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ripping HDCDs?
macdaddy
post Dec 27 2001, 13:03
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Is EAC missing something when ripping HDCDs? Is downsampling, etc. going on? I received a box set (Grateful Dead) of these for XMAS. I should be able to read full benefits via AP24/96 soundcard. Maybe it's me that is missing something..?

Thanks, in advance, for any input.
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Uosdwis R. Dewoh
post Dec 27 2001, 13:42
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Hello.

The HDCD technology work in the way that the mastering engineer "hides" a code within the audio signal (inaudible). Unless the software/hardware knows what to look for, it won't find it. EAC does not.

That, however, does not mean that EAC is incompatible with HDCD's. It simply means that it treats it like any other redbook CD out there.

To fully experience the advantages of a HDCD encoded CD, you need a decoder. The decoder recognizes the hidden code, recieves the instructions and performs the proper hardware switches that is called upon, such as peak restoration, filter switching and so on. In other words, you need a hardware HDCD decoder fitted in an onboard/outboard DAC. Your card does not have that, and I don't think one exists yet.

Although I've heard of some applications recognizing the code, such as WMP XP, it does not mean that you get a decoded playback. As far as I know, at least the filter switching, which is essential to the process, must be done with special hardware (a chip) fitted directly to the DAC.

About ripping:

As long as the audio data remains unaltered the code, and with it the benefits of the process, is maintained. You can rip the CD (some or all tracks, or just portions of tracks) with EAC, and as long as the integrity of the audio is ensured you can play them back from your computer and digitally transfer the signal to a HDCD-equipped DAC or burn an audio CD-R using a program of your choice.

Lossy compression formats such as MP3, MPC, OGG or any of the others ruin the data and the HDCD code is lost. Lossless compression restores every byte and thus the code is maintained. With something like Monkey's Audio that has a Winamp-plugin, you can get playback of HDCD-encoded material, even though it's compressed - if you have a decoder, that is.

Make sure you haven't set EAC to normalize or anything like that; any and all changes to the audio signal will destroy the code.

I use the above combination: rip HDCD's with EAC, encode with Monkey's Audio and play them back either by burning them to a CD, or outputting the signal through the digital output of my Audiophile 24/96 into a HDCD-equipped DAC or reciever.

Finally, a few links from where you can get more in-depth information about the HDCD process:
http://www.hdcd.com/about/whatisHDCD.html
http://www.hdcd.com/partners/proaudio/articles.html

Hope it helps.

Cheers,

Uosdwis
edit: added link
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macdaddy
post Dec 27 2001, 14:31
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Thanks for the reply...

So there is not a software player/decoder..? How about a winamp plug-in..?

I thought the soundcard (that we both seem to share) had the hardware juice to handle these things...

So what you're saying is that unless I specifically have a HDCD-certified receiver, there is no way I can fully experience the extra encoding...

Dolby Digital/ProLogic certified receivers and/or software filters and/or graphedit won't do the trick, huh..?

Is there any way of transcoding/converting the signal to .ac3, which might make it compatible with Dolby Digital receivers..?

Thanks again for any, and all, thoughts.
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Uosdwis R. Dewoh
post Dec 27 2001, 15:31
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HDCD works in an entirely different way than what you are suggesting. I suggest you follow the links in my post and read up on the technology. It's quite interesting, and you should find answers to all your questions. Also, their explanation should be better than mine. smile.gif

Cheers,

Uosdwis
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macdaddy
post Dec 27 2001, 21:37
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I have read through that site to which you linked above, and maybe I am simply misunderstanding what I read (if this is the case, thank you for your patience)...

What I read there is that there must be a DAC that can handle 20bit recording (which the ap24/96 can do), as well as a decoder to deal with the HDCD-specific part of the signal. This decoder can either be based on hardware or software (I assume, if windows media player can do it-as is implied on the HDCD site)...

You wrote:
QUOTE
Although I've heard of some applications recognizing the code, such as WMP XP...


I guess my question is, is there a way to do that decoding via software (other than windows media player)? And waht is the difference (and benefit?) of "recogniziong the code" if the player does not decode it (as you state above)?

