[Dvdauthor-users] Re: DVD authoring for teaching

[<nt...@ia...>]

> From: "Cyrus Patel" <cy...@fb...>
> Organization: Johannes Gutenberg Universitaet
> To: dvd...@li...
> Date: Thu, 29 Apr 2004 18:21:24 +0200
> CC: nt...@ia...
> Subject: [Dvdauthor-users] Re: DVD authoring for teaching
> 
> On 28 Apr 2004 at 12:17, dvd...@li...urceforge wrote:
> 
> > 1) The end users are comfortable on the Windows platform, so Windows
> > executables would be desirable.
> 
> define "comfortable". If they have enough savvy to use command 
> line tools, then dvdauthor will fit the bill just fine.
> 
Thanks for your feedback. They are not comfortable with command line tools, so I'll have
to setup the command line parameters for them.

> > 2) Bookmark and classify the raw video material.
> 
> you're beginning to sound like a powerpoint presentation. :)
> 
> > (list of files with in and out points and possibly
> > classification code(s) and descriptions)
> 
> thats better. :)
> 
> If I understand you correctly, what you want to do is build a 
> "storyboard". That is something you do on paper, or on a drawing 
> board. That way you have an overall picture of the whole project, 
> and can focus on individual snippets as needed and still not lose
> the overview.
> 
> Put each "scene" (as a screenshot for instance, but text will do too)
> on one sheet of paper. Hang the sheets up in the order that they will
> appear. "Walk" the film by describing each scene out loud to your 
> students. Voila! you are now a director. :)
> 
Thanks for your feedback. 

> > 3) Using step 2 (list of files with in and out points and possibly
> > classification code(s) and descriptions) create a DVD with menus. 
> 
> You already know how to make how to make titles only, and I won't
> go into menu creation here, as that has been amply covered in the
> examples linked from the dvdauthor home page.

Yes, I have seen some examples. My requirement is actually much simpler, but doesn't seem
to be covered with the standard tools. I would like to generate a menu structure from a
text file, containing the descriptions of the buttons. Generating each image by a bitmap
editor would be simply too time consuming. What tools are available to do this?

> 
> > I have the following additional questions:
> > 
> > a) What tools are available to automatically generate a set of menus
> > based on the classifications in step 2)? 
> 
> dvdauthor is not just a single program. It is a whole suite, and 
> includes tools for menu generation. ie, 'spumux'.
> 
> > A basic tool to generate menu items from a text file should be
> > sufficient (the material would be used for teaching purposes so 
> > the 'look' is not that important), 
> 
> dvdauthor/spumux do not place any limits on how fancy your 
> menu(s) _can_ be. 
> 
> How fancy they are is entirely up to you and the features of your
> favourite bitmap/picture editor.
Thanks for your feedback. 

> 
> > it is necessary to be able to logically restructure the menu buttons
> > according to the classifications in step 2. So it would be useful to
> > be able to specify on what page a specific menu item should be placed.
> 
> dvdauthor/spumux do not dictate structure. How you organize things is 
> up to you.
> 
Thanks for your feedback. 


> > Is it perhaps possible to hide a button visually using DVDAUTHOR? 
> 
> of course. :)  A "hidden" button is nothing but a button that is 
> transparent when in a "not selected" state, and something else (eg 
> the 4-color image of a fish as in "finding nemo") when in the 
> "highlighted"/"selected" state.
> 
Thanks for your feedback. 


> > The menu structure for my application basically corresponds to a
> > two dimensional grid (where the user can select say a row and then
> > play all the columns, or vice versa). However, for each element in
> > the grid there would be more than one version to play. 
> 
> > So presumably one would have to generate a menu for each of the
> > possible versions? 
> 
> Well, that depends on what decides which "version" to play. 
> 
Thanks for your feedback. Not sure if I understand correctly, but I can think of two
possibilities:

i) Generate a separate menu page (with buttons for each version of the file) for each
element in the two dimensional grid that is used. Link this to the main menu.
ii) Add buttons on the main menu for each version (possibly in different font/color). The
limitation of 32 buttons on a page means that one would have to do some preprocessing to
fit the required number of items on a page.


> > It would be desirable if one could easily navigate to closely
> > related entries in the grid (corresponding to hyperlinks in a web
> > page). 
> 
> Umm. The DVD specification was not designed for what (I think) you 
> have in mind. For instance, a) menus can only at most 32 buttons. 
> There are also limits on how many titles/titlesets you can have. 
> 
Thanks for your feedback. 

> > b) To change the play order it is possible to use cell commands in
> > different PGC's 
> 
> dvdauthor currently does not support cell commands.
> 
That is a pity!

> > c) As regard user interaction with a DVD, I assume something like list
> > boxes and combo boxes are not (directly) available? 
> 
> I think its time to clarify what a DVD menu is: 
> 
> A DVD menu is just a _picture_ (or a series of pictures == film). 
> The "buttons" are simply other bitmaps/pictures overlaid on it. In 
> fact, _everything_ you see on a DVD is a picture - even subtitles.
> 
> But if you really, Really, REALLY wanted to, you could make something 
> that /looked/ like a list box. Take a screen capture, and play with 
> that in your bitmap/photo editor to see what it would look like.
> 
Thanks for your feedback. I suppose one would have to make a separate bitmap for each
state of the list box or combo box? Would it be possible to generate XML code for
DVDAUTHOR to do this automatically?

