PGCs with different audio bitrate

[iomagic]

Hi!

I was converting one multi-PGC DVD recently, and the main title had 12 PGCs, the main one had bitrate 448, but the others had 384, and one had 192. When I tried to add all this stuff into a Scenarist, it screamed at me VERY loud, that I was a major violator of the DVD specification and I should not even get close to the authoring until I learn simple things.

Well, I had to use BeSweet to decode all streams and reencode them with 384... But why did this happen?? I mean, is this really a violation of a spec, or not? If yes, how did these guys make this DVD at all?

Thanks!

[mpucoder]

Whether it is a violation or not depends on HOW it is authored. Audio with different attributes (bitrate, number of channels, language, etc) must be placed into different tracks in the title set. However each program is not required to use all tracks, so switching bitrates is simply a matter of changing track number as the PGC links into the next.
More than likely, though, the PGCs with different audio bitrates are not even related. One is the main movie (in DD5.1), and others are special features (in DD2.0).

[iomagic]

So, does it mean that instead of trying to get all tracks under one title, creating several PGC, I had to drag them under one VTS, creating several titles? I was using Smartripper, and it only reported several PGCs, but I don't know what was the exact hierarchy of the disc - so here are two questions:

1. What is the best way to analyze it?
2. Is it imprtant at all? Maybe it's OK to create several titles under one VTS instead of several PGCs under one title, and then IFOUpdate will still take care of that?!

Sorry, I'm doing my best to learn all that stuff, but unfortunately, all guides are more "do this, do that" instead of "this is how it works, so in this case you do this, in that case you do that". I mean, there is not much explanation of the reasons behind particular actions, so, naturally, any deviation of the source from what is described in a guide causes confusion.

[TRILIGHT]

Originally posted by iomagic
So, does it mean that instead of trying to get all tracks under one title, creating several PGC, I had to drag them under one VTS, creating several titles?

That's exactly what it means. You can see this if you open the IFO in IFOedit and look at the structure. Out to the right of the PGC listing, you should see something similar to this:

PGC_1 (program chain): [Title(TTN): 1] [01:58:06.27 / 30 fps] (Programs: 31) (Cells: 137) (uses VOB-IDs: 1,2)

That "title" listing shows what title the PGC falls under. Thus, allowing you to use the different audio types in the different sections like you're trying to do.

As for the guides, yes, it can be a bit daunting at first. There is a LOT of information out there and not all of it is necessarily "up-to-date" or the best to follow for a given project. They were not written as an "end all, be all" of how to do every project, branching out like a flowchart for every possible combination out there. It would require far too much time and effort to write something like then. Then, as soon as you did, I could guarantee you'd miss that one new thing out there and someone would say "why is that not in the guide??"

The idea behind the guides is to give everyone a "leg up" with knowledge we did not have ourselves when starting out. Believe me, if you think it's hard now, it used to be MUCH worse! The function of the guides is to provide a few examples and get people thinking for themselves, being creative, and asking intelligent questions. They were never intended as an "A to Z" book on how to do everything out there. The more you read and the more projects you try, the more you will learn from the process.

[3coola]

Hi,

I have the same problem.
VTS_01 has 4PGC
PGC1 has 1 audio stream (AC3, 2ch, 224kbit/s)
PGC2 has none audio
PGC3 has one AC3, 6ch 5.1, 384kbit/s and one DTS
PGC4 has none

There is no difference for me when dragging all PGC to one Title, or dragging all PGC's to different Titles. Scenarist still reports differences in bitrate and LFE channels between PGC1 and PCG3.

However I have encoded the 2 channel audio with Soft Encode so it matches, but how do I keep original audio as it is?

Regards,
Ola

p.s Trilight! Keep up the good work with the guides!

[TRILIGHT]

Thanks 3coola! I'm not sure but I think what you are referring to requires the use of "dummy files". Your audio may only be 2ch for something and the movie has like 6ch on stream 1 and Scenarist complains. What you would do is use a "dummy" audio file (just a few KB) that is actually just an extremely small 6ch audio file. You place that on the same stream 1 as in the movie. This is sort of a "workaround" to get the compile done.

The second trick is to edit your IFO in the final compilation. (This is after you do all the IFOupdate stuff) If the audio you are wanting to use from that PGC is in stream 4 or something, you simply copy that stream number into the stream 1 position and then change the others to "0". I posted something about this in reply to someone elses post recently. You can find the actual location of these stream numbers I'm referencing by going to the bottom of my multi PGC guide (http://dvdguides.trilight.net).

[iomagic]

Mmm... Not sure it's such a good solution though.