Again, thanks for your patience-I am very interested in this, but the information on the HDCD site seems to purposely beat around the bush on these issues...
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macdaddy
post Dec 28 2001, 01:17
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Thanks for bearing with me...

I have bounced around the 'net for the better part of the day, and realize that you are right, and the signal needs a specific hardware chip to be decoded...

But I still don;t understand why the signal cannot be transcoded to aac or ac3..?

Anyways, thanks for the help.

PS: Is this a format that is worth the hardware (compatible standalones are relatively cheap)? Or is the format a flash in the pan that Micky Hart fell in love with, but will not be widely supported in the future?
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porky_pig_jr
post Dec 28 2001, 05:58
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you know, worrying about HDCD while doing the lossy compression doesn't make any sense to start with.

The main purpose of HDCD is to increase the quantization level, from 2**16 in a standard Red Book CD, to 2**20, but using 4 extra bits, 20-bit words, then cleverly hiding those extra bits in standard 16-bit word (Red Book). You need a good quality CDP or CDT with HDCD decoding chip, plus DAC which can properly convert this information to an analogue form, and finally - hopefully - your amp and speakers are good enough so you'll hear the difference between the same program encoded with 16 and 20 bit quantization levels.

But in lossy compression like MP3 or AAC we in fact decrease the quantization level to start with. That's one of the ways to compress. We increase the digital noise. This extra noise can be properly dealt with, but in resulting file the quantization level is less than 2*16. I just can't understand why in the world anyone should worry about not being able to capture 2**20 quantization levels. It would just make an encoder to work harder but at the end you'll have less than 2**16 anyway.

So - if you're about to loose your head, don't worry about loosing your hairs (as the saying goes)
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macdaddy
post Dec 28 2001, 10:06
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I wasn't so much interested in compressing the signal as I was in getting the enhanced/surround audio out of it. Apparrently, I am SOL without the hardware...

Are there any soundcards that have the necessary chip? Then the computer could do the decoding and output the signal to the RCA jacks just like a HDCD standalone...

Again I wonder if this is a format that will be widely adopted, and what the implications are with micro$oft's involvement..?

Thanks for the replies.
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Uosdwis R. Dewoh
post Dec 28 2001, 11:08
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Hello macdaddy,

I'm afraid these are common misconceptions about HDCD.

What HDCD is not:
*HDCD is not anything like the 5.1 formats and have nothing to do with surround sound.
*HDCD does not work using psychoacoustic compression, or in other words
*HDCD's are not "encoded" in the sense the term is used on this board

What it is:
*16 bit/44.1kHz plain old CD-audio (often referred to as "red-book)
*A process heavily dependant on the mastering engineer, who has several different options to choose from which will affect the sound on both compatible and ordinary playback systems.
*Designed to overcome some of the inadequacies of the red-book format, using very simple instructions embedded into the signal

The best way, I think, is to compare it to a system many of us have experience with: Dolby Noise Reduction (A, B, C, SR or whatever). [ In certain aspects, HDCD happens to works in a very similar way.)

With a cassette recorded using Dolby NR, you can play it back in every cassette player out there - no different tape speeds or anything. But, to get the benefits of the process you need a cassette player with Dolby NR.

QUOTE
The HDCD decoding process performs precise decoding of HDCD-encoded recordings and also provides a state-of-the-art digital filter for both HDCD and standard recordings. The decoding process begins with the HDCD decoder extracting the hidden code from the LSBs of the audio data and then decoding the commands contained in the hidden code. Signal peaks limited with Peak Extend are restored and low-level gain is undone, resulting in a signal with 20 bits of dynamic range. This signal then is interpolated to 96 or 8 8.2 kHz using a filter that is complementary to the anti-alias filters used in the A/D filter-switching process. The signal can be output at 96 or 88.2 kHz or further interpolated to four or eight times over sampled frequency to drive popular 18-bit to 24-bit D/A converters.


That's from the HDCD website. This is what HDCD decoding does. If you don't have a decoder or the code is destroyed, the decoding part can never take place.

QUOTE
I guess my question is, is there a way to do that decoding via software (other than windows media player)? And waht is the difference (and benefit?) of "recogniziong the code" if the player does not decode it (as you state above)?


