Hi Richard,

Congrats on the noise reduction software! I'm looking forward to the 
finished product.

That said, The major film studios here on the Left coast only archive 
the decoded audio files. Obviously, the source material is kept so there 
could be a policy change in the future.

The record companies (that I know of) do the same thing however, at a 
different sample rate. The record companies usually use a sample rate of 
96K or 192K at a bit depth of 24 or 32 bits. The Major film studios use 
a sample rate of 48K and a bit depth of 24 bits.

All of the decoding that I have been a part of has been with hardware. 
However, there is plenty of material left to do so there should be a 
robust market for your product.



Corey Bailey Audio Engineering

On 7/14/2019 2:42 PM, Richard L. Hess wrote:
> Hi, I think many of us agree that it's necessary to preserve both the 
> raw transfer and the decoded version of a file which has been recorded 
> with Dolby or DBX type noise reduction.
> When I first thought about it, I never imagined I'd be part of a team 
> that would produce a better decoder for Dolby A encoded tapes than 
> Dolby, but it's happening and humbling... So, it is a good idea to 
> save as much raw data as possible because who knows what else will 
> come along.
> Plangent is wonderful, but a bit problematic as it is still 
> inconvenient to properly archive the bias, but that's another story, 
> and I think in the long run it would be good if we could do that.
> MY QUESTION is: Are there any standards or recommendations that say 
> "keep the raw undecoded copy as well as keeping the decoded copy?
> It's for a paper that Federica and I are writing.
> Thanks!
> Cheers,
> Richard