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Pls Help me make a decision WRT the FeralA filters


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Need help in making a decision.  Just asking for input, and this is a very important crossroads.

 

The FeralA filters are now 'perfect'.   They work for everything presented, only 3 adjustments, and possible to bring it down to two -- both are dB type adjustments with narrow ranges.   There is also the calibration for decoding itself, but that also has been generally very stable on non-normalized consumer material.

 

Everything presented is cleanly decodeable, even the ABBA stuff, Carpenters and other previous 'problem children.'

There was a discrete change which opened up the full solution.   It is of similar form to the previous filter design, but a major 'hole' was patched.

 

My reality:  I recognize that I know that the audience is limited, and that not many people are truly enthusiastic, many probably not believing in the problem, even now...

 

Should I publish the filters or not?   I know that  there aren't very many DolbyA decoders out there, but there are indviduals who have strong marketing/sales abilities, and I have none.  It is very possible that with proper marketing support, someone could make a LOT of money on the filter designs (improved sound for everything, easy to adjust), but I also want to 'fix' the music.  I really don't mind if someone makes money on this design, but it doesn't seem right that 2-3yrs (probably 8yrs total) of part time work would be monetized by someone else, without supporting the person who did the work...

 

Note:  I don't care about money -- but I do care about fairness.

 

I like helping people, but there is a certain morality (or lack of) by some people in this world...

What do I do?   This is NOT rhetorical -- the filters are NOW perfect, I can create true DolbyA material from almost any pop FeralA stuff, often first iteration.  Anyone could use the filters now....

 

John

 

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Why not partner software companies that sell plugins for the Pro Audio scene? izotope?

 

I know nothing about this though, maybe you could ask in a Pro Audio forum like https://www.gearslutz.com

These places usually have members of the industry participating.

"Science draws the wave, poetry fills it with water" Teixeira de Pascoaes

 

HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256)

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Thanks for the feedback.

Yea, gearslutz is a good place -- I had some early discussions about DolbyA with them -- got good feedback back then.   I liked the AS people more (not that anybody has been rude recently -- just felt more at home), so I have been spending forum time here more than anywhere else.

 

I was interested in what semi-pro and consumers think...  I have one definite outlet through Richard & AES, but that would be a little more slow.  There are LOTS of skeptics with the pros -- Richard doesn't even seem to believe that i have a one-size-fits-all filter now.  (I had been employed for 30+yrs solving the problems that could not be solved.)   IT REALLY WORKS!!!  (Of course, kind of like my proclaiming incremental success, but there have been so many breakthroughs -- this stuff is hard, really hard!!!)

 

Maybe the best thing is to complete the filters in the DHNRDS DA, and implement the DHNRDS FA mode completely.  Even though I know that 99.9% of even advanced consumers won't really enjoy doing their own decodes, it has gotten so easy now that it is *almost* first attempt is perfect (it really IS htat easy now.)  About 2/3 of the time, material can be decoded IMMEDIATELY, with no adjustments!!!

 

Certain recordings *are* a little different, like Supertramp, but even they are fitting within the framework with changing a few of the 3 (or four if you count level calibration) settings.

.

I am decoding ABBA & Olivia with EXACTLY the same settings, and the later Carpenters albums are just a minor tweak on one of the settings.  IT IS REALLY EASY NOW!!!

 

I gotta DEMO first, about how trivial it is to use...  It wont' be fully trivial until it is divorced from SOX though -- shelving filters and rate conversion...  Shouldn't take too long to do when/if I am feeling well.  My difficulties are one reason why I want to pass the info off somewhere, and don't want it to disappear into the wind.

 

There is just not enough interest yet, and the only way to gen-up interest is through DEMOS.  I think that you are right though, gearslutz and Richard are probably the best approach.   If I give it to a plug-in writer, it is much bigger, because they'll want a DolbyA decoder also -- which I can provide a short/small one that has 'okay' quality (about that of the old HW.)

