AUTHORING AND RECORDING DVD-AUDIO DISCS

by Bruce Bartlett

Chances are you've been recording CD-Rs for some time. Maybe you'd like to step up to the next level: DVD-Audio discs. Compared to the CD format, DVD-Audio provides better sound quality, surround sound, longer recording time, and other media formats in addition to audio.

Compiling and recording a DVD-Audio disc can range from a simple drag-and-drop process (if the disc contains only audio), or can become quite complex, with a variety of sampling rates, bit depths, channels, video, web links, text, and so on.

To create DVD-Audio discs, you'll need certain software and hardware which we'll cover here. We'll also describe the basic steps in authoring a DVD-Audio disc. First, let's review some background information on the DVD-Audio format.

DVD-Audio

DVD-Audio is a DVD format which features audio programs. It also can have optional still pictures (slide shows), internet links, visual interactive menus, on-screen text and lyrics, and video clips.

DVD-Audio discs use PCM encoding. This encoding can be linear, as on CDs, or "packed" using Meridian Lossless Packing. MLP reduces the data rate up to 50% but without any data loss: the reproduced signal is identical, bit for bit, with the original signal. While a standard CD is a 2-channel format fixed at 16-bit/44.1 kHz resolution, DVD-Audio is a multichannel surround format with higher resolutions.

Compared to a standard CD, DVD-Audio permits:

• Better fidelity due to higher sampling rate and higher quantization (up to 24 bit, 96 kHz with six channels, or 176.4 and 192 kHz with two channels)
• Longer playing time in some formats (up to 6 hours of 16-bit, 44.1K stereo).
• More channels (up to six in the 5.1 scheme, allowing surround sound).
• Optional formats in addition to PCM, such as MPEG-2 BC, DTS, Dolby Digital, or DSD (Direct Stream Digital -- the format used in the Super Audio CD.)
• Option for different sampling rate and bit depth. on different channels. DVD-Audio allows a wide range of sampling rates, number of channels and bit depths. For example, a 4.7 GB single layer disc can hold a 75 minute program in which the left-center-right signals are 88.2 kHz/24 bit and the two surround channels are 44.1kHz/20 bit.
• Option for different formats on different tracks. One track might be 16-bit/96kHz surround, while another could be 24-bit/192 kHz stereo.
• Other optional media formats besides audio.

DVD-Audio content is stored in a separate DVD-Audio zone on the disc (the AUDIO_TS directory). The program can be copy protected by a digital signature signal and digital watermarking.

Most DVD-Audio players will also play DVD-Videos and CDs, and some will play Super Audio CDs. A DVD-Video player can play a DVD-Audio disc if the latter has a Dolby digital version of the audio in the DVD-Video zone on the disc. The digital outputs on a DVD-Audio player include PCM and Dolby Digital. Some units have DTS and DSD outputs. All have multichannel analog outputs. Future players might have Firewire (IEEE 1394) connections.

What You Need

Basically, you compile and record a DVD-Audio disc as you do a CD-R disc: with software, a hardware disc recorder, and blank discs. Specifically, you need DVD-Audio authoring software, a DVD-R recorder, and blank DVD-R discs. Let's look at each one.

DVD-Audio Authoring Software

Authoring software is used to compile a finished program in DVD-Audio format, such as songs, a slide show, web links, and an interactive menu which offers those selections. There are only a few DVD-Audio authoring programs. The major titles are: Sonic Solutions' Sonic Studio HD and DVD Creator, and Minnetonka's MASS 5.1

The highly popular Sonic Studio HD offers multitrack recording, editing, and mixing on a computer. "HD" means that it handles High Density audio with high sampling rates and high bit depths. The software can be used to master to CD, PMCD, DDP, DVD-Audio, audio for DVD-Video, and EMD. Sonic HD can provide surround mixes, multitrack sampling rates up to 192 kHz, and very fast editing.

Using HDSP processing architecture, Sonic HD can output 8 channels of 24-bit/96 kHz audio or 4 channels of 24-bit 192 kHz audio. Sample-rate conversion is included. Other features are PQ code editing, ISRC codes, UPC editing and support for CD-R and DDP. The system can be expanded with the HDSP Plug-in Processor.

In SonicStudio HD is a feature called "OneClick DVD." If your program is audio only, you can assemble playlists with just a few mouse clicks, as if you were mastering a CD. Another feature is Smart Content, which lets you set coefficients for automatic 6-to-2 fold-downs or mixes of surround audio programs into stereo.

