DSP and dither back to 16bit.  that should give you your answer.
Title: Re:upsampling for post-processing??
Post by: Chris K on January 23, 2004, 07:14:36 PM
first: it's not upsampling.  bit rate change has nothing to do with changing the number of samples

more bits = more precise numbers.  doing calculations in the 24 bit realm allows for more precision

thanks...that actually makes alot of sense...more precise numbers should equal better calculations which should equal better sound...in theory

my inqury has been satisfied...PLAY ON!
Title: Re:upsampling for post-processing??
Post by: Kelso on January 25, 2004, 03:56:38 PM
well it's stupid to use 48 kHz if the final product is a cd. For a very non-significant gain in quality in recording you will lose more at the final conversion. 48 to 44.1 conversion is a very complex conversion and it's destructive.  The proper way to go is 24/44.1 or 24/88.2 for cd mastering.
Title: Re:upsampling for post-processing??
Post by: zowie on January 25, 2004, 04:15:48 PM
well it's stupid to use 48 kHz if the final product is a cd. For a very non-significant gain in quality in recording you will lose more at the final conversion. 48 to 44.1 conversion is a very complex conversion and it's destructive.  The proper way to go is 24/44.1 or 24/88.2 for cd mastering.

That's a myth.   Math is math, it's not destructive if done properly, or even very complex, just large numbers.  Unless you're writing the code, what do you care?
Title: Re:upsampling for post-processing??
Post by: jpschust on January 25, 2004, 06:06:17 PM
well it's stupid to use 48 kHz if the final product is a cd. For a very non-significant gain in quality in recording you will lose more at the final conversion. 48 to 44.1 conversion is a very complex conversion and it's destructive.  The proper way to go is 24/44.1 or 24/88.2 for cd mastering.

no, the proper way is the highest possible bit and sample rate possible with the best possible conversion tools.  ideally id like to be working in 24/192, but just not enough out there that is up to that par yet.  yet.
Title: Re:upsampling for post-processing??
Post by: Kelso on January 31, 2004, 05:22:38 PM
Are you sure it's not destructive? Every pro audio software Iv' used propose different flavour of quality versus speed which would mean it is lossy (there is no "perfect" quality). Just thinking of what sampling is, I find it almost comparable to d/a a/d conversion, but maybe I'm missing something.
 Even if it's a very non-significant loss what's the point for 44.1 to 48 upsampling? If you use 96 right, but 48 it means losing space and processing time for almost nothing. Count more than realtime on a fast computer.