 

I gotta gen the interest!!!  I am almost willing to give it away if someone will actually use it to benefit 'music'!!

 

John

 

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3 hours ago, John Dyson said:

Thanks for the feedback.

Yea, gearslutz is a good place -- I had some early discussions about DolbyA with them -- got good feedback back then.   I liked the AS people more (not that anybody has been rude recently -- just felt more at home), so I have been spending forum time here more than anywhere else.

 

I was interested in what semi-pro and consumers think...  I have one definite outlet through Richard & AES, but that would be a little more slow.  There are LOTS of skeptics with the pros -- Richard doesn't even seem to believe that i have a one-size-fits-all filter now.  (I had been employed for 30+yrs solving the problems that could not be solved.)   IT REALLY WORKS!!!  (Of course, kind of like my proclaiming incremental success, but there have been so many breakthroughs -- this stuff is hard, really hard!!!)

 

Maybe the best thing is to complete the filters in the DHNRDS DA, and implement the DHNRDS FA mode completely.  Even though I know that 99.9% of even advanced consumers won't really enjoy doing their own decodes, it has gotten so easy now that it is *almost* first attempt is perfect (it really IS htat easy now.)  About 2/3 of the time, material can be decoded IMMEDIATELY, with no adjustments!!!

 

Certain recordings *are* a little different, like Supertramp, but even they are fitting within the framework with changing a few of the 3 (or four if you count level calibration) settings.

.

I am decoding ABBA & Olivia with EXACTLY the same settings, and the later Carpenters albums are just a minor tweak on one of the settings.  IT IS REALLY EASY NOW!!!

 

I gotta DEMO first, about how trivial it is to use...  It wont' be fully trivial until it is divorced from SOX though -- shelving filters and rate conversion...  Shouldn't take too long to do when/if I am feeling well.  My difficulties are one reason why I want to pass the info off somewhere, and don't want it to disappear into the wind.

 

There is just not enough interest yet, and the only way to gen-up interest is through DEMOS.  I think that you are right though, gearslutz and Richard are probably the best approach.   If I give it to a plug-in writer, it is much bigger, because they'll want a DolbyA decoder also -- which I can provide a short/small one that has 'okay' quality (about that of the old HW.)

 

I gotta gen the interest!!!  I am almost willing to give it away if someone will actually use it to benefit 'music'!!

 

John

 

How can one tell if a file is encoded with Dolby A and needs decoding? 

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7 hours ago, vortecjr said:

How can one tell if a file is encoded with Dolby A and needs decoding? 

I hate to say, if it is a POP CD, most likely is in 'feralA' form.   FeralA is so common that we are all used to it -- I could never accept it though, and one reason why I pretty much quit buying CDs in the late 1980s.  (Gave up on the hobby until my "research project".)

 

Here is the difference -- feralA (the common DolbyA encoding in consumer recordings) has a similar freq response balance to the correct sound, but the highs are all 'bunched up' (dynamic range compressed) and the stereo image is damaged.  The FeralA form isn't terrible, but it isn't accurate either -- the source of the 'vinyl sounds better than CD' argument.   That argument has little to do with the media, but instead a difference in mastering.   I am including two snippets from the carpenters as an example.   (When hearing the comparison, after hearing seveal examples, then it becomes an aahh haaa moment.)  I have a method to convert a CD to a DolbyA master-tape, then can decode it with a DolbyA decoder.

 

I am including two examples from the Carpenters (I can do almost any other older group -- same results)

Example #1 is from an original CD,  FeralA version is from the CD, Decoded comes from the CD, but properly decoded.

Example #2 is a remix/remaster from HDtracks, FeralA version direct from download, Decoded comes from download, but properly decoded.

(Sorry about mp3, and limited length snippets -- but does show the vast difference, real stereo.)

* I DID NO PROCESSING OTHER THAN DECODING WITH MY STANDARD FORMULA....

