LaserDisc Database
https://forum.lddb.com/

HDCD
https://forum.lddb.com/viewtopic.php?f=29&t=1158		 Page 1 of 2
Author:  elahrairrah [ 04 May 2012, 17:48 ]
Post subject:  HDCD
Anyone have and use HDCDs? I read about them years ago in Entertainment Weekly magazine (also the first place I read about HDTV and DVD way back in the early 90s) but never really looked into the format.

I bring it up now, because I finally bought a blu-ray player and intend to use that as my primary DVD player as well (since it is all-region.) And in pulling out my old DVD player, a Skyworth 1050P Progressive Scan (w/VGA output) I notice that it has the HDCD logo on it . . .

Image
(the logo is right next to the Dolby logo on the left side of the faceplate there)

. . . now I wonder just how capable this format is/was. I believe I only have one HDCD (even though I didn't know it was up until right now when I looked it up), City of Angels Soundtrack.

So I might now use the Skyworth as my CD player in my HT if the HDCD format is worth anything at all.

Anyone know anything about the format? I imagine I have to use the DVD player to handle the D/A conversion to decode the HDCD properly (thus connect the player via analog RCA cables)?
Author:  Guest [ 04 May 2012, 22:35 ]
Post subject:  Re: HDCD
I had this dvd player a few years ago,i thought the picture was kinda s****y due to shaking picture like the refresh is out of line.

The HDCD is kinda like SACD to my knowledge. There where 2 audio cd's and 1 movie dvd in the box when i had it.

The best way should be coax/optical for HDCD sound use.

Also:

High Definition Compatible Digital, or HDCD is a patented encode-decode process, now owned by Microsoft, that improves the audio quality of standard Redbook audio CDs,while retaining backward compatibility with existing Compact disc players. At over 5,000 titles,HDCD-encoded releases constitute a fraction of the total CD commercial music catalog.

A number of universal CD and DVD players include HDCD decoding, and version 9 and above of the Windows Media Player software (on personal computers with a 24-bit sound card) are capable of decoding HDCD.

An HDCD-encoded CD usually, but not always, has the HDCD logo printed on the back cover. An HDCD logo may also be displayed in Windows Media Player 9 or above when an HDCD encoded disc is played.
Author:  elahrairrah [ 04 May 2012, 23:03 ]
Post subject:  Re: HDCD
I never had the shaky image on this player. It was always rock steady and sharp on my end. Of course, I always used the VGA output. Not sure if the component output gave any different results.

Can't imagine using the digital output would decode it properly unless you're sending that PCM to a receiver/decoder that is also HDCD compatible. And HDCD isn't quite like SACD where there are two layers on the disc (a redbook layer for regular CD players and a SACD layer.) HDCD is just a way of mastering/encoding the CD. So a regular CD player is reading the same layer that an HDCD compatible player would read.
Author:  Guest [ 04 May 2012, 23:10 ]
Post subject:  Re: HDCD
So with other words this player just makes your cd sound better, if it got the HDCD logo?
Author:  elahrairrah [ 05 May 2012, 06:16 ]
Post subject:  Re: HDCD
Supposedly yes. An HDCD will play just fine in a regular CD player. But if you play it in something that sports the HDCD logo, the extra sound resolution of the format will be brought out.
Author:  hippiedalek [ 05 May 2012, 13:10 ]
Post subject:  Re: HDCD
I've only ever encountered and owned one HDCD; Tubular Bells, but I never had a player so I can't really comment on personal experience. I've read a bit about them though and the way I understand it is that HDCDs sound better than CD when being decoded properly but sound (very slightly) worse when played on a standard CD player. I don't think they're really comparable to SACD or DVD-A.
Author:  sdraper [ 05 May 2012, 18:32 ]
Post subject:  Re: HDCD
From what I always understood, this was just a way of getting 20 bit audio onto a 16bit Redbook CD. It would play as a standard CD, unless you had the proper equipment to decode the HD portion.
Author:  invenio [ 06 May 2012, 03:42 ]
Post subject:  Re: HDCD
My player also supports this http://www.oppodigital.com/dv980h/default.asp. I think I have a couple of these HDCD's in my collection but I can attest that it's nothing like SACD. First, it's still limited to stereo vs multichannel, and the overall bitrate is significantly lower than SACD or DVD-Audio. I view it as a slight modification on the redbook standard but not much of a true difference.
Author:  substance [ 06 May 2012, 11:53 ]
Post subject:  Re: HDCD
Its correct. Hdcd is 20 bit audio. A normal cd player can ignore that extra 4 bits so its backwards comp. Some cd/dvd players and receivers can decode it. Hdcd cds usually sounded super even on std cd players at 16 bit. I dont think there was ever any marketting or advertising for it. There are few titles with hdcd. It is not comperable to sacd or dvd-a as those are on dvd and offer multi ch/higher sampling audio
Author:  invenio [ 06 May 2012, 13:08 ]
Post subject:  Re: HDCD
substance wrote:
Its correct. Hdcd is 20 bit audio. A normal cd player can ignore that extra 4 bits so its backwards comp. Some cd/dvd players and receivers can decode it. Hdcd cds usually sounded super even on std cd players at 16 bit. I dont think there was ever any marketting or advertising for it. There are few titles with hdcd. It is not comperable to sacd or dvd-a as those are on dvd and offer multi ch/higher sampling audio


