Here is a list of HDCD that were identified (using the test convert I mentioned above).
I don’t think any of them were marked as HDCD when I bought them.
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Could you give us details on how to programmatically do this scan?
Just installed foobar2000 and the method to find HDCDs is just to: “Mark all tracks” - “Right-click” - Utilities - “Scan for HDCD tracks”.
Also to note, sometimes compilations might have 1 or 2 HDCD encoded tracks.
Ultimately I think if the Pacific Microsonics A/D converter was involved in the studio is the deciding factor if the album/tracks are marked HDCD.
Note: I’ve purchased 3-4 new release albums in the last year that are identified as HDCD so that A/D converter is still be used at studios. Wether all the HDCD features are implemented per disc is a different question.
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+1 on adding HDCD decoding. I have enough to make it a worthwhile addition for me.
No clear evidence exists that the HDCD.exe application – which I believe is under the hood for both dBpoweramp and foobar2000 implementations – is “incomplete,” per se. The only questions seem to lie with the accuracy of its Peak Extension and Low Level Extension dynamic range expansion routines, but both may be spot on accurate.
And you are incorrect elsewhere in this thread when you refer to the transient digital filter. That digital filtering is applied only on the Pacific Microsonics A/D end, not on the D/A end. In HDCD playback, no dynamic digital filter switching occurs, not even in PMD-100 hardware decoding.
All in all, you really should reconsider applying HDCD.exe processing to your rips. At the very least, it is good enough for the job, and it may be perfectly accurate to hardware decoding, which is woefully out of date by now, I might add. The PMD-100 digital filter chipset was built on a 600 nm process die. By comparison, the Snapdragon 821 chipset in my Google Pixel XL is built on a 14 nm process. Real hardware decoding for HDCD is long gone and not coming back. Oppo universal player implementations, for example, are just software running on off the shelf DSP chips.
AJ
In terms of actually selling the Roon product to end users, having it automatically decode HDCD is an order of magnitude improvement over dealing with the concept on the ripping side.
The whole concept of ripping/tagging cd’s is hard enough for the average music enthusiast.
Not only is ripping/decoding using foobar2000/dbPoweramp a pain it also only works for local content. Everything on tidal that is HDCD demands Roon support to be properly decoded.
I have decoded my local stuff and don’t buy much in cd-quality anymore but I stream more and more from Tidal and it would give you “Peace of mind” if you knew that Roon detected any HDCD content and decoded it.
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As I understand it from various discussions on the 'net, AJ Shepherd has it right - no commercial hardware ever implemented transient filter manipulation in HDCD playback, although the original patent mentions it. Changes in filtering would in any case be of minimal audible consequence relative to correctly decoding the dynamic expansions, which are definitely audible when used. Whether HDCD actually offers benefits over correctly dithered and noise-shaped Red Book standard is highly debatable, but as pointed out above a surprising number of CDs actually are HDCD encoded, probably because the Pacific Microsonics converters were well-regarded for their time and used by mastering engineers even on projects which are not very “audiophile”.
Recently, the popular FFMPEG library has implemented HDCD decoding, and there is a new open-source general purpose decoding library project: https://hydrogenaud.io/index.php/topic,112596.0.html
For examples of how HDCD impacts real world recordings, see: http://www.audiomisc.co.uk/HFN/HDCD/Examined.html
As a final note, I’ve found that my Oppo BDP-105 will decode HDCD through its USB input, on both analog and digital outputs. This is convenient because the Oppo serves as USB to S/PDIF converter in my setup. The same decoding does not happen when using the HDMI input, or as a DLNA end point.
Scott
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To be honest, I have a bunch of HDCD discs (mostly country, for some odd reason), and I’ve never been able to hear any improvement due to HDCD. (played on HDCD and non-HDCD players, and they sounded the same)
Trying to apply HDCD decoding to Tidal content would be largely a fool’s errand. Little chance of success. That Tidal uses FLAC ensures that the audio stream is bit perfect lossless to the Tidal file. But it does not ensure that the Tidal file is bit perfect lossless to the HDCD encoded CD. Tidal sources its files not just from CD rips. And the copyright holders or Tidal may apply digital processing to the files while maintaining at least 16 bit, 44.1 kHz CD quality resolution. Most damningly, all watermarked content on Tidal definitely is not bit perfect lossless to the original CD, HDCD encoded or otherwise.