 

 

04 - Reason to Believe-FeralA.mp3 04 - Reason to Believe-Decoded.mp3 10-Top Of The World [2004 Remix]-HDtracks-FeralA.mp3 10-Top Of The World [2004 Remix]-HDtracks-Decoded.mp3

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John, curious if these "FeralA" samples are also found in some of the pre-emphasis CD's out there from the early 80's?

 

@vortecjr has a good point. Is there some kind of tool perhaps that could scan a track and give us a reading like "This is 85% likely feralA."

 

The difference between the original and your decoded output is clear (and I agree sounds euphonic).

 

Archimago's Musings: A "more objective" take for the Rational Audiophile.

Beyond mere fidelity, into immersion and realism.

:nomqa: R.I.P. MQA 2014-2023: Hyped product thanks to uneducated, uncritical advocates & captured press.

 

 

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6 minutes ago, Archimago said:

John, curious if these "FeralA" samples are also found in some of the pre-emphasis CD's out there from the early 80's?

 

@vortecjr has a good point. Is there some kind of tool perhaps that could scan a track and give us a reading like "This is 85% likely feralA."

 

The difference between the original and your decoded output is clear (and I agree sounds euphonic).

I am 100% in sync with your ideas....

 

This is probably an excessive answer, but I so appreciate the feedback, I offer as complete a response as I can...

Also, my current project is available consumers on SUPER GOOD terms, but it is intended for the distributors and archives.  It is NOT like a normal consumer product, and is best described as 'Unix command line like'.   Consumers should NOT be burdened with these matters, but the state of the recordings necessitates it.  I do not encourage consumers (unless programmer-like technical types) to use the program as it is today.

 

Before answering Archimago & Vortecjr's comments, whose essence I agree with, I have to say very many, I don't just mean like 60%, but I mean 95% of the older CDs in my collection ARE FeralA.   I even have some HDtracks downloads that ARE FeralA...  These facts are one reason why I believe this to be more than a little important.   If it was like a 25% FeralA hit rate, I would probably be a LOT more passive!!!  I am definitely seeing greater than 90% of the early CDs.

 

Also, I suck at mastering and anything like mastering.   Any demo results that I do would NOT be the best possible results.  A person competent in mastering could do 1000% better than what I am demoing!!!

 

1)   Yes -- example:  my Nena 99 Red Balloons has both pre-emphasis (un-EQed) AND pure DolbyA.   The best way to describe the sound is *intense* :-).

1a)  Initially, sometimes CDs without the proper de-emphasis bit setting might sometimes initially sound like FeralA, trying to actually decode the preemphasis-CD without FeralA will sound like gritty-hell.  Decoding material which is not FeralA or DolbyA does NOT sound good -- especially egregious are vocals and material with lots of HF material -- it can become grainy.  Also, low levels tend to have a gating effect when decoding material that is not encoded.

 

2)  Detecting FeralA -- that has been a major challenge for me almost since the decoder was written.  It is even difficult for me, to be reliable determining FeralA when listening.   It is difficult even though I am very practiced -- I wouldn't expect anyone except the most exceptional golden ears to be reliable at first, before they get practice.   The kind of listening for FeralA goes far beyond my own reliable perceptive powers even though I am maybe accurate 90% of the time -- to me, that 90% isn't good enough, because can still lead to embarassment.  *I am working on a scheme where the DHNRDS DA decoder detects when it is "confused"*...   Well, you know what I mean -- when the dynamics are insane, I know that the code has enough information to say 'Bzzzt', probably not DolbyA/FeralA  :-).   Just gotta figure out exactly how/where to sense the confusion.*

 

* The DA decoder has all kinds of pictures of the signal, it has averages, RMS measurement, and it has the sin^2+cos^2 type detector scheme (using hilbert transforms), and things like that.   I should be able to detect the fact that the gain control has excessive excursions, such excursions would cause gating or a nasty kind of grittiness in the sound.

 

 

Since FeralA is really a kind  of 'DolbyA' encoding, it will have similar characteristics, but since the DHNRDS DA actually sees the pure DolbyA as converted from the FeralA, then it's internal consistency checks for 'craziness' can also be used to make a complaint that the material is NOT FeralA.

