Audio encoding in TMPGenc DVD Author motion menu

[jeanl]

People,
I'm puzzled by something. I created a background video for my menu, with a still frame and MPEG1 audio. I can check using VobEdit that the audio is indeed MPEG-1 encoded.
When I used this as my background for my menus in TMPGenc DVD Author 1.6, everything worked fine, but I noticed that in the end, the menus that TMPGenc creates contain LPCM audio!!! I have 6 menus like that, each with 1m30s of audio, the resulting VOB file is over 500MB!!
I don't see any settings where you can ask for the audio in a motion menu to not be decoded and stored as PCM. In fact, I'm not sure how to instruct TMPGenc DVD Author to not re-encode my video or my audio.
2 questions:
- If I create a still MPEG2 with audio with DVD Shrink, I know that the result is a small vob that contains exactly 1 I-frame and a bunch of audio packs (MPEG). If I use this in TMPGenc DVD Author, will I end up with a completely reauthored VOB (with multiple I-frames?)
- Is there a way to control that? I.E. to make it so TMPGenc DVD Author does not mess with the original MPEG video? (in the menus).

Thanks for any pointers.
jeanl

[jeanl]

Well, I bit the bullet and wrote a tiny app that puts the audio into the original still menu instead of relying on TMPGenc DVD Author to do that.
I'm using muxman to create a VOB with an image and the ac3 audio I want in my menus, then I use the small app to insert that into the menu VOB. I finish with an IFOEdit mock strip (to update the pointers in the VOB and in the IFO) and a couple adjustments in PgcEdit (still time, 1 cell command to loop the menu, and adjustment to the PGC's audio setup). It works well and the whole thing takes me 5mn to complete.

But since TMPGenc DVD Author isn't smart in the way it create motion menus with a single bmp (instead of creating a single I-frame followed by the audio, it inserts many video frames) I start by running MenuShrink on the DVD created by TMPGenc DVD Authors. This turns the menus into "true" stills (one I-frame). Then I insert the audio. This saves quite a bit of space which I can use to better encode my videos.

jeanl