Well, for starters, I'm still puzzled how they force Scenarist to compile their project on the first place. But the secondary problem is that the original IFO file would have particular number of audio streams, and now it will all be different for all titles we have there. Does it mean that IfoUpdate will take care of all this mess? :) And along these lines, do I understand right that since we don't do our own navigation, but inherit it from the original IFO file, it does not really matter whether we have multiple PGCs or multiple titles, since they all will be just a chapter points in the VOB, and then the original title/pgc hierarchy will be preserved (meaning - I might compile several titles, but after IfoUpdate they will appear to be multiple PGCs) ??

[TRILIGHT]

Of course it's a good solution. I do it all the time. I would not have told you to do it if it didn't work. hehe ;) As for the rest of what you said, I'm not sure I follow you. If you create a title folder and drop something in it, it creates a PGC by design. By editing the resulting IFO in IFOedit and adjusting the stream numbers as I said, you can make any stream available (or NOT available) in a given PGC.

Also, don't assume Scenarist is the de facto standard for Hollywood. I highly doubt it in fact. Ever try to create Closed Captioning in Scenarist? It doesn't! ;) However, you'll find a number of DVD titles out there (Reservoir Dogs, The Ninth Gate, just to name a few) that have them in place of subs. Also, I highly doubt that WB authors their discs in such a convoluted manner in something like Scenarist on purpose. They must be using an in-house solution (or at least something other than Scenarist) to have all their DVD titles authored the way they do.

[3coola]

Ok, I have read about the dummys, and it works fine.
There is one problem though. I can't seem to create DTS
dummys with BeSliced? AC3 5.1 and AC3 2ch works fine.

Regards,
Ola

[TRILIGHT]

Yep. DTS encoding requires some rather expensive software from SurCode. Do you really have extras in the same VTS as a movie with DTS audio? I've not seen that yet. Usually the movie is in it's own VTS.

[3coola]

Hi,

I have 4 PGC's in VTS_01

PGC1:
1)video
2)AC3 2ch 224kbit/s

PGC2:
1)video

PGC3:
1)video
2)AC3 5.1 384kbit/s
3)DTS

PGC4:
still menu

If I have understood You correctly, I need to place PGC1 audio as audio stream number three, to avoid Scenarist checkin for different types of audio between the audios tracks in the PGC's.
To accomplish that, don't I have to place a AC3 5.1 dummy as audio 1 in PGC1, and also a DTS dummy as audio 2 in PGC1 ?!

Regards,
Ola

[TRILIGHT]

Yep, you got it.

[3coola]

Then I need the software from SurCode ... :-(
Thank's for helping me to clear things out!

Regards,
Ola

[3coola]

I got an idea !

Can someone post audio dummy files of different formats ...?!

/Ola

[auenf]

Originally posted by 3coola
Then I need the software from SurCode ... :-(
Thank's for helping me to clear things out!

Regards,
Ola

http://www.minnetonkaaudio.com/


SurCode DVD-DTS (surround software encoder) $1995


hope you've been saving your pennys

Enf...

[3coola]

That's ... not cheap!
ok, where is the open-source version? :mad:

/Ola

[auenf]

there isnt even a DTS -> Wav conversion program, so i doubt there is going to be a free DTS compression program ;)

Enf...

[DIggedy]

Why is there a need for dummy audio tracks when you can just use multiple VTS? Then you have no structural limitations.

[TRILIGHT]

The idea is to recreate the original DVD structure for a proper backup, DIggedy. As such, those PGC's must be a part of the same VTS in order to be reintegrated with the original menu, etc.

[DIggedy]

Oh ok... I normally just extract & recreate the menus so I can make the layout from scratch.

[TRILIGHT]

Originally posted by 3coola
Can someone post audio dummy files of different formats ...?!

Go to http://dvdguides.trilight.net and click on the "Tips and Tricks" I added. You'll see links for the most commonly used audio "dummy" files.

I am not in the habit of doing things like this so please don't "look a gift horse in the mouth" and start asking me for software. I will not give you software!!

(BTW...that last bit was directed at everyone, 3coola. Just a little "disclaimer")

Another "disclaimer" for anyone concerned... I created these files using silent WAV files. As original files, I am not violating any rules. They are my own files that I made from scratch and am willing to share.

[3coola]

Hi,

back in business. Tested my movie where audio dummys was required.
One 384kbit 5.1 and one 784kbit DTS dummy.
it worked just fine! (using Scenarist)

Thanks Trilight!

Regards,
Ola

[TRILIGHT]

You're welcome! Glad you found them useful. :) I use em all the time.