AJ
Audibility of HDCD decoding will depend on whether the dynamic peak and/or low level extension features are actually used, and how much. If you look at the analysis of the RR recording of Liszt Mephisto Waltz in the second link I provided above, you can see that the decoded vs. undecoded dynamic range would be different by ~12 dB - quite a lot. On the other hand, like the Joni Mitchell Both Sides Now track mentioned in the same link, some HDCDs contain the HDCD “flag” but don’t use the compression/extension feature at all.
More or less, HDCD discs must use the optional Peak Extension function in the recording for there to be any audible improvement from decoding. Many HDCDs do not use Peak Extension. Some/all of your HDCDs probably do not.
I have ripped all of my HDCDs both to bit perfect 16 bit FLAC and to HDCD decoded 24 bit FLAC. For the HDCD decoded 24 bit FLAC files, I have added “Peak Extend” tags in Roon to the appropriate albums. Those albums should be played using their decoded versions. For example, see the dynamic range metrics from the 1998 remaster of The Cars’ “Panorama,” both with and without HDCD decoding:
http://dr.loudness-war.info/album/view/98417
http://dr.loudness-war.info/album/view/98415
That HDCD uses Peak Extension and gains several dB of dynamic range from decoding.
AJ
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Another example for some is: Emmylou Harris “Wrecking Ball”, it has peak extension. The DR of the tracks/album actually increases after decoding with the software HDCD decoder.
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+1 for HDCD decoding, however with a relatively low priority.
Issue here is, as far as I know, the binary to decode HDCD is only available for the Windows platform (Microsoft bought the tech from Pacific Microsonics a while back). Additionally, I am not aware of standard metadata that indicates when a file is HDCD-encoded, so you would have to pipe the 16/44.1 PCM data to hdcd.exe and see if the result coming out is 24bit or 16bit (the latter indicating there was no HDCD info in the stream).
So only on Windows or with a Windows emulator. This works on mac - I have decoded all of my HDCD albums to 24/44 using dbPoweramp+hdcd.exe running with Crossover. However, I would not want Roon bothering with this, it could make Roon less stable.
In my opinion there are many more important things for the Roon team to focus on…
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For those of you who happen to own not too many (ripped) HDCDs, there is a very easy way to convert the music files to 24-bit containing the expanded 20-bit HDCD information. You can do it free of charge solely by the the aid of foobar2000.
First you will have to to install the foo_hdcd.fb2k-component (latest version is 1.19).
Next you will have to change some setting with “Converter Setup”: Set “Output bit depth” to 24-bit and set “Dither” to never. Then put a check mark on “Processing->Additional decoding” to enable decode postprocessing (for HDCD decoding). The other settings may be set as usual. There is no other DSP resp. DSP-setting required!
By this method you may reconvert your HDCD-coded files in one single step to 24-bit flac files and just forget about the obsolete HDCD codec for all times (or until the recording industry will issue a real 24-bit remaster you cannot resist to purchase… ;))
Due to the small increase in information the 20-bit HDCD expansion adds to the 16 bit file the resulting 24-bit flac file will only be around 20% bigger in size.
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Hello Gentlemen,
I have found out recently that 2 of my CDs are HDCD encoded. I ripped them to ALAC as I usually do and during playback the sound was a mess. By the way, my DAC is HDCD capable.
In order to sort this out, I have used dbPoweramp DSP plug-ins. The HDCD reader and then the maximise signal gain based on peak volume. Volume of the final file sounds simmilar to the original CD (I could listen to it but it was braking up all the time). I have also tried the usual +6db for when one changes the encoding from 20bit to 24bit, but I found the volume quite low with that processing.
Do you seen any inconvenient in what I have carried out? It seems some of you are not keen on final volume processing and prefer Roon to do volume normalisation.
I dont use Roon normalisation. I tend to not process my files at all. I just rip CDs to ALAC and listen to them as they are.
Thank you.
Pedro