Animated Menu

[chrisc0le]

Hi

I am trying to create an animated menu in scenarist
here's what i have done so far:

open the vid in after fx split at relevant point, export layered PSD file from the end of 1st part, generate menu layout in photoshop ( with grab as background ) and make a subpic layer.

So i have an Intro VTS ( with intro video )
Menu ( same as last frame of intro vid )
outro VTS ( outro from menu )

is this the best way to do it? the jump from intro vid to the menu makes a small stutter in the continuity.

Also i guess i could use an further vid for the menu background?
Could someone please offer some tips on this subject?

Any help would be greatly appreciated.

regards

Chris Cole

[Arky]

Hi Chris, first of all, welcome to Doom9 forums :)

Looking at your post, it appears that you have an excellent grasp of what is required to achieve the desired result. Realistically, it is almost(!) impossible to create a truly seamless transition, during playback, from menu to outro to Title video. This is a limitation of the DVD spec. Basically, the player buffer is inadequate to playback non-seamless content in a truly seamless manner. There are, however, some ways in which you can reduce the amount of pausing as you jump from asset to asset. None of these are an outright cure - they are simply ways of making the best of a bad situation, shaving milliseconds off the irritating pauses. Unfortunately, though, some are more expensive to implement than others (in terms of software required).

*The first thing to mention, which is easy to manipulate, is the bitrate of your animated video streams. Although it may sound strange, keeping the bitrate of your video as low as possible will reduce the effects of jumping between assets, because the buffer is not 'hit' so hard.

*Secondly, the media on which you distribute your project has a small effect on things. What I mean by this is that recordable DVDRs are less reflective than professionally-replicated stamped silver disks. This has the effect of making it harder for the player's laser to rapidly seek out the incoming asset. This adds to the latency between assets during playback (BTW, you should also note, as a side issue, that these two issues combine in a broader sense to make high bitrate DVDR projects playback less effectively than low bitrate stamped silver disks. Although you may not be aware of it, some Hollywood authors deliberately ensure that the bitrate is not overly-high at the layer break point on DVD9 projects, in order to minimise the inevitable pausing as the laser transitions from one layer to the next - some players pause more than others at the layer break point. Furthermore, the same consideration can be applied in situations where true seamless-branching is not available to the author (as is the case with Scenarist, if used on it's own), but must nonetheless be attempted. The lower the bitrate, the more chance the buffer has of 'coping' - and I use the term relatively!)

*DVDMaestro and DVD Studio Pro 2 (both essentially the same program) use advanced abstraction layers to hide the complexities of DVD navigation programing from DVD authors. This leads to rapid and greatly-simplified authoring workflows, but there is a tradeoff. These programs occasionally implement unecessarily convoluted navigation routines, rather than implementing the fastest and 'cleanest' navigation paths. This means that each time a jump is executed from one asset to another, the player has to look elsewhere, to read a script, or value, before actually seeking the intended asset. Of course, this must happen to some extent with any authoring system's projects, but Scenarist, for example, does not use such an abstraction layer, and creates more efficient projects as a consequence. Another related issue with DVDMaestro and DVD Studio Pro 2 is that the abstraction layer places all your menus in VTSM 1, rather than (more efficiently) placing each menu in the same domain as the asset to which it primarily refers (i.e. placing each menu within the most-relevant VTS domain). This also means that the laser must go to VTSM 1 to find the menu, and then leave VTSM 1 and find the desired VTS. Of course, you are already using Scenarist, so you are maximising yout chances as a consequence, but I just thought I'd mention all this in order to give you a fuller picture! :D You could, of course, use this knowledge to strive to organise your assets as close to each other as possible, domain-wise...


If you needed to address this issue with a project which you had received in a fully-authored state, and did not have the project file and assets for, I know of one program which could help you implement an alternative menu setup, based on the above recommendations (irrespective of the authoring program used), but it's high-end and would probably be too much of a stretch for you unless you are authoring professionally. From what I can gather, though, you are authoring from scratch anyway.


*Lastly, I would point out that you could possibly concatenate your intro stream with your main menu stream and then use Scenarist to set a loop point at the join, such that it would play right from the beginning during initial menu entry, and then, when it reached the end, loop back to the 'join', thus subsequently avoiding the intro portion. Obviously you need to ensure an I-frame is present at exactly that point or Scenarist will be forced to snap the loop point to the nearest I-frame (which would look really amateur). Unfortunately, you would also need to create a script to allow the player to sense if the intro had already been played once, so that if the viewer returned to the menu, they would not be forced to sit through the intro again. This issue can be seen on quite a number of Hollywood disks, and it's quite unacceptable at that level of authoring, when a simple script would have avoided it completely. Now the only reason I have suggested concatenating the intro with the main menu stream is that it removes one of the navigation jumps from the equation (although only on the initial menu viewing). It's not hard, but it takes a little effort for not a massive amount of gain. There again, if you really want to author like a pro, and go the extra mile to cut down on pauses, then it's one option.

I hope I've given you some pointers. I'm only sorry I can't give you a total cure. As I said, though, it's primarily a DVDspec issue (incidentally, the new High-definition DVD spec will not suffer from this issue because the player buffer has been greatly improved).

If you haven't already done so, you might care to briefly glance over this mini-tut (http://forum.doom9.org/showthread.php?threadid=25844) I did. You are already competent, so it won't teach you anything new, but it might perhaps get you thinking at a tangent (often how I get some of my creative ideas :D )


Arky ;o)

[chrisc0le]

Arky

Great thanks for your reply it was very informative.
I would like to follow the single stream option with the loop point and the script, as as you say this is the way the pro's do it and that is what i am striving to acheive.

Ok After a little playing i can get a clip to play, then the subpic appear at the point that the menu images appear on the vid stream assign a cell point and set the post behaviour to loop back to that cell point and loop.

You mention i-frame is this the GOP frame ie: every 15 frames ( i think )? if so i guess i need to do a small sum to work out the nearest frame divisable by 15 and start my menu anim then and also set as the cell loop point.

Just one thing i have no idea how to go about setting the script you talk about to detect if the intro part of the stream has played previously.

PS i have not sat down and read your guide yet so if it appears in there sorry for asking.

regards

Chris

[Arky]

Originally posted by chrisc0le


You mention i-frame is this the GOP frame ie: every 15 frames ( i think )?


Correct.

If your MPEG encoder does not support manual insertion of I-frames (& many don't), then you can create seperate segments and then concatenate them, since all encoders place an I-frame at the start of a segment. See the link I gave you for a more thorough description.


Regarding the appropriate scripting, take a look at this tutorial (http://www.tfdvdedit.com/public/79.cfm) by Ian Shepherd. Don't worry that you are using Scenarist instead of the two programs mentioned in the tutorial. Scenarist will take care of the necessary scripting very comfortably.

BTW, if you haven't already done so, you might find this related thread (http://forum.doom9.org/showthread.php?threadid=72964) on the subject interesting.



Arky ;o)