[feckn_eejit]

Thanks to the software HDCD decoder built into Windows Media Player which will output at 24/44.1, I have been able to capture decoded HDCD data in higher-resolution WAVs, which can then be redithered to 16 bit for playback on a non-HDCD system, while retaining the benefit of HDCD's increased dynamic range.

Test track is Mahavishnu Orchestra's "Stepping Tones", from _The Lost Trident Sessions_ (a stealth HDCD!) since it's short and sweet.

Here is an image comparing a track before decoding, -6DB (top) and after (bottom) HDCD decoding. It isn't subtle!


Here is an image of the captured HDCD-decoded data in 24/44.1 (top), compared to that wave dithered down to 16/44.1 using Apogee's UV22HR algorithm (bottom).

Looks pretty much identical, so maybe this is a good way for those of us without HDCD decoders to enjoy some of the benefits...

Here is a comparison of the pure wav, ripped straight off the CD (top), and the HDCD-decoded, then dithered-down 16/44.1 WAV (bottom)


Finally, a comparison between the pure wav, -6DB (top), and the HDCD-decoded, re-dithered WAV (bottom). This looks the same as the first image, only both wavs are playable on a standard CD player with no HDCD decoder.


I know which one I'd rather listen to!

What a brilliant system HDCD is - compressed crap for the masses who want it LOUD LOUD LOUD, and something more dynamic for those of us who care and bother to get a playback system that will decode the "hidden" info. Pretty cool!

I will note that I understand the software HDCD decoder in WMP is not fully functional - it cannot possibly have all the same functions as a Pacific Microsonics digital filter chip can have i.e. switching filter modes, etc. But you certainly do get the dynamic range!

It should also be mentioned that not all HDCDs use the dynamic compression/expansion feature that this particular example does. I suspect there would be no benefit to using WMP's software HDCD decoder on HDCDs which do not use this feature.

 

[markl]

Quote:

What a brilliant system HDCD is - compressed crap for the masses who want it LOUD LOUD LOUD, and something more dynamic for those of us who care and bother to get a playback system that will decode the "hidden" info. Pretty cool!

Also one of the many attractions of SACD and DVD-A.

 

[GlendaleViper]

Quote:

Originally Posted by markl /img/forum/go_quote.gif Also one of the many attractions of SACD and DVD-A.

I wasn't aware that DVD-A had this functionality. For that matter, isn't this only true of hybrid SACDs? Regardless, a very interesting post - not subtle changes indeed!

 

[digitalmind]

HDCD or no, that cd is still clipping like mad. It's better, though.

 

[colonelkernel8]

mmm, SongView anyone?

 

[regal]

So is it possible to decode the HDCD and save it as a 24bit Flac which you could then send thru a soundcard digital out to a non-HDCD DAC?

I'm wanting to get the 20 bit resolution out of the computers digital out ?

 

[PsychoZX]

Quote:

Originally Posted by regal /img/forum/go_quote.gif So is it possible to decode the HDCD and save it as a 24bit Flac which you could then send thru a soundcard digital out to a non-HDCD DAC? I'm wanting to get the 20 bit resolution out of the computers digital out ?

Yes it is. You can use the WAV Output plugin for WMP.

http://www.chronotron.com/content.php?page=products2

 

[Eric Carroll]

Here is a snapshot of the results I get.


The test track is part 1 of Tublar Bells by Mike Oldfield, remastered 2000 version.

The top trace is the 16b direct rip with EAC.

The second trace is the 24b capture using the chronotron plugin, 24 bit sound card with 24 bit enabled, WMP9 and the HDCD icon lit.

I cannot explain why the levels are so much lower on the 24b version.

Any idea what is going on here?

 

[chip555]

Quote:

Originally Posted by Eric Carroll /img/forum/go_quote.gif Here is a snapshot of the results I get. The test track is part 1 of Tublar Bells by Mike Oldfield, remastered 2000 version. The top trace is the 16b direct rip with EAC. The second trace is the 24b capture using the chronotron plugin, 24 bit sound card with 24 bit enabled, WMP9 and the HDCD icon lit. I cannot explain why the levels are so much lower on the 24b version. Any idea what is going on here?

looks like the 24bit or bottom image is correct. remember that the HDCD is 20 bit, so wmp will pad it to 24bits, thus you see extra space around the wave form, since they are the same size, the bottom one looks smaller to fit in the size window its in.

When i listen to 24bit from my pc using wmp to my dac, i have to turn the volume up a lot to get the same loudness. But the difference is that i get more punch, dynamic range, and what i believe to be sharper (less muddy) sounds.

 

[adanac061]

Hmmm this has got my attention.

I'm gonna test it as well using Paula Cole's hdcd.

I'll compare the ripped wav with the output from that plugin.

PS: It's 20bit not 24bit.


=============================
edit.

OK results are in.

I got the same results as Eric Carroll
This is the output normal wav on top
supposed 20bit wav on bottom. The bottom one is much quieter.

But if I amplify it to match ti looks like this.
Not much difference.

It seems the drop in volume is attributed to this:

"Peak Extension
Peak Extension is a restorable (with HDCD decoding) soft peak limiter that allows peak levels of up to 6 dB above standard full scale peak level (+6 dBfs) on 16-bit HDCD-encoded recordings without generating "overs." The limiter has a carefully crafted "easy over" curve, designed to mimic the sound of analog tape saturation, which operates over an input signal level range of -3 dBfs to +6 dBfs. This squeezes the top 9 dB of the input signal's range into the top 3 dB of the 16-bit recording.

During HDCD-decoded playback, the peak limiting is undone by the HDCD decoder chip using a precisely mapped inverse of the limiting curve controlled by a hidden code. The dynamics of the original material are restored up to +6 dBfs, thus extending dynamic range by up to 6 dB. During undecoded playback, the effect of Peak Extension is that of a very high-quality standard limiter. Use of Peak Extension is optional in the 16-bit HDCD encoding process."

 

[infinitesymphony]

Be sure that it doesn't sound "better" just because it's quieter. As chip555 said, outputting 20-bit resolution at a padded 24 bits will make the signal quieter than normal. Try normalizing the new 24/44.1 waveform for a comparison with the original 16/44.1 non-HDCD output.

 

[adanac061]

Quote:

Originally Posted by infinitesymphony /img/forum/go_quote.gif Be sure that it doesn't sound "better" just because it's quieter. As chip555 said, outputting 20-bit resolution at a padded 24 bits will make the signal quieter than normal. Try normalizing the new 24/44.1 waveform for a comparison with the original 16/44.1 non-HDCD output.

Yes, thats exactly what I just did above?

It's exactly the same so either A) It doesn't work or B) The cd I used doesn't take advantage of the extra dynamic range feature.

I'd like to think B)

But we need more people to try it.

 

[a shovel]

Dumb question but I installed chonotron 3.5 plugin, enabled it in wmp10, and then what? Where does the wavex file appear? I must be missing something here..

 

[adanac061]

You have to selct the output the first time you play a cd.

 

[Iron_Dreamer]

I got this working and checked out a few CD's I have. Tool's Lateralus and Zero Hour's Towers of Avarice both showed no improvement in dynamic range. Their waveforms were both 6dB quieter than when they were ripped normally. However, the score of Independence Day did gain some DR, generally about 3dB in the peaks, with 3dB on unused headroom.

I read on another site that a lot of HDCD's actually don't use DR expansion, thus accounting for the varying results.