Burning a 24 bit stereo audio CD-R for my DVD player.

[Circlotron]

Nowadays, every man and his dog sells dvd players that will both read cd-r's and have 24 bit d/a's. It is a relatively straightforward thing to burn a normal *16 bit* 2 channel audio cd so it will play in your dvd player. What I want to know is - what is the file format details so I can burn a *24 bit*, 48 or 96kHz 2 channel cd that will take advantage of that nice 24 bit d/a?

I only(!) want an improved version of the standard 2 channel cd, nothing outrageous. Maybe someone out there has some software that can do it already. Seems to me it is a project just begging to be done. We already have the hardware, just a matter of telling it what to do!

[schmad]

Originally posted by Circlotron
Nowadays, every man and his dog sells dvd players that will both read cd-r's and have 24 bit d/a's. It is a relatively straightforward thing to burn a normal *16 bit* 2 channel audio cd so it will play in your dvd player. What I want to know is - what is the file format details so I can burn a *24 bit*, 48 or 96kHz 2 channel cd that will take advantage of that nice 24 bit d/a?

What I'm not sure about is how you master LPCM/MLP onto CD media. I mean, sure you *can* get the data on there, but I don't know what the specifcation (eg think Red Book for CDs) is like. One of the software packages that I read about for DVD-A mastering, discWelder, isn't cheap at $3495.

See http://www.discwelder.com/ for more info.

[Christer]

Circlotron,

maybe you should tell whether you are asking about the data
format on the DVD or the file format for the source file for the
DVD burning software.

For instance, under Windows I would guess that a DVD burning
software would accept a wave file (.wav) and these have a
very straightforward data format which is flexible in the sense
that the header specifies the number of channels and bits and
the sampling frequency. Wave files could thus be used to store
24-bit data with 48/96kbit sampling frequency.

[Circlotron]

My biggest problem is the unknown e.g. how does exactly does the dvd player recognise whether it has 16 or 24 bit source material? Is it in the header file too? I only want to burn to a standard CD, not to a DVD because I don't have a suitable burner. I wonder what would happen if I simply made a 24 bit 48 kHz wav file and just tried to burn it as a cda file?

The reason I was wanting to know the file format is then I could presumably generate the file on hard disk and then simply copy it in it's unaltered state to the CD-R. Of course I don't actually know whether their *is* a standard for plain 24 bit 2 channel CD disc (not DVD disc). If there is not, then it remains to be seen whether what I want to do can in fact be done. I hope so...

[AudioFreak]

Originally posted by Circlotron

1)
My biggest problem is the unknown e.g. how does exactly does the dvd player recognise whether it has 16 or 24 bit source material? Is it in the header file too? I only want to burn to a standard CD, not to a DVD because I don't have a suitable burner. I wonder what would happen if I simply made a 24 bit 48 kHz wav file and just tried to burn it as a cda file?

2)
The reason I was wanting to know the file format is then I could presumably generate the file on hard disk and then simply copy it in it's unaltered state to the CD-R. Of course I don't actually know whether their *is* a standard for plain 24 bit 2 channel CD disc (not DVD disc). If there is not, then it remains to be seen whether what I want to do can in fact be done. I hope so...

1) Wont work, if the software even allows you to go ahead, it will down sample everything back to 16bit/44kHz

2) To my knowledge, there is no such standard. Basicly I dont think you'll get a DVD player to read 24bit audio off a CD. However, it may be worth having a look at the HDCD standard as this allows 20bit audio from a CD

[sangram]

SACD is 24-bit (?). HDCD is 20-bit. Redbook is 16-bit. Not sure if *any* burning software is capable of burning SACD yet, or even if regular CDR/W drives recognise this standard.

The DVD-A standard is multichannel 24-bit. Again, mastering software is expensive/does not come bundled with drive.

You can try burning a 24-bit wave file onto a CD-R and trying to play it (data CD, not audio - audio will resample it down to 16-bit). May work, may not work, but for a few cents what does it matter? I have seen CD-players that can read wave files off a CD-R so long as there were only wave files on the disc (not a single other piece of data) - some portables and minicompos can do this.

You may get lucky. Keep us posted anyway...

[AudioFreak]

SACD is actually a DVD format... I dont think it will work on a CD

[hifiZen]

There is no standard AFAIK for MLP material on CD. MLP and 24-bit audio are only defined as standards in the DVD specs. The basic reason is bandwidth limitation. Full-blown 24-bit PCM or even MLP is high bitrate stuff, which well exceeds the specified max bit rate for CD media. It's doubtful that the player can read back data beyond about 2X speed. Beyond that, all consumer DVD loaders first check the physical medium, to see if it's CD or DVD. If it's CD, they switch on the CD laser and change into a CD read mode. The decoder also usually knows that it's looking at a CD, so only standard CDDA and CD-ROM formats are typically supported.

SACD is indeed based upon the DVD physical standard, which is why most DVD loaders are actually capable of reading the SACD physical layer, although they may not be able to play them back. For some discs, the SACD layer goes right on over a standard CD layer, which can be played by non-SACD players. Interestingly, SACD extends the DVD specification to include an additional signal modulation not present on normal DVD material. What they do is modulate the <i>width</i> of the pits so that the raw RF/EFM+ signal coming out of the analogue read-channel processor contains some information which must be specially decoded by some proprietary SACD hardware. This extra data rides on top of the DVD-like data, and is used to decrypt it and eventually spit out the 1-bit audio data for playback. The process of recording an SACD is therefore somewhat more involved than plain old DVD recording. More to the point, it is proprietary, so I rather doubt you'll see any SACD burners appear on the market. There is a lot about the SACD spec which isn't public, and I'm sure Sony will do their best to keep it that way!

[hifiZen]

Oh yeah, I just remembered... I think it is possible to put 24/96 or 24/48 material which has been DTS encoded (compressed) onto a CD and play that back on a standalone DVD player equipped with DTS capability. This is what you get when you buy a DTS-Audio disc in the store. They come in DVD-Audio style jewel cases, and generally only play in DVD players, so there's some subtle trickery going on there, trying to mimic the real high-resolution DVD-Audio formats. Anyway, I believe the data is actually contained in a CD format, and so is probably 'burnable'. Of course, it's no substitute for real MLP...

[Circlotron]

Originally posted by sangram
You can try burning a 24-bit wave file onto a CD-R and trying to play it (data CD, not audio - audio will resample it down to 16-bit). I have seen CD-players that can read wave files off a CD-R..
You may get lucky. Keep us posted anyway...

Yeah, I'll give that a try. Ordinary cd audio files are interleaved for the sake of error correction, so whether a wave file as a data file would be interleaved as well, or whether a single scratch would make a click noise...? I just wanna make my 24 bit D/A work.

I was thinking too, what might be interesting is to get a 16 bit audio track and use some software to realign the data points using a line of best fit for the last X data points, sort of like what a graphing program does, and then writing these points to 24 bit resolution rather than the previous 16 bit pigeon-holing. Might make it sound better.