Firstly: No, there is no way to decode HDCD's using software only. Secondly: There is none! I guess that's just some sort of marketing trick; they bought the company that invented the technology (Pacific Microsonics) and want to show off or something. Just because a virtual light is lit does not mean that the signal is decoded. It is not.

Having said that, with Microsoft involved there is a bigger chance that newer soundcards will be equipped with decoder-chips, but I don't know when, if ever, this will happen.

About the format's advantages and future:

Like I stated above, much of the HDCD-process is up to the mastering engineer. There are trade-offs; certain options will affect the undecoded playback (non-HDCD systems) negatively, while leaving them out means not taking full advantage of the possibilities at hand. Most HDCD's are compromises.

It should also be said that, like any other format, HDCD's are only as good as the source material - ye olde "you can't polish a turd" dogma certainly applies.

The format will live quite happily until DVD-Audio or DSD has completely overtaken the market. When properly done, it does offer significant advantages over regular CD's. If you're interested, I say check out the Denon DCM-370 CD changer. Although a bit dated, it sounds very very good on both HDCD's and regular ones and can be had for under $150.

There are plenty of good-sounding HDCD's out there. Here's a few:

Beck - Mutations (1998) - sweet, but mastered too loud (not a lot of dynamic range)
Beck - Midnite Vultures (1999)
Crowell, Rodney - The Houston Kid (2001)
Springsteen, Bruce - Tracks (box) or 18 tracks (1998/1999)
Young, Neil - Silver & Gold (2000)

Hope this made things clearer.

Good luck!

/ Uosdwis
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macdaddy
post Dec 28 2001, 19:14
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Thanks for all of the replies and answers...

The catalyst for this whole discussion is that I received a box set of these things for Christmas (Grateful Dead-"The Golden Road"). I have been reading things for over a year about how the band's drummer has been remixing everything, etc....

The discs sound much better than any of the other sources I have with the same material. But I have also seen the drummer talking about how he put a surround mix on the thing, and that he mixed it with all this in mind. From what I read, I saw no evidence of surround/multichannel capabilities in the HDCD format, either-but I just saw the guy talking up the surround mix on techTV (of all places)...

Anyway, after following your links, I found that the only solution is to find a player-I, too, see that they are relatively inexpensive. I didn't see the Denon, but I think they make quality stuff. Maybe I will look into picking one up...

I am assuming that these CD players send the decoded, enhanced signal via RCA left and right jacks (as per standard CD players), and not via a toslink or coaxial connection...

As always, thanks for taking the time to help.
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maciey
post Dec 28 2001, 20:19
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Maybe the tracks were encoded with dolby® pro logic II ™, apart from HDCD, too? I think that neither of them collides with the other?
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user
post Sep 8 2002, 23:49
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Hi,

some short answers:

EAC is able to rip HDCD's accurately !

Eg, With nero you can burn again a CDDA, which contains same HDCD informations !

I have tested it myselfs.
There was a thread at r3mix forum


Monkeys audio ape (lossless packer) saves the HDCD infos, too.

Lossy packers like mp3, and so on, will not save HDCD info !


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Frank Klemm
post Sep 9 2002, 01:14
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QUOTE (Uosdwis R. Dewoh @ Dec 27 2001 - 02:42 PM)
Hello.

The HDCD technology work in the way that the mastering engineer "hides" a code within the audio signal (inaudible). Unless the software/hardware knows what to look for, it won't find it. EAC does not.

That, however, does not mean that EAC is incompatible with HDCD's. It simply means that it treats it like any other redbook CD out there.

To fully experience the advantages of a HDCD encoded CD, you need a decoder. The decoder recognizes the hidden code, recieves the instructions and performs the proper hardware switches that is called upon, such as peak restoration, filter switching and so on. In other words, you need a hardware HDCD decoder fitted in an onboard/outboard DAC. Your card does not have that, and I don't think one exists yet.

Although I've heard of some applications recognizing the code, such as WMP XP, it does not mean that you get a decoded playback. As far as I know, at least the filter switching, which is essential to the process, must be done with special hardware (a chip) fitted directly to the DAC.

