DIY Audio Test DVD - Page 4

We are in the home stretch.

I just burned the first completed beta disk.

Now I have to go through and make sure everything is in the right place, and is at the right SPL. This will take a few more ( wifeless ) days. Then all I have to do is fix the errors (with several hundred options there is bound to be a few) and render the final cut.

Two weeks maybe?

I might need to go ahead and hit up swithey.

This is why it is taking so long.

The beta disk worked fine on my computer last night. I get home today ready to toss it into the DVD player, and it doesn't work. There is no way to get to the menu. It just starts off with a 20-200hz FL sweep, you can skip through about 8 other tests and that is it.

I went through and double checked all the settings and tweaked a few, and I'm in the process of burning another right now.

Wonderful.

Hope I screwed the burn up last night, and haven't found another menu limit.

It is confirmed. I hit another limit.

I'm going to have to go back to the 2.0 side and cut some menu levels to make room for all the rest of the 5.1 goodies.

The good news is I found another way to add the stereo stuff, so I'll only have to cut menu levels not content. The bad is that this pushes the completion date out again.


One thing I haven't asked about yet, DD levels. Avia and DVE are encoded with a -27db dialnorm setting. This means -20db from the DVD should play as 81db not 85db. This also means that DTS and non(+4)dialnorm DD DVDs are 4db hot. (109db peaks)

I have encoded everything at -31db (dialnorm off/+4), so that -20db is 85db and 0db is 105db.

This is the way I want it. If any of you would prefer a -27 dialnorm option let me know. ASAP

ETA? I'd rather not stick my foot in my mouth again.

Dialnorm? Hmmm...
Dialogue Normalization, Dynamic Range Control, and Downmixing are all separate DD metadata influenced parameters. They can influence one another, but Dialnorm is not effected by anything else. When engaging a Downmix DRC is affected, but not Dialnorm.

Dialnorm is supposed to be used normalize average volume from program to program. In movies this is mostly the dialogue, in say broadcast TV it is the average A-weighted loudness. IE, the loudness of people talking on a DD track in Click should be the same as Half Baked, or an HD NFL game. (notice the highlighted words.)

Dialnorm is indicated by a number from -31db to 0db at the encoder level. This number is chosen by where the average levels are at on a sound track. Bare with me a minute. Now the highest "volume" coded on a DD track is 0db. When played on say, the center channel you should get 105db on an SPL meter at your seat. This means -31db on the track plays back at 74db. A disk with a dialnorm of -31db has nothing done to it. (the ARV will say +4db, I'll get to this in a minute.) Now lets say you have a track with a normalized level of -21db. The DD decoder (AVR) will "turn down" everything by -10db to match the loudness to the chosen -31db level.

Now Dolby set the the default levels for home equipment as -27db. This is why you get +4db on you AVR with a -31db dialnorm, and nothing indicated at -27db. They wanted the option of boosting a track if one needed it. This is going to screw a few brains, but nothing is being done to the signal when it says +4db, and at anything other than than that the volume is being decreased. This is why it is said that DTS is 4db hotter than DD. It really isn't. Most DD disks are just retarded a few dbs by default.

This is why I am going with -31db. This will set the correct max setting for DD and DTS. It's really no big deal, just preference.

Disclaimer-This is not gospel, just something I threw together off the top of my head at work. Check out Dolbys site for the real run down.

I'm really sorry this is taking way longer than expected.

Every time I make headway, I have to go backwards are do it all over again. Between work and the wife's "you spend to much time on the computer" kick the last few months my actual window to work on the project has really almost closed.

That said, I do have an almost completed demo going now. The problem last month was that I have had to go back and pretty much start over. I had to change the default DVD disk audio codec, and redo how the 2.0 side accessed it's audio to get everything to work together on a stand alone DVD player. (It works great on any computer, but nothing else will play it correctly as it was.) Unfortunately this means that all the audio is now trans coding to the wrong levels. It doesn't make sense and shouldn't be happening, but it is. I am now going back through the waves and tweaking them to the same levels across the entire disk with the ac3 files as the base. Once I get the samples on the demo correct all that is left is correcting all the other waves and inserting them back into their correct places.

Once again, I'm very sorry for the wait. I really wanted to be done in Jan. Now March has shown up.

As insane as this sounds it is exactly correct.

A couple of years ago I would have laughed this off as a joke. I few years married is a real eye opener. The funny thing is you can never convince them that there is no competition between them and whatever it is at the moment.

Update

OK, as of right now my wife has a buisness trip scheduled starting on March 19th lasting 20 days. This means I get unlimited computer time, and this project is first on the list.