Seamless Branching DVD: what I need?

[SurfDrifter]

The only unusual attribute of our finished VOB will be that TFDVDEdit will have created and interleaved a small amount of material with Chapter 7 in PGC 1. The amount, as I described above, will be 10% of Chapter 7. Now this will be fairly negligible, however, you might care to look at all your chapters prior to removing one in the manner that I did, in order to choose the chapter which is shortest, and will thus require the least amount of filler for interleaving purposes.

OK, i understood what happens now with seamless branching and to clear things out, when I was asking about "distance", i was referring on how long can the laser jump without emptying the buffers.

Back to my question. The 10% is ALWAYS used from the omitted chapter/chapters? This means that even if there's a chapter with duration 1 sec, will use as a "stepping stone" a 3-frame sequence?
Will this be seen on my television screen? In your example, let's say that chap.7 was 2 minutes long, that means that i will have to see 12 seconds of the omitted chapter? I guess not, but i didn't understand how the "stepping stone" works.

You appear to be pretty creatively-minded, and that’s what this is all about!

I'll give you 2 ideas that i have compiled in my spare time, just for fun.

1) Create multi-angle DVD menu.

I had a subtitle menu that had two options. Subtitles ON and subtitles OFF.
The actual selections were on a sign just like the neon signs on motels. The word "Subtitles" was lit always and the one angle was with "ON" selection lit and the other angle was with "OFF" lit. So every time the user pressed the button "ON" or "OFF" the angle was changin, so as to have the menu "Seamless" without stopping the audio track running. Of course this was a "button-over-video" thing.

2) Stop users from removing P-UOP's!
Doom9's members will hate me!

Let's say you have a series of FBI warnings, logos,etc. that suck big time, but you want to MAKE SURE (...what a sadist!) that your audience will see it.

Place them all at one separate VTS set and start linking them, from the first to the last. Of course you'll have activated all P-UOP's. Now, the last track you want your audience to see, link it to a dummy PGC on VMG, so as to lead it wherever you want.

Now, here's the fun part! Create a Root Menu at the VTS you have all the logos that leads to a dead-end, probably to phrase saying:"P-UOP's removal not allowed!". Do the same on the Title Menu on VMG and prohibit title menu call on all VTS's and of course Root Menu call(and everything else) on the VTS with the logos.

This means that if the P-UOP's are activated, everyting will work fine, but if someone removes them and presses Root Menu on his remote to skip them, it will lead him to dead-end!

Of course, Root Menu calls can be made on other VTS's, but no Title Menu call(since it will lead to dead-end). I'm sure it can be done (to have title menu calls that work correctly from other VTS, besides the one with the logos), if authored with proper GPRM arguments, but i was bored to go that deep.

Even imaging a phrase saying that "Illegal attempt to copy DVD. DVD playback halted!". It's going to be fun...

Now, you're free to hate me!

[Arky]

Apologies for the delay in getting back to this, Surfdrifter. I've been away from home for the last 6 days and am now back to writing my articles, so between both of these factors, I've not had much time for the forum.

Originally posted by SurfDrifter
OK, i understood what happens now with seamless branching and to clear things out, when I was asking about "distance", i was referring on how long can the laser jump without emptying the buffers.

Well, with respect, from a practical standpoint, this is a bit of a moot point. The DVD spec does, of course, stipulate both a minimum and maximum jump distance, so that the consumption rate of the Decoder (Vo) remains satisfied. However, within this range there is room to maneouvre, subject to the number of streams comprising the interleaved section, and their respective bitrates, for example. Therefore, although the DVD spec parameters must, of course, be satisfied, when calculating appropriate jump distances, these jump distances will vary considerably depending on the scenario at hand (also note that spec parameters aside, in practice, other variables will affect how well a player copes with interleaved material, such as seek time and data transfer rate of the drive itself, and how much buffer memory the designer saw fit to include.) In short, yes, there are maximum and minimum limits on jump distance, but real world situations dictate different distances according to specific context. I am writing a technical article on this at the moment, so it is pointless going into extreme detail here and now. (this article should satiate those of you with a thirst for the low-level stuff, although this is not necessary in order to put TFDVDEdit's Seamless-Branching interleaving capabilities to practical use).