Sonic Studio DVD Creator is the first and the most popular DVD authoring program. It handles both DVD-Audio and DVD-Video formats. Like a mastering program, DVD Creator lets you assemble a playlist or a sequence of song mixes. Other media -- such as video or web links -- can be included. Since this article focuses on DVD-Audio, I won't go into the many DVD-Video authoring features of the program, but they are impressive.

System requirements for DVD Creator (and HD) are a Power Mac G3 or G4 with Mac OS 8.6 or later, 385 MB memory, 20 GB hard drive, a DVD-ROM drive, and perhaps a DVD-R recorder.

If you want to make pure audio DVD-Audio discs, Sonic HD will do the job. If you want to include video, etc. along with the audio, Sonic DVD Creator can handle it. You might first create your audio mixes with HD (maybe in surround and 24-bit/96kHz), then load them into DVD Creator.

Sonic DVD Creator includes Dolby Digital encoding and decoding, DVD-Video and DVD-Audio authoring, formatting, and an output to DVD-R (DVD Recordable discs) or DLT (high-capacity tape-drive backup). Other features are NoNOISE which removes noise, and an MPEG-2 video encoder.

Sonic Solutions is at http://www.sonic.com. Sonic, Sonic Solutions, the Sonic logo, HDSP, SonicStudio HD and DVD Creator are trademarks of Sonic Solutions. System price is around $25,000.

Another major DVD-authoring package is MASS 5.1, a bundled product containing three items:

1. Minnetonka's Mx51 -- a program to mix 5.1 surround sound, including a "Build your own mixer" GUI and automated surround panners.

2. Minnetonka's MASS 5.1 -- a program to compile those mixes for DVD-Audio. You drag-and-drop soundfiles from one window to another to create your playlist. Then you press the Record button and burn the DVD-Audio disc.

3. A Pioneer S201 DVD-R recorder. This drive connects to your computer via a SCSI port. It can make data DVDs and audio DVDs.

In MASS 5.1, each channel's signal is a separate Wave file. MLP data compression is an option. As of May 2001, the price is $9495 for the complete package. The software runs under Windows 98, 2000 or NT. To see some screen shots, visit Minnetonka's web site at www.minnetonkaaudio.com.

DVD-Audio Recorders (DVD-R recorders)

In addition to software, you need a DVD-R recorder. Like a CD burner, a DVD-R burner is a drive that can record on blank discs. It records up to 4.7 GB of data on a 5" single-sided, single-layer disc. The non-erasable data can be audio, video, images, graphics, or computer files. Suited for creating test discs for DVD-ROM or DVD-Video productions, a DVD-R recorder also works as a DVD-ROM player, which plays computer data files. Typical prices are around $1000 (May 2001).

DVD-Audio Blank Media

These write-once discs have dye on one side like a CD-R. Handling up to 4.7 GB on a single-sided disc, they can record DVD-Video, DVD-Audio, or DVD-ROM files. Expected lifespan is over 100 years and typical price per disk is $29.00 (May 2001).

The DVD-Audio Authoring Process

Let's say you have the software, the burner and some DVD blanks. How do you actually put together a DVD-Audio disc?

If your DVD-Audio disc will contain only audio (music), authoring is a simple process of drag-and-drop or mouse clicking to create a playlist of songs. Each song is typically a 6-channel, 5.1 surround mix. If you want to include video clips, visual text, still photos, and so on, the process is complex. I'll give the main steps below, but the software instructions will fill in the details.

1. Collect the source material: multitrack audio tracks, images for ASVs (still videos), text, web links, and other DVD-ROM content.

2. Edit the source material: Make surround or stereo audio mixes; edit images, edit text, and so on.

3. Define the track start and end points (PQ subcodes); data-compress the audio with MLP (Meridian Lossless Packing).

4. Author the program; create a navigation menu. Create menu graphics, photo clips, and hot buttons on the menu.

5. Add copy control information (CCI) and fold-down coefficients (the relative loudness of surround tracks in the stereo mix). You might include a DVD-Video zone, which makes the disc compatible with DVD-Video players. This zone needs to include Dolby Digital or DTS audio and ASV's.

6. Make an image file of the program on your hard drive. This image file combines the DVD-Video and DVD-Audio zones.

7. From the image file, write to a DVD-R to test the program. If it's okay, write to a DLT tape backup drive.

There you have the basics of authoring DVD-Audio discs. Although the hardware and software are expensive, we can expect prices to drop as the format takes off. Eventually, many more engineers will be able to release surround recordings with sound quality exceeding that of CDs.

Copyrighted 2001 by Deltamedia. May not be reproduced in whole or part without permission.