> > I realize that a DVD player cannot hope to emulate the sophisticated 
> > indexing / search functions available on a computer, but still
> > wonder what is (in principle) possible today?
> 
> A DVD Player _is_ a computer. Not a general purpose one that you are 
> using to read this message with, but a highly sophisticated 
> specialized one, that does one thing only, and does it very, very 
> well - much, much better than your desktop computer ever will. :)
> 
> It is designed to be cheap, fast, robust, user-friendly, quiet,  
> crash-proof, look good, and not need oodles of memory or Mhz. 
> And like your desktop computer, it was not designed to wash your 
> clothes, start your car, make cellphone calls, and all the other 
> things that other specialized computers are designed for.
> 
Thanks for your feedback. As a DVD remote only have numeric keys (and not a alphanumeric
keyboard), it would seem to limit the search capabilities compared to a regular computer?

> > d) Is it possible to update the index .IFO files on the DVD after
> > writing? 
> 
> Did you mean "patch" when you said "update"? If so, yes (not once its 
> on a -ROM of course) as long as the file's length does not change.
> 
> Incidentally,... DVD players do not even "see"/use the .IFO/.VOB/.BUP 
> "files"/filenames. They are all purely sector based, which is why all
> DVD "files" as you see them on a desktop computer are an even 
> multiple of 2048 bytes long.
> 
Yes, but surely it has to read the menu definitions from somewhere? I have played with
IFOEDIT and it seems as though the DVD uses absolute sector values (determined from the
IFO files) to jump to the correct places? Otherwise one could simply delete the
IFO/.VOB/.BUP files without changing playback.

> > After using the DVD t is likely that new 'Play orders' would
> > be generated. Updating the DVD with just the index files would then be
> > useful (prerably on recordable DVD material instead of rewritable
> > DVD).
> 
> Its not impossible, but there are no (semi-)automated tools to 
> help you do that. If you're not afraid of learning by trial and 
> error, even if that involves making quite a few unplayable DVDs 
> in the process, take a look at 'IFOEdit'.
> 
In my application the .VOB files would likely stay the same, but the .IFO/.BUP files would
change. Would it be possible to compute and adjust the new locations in the new .IFO file,
based on the contents of a previous DVD?


> > e) Is it possible to cut out unwanted video material from the DVD
> > (based on step 2)? As far as I know DVDAUTHOR does not at present have
> > provision to specify an in and out point in a MPEG file?
> 
> Logically cut, yes. Use the <cell start="xxx" end="xxx" /> sequence. 
Thanks for your feedback. However, if I understand correctly the <cell start="xxx"
end="xxx" /> sequence would place a copy of the entire file on the DVD (and not cut out
just the desired portions of the video)?



> Physically cut, no. dvdauthor is entirely non-destructive. :)
> Do physical cutting using a GOP-level cutter or the mpeg tools 
> built into 'Tmpgenc'.
> 
Thanks for your feedback. I have used the mpeg tools built into 'Tmpgenc', but find the
GUI cumbersome. Is there a tool available that can cut/join MPEG/VOB files using command
line parameters (preferably with a Windows executable)?



> > f) Is there a tool available that can allow easy editing of an
> > existing DVD? The user should be able to extract any 'Chapter' or
> > 'cell' easily from the DVD (preferably using the existing menu
> > structure). 
> 
> This can be done with the individual pgcs. See 'dvdshrink' and reauthor 
> mode. 
> 
Thanks for your feedback, I'll have a look. 

> Using the existing menu "structure" is not possible, because, as I said 
> before, the menus are _pictures_, and as such are not machine 
> interpretable.
> 
Thanks for your feedback. I was thinking more in the line of importing the existing menus
(after modification to add a few buttons) in DVDAUTHOR and then reauthoring the DVD.

> > g) Is it possible to 'merge' an existing DVD with a DVD authored by
> > DVDAUTHOR (reauthoring)? The idea would be to use the menus from an
> > existing DVD and add extra menus and functionality using DVDAUTHOR?
> 
> Yes. 
> 
> Step 1. Extract the menus from the existing DVD as mpegs - For 
> example, use 'dvdshrink' reauthor mode to extract the menus as
> individual titles (one .VOB file per menu).
> 
> Step 2. Then run the entire set (beginning with VIDEO_TS.IFO) 
> through dvdunauthor in order to generate a new set of .VOB files 
> that include palette information.
> 
> Step 3. Those second set of .VOB files can be used in the <vob 
> file=xxx> statements in dvdauthor. Determining which button on screen 
> goes with with which <button>...commands...</button> in the xml can 
> be done either using trial-and-error, or by "disassembling" the .VOB 
> with spuunmux.
> 
Thanks for your feedback. Where can I find documentation on dvdunauthor?

> > Best regards,
> > Theo
> 
> All the best with your venture. :)
> 
Thanks for all your feedback and help!

> 
> ---------------------------------------------
> * Windows NT:  No Thanks; Not Trusted, Not Today, Not Tomorrow.
> 
> 
> 
> 
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