Originally posted by SurfDrifter

Back to my question. The 10% is ALWAYS used from the omitted chapter/chapters? This means that even if there's a chapter with duration 1 sec, will use as a "stepping stone" a 3-frame sequence?
Will this be seen on my television screen? In your example, let's say that chap.7 was 2 minutes long, that means that i will have to see 12 seconds of the omitted chapter? I guess not, but i didn't understand how the "stepping stone" works.

Ahh, no, sorry - I was covering so much ground previously that I was not explicit enough on this point. The 10% is actually drawn from outside of the boundaries of the scene removal - in other words (using my previous example for the sake of descriptive consistency), approximately half the 'stepping stone' material could be drawn from the end of Chapter 6, and half of it from the beginning of chapter 8. This would mean that these small 'encroached-upon' portions would be duplicated, and therefore that the Seamless-Branching points would be moved sideways accordingly, so as to encompass them (i.e. moved sideways such that the branching began at the end of the preceeding common material / at the beginning of the duplicated material, and ended at the end of the duplicated material / the beginning of the subsequent common material. Obviously, we would not want these new cell boundaries to be directly accessible using the 'Next' or 'Previous' chapter keys, so we would author the cells so that they did not constitute new PTTs in their own right - a very easy task to accomplish using TFDVDEdit's PGC map).

Now although all of this could be manually achieved by taking it into account during the NLE process, and during the subsequent DVD authoring process, it is another element to contend with which it would be nice not to have to. In a(nother) stroke of sheer genius, John Brisbin has automated even this task, such that the DVD author need never even bother to take it into consideration! Consequently, one need only author as normal - all cell boundary manipulation, for the purposes of encompassing adequate 'stepping stone' interleavable material from the existing surrounding material, is taken care of behind the scenes. In fact, in an effort to improve efficiency even further, this automated routine does not draw material from both sides of the removed scene gap. Instead, it simply creates only one new cell boundary, so as to encompass material preceding the scene removal. This new cell boundary is of course created in the way I described, so as to avoid constituting a new PTT in it's own right. You just have to see this operate to see how unbelievably cool it is!

And just to reassure you, the results of all of this is a perfect Seamless-Branching title, absolutely indistinguishable during playback from the output of the Panasonic or Toshiba systems. Incredible, but true.


Creative Suggestions:

1) Multi-Angle DVD menus are a nice idea, and are technically possible in theory. They can be authored, that is not in question. Certainly, it is possible to build Titles and move them out of their compiled VTS domain to another (VTSM or VMG, for example). As has been noted by certain (creatively-minded!) individuals (Dimmer and yourself, being 2 such examples on the Doom9 board), there is a theoretical workaround for achieving consistent audio where full colour embedded graphics / video need to change appearance from one state to another. Furthermore, the use of forced-action buttons is entirely legitimate for angle-switching. However, the question is one of player-compatibility. There has been discussion on this topic on Tully's DVD List in the past. I do not recall the exact post, but I believe someone mentioned that player compatibility might be reduced (presumably on the basis of first-hand experience, but I can't be certain until I dig it out again). I will go back and find this post and include the relevant details extremely soon (am not on my home PC at the moment and can't remember my auto-completed password!). This is not to say that I have given up on the idea at all. It's definitely something worthy of investigation. It's just that we are talking about such rare and creative techniques here, that many DVD player designers do not take them into account, even though they theoretically fall within legitimate DVD spec parameters. Note that we will also be testing seamless interleaving in the menu domains, but this is not the same challenge to a player as multiangle is. Both are interleaved, of course, but it is the notion of 'angle-changing' that may (or may not - I hope it doesn't!) confuse a certain proportion of players out there. Time will tell.


