dvdauthor: auto-skip chapters?

[Dan203]

I'm trying to figure out if there is a way to setup a dvdauthor XML file in such a way that it automatically skips specific chapters assigned to a single file. Specifically I'd like to take an MPEG2 file captured from live TV and mark the commercials with chapters which are then automatically skipped during playback.

I know that you can put a jump command in the <post> tags but what I'm not sure is whether or not the commands in <post> are called after every chapter or only after the complete file has finished. If it's called after every chapter then I should be able to accomplish what I want by using a little script to skip every other chapter.

Dan

[setarip_old]

Hi!

May I ask why you don't simply edit out the commercials from your MPEG-2 captured file, before converting to DVD format?

[Dan203]

I knew someone was going to ask that. :) I should have explained better. What I'm doing is writing a simple DVD creation program around dvdauthor. I don't have the skills to write an actual MPEG editor, but I thought I might be able to offer rudamentry "editing" capability by simply hiding the commercials in "auto-skip" chapters. I know there are standalone DVD recorders that use this trick to allow editing on DVD+RW disks, but I'm not sure if it's something that can be done in dvdauthor or not.

I know the easiest way to find out is probably just to give it a try and see what it does, but I wont have time to actually do that for a couple of days so I thought I'd ask to see if maybe someone else already knew if this was possible or not.

Dan

[mpucoder]

I'm reluctant to answer since you did ask specifically about dvdauthor, and I am not very familiar with it. But this can be done with Scenarist, DVDMaestro, and MuxMan. Make a cell out of each commercial break that is not included in the PGC for the movie. This will, of course, be non-seamless and pause for up to a second on many players.
Version 0.17 of MuxMan has the ability to perform linear editing on the source files, meaning you can string together portions of the source files to make a seamless title containing only the program material. (see the Start and Run Length statements here (http://www.mpucoder.com/Muxman/mxp/vidstrm.html) and here (http://www.mpucoder.com/Muxman/mxp/audstrm.html) )

[Dan203]

Thank you. Your information pointed me in the right direction and lead me to the answer. For anyone else who may have been interested in doing this you have to use the dvdauthor <cell> tag which is almost completely undocumented. Here is an example...


<pgc>
<vob file="video1.mpg">
<cell start="00:00:18.15" end="00:05:46.15" chapter="1"/>
<cell start="00:10:17.15" end="00:17:51.00" chapter="1"/>
</vob>
<post>jump title 1;</post>
</pgc>


This will cause the DVD player to only play the video segments outlined in the <cell> tags.

Dan

[Dan203]

I was just playing with this a little more and I discovered that the cell points are not frame accurate, so using this for editing is not 100%. I think it works well enough for my purposes, but I think I'll also add a blurb to my program suggesting people use VideoReDo to edit the content first if they want more accurate edits.

Dan