 

Even though I have the decoder working -- IT IS NOT REALLY A FINISHED PRODUCT -- I just don't know how to get there from here.  I have a real perceptual limitation that makes GUI programming much more than a challenge for me, so the program is command line.  I have simplified the tweaking requirements for FeralA down to the point that command line usage is more tolerable than doing the filter conversion with SOX (really intricate.)

 

1)  The DHNRDS DA (DolbyA decoding only) IS working totally perfectly, beyond perfectly, the best ever and probably best possible DolbyA decoder.

 

2)  FeralA command usage is a real problem right now.  Requires a list of SOX filters to do the conversion from FeralA to DolbyA so that the DHNRDS can decode.   Happily, I have all of the software 'ducks in order', and building the full FeralA capability into the DHNRDS  is a matter of converting the sox filters (which are very consistent from recording to recording) into a bunch of 2nd order shelving filters in C++, and give access to the approx 3 parameters needed to adjust to each recording.   (The default setting will actually work for most of the older CDs -- directly.)   I probably need a day or two of serious concentration to build-in the infrastructure.  I already have a thread allocated for the FeralA EQ.  (The DHNRDS DA is very multi-threaded, it will find CPU cores all over the place :-)).

 

Thanks, and I am still improving it (trying to make it very usable.)

John

 

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On 2/20/2020 at 4:51 PM, John Dyson said:

Detecting FeralA -- that has been a major challenge for me almost since the decoder was written.  It is even difficult for me, to be reliable determining FeralA when listening.

 

Some DACs indicate pre-emphasis in CDs (i.e. a Parasound I had at one time).

Perhaps the software could indicate pre-emphasis. That would be a good start. (don't know if such software already exists for WinOS, I'm on MacOS)

 

Regarding the software, even though I listen mainly to classical plus some "vintage" jazz, I might be interested in an inexpensive piece of software but I would like to be able to have some control over the result, maybe 3 different curves and a low dynamic expansion setting or perhaps even a bypass of this feature (if I understood it correctly).

 

The reason I suggested a pluggin is that it would (probably) make it compatible with all OS platforms.

"Science draws the wave, poetry fills it with water" Teixeira de Pascoaes

 

HQPlayer Desktop / Mac mini → Intona 7054 → RME ADI-2 DAC FS (DSD256)

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1 hour ago, semente said:

 

Some DACs indicate pre-emphasis in CDs (i.e. a Parasound I had at one time).

Perhaps the software could indicate pre-emphasis. That would be a good start. (don't know if such software already exists for WinOS, I'm on MacOS)

 

Regarding the software, even though I listen mainly to classical plus some "vintage" jazz, I might be interested in an inexpensive piece of software but I would like to be able to have some control over the result, maybe 3 different curves and a low dynamic expansion setting or perhaps even a bypass of this feature (if I understood it correctly).

 

The reason I suggested a pluggin is that it would (probably) make it compatible with all OS platforms.

There is a 'tape decompressor' in our queue  -- that is, to remove tape compression.   Some people love it, but others are frustrated.   With the expansion algorithms in the DA, the super fast expansion (actually nonlinearity) can be partially undone without adding more distortion.

 

A GP expander is also in the queue.   The technology in the DHNRDS DA (acutally partially removed, but can be re-inserted) totally removes the distortion effects of even infinitely fast expansion.   Remember the old 'auto-corellator'?  (Phase linear, I think.)   Hows about a *perfect* auto-correlator?   I have acutally snipped out the DolbyA curves from the DHNRDS (for testing), and got perfect expansion, but ZERO distortion....   So, infinitely fast attack/release (well, you know what I mean --- as fast as the signal waveform), but zero distortion? :-).

