[Riredale]

Dan:

Using Nero’s CD/DVD Speed utility was an eye-opener for me. If you have the time, download it and take a look at your disks. Use the “Disk Quality” tab and have it run through your burned disk.

What amazed me was how many errors even a “perfect” disk had. I guess the designers of the DVD process realized that they were pushing practical limits so they incorporated very robust error-correction mechanisms in the standard. I’ve read that a disk is marginal only if the upper graph shows errors way above 280 for significant parts of the disk, or if the lower graph shows errors way above 8 for significant parts of the disk. Otherwise, the error-correction routines completely repair the read mistakes.

In a very short time you’ll be able to get a feel for your burn process. I also strongly suggest you get your hands on some Taiyo Yuden DVD-R blanks (the premium ones, not the value line ones). I bought some yesterday for $0.33 each from SuperMediaStore. It makes a big difference, according to Nero.

[Riredale]

Bill:

DPI has no relevance to video. It’s a measurement that typically defines the pixel structure on printed documents.

NTSC DVD is comprised of frames of still images measuring 720×480 pixels, with about 30 such frames per second. The raw video at the source is compressed with an encoder using the MPEG2 process and typically the bitrate coming off the DVD ranges from 2 up to about 10 megabits per second. If one works through the math one concludes that a single-layer DVD (which can hold up to 4.38GB of data) can show anywhere from about 1 to about 5 hours of continuous video, based on the bitrate used.

Still photos require only a very low bitrate to look clean and sharp, while rapid motion video (such as something shot while walking or from a moving vehicle) needs a high bitrate. If you use a bitrate lower than the optimum then you’ll see MPEG2 artifacts which impart a “blocky” or “grainy” appearance to the video.

Note that “DPI” never comes into the discussion. That’s a printing term.

In practical terms, one can get typically 90 minutes of excellent-quality video (720×480 pixels) on a single-layer DVD with a typical MPEG2 encoder, and up to about 2 1/2 hours on that same DVD disk if a really excellent (read: expensive) MPEG2 encoder is used.

Hope this helps.

[Riredale]

If you want to get fancy you can create a new audio mix on your favorite NLE by bringing in the original soundtrack and then recording the director’s comments. Then you mix the two, making sure to bring the soundtrack down when the director is about to speak and back up when he’s quiet for more than a few seconds. Then render the results into a new into Dolby Digital and bring it into your authoring program. Having a commentary track adds a great deal to a project, in my opinion.

[Riredale]

Replicated or duplicated? Replicated means a pressing, duplicated means a burning.

The reason I’m asking is because replicated disks are virtually 100% compatible but are expensive to make in small quantities. A burned double-layer disk is much more problematic. In my experience and based on many reviews I think the consensus is that the only game in town for reliable double-layer playback is to use only Verbatim DVD+R DL blanks. Both the silver (uncoated) and the matte white topped disks work well.

The disks are expensive but seriously are the only bulletproof solution in many discussion groups.

With a really good MPEG2 encoder you could probably get away with putting everything on a single-layer disk. With 1GB of extra material you’d probably be encoding your video at about 4.9Mb/sec which is possible with first-class encoders. I am not familiar with the Adobe products. I personally edit in Vegas, encode with CinemaCraft, and author with DVDLabPro.

[Riredale]

I’ve done thousands of full DVDs and have had very few issues:

(1) You can burn as fast as the disk is rated, with some exceptions. To prove my point, get a copy of Nero’s CD/DVD Speed utility and check the error rate of disks burned at various speeds. In my personal experience, a full (4.38GB) disk burned at 4x, 8x, 12x, and 16x shows very low error rates at the first 3 speeds and only shows increasing errors at the outer edge at 16x. So I use 12x (the media is rated at 16x).

(2) By far the most critical factor in compatibility is the brand of the medium. I use Taiyo Yuden DVD-R blanks, which are about the best in the world and can be bought from places like Meritline or SuperMediaStore for about $0.30 each in quantities of 100.

(3) You can burn at any datarate up to the technical limits of the DVD format. To make life a little easier for the DVD player, however, I generally set an upper limit for video + audio at about 9Mb/sec. I set my lower limit at 2Mb/sec, and set the average based on the amount of material that I need to put on the disk using the formula BRavg = ( 600 / MinutesOfVideo ) – BRaudio. If I’m using DolbyDigital audio, the audio bitrate is 0.2, while raw audio is 1.5.

If I’m putting 90 minutes of material on the disk and the audio is DolbyDigital, then BRavg = ( 600 / 90 ) – 0.2, or about 6.5Mb/sec. So I encode the MPEG2 video with 2, 6.5, and 9 for min, avg, and max.

Use a name-brand burner, TY blanks, and a well-known authoring program and you will never have playability issues on any player. For years I used full-face labels, but some DVD players throw fits with labels. I now use the glossy white “Watershield” blanks that TY sells for about $0.80 and which print beautifully on my Canon IP3000 printer.

[Riredale]

Lots of choices. My favorite is DVDLabPro, which offers all of the functionality of the old standardbearer Maestro with a graphical navigation window similar to Scenarist. An amazingly powerful yet friendly authoring program.

[Riredale]

Surround-sound is my specialty. I shoot documentaries with a 4-channel audio setup mounted atop my camera. The front 2 channels are recorded onto the HDV tape; the rear 2 channels are fed into a Minidisc recorder.

After editing the video and getting the front audio right, I pull in the individual rear audio clips and sync them, then adjust levels. Once I am happy with video and audio, I encode the 4 audio tracks into a single ac-3 file (5.1 would follow the same process, but you’d have a center channel and an “LFE” channel, which in my view is totally bogus, unless you’re encoding for a 50′ screen in a large theater. To each his own…).

I use Vegas for all this, which makes it a very simple and clean process. Once I have the ac-3 file and an mpv video file (the MPEG-2 encoded elementary video stream) then I can take these into the authoring program and build my DVD.

Generally, stereo ac-3 runs at about 200Kb/sec; I run my 2/2 Dolby Digital audio at 320Kb/sec. A 5.1 file would probably need a bitrate around 400Kb/sec. You look at the total running time of your DVD, then use the following formula:

overall bitrate = 600 / minutes

so if you have a 90 minute video, your overal bitrate has to be 6.67Mb/sec in order to fit on a DVD-5 disk. Subtract from that your audio bitrate (say, .4Mb/sec) and you’re left with 6.27Mb/sec as your average video bitrate for your MPEG2 encoder. I would use min=0, avg=6.27, max=9.

Hope this helps.

[Riredale]

If you’re curious about DVD burn quality, just download a tool such as the free Nero DVD/CD Speed. This program analyzes the information on a DVD and can show the error rate at different places on the disk.

Keep in mind that every DVD throws out lots of errors, just because of the nature of the process. Correspondingly, the DVD standard includes a remarkable degree of error-correction on multiple levels, so that even a disk with many errors will deliver a perfectly accurate final result. With the Nero tool you can see for yourself just how many errors there are. I agree that Taio Yuden disks are about as good as DVD-R gets.

BTW I always record at 8x. There’s nothing to be gained by recording slower, and you lose time.

[Riredale]

I have found that even if there is a DVD that won’t play properly in a DVD player, I can make a clean copy that will play. I think the reason is because the reading software on a PC is much more aggressive in getting the data off the disk, and will slow the drive down and read the disk multiple times until it’s satisfied. Once you have a clean copy of the VIDEO_TS folder, you can burn clean new copies.