Ted, was this ever discussed? Can the DS do HDCD processing for those few HDCD encoded CDs that are still hanging around?
Nope, proper decoding would now require a license from Microsoft and to the best of my knowledge I’d have to use their code. Besides the expense, I know that it wouldn’t fit in the FPGA along with our current code.
I do know that there’s an HDCD decoder available for foobar2000 so you’re not out in the cold. FWIW there are a lot of CDs marked as HDCD that don’t use any of the encoding features so the real population of discs that could benefit from HDCD decoding isn’t as big as it might appear.
If you use dBpoweramp to rip your CDs there is an HDCD DSP plug-in available. It was based on the decoder in Microsoft Windows Media Player (MS bought Pacific Microsonics so it owns the HDCD technology) but, since it’s Microsoft, it’s a half-assed decoder and, as I understand it, handles some but not all of whatever magical processes HDCD entails. I rip my files with and without the decoder and generally I think the files sound better with the decoder. Weirdly, when playing the decoded HDCD files, the DS display flips between 24 and 16 bits (and maybe 20 too). The files should be 24 bits but with the last 4 bits empty. Note that if you use the plug-in, you have the option of boosting the volume by 6 dB (HDCD discs are generally recorded with the volume down 6 dB). I use the option and have not had any noticeable issues but I’m told this could result in clipping with some discs.
Thanks Steve. Yes I do use dbPoweramp but never used the HDCD plugin. I always figured it probably would not work all that well. Guess it’s worth giving it a try.
I wish someday Microsoft would use their whole ass.
stevem2 said Note that if you use the plug-in, you have the option of boosting the volume by 6 dB (HDCD discs are generally recorded with the volume down 6 dB). I use the option and have not had any noticeable issues but I'm told this could result in clipping with some discs.This makes sense. The largest asserted advantage of HDCD is an increase of 4-bits of dynamic range, 6dB of which are on the loud end. A decoder should appropriately produce 20-bit files.
Another bit of HDCD trivia: HDCD compliant hardware players have double the nominal peak voltage output.
Loosely related to this thread, a few months back I snagged an HDCD copy of Mannheim Steamroller Fresh Aire (I), ripped it with dBp. I played it back through Foobar2000 and compared it with a rip of the original CD release of the same album and the HDCD version did sound better. Of course, I have no way to tell if this improvement was due to the HDCD encoding or other mastering differences with the newer release.
I think that the only part of the HDCD decoder that is used in computer software is the headroom expansion component. The other HDCD processing tricks that I know almost nothing of are rarely if ever implemented… Of course, it is not unusual for Micro$haft to do things like this half assed. 
If the HDCD improvements were consistently achievable (with good mastering) it is a pity that it was not used more often. Was this a licensing thing where they priced themselves out of the market, or was it something else that killed it?
Just thought I would throw this in. 
J.P.
I imagine it died because consumers did not care.
Without demand in the marketplace, producers are not going to add steps or spend extra money. And thus they stopped spending resources on HDCD.
I’ve used dbPoweramp with the hdcd plugin to rip my hdcds to 24 bits. I found out about dbPoweramp/hdcd after ripping all my cds to 16 bits using EAC which doesnt know about hdcd so I’ve heard them both ways. I hear quite a difference and always prefer the hdcd rips.
I know this is an old topic, but the question does not go away for those with some HDCD badged CDs. In my case mainly Linn.
When I ripped my CDs to FLAC using dBPoweramp I too used the DSP for HDCD decoding when detected, and no dB lift. My CD player does not decode HDCD. Until recently my CD player always sounded better then my streamer anyway (which was used for convenience and internet).
I now find that playing through a DSjr (Torreys) - the digital output from the CD player sounds better (more natural) than the FLAC file which has had HDCD applied. This is counterintuitive but seems to hold good over many CDs.
Even stranger, the Cd source is displayed as 24bit and the FLAC file as 16bit. However mControl shows the file as 24bit. So no help there! Best use your ears and choose.
Thanks, Stephen, and welcome!