 

That technology is in the DHNRDS right now, but it is focused purely  on DolbyA things at this point.   The user interface for command line is already very complicated enough (take a look a the manual on DHNRDS.com.)   Imagine adding at least 1 more complex command (--feralA mode) and then a GP expander (about 3 more switches.)    After adding feralA, then the DA/FA program itself is at the end of its development.  Next will be the TD  (tape decompressor) and hopefully C4 (Telcom C4 decoder, but so few people really need it.)   A GP expander was started in 2010, but got diverted by the DA.

 

Part of the 'proprietary' section of the DHNRDS has some trade secret expansion (or compression) algorithms that almost totally effectively remove modulation distortions (and IMD also.)   It is very similar in concept to Orban Patent US 6,205,225 - it isn't structured the same, but does a lot more than the Orban patent, and much much much better.   Computer DSP software gives many more degrees of freedom than can be done in the HW design.

 

My original project was a multi-band expander, but with what I have learned on DolbyA, I think that it would be a very interesting project once I can finish the DA and others on the list.

 

As it is, the DA undoes the problems with CDs with 'perfection', but there is also no 'less aggressive' DA that some people might want.  Once the FeralA (direct CD) signal is converted to DolbyA, it becomes intolerable.   Anyway, thanks for the input!!!

 

John

 

 

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Got a mini-announcement --

after a day or so of work, I have merged the complicated SOX filter command line into the DHNRDS DA program, and it is working great.  I am not sure why, maybe because it is easier to use and adjustment is so much easier -- but the sound quality appears to be a little better.

There are other changes also - internal automatic conversion from 44.1k to 88.2k sample rates and other benefits that eliminate the need for an external program.  There are still a few nits, and it is still at least a week away from having something usable as 'truly working code', but the results so far are very encouraging.   (I can do things like sample rate conversions & shelving filters much more optimized to the application than GP code.)

 

John

 

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I have been testing the command -- and sorry that the DHNRDS is command line based, now a feralA decode is now not much more complicated than DolbyA is.  It took a long time to develop the technology for this simplicity of use.  This handles the EQ and rate conversion to 88.2k from CD 44.1, it also works 96k from 48k, and is done automatically because of the low input rate.  The output is currently default 24bit signed, but I am thinking about changing the default output to the professional floating point instead.  (I actually thought that it defaulted to floating point, but during testing I found it was 24 bits.)  Actual DolbyA decoding is actually simpler because it doesn't require the --fa, --f3k, --fm3k and -fhf switches.   The quality of the command below is lightyears more clean than a true DolbyA.

 

I have shown the sox command portion of the old feralA decoding to some people who might be reading this -- believe me, the new command below is MUCH MUCH MUCH more simple to use.

 

The hard part is for the --fa,--f3k,-fm3k and --fhf switches, but is actually easier than it used to be.  Most of the time, the settings are fairly easy to find now.

 

Here is the command (as typed from a Linux bash prompt, Windows would be little different):

> /usr/local/bin/da-avx  --outgain=-3 --info=3 --fa --tone=-12.85  --xpp --f3k=3.0 --fm3k=6 --fhf=-2.0 --input=CDinfile.wav --output=outfile.wav
 
--outgain=3 might not be needed, depends if output goes over 0dB, output is default floating point 88.2k
 
--tone=-12.85 is also the default, not super critical, but can vary between -12.75 to -13.00 on UN-NORMALIZED CDs.
--info=3 isn't really needed, just gives progressive stats
--xpp is the high quality decoding mode
--f3k, -fm3k --fhf are the EQ parameters -- don't vary much.
 
Anyway -- this is not really intended for consumers, but as this project is introduced more in public forums (e.g. AES), I sure hope that the distributors start taking quality seriously.   There is almost ZERO profit (in fact, not profitable) even if we sold 10000 units, which we will not...  We'd be lucky to sell 100 copies, because recording quality is given lip service, and higher sample rates, but the data is poorly handled.   Maybe some enthusiasts and of course the main application:  Archives, will be able to benefit.
 
