I-Frame MPEG-2 - how?

Neil Wilkes wrote on 8/26/2012, 9:06 AM
Is it possible to render just I-Frame MPEG-2 output in such a way that the resulting video size remains very, very small?
Here's the problem.
My main occupation is audio work, and we do a LOT of DVD-Audio authoring, with associated Video_TS for compatibility reasons.
Authoring the Video_TS requires a non abstraction layer tool or you get spec violations by the dozen. This leaves me with 2 options.
1 - Scenarist SD
2 - Media Chance Labs DVD-Lab Pro.
The problem with Scenarist is that you cannot create a seamless slideshow that also has song markers where the "video" is a single still per track.
The problem with DVD-Lab Pro is that it's timing sucks on Audio-Only titles, as it drifts along the timeline, and the longer the timeline the less of a match there is between the track markers you enter & reality.

The workaround is a low bitrate MPEG-2 file and Scenarist.
The problem is that a low bitrate video file still comes in at around 2500 to 3000 kbps for it to look any good, yet there are DVDA titles out there wherethe Video_TS has MPEG-2 for the album length at just a few tens of Mb for the video section.
I suspct this is done by using a single I-Frame for each song - how can I make this in Vegas, please?

Comments

john_dennis wrote on 8/26/2012, 2:25 PM
"I susp"

That's a looooooong group of pictures. Before spending a lot of time creating templates in Vegas Pro that may not be incompatible with the authoring software or the DVD-Audio specs, I would want to know for sure if that assumption is actually true.

If you can acquire one of these vobs, you could open it in VideoReDo. Under the View menu, select Display On-Screen Information. As you navigate through the video, one frame at a time, the I, P, and B frames will be displayed.
Paul Masters wrote on 8/26/2012, 3:16 PM
Hello:

I looked at DVDA for doing an audio DVD but used DVD LAB PRO because in many ways it was easier to do what I wanted.
Each selection is a play only that selection and each have a graphic with it.

It is easy to render each selection in Vegas. Set a marker at the start of each selection. Run a script to convert markers to regions (found in the scripts forum I think). Use the batch render script to do each region as a separate file.

In DVDA there are 2 ways to do that, but each has a number of limitations.

Each selection is a menu 'page' (cell).
The audio apparently can be any length. The image can be problematic. DVDA has two sizes, the one it shows initially and the 'original' size. If you can make the image to fit the screen, or be the size you want, than no problem. A PSD should work for the 'background'. Text can be added for the selection information.
As it is a 'menu' you can't fast forward / back and there is no way to have chapters.
I don't see anyway of having multiple images and even if there were, no way to align them to multiple audio selections.
The audio is rerendered. The only options are PCM stereo, AC3 stereo and AC3 5.1. I don't know if multi track PCM would be allowed or what the result would be.
You would need a button to return to the album menu and or main menu.
The end action of the page wold be to auto activate a button.
Compiling a project with the 'main menu' (one button to the next page) and the page with an image and AC3 5.1 audio of about 50 minutes, the folder is 86.9 M.

An audio compilation.
This can have an image. I don't know if multiple images per selection are allowed.
Fast forward / back is allowed. Still no chapters.
The audio is rerendered.
You can add a button 'on the video'.
Compiling as above with an audio compilation the folder is 86.6 M.

There is a 'slide show' called a video compilation.
Fast forward / back is allowed. No chapters.
The audio is not rendered, but the video is.
As the compiled folder is 1.43 G using the same audio and image as above, it appears to not provide the 'compact' video / image you (and I) are looking for.

There is an option in Vegas to set the frequency of I frames, but that would make the video file larger as far as I know. Also, you would still have to have the video the required length and thus take up a lot of space on the disc.
(From what I can tell, AVC puts I frames every 15 frames, but AVC is not allowed on a DVD.)

Hope this helps.

Paul Masters

FWIW... Using DVD LAB PRO, I got 207 selections in 20 albums for a length of 14 hours 34 minutes 27 seconds on 2 DVD. It would have fit on 1 by size but a DVD can only have 99 chapters.
musicvid10 wrote on 8/26/2012, 8:08 PM
"Is it possible to render just I-Frame MPEG-2 output in such a way that the resulting video size remains very, very small?"

I-frames or small files, pick one.

I-frames-only means no interframe compression, which is how MPEG-2 makes its files smaller.
;?)