2) You're a sick man! lol.

In principle, I guess you could do what you suggest, but I think you would be lynched for it afterwards - We'd start seeing the emergence of 'De-SurfDrifter' routines in IFOedit and DVD Shrink, to put people out of their collective misery! BTW, were you aware that TFDVDEdit can adjust UOPs on a NavPack by NavPack level? It's an insane level of control (although, unlike your example, these could theoretically be removed by anyone with ripping software. My perspective on DVD, though, has always been one of creativity, rather than ripping, so this does not really concern me). Prohibiting and allowing UOPs on this microscopically incremental basis means that, for example, you can disable angle switching only at certain periods during playback of the angle block. The creative possibilities are just huge.

If you have any further questions, or you feel I have not satisfied your existing ones, then please let me know.

Kind regards,


Arky ;o)

[SurfDrifter]

You're a sick man! lol

Maybe, but imagine the potential! ( )

You could place REALLY HIDDEN extras there, that only fans of DVD's can discover, or maybe a simple hidden video, to serve as a watermark, since you'll be the only one to know that it exists.

Think about this idea.

In your extras menu, you place a button saying "Experts Section"
If the user selects it, it will lead him to a numerical pad, asking him to enter a 4-digit code. I bet you know how to make this thing work, so i won't explain how it would work.

The great fun would be, if you were saying that the code is hidden in a title or menu, that contains 1000 still images and ONE of them is the genuine code (with a riddle or sth). Everybody will start, ripping, demuxing the DVD, just to find the code. Well, at least for few days, because later the code will be posted in an easter-egg web site!

Or something similar, would be nice. The fun is to find interactive ways to make the end user have fun.

BTW, how you move a multiangle track from its compiled title to a Language Folder, so as to work as a menu?

BTW, were you aware that TFDVDEdit can adjust UOPs on a NavPack by NavPack level? It's an insane level of control (although, unlike your example, these could theoretically be removed by anyone with ripping software. My perspective on DVD, though, has always been one of creativity, rather than ripping, so this does not really concern me). Prohibiting and allowing UOPs on this microscopically incremental basis means that, for example, you can disable angle switching only at certain periods during playback of the angle block. The creative possibilities are just huge.

Now, on another subject...Yes, the creative possibilities are huge, but the creative possibilities of our customers are sth like...non-existent.

To put it simply, here in Greece the DVD is Stone Age. The "advanced"
customers ask for a "play all" when dealing with anime, but nothing more. Many come and say:"Just make it automatically play...Menus? What are these? Do you serve food here? Damn it man! I asked for a DVD, not a menu!"

Oh, and a little remark on the ...My perspective on DVD, though, has always been one of creativity, rather than ripping, so this does not really concern me.

I don't see any creativity, FORCING someone to see all the FBI logos, trailers, without being able to FF.
At least on VHS, you could FF this things. Besides, ONLY by existing in the DVD, serve their purpose. It's a legit thing to have an FBI warning. If the customer want to skip it, its his problem. If he copies it, he can't say to the court:"I FF the warning, so i didn't read it".

I ALWAYS leave my warnings and initial videos "unlocked", so as if the user presses Root or Title, to move directly to Main Menu.

And also don't forget that nowadays, people buy more and more movies due to collectability of the medium.
So, I don't to buy a "Widescreen Ultra Platinum Extended Superbit DVD Collector's Edition" and have several UNSKIPABLE trailers, logos, FBI warnings and EVERYTIME i insert the DVD, I'd have to watch them all from the beginning. Even when i put a movie late at night and fall asleep, the next time, i'll have to watch them all over again.

So, sometimes removing P-UOPS, it's very wise thing to do.
I bought "remote selector v.2.13", so as to remove P-UOPS "on-the-fly". It supports also Creative's DXR3, so it's even greater!

I, of course, agree with the creative part of your thought, but i can never accept, the fact that narrow-minded customers, want to abuse the power of DVD.

