Extract HDCD, How I Can extract HDCD by software? Options

[krabapple]

I just came across this post and I had a question for. #2 threw me off when you said "reversible dynamic compressor." are the signal peaks actually compressed (or limited?) or is it a compressor acting as an expander (the "reversible" part is what lead me to believe you were describing a compressor reversed)?

Compression during encoding (in the studio), expansion during decoding (in the player) -- it's enabled by the 'peak extension' option available to the mastering engineer.

[MRC01]

are the signal peaks actually compressed (or limited?)

When playing an HDCD encoded CD on a normal (non-HDCD) player, yes - you will usually get dynamic compression (if the HDCD encoding used this feature).

The $64k question is: why? They're not using the full 90+ dB of dynamic range that CD offers, and even after expanding the compression, most recordings still don't use that 90+ dB of dynamic range. In other words, the compression (or "peak extension" as they call it) is pointless because standard redbook CD already offers more dynamic range than they are using.

My cynical side says it's a way to make money by licensing a technology to make recordings "sound better". I use the words "sound better" loosely, since what they're really doing is making the redbook CD version sound worse so when played through the licensed HDCD decoder it sounds better. But ultimately, when played on an HDCD decoder, it should sound the same as it would have sounded if they had never used HDCD or dynamic compression at all.

[Wombat]

This tool is pretty interesting. I haven´t much HDs but one of them "Yim Hok-Man - Poems Of Thunder, The Master Chinese Percussionist" i bought for 7.95 at Amazon is a HD showing no sign of it on the box. Only a small info in the booklet about mastering equipment using it.
In the first song are some strong Kudo drumhits that are real distorted.
Decoding it with the peak extension found makes these drumhits absolut clear!
Looking in an editor shows the non decoded one as totally smashed.
I replagained both and did an abx in foobar with no problem.

[skamp]

I also tried this with 3 of my HDCDs, and found that for tracks encoded using "peak extension" you can gain considerable compression improvement by using very small block sizes. I found that --blocksize=4410 worked nicely, and on some tracks --blocksize=2205 was even better. And I'm talking like 5-10% better compression!

These are the results I get for the Joni Mitchell "Blue" HDCD, with Monkey's Audio 3.99-u4-b5, wavpack 4.41.0, flac 1.2.1 (all under linux):

16-bit WAVs (not HDCD decoded)

CODE

176.9 MiB    mac -c5000 (Monkey's Audio insane)
185.4 MiB    wavpack -hhx6
191.1 MiB    flac --best

As expected, here Monkey's Audio compresses much better than WavPack, which itself is substantially better than FLAC.

24-bit WAVs (HDCD decoded), default blocksizes

CODE

338.9 MiB    mac -c5000 (Monkey's Audio insane)
210.6 MiB    wavpack -hhx6
198.8 MiB    flac --best (default blocksize: 4096)

I thought there was something wrong with my setup, until I saw Walrusbonzo's results, confirming mine. I can't believe how bad Monkey's Audio fared.

24-bit WAVs (HDCD decoded), custom blocksizes

CODE

196.6 MiB    wavpack -hhx6 --blocksize=4410
197.1 MiB    wavpack -hhx6 --blocksize=2205
196.1 MiB    mix of the above (smallest encodes from each)
197.1 MiB    flac -l 12 -b 2048 -m -e -r 6 (equivalent to --best)

Now we're talking! Overall, wavpack with a blocksize of 4410 fares better than with a blocksize of 2205, although some tracks (4, 6, and 7) are indeed a bit smaller with the latter.
Note: Monkey's Audio doesn't provide the ability to change blocksizes.

[foo_lover]

I was thinking of having HDCD decoder as foobar2000 plugin and came to conclusion that it won't fit in player's model... It would break replaygain, for example. So, the only reasonable implementation of HDCD decoder would be as a part of player's core.. IMHO, of course.

[kremb]

Here is what I did. I'm not sure if I notice any appreciable difference in quality but what the heck.

EAC to .wav files

hdcd.exe .wav files to 24 bit .wav files

import 24 bit .wav files into itunes at 320kbps AAC

Burn itunes playlist to CD


*****

here are the size of the various wave files I burned to CD

original EAC Rip - 23 870 KB - lame mp3 via foobar - 3816 KB
24 bit .wav via hdcd.exe - 35 804 KB - lame mp3 via foobar - 3754 KB
.wav from itunes burned cd via EAC - 23 870 KB - lame mp3 via foobar - 3704 KB
.wav from nero burning 24bit .wav to cd - 23 870 KB - lame mp3 via foobar - 3762 KB

*****

I think I have answer my own question, I didn't think the AAC was going to be so lossy. Looks like simply burning the 24 bit wav files using nero audio selection is the best choice if a person is determined to try and include all 20 bits of data in their NON-hdcd CD backup.

