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All information in these pages is copyright (c) 1989-2002 by Roger Nichols. All rights reserved. Permission for personal reference only, and may not be reproduced by any method without written permission.

I Feel Disc-Connected, Part-1
by Roger Nichols

Audio-DVD-Audio

As some of you have figured out, there is a difference between audio for DVD and DVD audio (DVD-A). Audio for DVD takes in all of the possible formats for audio that accompany the video on a video DVD. (They don’t call them DVD-V because nobody knew that there was going to be a DVD-A.) DVD-A is the new format that allows for discreet 5.1 channel audio, and sample rates up to 192kHz. There can be video for menus, but most of the disc is dedicated to audio. You can also build a DVD that is half DVD-A and half DVD-V so that the consumer can play it back on his DVD video player before he buys a DVD-A player.

In January 1999 DVD burners cost $17,000 and blank media was $45. Within six months drive prices dropped to $5,000. In 2001 Apple delivered the 733mHz G4 with a drive that would record DVD-R and CD-R (Pioneer DVR-103). The combination was only available from Apple until the end of that year, after which you could buy DVD-R drives alone for $500. As of this writing DVD-R/ CD-RW internal drives are $269 (Pioneer DVR-A04.) There are DVD-R and DVD+R drives from HP, Sony, Pioneer, Hitachi, and many other manufacturers. Blank DVD-R media is now $3.00 at CompUSA and $0.98 bulk price on the Internet. The next generation of 4x DVD recorders was announced last month.

DVD video.

On a DVD video disc you can have a stereo PCM channel at 48kHz sample rate, a Dolby Pro Logic 4 channel encoded into a stereo PCM bit-stream, a 5.1 channel surround mix encoded into a Dolby Digital (AC-3) bit-stream, or a 5.1 channel surround mix encoded into a DTS bit-stream. You can also have as many of these variations as you want, as long as the total bit-rate including the video does not exceed 10.085 megabits per second. There are software encoders available for Dolby AC-3 and DTS.

There are DVD authoring solutions for both Mac and PC platforms. Authoring a video DVD is a multi-step process that has a fairly steep learning curve if you want to be able to exploit more sophisticated DVD features like multiple camera angles, motion menus, sub-menus, multiple language audio, and sub-titles. There are also drag-and-drop programs for novice users that make DVD authoring as easy as burning a CD full of MP3s.

Before you can author your DVD you must have the final edited video program material, stills for menus, menu background video or stills, sub-title text, and all of the audio elements ready to go. The video can come from a video house, from an existing video that is being converted to DVD, or you can shoot and edit it yourself on one of the many video-editing programs available for both Mac and PC. The audio can be the original audio from the video, remixed multi-channel surround audio, additional music and effects added to the audio, or alternate audio tracks for foreign language distribution.

You can’t have your cake and eat it too. Now that you have decided on all of the audio tracks and camera angles, you have to make sure that it will all play back. The maximum bit-rate for DVD video is 10.085 megabits per second. If you digitize the video at the highest quality, and add PCM audio, AC-3 and DTS, it won’t all fit on the disc. You either have to leave something off, or lower the bit-rate of one or all of the elements. Since I am an audio guy, I just tell them to leave off the video. Not really, I just have someone lower the bit-rate of the video encoding so that all of my audio tracks. Calculate the bit-rate for all of the audio tracks and whatever is left determines the bit-rate for the video.

After you have solved all of the bit-rate mysteries and all of the elements are gathered and compiled by the DVD authoring program, you can burn a DVD that will playback on almost any home DVD player (some early first generation players have trouble with DVD-R.)

He Broke IT, He Broke It!

Since the actual files that reside on the DVD are well defined, it doesn’t matter whether you do your authoring on a PC or a Mac, well, almost.

My daughter, Ashlee, directed, shot, and edited a promotional video for a comedy troupe in Miami. Everything was shot on DV and edited in Final Cut Pro. All of the authoring was going to be done in DVD Pro on the Mac and the client wanted to be able to burn DVDs on a PC from the DVD Pro mastered files. Good plan.

This comedy troupe had a nice six-figure budget. The only problem was that all six figures were zeros. The client bought a new PC with a DVD burner and its bundled software, Power Director Pro, an all-in-one video editor/DVD creator/DVD burner package, and Vivastar CD and DVD burning program. I loaded the client’s software on my PC to see if I could figure out how to work out the kinks and supply her with the correct files. The Power Director Pro software would not let you burn a DVD with files created elsewhere. The only thing you could do was capture the video from a DV camera, skip the editing and create the DVD. When it got to the DVD burning part, the program locked up and forced a re-start. After the third time, I gave up.

Plan “B.” I switched to Sonic MyDVD 3.5, which came bundled with my Pioneer A04 drive. I had to capture the video again and create the DVD in MyDVD. When you capture video from a DV camera, the image on the computer monitor jumps because the priority is capturing, not displaying. That is fine with me. It turned out that there were tons of skipped frames because somebody couldn’t keep up. The software never reported a problem. It captured anyway and built a bad DVD. Final Cut Pro aborts if there is any skipped frames during capture, so I thought everyone else did also. I figured a 2.4 GHz P4 with 1 Gigabyte of 533 MHz memory should be able to keep up with some stinking DV video, so I blame the software. I didn’t have time to trouble shoot, so on to plan “C.”

Sonic has one very cool feature though. The DVD authoring session documents are saved on the DVD along with all of the necessary files needed for the DVD playback. You don’t have to keep your files on your hard disk. You can insert the DVD in a computer DVD drive, double click on the Sonic session document, and the DVD opens in the authoring software. You can then add more video, edit the video you have, create new menus, and burn an updated DVD. If you are using a DVD-RW disc it will erase the disc and build your new DVD. Cool.

So anyway, my next step is to get all of the files authored in DVD Pro on the Mac, move them over to the PC, and then just burn a DVD-ROM. That should work, right? I got all of the files transferred; loaded them in the DVD burner program and clicked on BURN. The program yelled back, “No recording device found on this computer.” The software would only recognize the DVD-R burner that it came with, not my Pioneer 103 that I pulled out of my G4, or the Pioneer A04 already connected to the PC. I could not verify her software on my machine, I either had to go to her office and try, or switch to some other DVD burning software.

So I guess for the next month I will either be checking trial downloads, killing myself (again) or maybe spending some time over at the client’s office. Don’t tell my wife.

DVD-A

I authored my first DVD-A disc with Minnetonka discWelder STEEL. I took the DVD-R down to my local Sound Advice store to see if it would play on all of their DVD-A players. The salesman said, “You can’t make DVD-A discs at home! You need at least $50,000 worth of gear to do that!” Play this, DVD breath.

In two months, Part 2, the DVD-A connection, DVD-A authoring, MLP, DTS, and AC-3 encoding, and a full review of discWelder STEEL.