To tell you the truth, i might be "on the other side" now, but i started my adventure with DVD's with doom9.org! This site is responsible for my business career, so this means that some time ago, i was in the ripping scene...

[DaRat]

Hey! Nice topic, I have a few q's and comments if you guys don't mind. First Arky, why would your solution for a backward order pgc do it seamlessly. I just don't get it. Maybe because I'm a bit tired or my english is not good enough for this one. I was under the impression that the navigation stuff in the DSI packett can only point forward for the next chunk of data, so without duplicating the cells it still seems impossible for me. Or I missed something?

For the multi-angle menus I found the track buffer being the biggest problem. It plays whatever it has in it and then pick up the new angle data, so it results in a really poor response time (around 1 secs at least in my experience). It would be fun to make instant changes but for this you'd have to clear the buffer which can be accomplished only by doing a non-seamless stuff which would make this all pointless. Too bad.

On the creative part: also see the thread about menus w/animated subpics, it seems it _may be_ possible to do it but still did not had the time to make a test dvd and see how it works on standalones. If it could be accomplished it would mean a whole new way to make menus, just imagine...

Unortuantely there's no way to prevent clever people hacking your dvd apart, digging out the necesary info. With your copy protection all they have to do is set a single pre-command in the title/root menu linking to the real menu and remove protection stuff there. This goes for the code but it's possible to cause headache with this one if you put it in a video simply interleaved into the middle of the main movie. It would cost a good fortune to pick the correct nav pack to get the code not to mention the possibility to put in ALOT (and i mean ALOT, they won't take too much space) separate dummy pgc's there with unused menus and codes in them.

(edit: reminds, you could do this truly random, like multiplying a RND value by a counter's value which counts 'till the user press next, this would involve a shitload of work but it's pretty unpredictable except it's still possible to extract the content itself.)

Another creative thing is text screens with animated background. You can cut the space needed into 1/15. That's 15 pages of text for one motion menu which won't be too big since it should not contain any bright/colorful/fastmoving/etc object else the text would be hard to read. This is possible with acceptable response time (about 15 frames or 15/25th of a second <- pal land), I did a test for this also, it looks pretty cool, continuous video and audio for the text. The idea behind this is the same as it is behind the multi-angle: a subpics stream change won't make the action non-semaless.

Even another would be a truly seamless transition from one motiomn menu to other one. The idea behind this is to make a intro for the menu then loop about 12 frames forever (well, about 900 times, that roughly equals seven mins of menu ) using Violao's seamless menu looping guide then, after user interaction link to a outro but this seems pretty hard to do (if not impossible) since it involves either a jump (forward but it's still a jump) or a check at the end of the loop which would obviously make it non-semaless. Tough it's not clear what would happen if a player sees a command but get a seamless flag before that. This would be cool also.


Anyhow you're right Arky. It seems most ppl are into this only because the backup thing. It's sad to see how few ppl post here (adv dvd auth) nowdays.

[Arky]

Originally posted by DaRat
...Arky, why would your solution for a backward order pgc do it seamlessly. I just don't get it. Maybe because I'm a bit tired or my english is not good enough for this one. I was under the impression that the navigation stuff in the DSI packet can only point forward for the next chunk of data, so without duplicating the cells it still seems impossible for me. Or I missed something?

Ordinarily, a reverse-ordered PGC would of course result in non-seamless playback - that was why I was at pains to carefully describe a solution which would 'fool' the seamless-interleaving routines in TFDVDEdit into physically reordering the VOB so that it physically matches the desired order of cell playback, according to the PGC. Because the cell has been physically reordered, the playback is now truly seamless, and there is no significant duplication (save for the 10% caveat I described in detail) because, in the example I gave, the original forward-ordered PGC is no longer required.