John
 
 
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I am hoping that there is room for sales (and  very limited demo access) for folks like me. I use SOX from the command line to generate upsampled files with varied parameters to arrive at optimum settings in playback software, and would like to try your approach for use on my digital library. I'm not particularly adept, but am comfortable with simple linux/unix shell scripting and command line interfaces.

 

At a more basic level, could you point me to a summary of FeralA/Dolby A -- what it is and how it was used in the early digital decades. I can guess, and will chase the answer myself, but a link would probably save me, and others, some time.

 

Thanks,

Skip

 

 

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Just now, Skip Pack said:

I am hoping that there is room for sales (and  very limited demo access) for folks like me. I use SOX from the command line to generate upsampled files with varied parameters to arrive at optimum settings in playback software, and would like to try your approach for use on my digital library. I'm not particularly adept, but am comfortable with simple linux/unix shell scripting and command line interfaces.

 

At a more basic level, could you point me to a summary of FeralA/Dolby A -- what it is and how it was used in the early digital decades. I can guess, and will chase the answer myself, but a link would probably save me, and others, some time.

 

Thanks,

Skip

 

 

Even though the development has been going on for approx 5yrs, we have not done a lot of documentation.  There is a manual at DHNRDS.com, but is in the midst of being updated with the FeralA capability.  (In fact, I need to provide the source info for the document -- my project partner does the documentation / interface with the pro community/talks at AES etc.)

 

Here is the general story:   DolbyA had been used for analog audio tape noise reduction in professional settings -- even still today in some limited cases.   DolbyA is like an intense version of DolbyB or DolbyC -- but is much less compatible than DolbyB/DolbyC to listen to without decoding...

 

FeralA is my name for material which has been sold to consumers on digital media since CDs came out.   That original 'digital' sound that people complained about back then was substantially caused by the use of DolbyA being equalized instead of decoded.   Once DolbyA material is equalized, it sounds like a multiband compressor had been used on the recording.  This is a major reason for the difference between 'vinyl' and 'digital'/CD sound.

 

Remember -- a huge percentage of early ('60 through early '90s) recordings on digital media as sold to consumers is NOT the properly decoded DolbyA recording, but instead is this 'FeralA' form, where the actual, hopefully higher quality recording is available if the signal is properly equalized to recover the DolbyA signal, then decoded with a DolbyA compatible decoder.   Proper decoding doesn''t necessarily result in more enjoyable listening experience -- sometimes the compression might be a good thing.  So -- I don't do subjective comparisons or judge others enjoyment -- I am interested in recovering the recording as mixed in the studio -- THAT Is my project.

 

----

My project originally was to develop a full quality DolbyA decoder.   That has been in varying stages of completeness until recently, when it simply cannot be made to work any better...   The DolbyA decoding project is complete, and a workable tool for extracting better-than DolbyA HW quality from old tapes and recordings backed up onto digital, but not DolbyA decoded.  (The DHNRDS DA really DOES almost reach into the signal to remove the distortions that would otherwise be created by the decoding process -- in a way...)

 

Next, this new FA project, actually started 5+yrs ago also, but on the back burner -- how do we correct all of those recordings in consumer hands, or better yet, can we make a tool for distributors to correct the recording?.   Nowadays, the normally available recordings, even to the distributors are in the FeralA form!!!  That is a sad state of affairs because the original quality is not normally accessible even as high-res material or remastered material.   I have been dabbling in doing the correction to the consumer recordings so that they can be properly DolbyA decoded along with the compatible decoder itself.   After a couple of years of very subjective & objective experimentation, I found a formula for the corrective filters which change the 'consumer' compressed 'errsatz-DolbyA' material (FeralA) into true DolbyA so that essentially a master tape can be recovered.

 

The DHNRDS can decode DolbyA format tapes and also the normally digital FeralA format that is in the hands of consumers.   Two days ago, since I had determined the correct set of filters to do the correction, I just added the FeralA mode into the DHNRDS DA decoder.  So, now I call it the DHNRDS FA (for FeralA) and DHNRDS DA (for DolbyA.)   There are a few more features that need to be added -- the most important is real-time play through the Windows audio subsystem.  Normally, for Unix like OSes, I use the SOX play command, but that is an anathema to the Windows approach that 'one program does it all'.

