Multi-Angle/Seamless Branch Scenario

[bkm]

Hi everyone, first post here.

I'm about to embark on a creative project for a client but I need to make sure it's even possible to accomplish on available authoring systems - before I do.

I've been reading through many forums and articles on this and many other sites, but rather than answering my questions, it's simply raised more - and now I am more confused than ever - I guess I am bigger newb that I thought ! :o

I know true seamless branching is not available to us budding enthusiasts, so I am not going to ask the question that's been asked a hundred times already. *grin*

However - I was wondering if my scenario is still possible using other techniques which are available to us. As I currently understand, seamless multi-angle can have unique audio for each angle, yeah? I could be wrong...

Anyway, this is my scenario - if someone with the right knowledge could tell me whether or not its technically possible - even with a simple yes or no, it would be greatly appreciated !!!

Scenario:

A PGC plays through, at points it can randomly split onto different paths (each with individual audio and video). These seperate paths can be of equal length if they have to be. These random paths then all migrate back onto the original path. Later on the PGC, this same random choice of another 3 paths is available, which all eventually lead back onto the original path. Here is a diagram that illustrates my scenario:

http://csusap.csu.edu.au/~bmorto03/Creative%20Portfolio/diagram.PNG

So for example, one play through of the PGC could be:

A > B1 > C > D3 > E , whilst another could be A > B2 > C > D1 > E, all seamlessly.

So .... I would love a definitive, conclusive answer. Can it be done?

[mpucoder]

Well, sort of. It's the random part that makes this problematic. In order to playback seamlessly there can be no cell commands, and, therefore, only one path through the video for the PGC. That gives you two choices, either make a PGC for every combination of paths and choose the PGC randomly at the beginning for seamless playback, or make the random choices via cell commands and endure a slight pause in playback.

As for the multiplexing, angles which have different audio or subpictures are called non-seamless even though they playback seamlessly. Here the non-seamless refers to the ability to change angles. It's a small distinction, but important when choosing the authoring program. "Angles" with different playback durations are called stories, and very few authoring programs can do this. The cheapest (atm) that I am aware of is Trai Forrester's DvdAfterEdit (http://www.dvdafteredit.com/), which runs on Mac's only and requires already authored material.

[bkm]

:thanks:

Thanks for the reply. I guess I can create every permutation of paths, there is a fair bit of content but it's possible on a dual layer disc. However - just need to clarify - about the 'random' functionality of selecting a PGC:

... and choose the PGC randomly at the beginning for seamless playback,


By this do you mean I can simply fashion a single button on a menu, and when the user activates it can randomly pick one of the PGCs to play? Because this is ideally what the client wants, the user is not supposed to have control over the content they see, more or less its supposed to be 'random' and 'fresh'.

[Zeul]

set one of the gprm registers to random value. You specify the value range in the command.
For example in the FirstPlay PGC set the GPRM0 to any value between 1 and 3:

rnd GPRM0,3

Now if you were to create each 'path' as a different title then also in the FirstPlay PGC you set a jumpto title command with a conditional compare:

rnd GPRM0, 3
If ( GPRM0 == 1 ) JumpTT VTS1_Title1
If ( GPRM0 == 2 ) JumpTT VTS1_Title2
If ( GPRM0 == 3 ) JumpTT VTS1_Title3

[bkm]

Excellent. I didn't really know much about command sequences, but now I've read up on them - can anyone say 'newb'. Thanks for the advice guys!

I have one final question if you could help me out. Having to author every permutation of the above scenario will be more detrimental to size and quality than I initially thought, so I have in the meantime thought of a different logic to achieve the scenario that eliminates the repetition of content, this time using playlists.

Instead of multiple PGCs - each an inidividual pathway of the scenario, can it be achieved by placing all the content sequentially on a single PGC, with a logical playlist selecting the appropiate chapters for playback?

Working with the same scenario above, a diagram showing the new logic would be:

http://csusap.csu.edu.au/~bmorto03/Creative%20Portfolio/diagram2.PNG

So, possible chapter playlists are:

1 > 2 > 5 > 6 > 9
1 > 4 > 5 > 7 > 9

etc.

So I guess the new question I am asking is, will the above playlists (and the other logical possibilities) play seamlessly ? As I currently understand, if a playlist simply advances linearly, but not necessarily consecutively - it will be seamless ?

[DaRat]

Well, sort of. It's the random part that makes this problematic. In order to playback seamlessly there can be no cell commands, and, therefore, only one path through the video for the PGC. That gives you two choices, either make a PGC for every combination of paths and choose the PGC randomly at the beginning for seamless playback, or make the random choices via cell commands and endure a slight pause in playback.
Is it possible to go around this with a invisible, 1 gop long auto action BoV?

[dgoodbourn]

Is it possible to go around this with a invisible, 1 gop long auto action BoV?
Yeah, why not have two BoV. One to set the random value to a GP, and the second to change the streams by the GP. This is all good and works great except I've come accross 1 player that doesn't initiate the auto action button. But apart from that player, it works a treat.

D.