Looping video on menu

Videot wrote on 11/15/2004, 11:00 PM
On a scene selection menu I just choose a short scene of clouds which runs only for a few seconds & told this video to loop. I then added some audio which runs for for much longer than the video. I had hoped that the video would continue to loop as the music played but this isn't whats happening. The music plays until the end of the track & the video is seen only for a few seconds & then nothing but black. Can I get the video & audio to play continuosly until a scene is selected?

Comments

mbryant wrote on 11/16/2004, 4:36 AM
If you make the length of the audio same as the video, they will loop “together”. Or you could make your cloud scene longer, to match the length of the audio.

I don’t think there is any way to have your short video loop while the long audio plays (i.e. having the video loop separate from the audio).

Mark
ScottW wrote on 11/16/2004, 4:43 AM
I find it best to prepare my motion menus backgrounds in Vegas before bringing them into DVDA - this way I have fairly complete control over both the audio and video and how they interact.

For example, let's say I have 30 seconds of audio and a 5 second loopable video clip - I can place both on their respective timelines and then just drag the right hand side of the video clip until it lines up with the end of the audio.

The result I then render out as a DV AVI file (I don't usually render my motion menus to MPEG-2 since DVDA is going to recompress them anyway, so by starting with AVI I avoid some quality loss).

--Scott
Videot wrote on 11/16/2004, 5:18 AM
I was aware that I could create an event that had both the audio & video of the same length & use that. I would have thought that the loop idea had it worked would have at least achieved the same thing but at a much smaller file size.
ScottW wrote on 11/16/2004, 6:22 AM
No, it doesn't work like that.

When DVDA (or any authoring software for that matter) builds the project, the audio and video get multiplexed together into an MPEG-2 program stream. The stream is read by the player in a linear fashion - you can't say something like, "ok, stop reading the video information at this point and go back to this point in the stream, but continue to read the audio from this point forward" - if you think about the mechanics of how a DVD is physically read, this will make more sense - you'd be asking the player to read from 2 locations on the disk at the same time using a single laser.

In your case, DVDA was forced to multiplex a black video picture along with the audio where no video existed.

--Scott

JackW7 wrote on 11/16/2004, 8:29 AM
Scott, you say that DVDA will re-render an mpeg2 motion menu. Why is that if it is already dvd compliant? Doesn't it just leave all mpeg2 files that are already mpeg2 compliant?

Thanks,
ScottW wrote on 11/16/2004, 11:09 AM
When you add text, thumbnails (animated or otherwise), buttons, whatever, DVDA must create a composite video stream with all of that additional information. If you have a motion background that's MPEG-2, DVDA must first decompress the stream, create the composite and then re-compress the result.

Consequently it doesn't make any sense (at least to me) to render motion backgrounds from Vegas as MPEG-2.

Now, if you use an authoring application like DVDlab, then you don't have any choice but to render from Vegas as MPEG-2 (elementary stream), but that's because DVDLab doesn't have a built-in encoder, so you must literally build the menu yourself in something like Vegas and then DVDlab just places the various button masks into the final product.

--Scott