*****

Feel free to tell me where my logic is flawed and should just settle with the backwards compatible hdcd playback.

Does anyone have another suggestion to try and use the most of the 20 bits of data on a regular CD? Is this a job for soundforge? Or into some sort of DVD format that will decode ALL 20 bits?

*****

I've decided to author a dvd with still frame photos for video and the 24 bit wav files for the audio. I'm using pretty simple authoring software called TMPGEnc DVD Author. I think it's going to work out pretty well, other than I'll have to play the tracks on a DVD player.

Hope my long winded process helps someone else.

Enjoy your tunes!

*****

easier said than done. dvd author program insists on reencoding some black box method to AC3.

Thus ....

I decided to compress to 24 bit flac and listen to them via my Ipod using Rockbox. I THINK i can notice a difference with my cans on vs a good little cd player I have. We'll have to see how much of an audiophile I really am as I only have 2GB on my ipod.

This post has been edited by kremb: May 27 2008, 07:05

[Nubben]

dBpoweramp R13 (just released) now contains an option to rip these into 24-bit wav/aiff files.

Nubben

[odyssey]

I was thinking of having HDCD decoder as foobar2000 plugin and came to conclusion that it won't fit in player's model... It would break replaygain, for example. So, the only reasonable implementation of HDCD decoder would be as a part of player's core.. IMHO, of course.

Did you see the latest changelog? They implemented some replaygain stuff for 3rd party components. What exactly it is or how it works, i have no idea about, but maybe it might come in handy?

[Walrusbonzo]

POST RESURRECTION!

Any news on a HDCD decoding plug-in for Foobar?

[Tropican]

Hey, does anyone know anything about the new "0.2" version of HDCD.exe? http://www.srcf.ucam.org/~cjk32/hdcd/

It's been there since November. I can't find any indication of what's been changed/improved.

The fact that http://www.srcf.ucam.org/~cjk32/hdcd/hdcd.zip points to this new build makes me think its stable?

[markanini]

The 0.2 dev build contains API which should make it easier to create a foobar2000 plugin...

This post has been edited by markanini: May 3 2009, 02:39

[TheodoreG]

I am trying to capture the decoded HDCD audio from Windows Media Player using Total Recorder Professional 7.1. I can only get Total Recorder to recognize 16-bit, not 24-bit formats played from Windows Media Player. This is using Windows XP SP3. Therefore I cannot seem to obtain 24-bit output from HDCD's, even with 24-bit CD audio enabled and the HDCD logo displayed.

I created in Adobe Audition some Windows Media Audio files in 24-bit format. When I play them in WinAmp through Total Recorder's driver, Total Recorder correctly recognizes the audio format (44.1 kHz, 24-bit). If I play the same Windows Audio-format files in Windows Media Player (version 9 or 11), Total Recorder identifies the audio format at 44.1 kHz 16-bit (not 24-bit).

Similarly, when I play an HDCD in WMP (version 9 or 11), Total Recorder recognizes 44.1 kHz, 16-bit format regardless of whether 24-bit CD playback is selected for the Speakers device in WMP.

Note: Total Recorder does support 24-bit recording and playback in its current version, as I mentioned in the example above involving 24-bit playback from Winamp. In fact, I use Total Recorder to record live music when I am doing sound in 96 kHz / 24-bit format.

Note 2: I am aware of the utility hdcd.exe version 0.2. But I would like to do a reality check using a few physical CDs that are encoded with HDCD, playing through Windows Media Player.

This post has been edited by TheodoreG: Jul 15 2009, 18:35

[Cavaille]

I am trying to capture the decoded HDCD audio from Windows Media Player using Total Recorder Professional 7.1. I can only get Total Recorder to recognize 16-bit, not 24-bit formats played from Windows Media Player. This is using Windows XP SP3. Therefore I cannot seem to obtain 24-bit output from HDCD's, even with 24-bit CD audio enabled and the HDCD logo displayed.

I created in Adobe Audition some Windows Media Audio files in 24-bit format. When I play them in WinAmp through Total Recorder's driver, Total Recorder correctly recognizes the audio format (44.1 kHz, 24-bit). If I play the same Windows Audio-format files in Windows Media Player (version 9 or 11), Total Recorder identifies the audio format at 44.1 kHz 16-bit (not 24-bit).

Why so complicated? Just use a WAV-output Plug-in. With that you´ll be able to extract HDCD to extensible .wav. A tip: create an image of the disc with EAC first and mount that image as a virtual drive - that way you can go around the crappy grabbing engine in WMP. WMP will still recognize the image as a CD (and therefore as a HDCD) if it is mounted as such. But note: if you activate the 24-bit-disc playback, WMP will also change non-HDCDs (volume will be reduced for 6 dB and the bit resolution will be 17 Bit).

