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In Reply to: Re: that has to do with limited disc space as both the DVD and CD layers are thinner so they can fit in regular CD playe posted by jimby on October 25, 2004 at 21:10:45:
Jimby:Let's take Diana Krall's The Girl in the Other Room>, which has a running time of 55:33.
Using Meridian's MLP project calculator, I come up with 4GB for audio content assuming 24/96K Six-Channel and dedicated 24/96K Stereo tracks. Including the bare minimum for backwards compatibility for DVD-Video, a DD track (5.1 @ 448 kbits/second) still gives us about 500MB for video extras. Adding a DTS track does put you over the top, but IMO it's pointless to include both.
So either there are more than 500Mbytes of video extras, or you're encoding with DD and DTS. Why not a little less on the video side (I notice now there are 3 videos included) for a better sonic experience?
Follow Ups:
Well John,A couple of points:
1. Regarding your MLP estimates, it's obvious that you have never made a DVDA title before if you think you can produce a title based on the best estimates of that tool. :) The truth is that MLP compression is entirely dependent on music content and will vary significantly from title to title. We always start off planning a disc with the highest sample/rate bit-depth we have, but many times we get a call from our authoring engineers about audio that won't compress well and won't fit on the disc. This is exactly what happened on the Diana Krall disc.
2. Dual Disc is marketed as having a lot of extra video content in addition to surround sound. Cutting videos is not an option, and the space that would be gained is usually not significant enough to make a huge difference.
3. The major limit in capacity is not caused by videos or graphics, but by the fact that we are limited to a DVD5.
4. You forgot to figure in the disc overhead, catalog, and menus in your math.
5. Making a disc is NOT like a jigsaw puzzle where you get to move pieces around all day to see what is the best fit. We don't have that luxury. For example, solicitation sheets have to be created far in advance of release for retailers in which the content is locked down. And believe it or not, the artist frequently has a say in what content goes on the disc. Imagine that.
I hope you can answer.From little scraps of information I found the following:
That DualDisc is a trademark of the RIAA.
and that the DualDisc trademark seems free of licensing issues other than the license issues related to the actual content.Is this correct?
Jimby:1. Regarding your MLP estimates, it's obvious that you have never made a DVDA title before if you think you can produce a title based on the best estimates of that tool. :) The truth is that MLP compression is entirely dependent on music content and will vary significantly from title to title. We always start off planning a disc with the highest sample/rate bit-depth we have, but many times we get a call from our authoring engineers about audio that won't compress well and won't fit on the disc. This is exactly what happened on the Diana Krall disc.
Based on the values, I seem to be using the same estimate tool Christine used elsewhere for a 60 minute title. Any content going through any lossless compression algorithm (music, text, programs (binary data)) will have compression variations, but you can get quite good estimates of compression based on the material being fed to the compression tool.
When the disc comes out, it's going to be interesting to see what amount of space is being used up by which portions of the title. I would prefer that video take a back seat to audio on what is primarily an audio product to this consumer.
I did a test of some titles vs. the calculator and was surprised to find that the Three Doors Down title was the least accurate (within 10%). A couple of Diana Krall titles were .1 and .2 GB off (within 5%), and a Steely Dan title was also .2GB off (also within 5%).
IMO, these aren't terrible margins of error given the somewhat unpredictable nature of the material.
2. Dual Disc is marketed as having a lot of extra video content in addition to surround sound. Cutting videos is not an option, and the space that would be gained is usually not significant enough to make a huge difference.Where has DualDisc been marketed at? Nowhere that I've seen. Maybe that's how the product is going to be marketed, but to date there hasn't been any marketing to speak of for a format that is literally just getting off the ground.
3. The major limit in capacity is not caused by videos or graphics, but by the fact that we are limited to a DVD5.
We'll assume you're going for good video quality, with a 6 Mbits/second average rate. That translates to about 50 Megabytes of storage per minute. At 15 minutes of content, you've just chewed up 750MB of space. So yes, video inclusion does in fact limit available space for audio. Everything on the disc is competing for the available bits. The proof will be in the content -- seeing what average bit rate is dedicated to video, and video content sizes.
It's disappointing to me, as generally speaking the Universal discs have been of very high quality and I'm looking forward to some of these titles in High Resolution PCM.
4. You forgot to figure in the disc overhead, catalog, and menus in your math.
Speaking of strictly non AOB content, it's less than 50 MB per disc, and the Meridian calculater was very close (5% error) on 5 of the 6 titles I used from my collection.
5. Making a disc is NOT like a jigsaw puzzle where you get to move pieces around all day to see what is the best fit. We don't have that luxury. For example, solicitation sheets have to be created far in advance of release for retailers in which the content is locked down. And believe it or not, the artist frequently has a say in what content goes on the disc. Imagine that.
Content is a seperate issue from sampling rates that are provided in the final product. As a consumer, why shouldn't I prefer audio as a higher priority than video?
I don't see an extra days (or even weeks) worth of effort as being that big a deal if it makes a noticable impact on the delivered quality. It's not like we haven't seen titles pushed back for weeks or months in the past.
... you did it very well.i agree totally with your comment that many people don't fully appreciate the overheads, compromises and limitations that need to be taken in account when authoring a disc and releasing a title.
for what it's worth, i for one am glad that universal seems to be the only label that appears to be committed to both formats and you guys are doing a great job with the titles. keep 'em coming! i'll keep buying, as long as my wallet can hold out :-)
given the limitations of DVD-5 and DualDisc, will you guys release fully featured dual layered DVD-As in addition to DualDiscs? some of us would gladly sacrifice CD playback for better content.
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