I think you are correct on the above. However, I read that HDCD played on standard (non-HDCD players) players can actually sound worse as they substitute the last bit in the data stream. It is the "least significant bit" but this may have small degradation of sound. This is the qoute from wikipedia:

"HDCD encoding places a control signal in the least-significant bit of a small subset of the 16-bit Red Book audio samples (a technique known as in-band signaling). The HDCD decoder in the consumer's CD / DVD player, or in some cases audio receiver, if present, responds to the signal. If no decoder is present, the disc will be played as a regular CD.

In itself, the use of the first bit in the dithered least-significant bit stream will degrade the sound quality on a non-HDCD player by decreasing the signal-to-noise ratio but only by a minuscule amount. HDCD Peak Extension, if chosen in HDCD mastering, will apply compression to the peaks which will be audible in playback on a non-HDCD system which does not apply the appropriate expansion curve."

So if your player does not support HDCD, ideally you should try to get non=HDCD versions.

My opinion is that if you really enjoy high quality music, you would probably buy a higher end CD player anyway and thus would have this capability built in so going with HDCD would be the preferable method.
Author:  elahrairrah [ 07 May 2012, 14:31 ]
Post subject:  Re: HDCD
Well, the one HDCD encoded disc that I do have, City of Angels Soundtrack, sounds good through a regular CD player (and when I play it on my PC with Windows Media Player, the HDCD flag does pop up in the player) so if it will sound better on an HDCD compatible player, I might as well use it.

Only problem is, the disc is a little scratched so the Skyworth won't read it. I'm going to purchase a used copy soon since that soundtrack is worth hearing in a better format.
Author:  disclord [ 07 May 2012, 20:37 ]
Post subject:  Re: HDCD
HDCD is basically a CD equivalent of Dolby, CX or DBX Noise Reduction, that uses both low level and peak compression during recording and expansion during playback, allowing about 18 to 20 bits dynamic range to fit into the 16-bit CD in a compatible manner. Unlike Dolby, CX and DBX, however, HDCD decoding is controlled not by the signal itself but by a control signal buried as a digital dither like signal in the 16th Bit. Since the control bit is only inserted for hundredths of a second at a time, and only when needed, it has no real affect on sound quality quality. Playing an HDCD encoded recording without decoding will give altered playback compared to the original since the compression applied during encoding isn't undone.

Amazingly, most HDCD's don't use any part of the process, either the peak extension or low level expansion. They just light the HDCD light to indicate that the signal has been processed through an HDCD encoder. No HDCD has ever used the reconstruction filter switching that was heavily talked about while HDCD was marketed and the HDCD chip from Pacific Microsonics couldn't even switch filters if it had been used. Other aspects of HDCD such as frequency expansion, to simulate greater bandwidth, were never implemented.