Even less complicated is the HDCD decoder in dbPowerAmp. You can use that one with the already extracted wave-files.

[krabapple]

.

Even less complicated is the HDCD decoder in dbPowerAmp. You can use that one with the already extracted wave-files.

dbpoweramp's decoder is simply hdcd.exe, I think.

[greynol]

http://www.hydrogenaudio.org/forums/index....st&p=571890

[TheodoreG]

Why so complicated? Just use a WAV-output Plug-in. With that you´ll be able to extract HDCD to extensible .wav.

I did not try the plugin because I was doing a reality check of the playback of 24-bit audio -- which would mean that Windows Media Player playing 24-bit files or CDs in 24-bit mode should pass 24-bit data to the audio device. It only passed 16-bit data, hence my concern. If it does not do that correctly, then I would not necessarily assume any plugins in Windows Media Player are getting true 24-bit data.

[Cavaille]

I did not try the plugin because I was doing a reality check of the playback of 24-bit audio -- which would mean that Windows Media Player playing 24-bit files or CDs in 24-bit mode should pass 24-bit data to the audio device. It only passed 16-bit data, hence my concern. If it does not do that correctly, then I would not necessarily assume any plugins in Windows Media Player are getting true 24-bit data.

Oh. Well, for that there could be many reasons. 1. your soundcard isn´t really capable of playing 24 bit - or more precise, its driver does not report 24 bit (although I don´t know if WMP really goes back to 16 bits if the card driver reports so) 2. the kernel mixer could prevent the stream going unaltered from WMP to the card. 3. HDCD isn´t 24 bit. It merely is 17 bits when decoded (and only because the volume is lowered for -6dB) and 'quasi' 20 bit when some of the switches kick in. Maybe the software you use for recording misinterprets this as 16 bit.

Someone may correct me on that but I think that the kernel mixer is your problem here. If my memory serves me right it will use the first audio signal as some kind of reference for every other audio signal that will be played afterwards. Meaning: if you played or recorded a 16 bit signal it will stay that way unless you turn it off. Kernel mixer won´t be switching bit depth automatically during playing or recording them. Other members can certainly clarify this if I made a mistake.

I can tell you from my experience that WMP really is capable of decoding HDCD and there is plenty of evidence for this here in this thread (if I´m not mistaken) and on the web. Why do you want to find it out in the first place?

[Weeping Robot]

Ah, the fun old HDCD question. Was browsing on another forum today and the topic came up, which reminded me of an old, unanswered question I had regarding HDCD decoding. Specifically, from this thread. Money quote: "Any idea if [pregaps actually missing] affects HDCD playback?" From what I understand, the HDCD information is stored in the "LCBs" (least significant bits) and in only a minority of the... samples? I suppose, then, the key question is whether any HDCD "flags" are set in pregaps. My guess is no (are pregaps even audio information, really?), but it would be nice to know for sure.

By the way, something else I was wondering: what if your rips aren't offset correctly (in EAC, drive offset I mean). Does the HDCD "flag" rely on correct alignment (or cue sheets) as a reference? If each sample (or whatever) contains the HDCD information, than I suppose none of that would matter... and that might solve my missing pregaps question too.

This post has been edited by Weeping Robot: Sep 13 2009, 22:06

[greynol]

There is no reason that pregaps cannot contain HDCD information since pregaps (like any other part of a track) contain nothing more than audio information and subcode data*. It is my understanding that offsets have no bearing on HDCD decoding either.

(*) subcode data has absolutely no bearing on HDCD decoding.

This post has been edited by greynol: Sep 14 2009, 20:43

[Axon]

Is HDCD 100% stateless? If not, then pregaps matter.

[greynol]

Suppose I press skip half-way through the playback of a track, does that mean what I have heard up to that point was not decoded properly? Of course it doesn't.

Does this mean that the next track will not be decoded properly? I seriously doubt it.

This post has been edited by greynol: Sep 14 2009, 20:50

[Axon]

Suppose I press skip half-way through the playback of a track, does that mean what I have heard up to that point was not decoded properly? Of course it doesn't.

True, but it's the answer to the wrong question. The question really is "is the playback after the skip always decoded properly?", and the HDCD patent very unambiguously implies the answer to this is "no". There is no reason why the same answer cannot also apply for ripped tracks that lack pregaps.

This post has been edited by Axon: Sep 14 2009, 21:11

[greynol]

It should be quite trivial to test and my guess about the outcome is that removal of pregaps will not matter.

This post has been edited by greynol: Sep 14 2009, 21:15

[Axon]

Yeah. Somebody who actually cares about HDCD should probably look into this.

[greynol]

I want to add that such a test need not be constrained to the removal of pregaps. XX frames of data could be removed from the middle of a track instead. My point is to drive home the fact that audio data marked off as a pregap is no different than audio data that isn't marked off as a pregap.