Originally posted by DaRat

For the multi-angle menus I found the track buffer being the biggest problem. It plays whatever it has in it and then pick up the new angle data, so it results in a really poor response time (around 1 secs at least in my experience). It would be fun to make instant changes but for this you'd have to clear the buffer which can be accomplished only by doing a non-seamless stuff which would make this all pointless. Too bad.

Well, it's not perfect, but you can improve the angle-switching response time by shortening your GOP structure when you're choosing your MPEG encoding settings. Obviously, the manner in which the interleaved jump distances have been calculated is an important factor here, too, and some programs are better than others at calculating these (the Mixed Angle and Multi-Angle interleaving routines of Maestro and DVD SP are, arguably, not quite as well-implemented as those in Scenarist, for example (recall that I said there is a range of possible values in any given instance, not just one possible absolute value. Therefore, there is room for 'strategy' on the part of the programmer, hence differences in the end results, depending on who programmed the interleaving routines, even though each of the strategies may 'work' and be perfectly spec-compliant).

Originally posted by DaRat

On the creative part: also see the thread about menus w/animated subpics, it seems it _may be_ possible to do it but still did not had the time to make a test dvd and see how it works on standalones. If it could be accomplished it would mean a whole new way to make menus, just imagine...

Yes, it CAN be done. I personally witnessed Prof. Uli Plank do this at the TFDVDEdit stand at NAB. The procedure is actually quite logical, but I'm afraid I can't describe it here because it is part of the members section of the 'Edit website.

Originally posted by DaRat

Unfortunately there's no way to prevent clever people hacking your dvd apart

Yes, I quite agree. As I said before, though, my interests lie in the realm of creating new projects, rather than disassembling them (I get the impression you may have interpreted that previous remark as a 'dig' at you, or the wider ripping community, SurfDrifter, but that's not how I meant it. I simply meant that just because someone can disassemble something does not mean it is not legitimate to create it in the first place, and there are some great creative reasons for prohibiting UOPs. It's just that P-UOPs always get a bad rep because of Hollywood studios' unfortunate penchant for using them to force viewers into watching FBI warnings etc.).

Originally posted by DaRat

Another creative thing is text screens with animated background. You can cut the space needed into 1/15. That's 15 pages of text for one motion menu which won't be too big since it should not contain any bright/colorful/fastmoving/etc object else the text would be hard to read. This is possible with acceptable response time (about 15 frames or 15/25th of a second <- pal land), I did a test for this also, it looks pretty cool, continuous video and audio for the text. The idea behind this is the same as it is behind the multi-angle: a subpics stream change won't make the action non-seamless.

Yeah, that's a nice one. See here for a discussion on several ideas.

Originally posted by DaRat

Even another would be a truly seamless transition from one motion menu to other one. The idea behind this is to make a intro for the menu then loop about 12 frames forever (well, about 900 times, that roughly equals seven mins of menu ) using Violao's seamless menu looping guide then, after user interaction link to a outro but this seems pretty hard to do (if not impossible) since it involves either a jump (forward but it's still a jump) or a check at the end of the loop which would obviously make it non-seamless. Tough it's not clear what would happen if a player sees a command but get a seamless flag before that. This would be cool also.

Well, I don't see how you could jump from any (i.e. a random) point during playback of a motion asset and have the jump be seamless, regardless of whether you use interleaving or not. Unless I have misunderstood you, I think you are right - this doesn't seem possible.

Originally posted by DaRat

Anyhow you're right Arky. It seems most ppl are into this only because the backup thing. It's sad to see how few ppl post here (adv dvd auth) nowdays.

Well, I have learned a lot in DVD from Flexion and Doom9, for which I will always be thankful, and I hope I have given something back to fellow members, too, over the years. However, there does seem, perhaps, to be an even greater emphasis on ripping these days than there used to be. Don't misunderstand me - Fair Use is ok in my book, it's just a pity that there doesn't appear to be a larger proportion of people creatively authoring original material as well. However, it is the desire for creativity which led to this thread being started in the first place, so perhaps things aren't so bad...


John ;o)