MiniDisc, DTS and AC-3 all had the ability to be flagged as HDCD to indicate that the signal had been processed through the Model Two HDCD encoder, which still highly thought of as an AD encoder, even when not using the HDCD process.

HDCD was lots of marketing hype with some good features... Microsoft wanted it for the basic in-band signaling technology - supposedly as an anti-piracy measure. There is a ton of info on the web about HDCD, starting with the original HDCD AES paper, although the AES paper has a lot of misleading information in it.
Author:  elahrairrah [ 16 May 2012, 05:48 ]
Post subject:  Re: HDCD
Well, this was all for naught. Tried two different HDCDs but the Skyworth straight up won't read them. Will read regular CDs, but when plopping in an HDCD, it says "NO DISC."

And I don't intend to try to find another HDCD capable player. So I guess I'll never really know the quality!
Author:  invenio [ 16 May 2012, 12:10 ]
Post subject:  Re: HDCD
I probably would not go crazy looking for a specific "HDCD" player. If you want a CD player with better capability, I would look for one that reads SACD's as that is actually a significantly better format. Unless you have really high end speakers, preamps, amps, you probably would never notice the difference between "regular" and HDCD disks anyway.
Author:  elahrairrah [ 16 May 2012, 13:00 ]
Post subject:  Re: HDCD
Yeah, it was just that since that DVD player was HDCD capable, that I wanted to see what the quality was like. I wasn't expecting SACD or DVD-A quality at all (especially since HDCD technology was developed in the late 80s!) It's just that I've known about the format for years and never really got to see what it was like, and now I would seemingly be able to do so . . . or not!

I think with my setup (Pioneer Elite VSX-27TX receiver, Pioneer CS-99A speakers) and putting the DVD player's RCA outputs to the analog passthrough on the receiver (so there is no further audio processing on the signal--just amplification) I would be able to hear the quality (or lack thereof, if that were the case.)
Author:  invenio [ 16 May 2012, 15:35 ]
Post subject:  Re: HDCD
The Pioneer CS-99a, those are the big old school speakers, correct? Made in the 70's, they had a huge 15" woofer on them. Am I correct on that, or am i thinking of a different speaker?
Author:  elahrairrah [ 16 May 2012, 16:18 ]
Post subject:  Re: HDCD
That would be them!

Image
Author:  dewdude [ 24 May 2012, 15:48 ]
Post subject:  Re: HDCD
Hate to kick up old topic, but I just walked in.

The main advantage behind HDCD aside from it's compansion capabilities; was the fact the standard called for higher quality ADC's to generate a 20-bit signal and specialized noise-shaping. Whether or not the release used any of the HDCD features like peak-extension still meant you were essentially listening to 15-bit dithered audio; the control bit is still being used to indicate HDCD is there.

A few years ago, a plugin came out for Windows Media Player gave you disc-writing capabilities. Why does this mean anything? Since Microsoft bought the company that created HDCD, Pacific Microsonics, they put a software based HDCD decoder in Windows Media Player. Enable 24-bit mode, pop in an HDCD, activate plugin; and you'd get a bunch of wav files that are the "decoded" 20-bit audio...which comes out in 24-bit format. That method was a pain in the butt; but later in 2008, a software encoder in the form of a command-line exe was released. I believe it mostly connects to the decoder built in to WMP (since version 9); I haven't tried running it on any of my older windows virtual machines. dbPowerAmp built the functionality in to their decoder as a plug-in; since properly-ripped lossless formats will have the control stream.

I've compared the audio from both the decoded HDCD with the undecoded varient a number of times. One of the first things HDCD does is lower the amplitude by 6dB, which is half. This results in a much quieter playback. In fact, forcing the HDCD decoder on non HDCD-encoded content simply yields a file 6dB lower than it's input. While some releases didn't use peak-extension, the software decoder has it permanently enabled. If it's there, there's a difference in the peaks, if it's not, it's just 6db lower.

Back in 2008, I took this screenshot of a waveform view of a track, one decoded, one not.
Image

That track used peak extension to some degree, but the audible difference is very subtle. Both tracks were "normalized" for the screenshot; their loudest sample peaks at 0dBFS; so the scale between them would match.