About ripping:

As long as the audio data remains unaltered the code, and with it the benefits of the process, is maintained. You can rip the CD (some or all tracks, or just portions of tracks) with EAC, and as long as the integrity of the audio is ensured you can play them back from your computer and digitally transfer the signal to a HDCD-equipped DAC or burn an audio CD-R using a program of your choice.

Lossy compression formats such as MP3, MPC, OGG or any of the others ruin the data and the HDCD code is lost. Lossless compression restores every byte and thus the code is maintained. With something like Monkey's Audio that has a Winamp-plugin, you can get playback of HDCD-encoded material, even though it's compressed - if you have a decoder, that is.

Make sure you haven't set EAC to normalize or anything like that; any and all changes to the audio signal will destroy the code.

I use the above combination: rip HDCD's with EAC, encode with Monkey's Audio and play them back either by burning them to a CD, or outputting the signal through the digital output of my Audiophile 24/96 into a HDCD-equipped DAC or reciever.

Finally, a few links from where you can get more in-depth information about the HDCD process:
http://www.hdcd.com/about/whatisHDCD.html
http://www.hdcd.com/partners/proaudio/articles.html

Hope it helps.

Cheers,

Uosdwis
edit: added link

- HDCD can be read out using normal CD grabbing programs
- HDCDs can be normally copied.
- HDCD contains some hidden information in the signals which is used by HDCD decoders
to assist DA convertion
- HDCD is 16 bit, 44.1 kHz
- First upsampling stage (44.1 -> 88.2 kHz) can select 4 different filters.
So you can choose between flat frequency response and fast impulse response.
- HDCD uses subtractive dither
- HDCD can use dynamic compression by 6 dB. Compression scheme is invertible.
- HDCD normally use noise shaping. Noise shaping is selected depending on the noise floor
of the recording.
- HDCD have a lot of things specified which are undefined on normal CDs


--------------------
-- Frank Klemm
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Awesome1
post Jun 13 2004, 04:32
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Ahead Nero mentions the ability to use the HD-Burn process, but gives no information about how to do it? Do you need specific CD writers and software that supports burning HD-CDs? I have an RCD-1072 Rotel cd player which supports HDCDs... I also have seached at google how to but have found no info on how to do so...
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Cygnus X1
post Jun 13 2004, 05:11
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QUOTE (Awesome1 @ Jun 12 2004, 10:32 PM)
Ahead Nero mentions the ability to use the HD-Burn process, but gives no information about how to do it? Do you need specific CD writers and software that supports burning HD-CDs? I have an RCD-1072 Rotel cd player which supports HDCDs... I also have seached at google how to but have found no info on how to do so...

I'm afraid you're confusing HD-Burn and HDCD, which are two completely unrelated concepts. HD-Burn is a method by which some newer CD-RW drives can cram more data on a standard 80-minute CD-R than usual by using a different error correction method and modified writing techniques. Some HD-Burn drives will let you put 1.4GB onto a 700MB CD-R, an increase of twofold. HDCD, on the other hand, is a completely unrelated enhancement to audio CD's; as far as I know, no software offers HDCD authoring. Since the benefits of HDCD are small, if even noticeable to most people on most equipment, you won't be missing out on much.
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user
post Jun 22 2004, 12:23
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The excellent summary of Frank Klemm above tells all to HDCD topic.

Once you have extracted (eg. by EAC's secure mode) a HDCD to a Lossless format like FLAC, ape, wavpack etc. or simply uncompressed 16/44.1-waves,
you can burn the 16/44.1 waves simply by Nero or any other simple burning program to a CD-R/RW as Audio-CD, and play this CD in any CD-player.

If the CD-player has a hdcd decoder built in, fine,
or you need digital connection to an amp with hdcd-decoder, like my Harman kardon HK avr 5000 eg.,
even HDCD works via playing from my PC-drives, then you need a non-resampling soundcard, which passes through unaltered digital PCM, 16 bit /44.1 kHz, with digital connection pc -> amp/hdcd-decoder
Dithering would be poison for the hdcd information inside the stream.


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