A Proposal for a Copy Optimized DVD Audio Format

Copyright © 2005 Michael David Crawford.

This work is licensed under a Creative Commons Attribution-ShareAlike 2.5 License.

I got to thinking about something after setting up the Ogg Vorbis and cdparanoia tools on my Mac so I could back up my collection of two hundred compact discs to a few DVD-Rs.

I'm writing to suggest the community work together to specify a standard for the format of DVD Audio disks that will be Free as in Freedom. There are a couple of competing standards in the works for DVD Audio that have the advantage of higher audio fidelity than CDs (sampled at, say, 24 bits instead of 16) and that can hold more hours of music, but it's already clear that the companies behind the standardization efforts consider copy-protection their first priority.

You can be sure that the very finest minds in cryptography, mathematics, physics, optics and electrical, mechanical and software engineering are working together, and working very hard, to make sure that when 24-bit Britney Spears DVD Audio disks hit the stores that they won't end up on eMule the very next day, in fact not even within the next decade. I don't think a very serious effort was made to ensure that the DVD Content Scrambling System was entirely secure. I also don't think that mistake will be made a second time.

Could there be a better way?

Many musicians actively promote the copying of their music. AGNULA Libre Music is an archive of music that is not just free to share, but copylefted - the tracks must have the Creative Commons Attribution-Sharealike or EFF Open Audio License to be hosted there.

What sort of DVD Audio format would AGNULA's musicians like to distribute their music on? How about DVD disks that are optimized for copying, whether it be through burning physical copies or sharing on the Internet?

What I envision is a disk format that is rigorously specified so that it will work reliably in the simplest embedded devices like car dashboard and home stereo players, but with completely unprotected Free Lossless Audio Codec files on them.

A DVD can store a lot of music in FLAC format if it's just 16 bits, but FLAC can store samples up to 32 bits. The greater storage capacity of DVD will not only allow Copy Optimized DVD Audio music to sound better than CDs do, but allow more channels than stereo's two, to provide surround sound or a separate channel for each performer.

(I just discovered how to make cue file backups with FLAC so I can finally properly back up my collection. I've lost several CDs to bad scratches and even a couple to my dog who likes to chew things that shouldn't be chewed.)

While most people can't hear the difference between 16 and 32 bit audio, higher-resolution samples enable one to edit audio tracks without loss of fidelity. Mixing audio tracks and applying acoustic effects loses numerical precision each time it is done. Starting with larger samples enables the final product to retain a true sixteen bits of real precision. Thus artists could encourage other performers to mix themselves into a track in such a way that it still sounds good.

But here's the key: each file will be named in a way that's optimized for file sharing, with artist, album, title and track number right in the filename, and with all the right metadata already embedded in the file when the track was mastered at the studio. To share such a track you just direct your peer-to-peer filesharing application to your DVD drive so it will share the same music you're listening to, or have your friends copy the tracks onto their computers' hard drives, or else just burn them copies of the whole DVD.

But wait: there's more! The DVD disk itself will have a metadata file in its root directory that will specify the contents of the entire disk. My idea is that one could make a bit-for-bit reconstruction of the whole disk just by grabbing this one metadata file and then looking for the tracks on the file sharing networks. This file would be one or two kilobytes of XML that would have each track's metadata as well as its md5 hash so it can be uniquely identified over the net.

Music labels that offerred such DVDs - and there are music labels which encourage copying - would host the metadata files for each of their albums on their websites in much the same way as many Free Music sites now host Bit Torrent files. (Don't have Bit Torrent yet? Download it right now.) The music labels wouldn't have to offer music file downloads if they couldn't supply the bandwidth or technical expertise, because those who possessed the DVDs could supply the actual bits.

It is extremely important that the Copy Optimized DVD Audio format be rigourously specified in a technical document that has passed through an extensive review process. That will encourage embedded player manufacturers to support it, just as they have begun to support the Ogg Vorbis format. Perhaps all the aspects that have to do with networking, like the contents of the disk-spec metadata and a standardized way to share Copy Optimized DVD Audio disks over the Internet could be standardized by the Internet Engineering Task Force.

Importantly, the disc and file metadata would explicitly specify a license, even if it's just "All Rights Reserved". Creative Commons already explains how to specify the license in an MP3. Most musicians don't know that if they don't explicitly supply a license, they implicitly forbid others to share their music. It's important to make the terms of music licenses just as rigorously clear as they are for Free Software.

Now, imagine what this would do to the copy-protected form of DVD Audio. On the one hand, you could get very high quality recordings of all the top pop stars that way. On the other hand, if you wanted to listen to the same tracks on your portable player you'd have to pay separately to download copy-protected files from a commercial music download site, or maybe there would be some process of obtaining a license online that could transfer a low-quality file from a DVD to a player in such a way that Warner Records' intellectual property rights could be preserved.

Or, you could listen to indy bands who really are a lot more creative and forward thinking than the tedious crap that the big record labels and the Clear Channel Radio Monopoly continuously force upon us, and you wouldn't have to deal with any expensive hassles to listen to it on your portable player, in your car, to burn to regular CDs for your antique players, or to share with your friends or over the Internet.

I assert this would prevent copy-protected DVD Audio from succeeding in the marketplace. Maybe the industry consortium behind the present standardization efforts wouldn't put in the metadata to encourage copying, but I expect they wouldn't go very far if no one would buy their damn copy-protected discs. In the long run I expect they would remove the encryption so they have some hope of selling anything at all.

I'm very sorry but I have an awful lot on my plate and I simply don't have the time to work on something like this. I also don't have the background required to write such a document. (I can promise I will write a CD ripper that's a lot better to use than any that I've tried so far, and place it under the GNU General Public License. Frankly I cannot comprehend what anyone finds appealing about iTunes, it drives me bananas and is buggy as all get-out.)

On Eating One's Own Dog Food

I want to explain why the Copy Optimized DVD Audio format is important to me personally. You see, I am a musician. Not a professional one, not yet, but that is my goal. I have decided I must make my music as free as the wind.

If you like piano music, you can download my album Geometric Visions. It's just in MP3 format but now that I finally have an ogg vorbis toolchain setup I'll go make oggs, maybe they'll be there by the time you read this.

I once had a very proprietary license notice on my music but I spent over a year contemplating giving it a copyleft license, ever since discovering AGNULA Libre Music. It was a painful decision, but I finally took the plunge just this very moment: while working on this draft of my proposal I took a break to place my entire album under the Creative Commons Attribution-Sharealike 2.5 License.

I've been learning Lilypond so I can post the scores soon. I'll be copylefting them, the source code to my music, as well.

I'm not the only one who feels this way. For example, Kuro5hin member Dac Chartrand is a Montreal music producer who owns the new record label Trotch. Dac's a pretty forward thinking guy as he offers free downloads of some of his artists' music and actively encourages those who purchase his CDs to share them. Trotch's launch party is on September 8th at Sapphir's Mix Thursday at 3699 St-Laurent, Montreal if you are in the area.

The band Fitehouse published the Fitehouse General Public Music License (PDF) that was inspired by the GNU GPL in that it requires one to supply the source to recordings along with any copies. In this case the "source code" is the raw, unmixed studio tracks from which the recording was created, so that one could mix one's own version of a song.

The first FGPMLed song is "Running Scared" which appears on their EP The Bomb. At the bottom of that page are links to ten uncompressed WAV files of about fifty megabyes apiece, being the original studio recordings from which Running Scared was mixed.

Intrepidly,

Michael D. Crawford
crawford@goingware.com

Tilting at Windmills for a Better Tomorrow.

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