 

When this version is ready ( a few weeks), I'll make some copies available gratis, with a generious license timeout.   I do NOT want to do anything with money -- but there IS the professional side of the project which does charge for the decoder, but it is a nuisance fee.   I hope that the requests aren't too numerous, but I'll make 3month timeout versions of the decoder for mostly consumers to play with and see if they like it.  It is NOT shiny and doesn't have blinking lights (other than a progress indicator), but does make good sound with the correct settings.

 

It is an industrial tool, but I won't say no to anyone who wants a copy....  It can sometimes do amazing things to recover the original studio-produced recording.   After listening to properly decoded materials, perhaps most important is the recovered stereo image...

 

I'll keep people on AS updated about the status.  I am not holding back anything from anyone -- I am also planning on offering the 1st level of decoding algorithms to serious plug-in programmers -- I don't do 'plug-ins', but live in the C++ multi-threaded programming world.  It would be too much of a distraction for me to try to learn the plug-in environments - but I am willing to support someone who wants to do it.  There is a subset of the program that can decode DolbyA with roughly the quality of the old HW, and it requires approx 1/3 of a Haswell core to decode realtime at 96k.   Even the stripped down decoder takes lots of CPU, and to attain that performance level, the code runs 90+% of the time in SIMD instructions!!!*

 

* The higher quality modes of the program, which also use the basic decoding algorithms, also does some manipulations to avoid the intermodulation distortion that is naturally created by the attack/release methods for DolbyA, and additionally the fast gain control operations on DolbyA effectively modulate the audio, thereby creating sidebands.  Those sidebands are a reason for the DolbyA fog that recording purists have known about since it was introduced.   The DHNRDS DA mitigates the effects of the DolbyA fog creating sidebands.  (Uses quadrature techniques to partially cancel the audible parts of the sidebands -- sort of.)

 

The normal version of the program runs on Windows, it needs at least SSE2 for the slower version of the program but the faster one can run on AVX2.   The code is so very highly optimized that the two builds are almost totally different (using an automatic mapping of functions per CPU type would definitely be slower.)   I can make Linux versions available also -- the DHNRDS actually runs MUCH nicer on Linux.   I don't do GUI programming either, if someone wants to write a GUI, I can define an interface :-).   Anyway -- it IS now very much easier to use for FA decoding, and will keep everyone up to date.

 

John

 

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Thanks, I was on the right track except I suspected that Feral A was an attempt to clone Dolby A and avoid royalties. Sounds like it's more a process whose output should have not contiued past the first generation.

 

I look forward to coming to grips with DHNRDS FA once you deem it ready for not-quite-prime-time.

 

Skip

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1 hour ago, Skip Pack said:

Thanks, I was on the right track except I suspected that Feral A was an attempt to clone Dolby A and avoid royalties. Sounds like it's more a process whose output should have not contiued past the first generation.

 

I look forward to coming to grips with DHNRDS FA once you deem it ready for not-quite-prime-time.

 

Skip

Best way to describe feralA:

 

This is what should happen:   DolbyA master -> DolbyA decode (slow) -> mastering -> consumer

This is what happened:  DolbyA master -> tricky/cute EQ (very fast)  -> mastering -> consumer.

 

The decoding is limited to real-time (that is, a 45minute recording takes 45minutes to decode.)   When doing EQ, that can be done in seconds.

 

All DolbyA encoding is:  a well defined multi-band compressor.   When the output is EQed to sound sane, it is like a relativly mild (by today's standards) compressed signal....   It is MORE compressed than what is produced in the studio, and because of some of R Dolby's genius, it only causes minimal damage when compared with a set of simple JFET compressors.  (There are really ingenius tricks in the design of the DolbyA units!!!)

 

John

 

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