LPCM audio in menus with TMPGenc DVD Author

[jeanl]

People,
I'm running into a problem using TMPGenc DVD Author. I create a motion menu using a still with ac3 audio (muxed with muxman). But when TMPGenc DVD Author creates the menu, it decompresses the audio to LPCM! I end up with over 500MB of menu (6 menus, each with about 1 mn 30 of audio), which mean my DVD exceeds capacity.
I don't think there's a way to avoid that in TMPGenc DVD Author, at least I haven't found one.
I'm thinking of fixing it after the fact, by remuxing the ac3 audio, but I'm not sure how to do that, because I want to preserve the video, the subpics and the button info in the navpacks (remember, it's a menu!).

Is there a way to do that? It seems to me that all the muxing tools start from elementary streams, which makes me think the button info will be lost. I think I could enter the button info in muxman, but that a ton of work (6 menus with 8 buttons).

Any idea?
Thanks in advance!
Jeanl

[echooff]

Just a thought, do you have the re-encode audio selected in environmental settings? Mine never does what yours is doing.

[jeanl]

Originally posted by echooff
Just a thought, do you have the re-encode audio selected in environmental settings? Mine never does what yours is doing.
Yours does not?! I'll double check. But this is only happening in the motion menus. The title VOBs are not being re-encoded...
jeanl
EDIT: I checked, but I can't find that option in the environmental settings.. I have this option every time the videos are imported, but not as a global setting. I also checked that the title vobs do have mpeg1 audio, as expected.
Can you double check that your motion menus don't have LPCM audio? I'm really puzzled. Also, do you have the AC3 plugin? I don't, and that might be the difference...

[echooff]

Yes I do have the ac3 plugin. Maybe thats it.

[jeanl]

Originally posted by echooff
Yes I do have the ac3 plugin. Maybe thats it.
mmm that could be it. I'm not sure I can get a demo version to see if that's really the problem...
Thanks though!
Jeanl

[Mrsash]

As far as I know it does the same for me. I usually use vcd files to burn on a dvd. but I find that the motion menus are reencoded by tmpg to 720x576 Video and Lpcm Audio.

[jeanl]

Originally posted by Mrsash
As far as I know it does the same for me. I usually use vcd files to burn on a dvd. but I find that the motion menus are reencoded by tmpg to 720x576 Video and Lpcm Audio.
That's really bad. Thanks for checking... I'm looking into a simple way to avoid that, but haven't found one yet. Not easy to remux the ac3 into the menu while keeping the button info and the highlights... No simple 1-click solution I'm afraid...
jeanl

[jeanl]

Well, I bit the bullet and wrote a tiny app that puts the audio into the original still menu. 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 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.


Another thing: 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. The resulting VOB is much larger than it would need to be. I have found that running MenuShrink on it can save quite a bit of space which you can use to better encode your movies.

jeanl

[Mega-Splat]

AFAIR, it does not use AC-3 for the menus. So yours is working correctly. DVD Author is a great program that I really have no complaints other than the lack of AC-3 useage for menus and also the fact that it re-encodes AC-3 tracks taken from DVD imports. IOW, say you want to create a DVD with chapter points from a source DVD that has none. Everything works fine but even if you choose the same AC-3 bitrate that the original AC-3 audio is in DVD Author re-encodes the AC-3 track anyhow. It's a waste of time and degrades the audio. Other than those two knitpicks :D , I think it's a great program.

[jeanl]

Mega-Splat, are you sure that AC3 audio gets re-encoded in the title domain? I use TMPGenc DVD Author a lot, I feed it m2v files and ac3 files, and I don't think the ac3 gets re-encoded (besides, I don't have the ac3 plugin, but maybe the "plugin" is alreay inside DVD Author and all you need is an enabling key).
How can you know for sure that your ac3 is re-encoded? Did you demux the output VOB and compare the original AC3 with the demuxed one?

jean