As someone who has the gear to notice subtle differences; the two do in fact sound different. But to the average ear, the non HDCD decoded version would actually sound just fine; and it's that way with a lot of albums. Most of the stuff is a casualty of the loudness war anyway. If anything, HDCD allows one to, undo it, so to speak. I've actually gotten very similar results in my DAW using a set of plugins on content that wasn't HDCD decoded in the first place.

SACD on the other hand, is an entirely different ball-game. It is a bit-stream based format that resembles more of what comes right out of an analog-to-digital converter. The concept behind it is much too complex for me to be able to put in to words, and isentirely too long to post here. Good reading can be found in the wikipedia articles on SACD, DSD, Pulse Density Modulation and bitstream decoding.

Another random fact. SACDs store information in pulse density modulatiom, LDs used Pulse Width modulation. Both formats contain no coded information, its just "random bits".

Just my $.02.

-Jay
Author:  elahrairrah [ 24 May 2012, 16:02 ]
Post subject:  Re: HDCD
Well, I've read up on SACD and DVD-Audio in Widescreen Magazine since their introduction so I have some idea of what they are capable of. I've also known of HDCD for years (since the format is much older than SACD or DVD-Audi), just never had the chance to see what it can do. I wasn't expecting SACD quality for HDCD (being 10+ years older and whatnot!) Just expecting "better" than standard Redbook audio if played on the proper equipment.

Thanks for your input though. It is appreciated.
Author:  dewdude [ 24 May 2012, 23:41 ]
Post subject:  Re: HDCD
This is what I've been saying on audio forums for years; better is an entirely subjective idea from one person to another.

Is HDCD an improvement over Redbook? Technically, no. Redbook audio uses 16-bits for audio information, HDCD uses 15; it amounts to a loss of about 3dB of dynamic range. If anything, it's closer to the concept behind using Dolby B on cassettes. It sounded ok without a decoder; and was, technically, better, when decoded; and they're both companding formats.

In practicallity, Dolby B was only mediocre even on the best decks; and the improvement in HDCD depends on many variables. The quality of the mastering, the encoders used, the features of the process; then there's quality of the decoder, the analog stages in the signal path from the DAC and HDCD output to the time it reaches your ears. Much like the lower-end LD players didn't look as good as the more expensive units.

I always found it interesting that the format war between DVD-Audio and SACD pretty much amounted to each side throwing water balloons at each other. Had DVD-Audio been included in every DVD player; we'd probably have seen a HUGE adoption. But the fact remained that there was no "general purpose" player that did both DVD-Video and DVD-Audio; those features were reserved for high-end players.

Sony had some slight success building a line of DVD players that came with SACD standard. But it didn't help format adoption. DVD-Audio has pretty much died. I haven't seen any list any releases in a while. SACD is on life-support; it's a niche market with a very limited appeal. You see mostly jazz and classical releases. Almost nothing modern. To put it this way; every PS3 in existence is able to play back SACD. Most people have no idea what SACD even is.

I think one of the reasons SACD is still somewhat around is the anti-piracy aspect of it. DVD-Audio was cracked a few years ago; so now all you have to do is click a few buttons and you'll get extracted audio from the thing. SACD however...can't be read by a standard DVD-drive. You can't burn content in SACD format that will work either. There are maybe 3 or 4 players on the market that can read a format that contains DSD audio in a special format on a DVD drive...and only the PS3 with some very old and very hacked firmware is even able to digitally extract the SACD sectors.

But still, the overall quality of anything starts at the source. I've got several copies of Dark Side of the Moon; including the SACD version. The SACD version, if anything, sounds perceptually worse than any of my redbook formats. This is most because the seriously high resolution and way it stores it's audio allows it to come through; and the master tape was older than when the other transfers were struck. Honestly, that album isn't even recorded to a standard that calls for audiophile...but we can discuss that some other time.

-Jay
Page 1 of 2 All times are UTC [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group
http://www.phpbb.com/