Any experts on mpeg audio?

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tonyjer
Posts: 196
Joined: Thu Mar 03, 2005 12:41 pm

Any experts on mpeg audio?

Post by tonyjer »

Hi Everyone

Was davised fairly recently to use mpeg rather than lpcm to allow the use of a higher bit rate.(Torsten and others)

Pleased to say that it does allow this but I have an unrelated problem.

The video file created with mpeg audio plays OK as it is but when you put it into a TS folder and then shrink the sound disappears!!

I created 2 separate video files, one with lpcm the other with mpeg and combined them onto one TS to shrink.

When I played the resulting DVD the lpcm one had sound while the mpeg video was silent.

Has anyone come across this before.

(I used 224 kbps-perhaps this was too low)

(I use PAL not NTSC)

Regards

Antonio, Anna y Eduardo Felipe
Antonio y Anna
THoff

Post by THoff »

I've not used DVD Shrink on a disk with MPEG audio since I'm in a NTSC country, but DVD Shrink doesn't touch the audio portion at all, only the MPEG2 video. As such, it shouldn't matter what audio format you use. Are you using an up-to-date DVD Shrink?
tonyjer
Posts: 196
Joined: Thu Mar 03, 2005 12:41 pm

mpeg audio problem

Post by tonyjer »

Hi Torsten

Shrink is version 3.2.0.15.

In your earlier advice you suggested mpeg at 224kbs. I inadvertently used 224. Would this have made a difference?

Encantado y conocerle

Antonio, Anna y Eduardo Felipe
Antonio y Anna
THoff

Post by THoff »

No it shouldn't, because DVD Shrink doesn't touch the audio.

The only thing I can think of is that there is a bug somewhere in DVD Shrink (and it's a very solid program), or that you deselected the MPEG audio.

Are you reauthoring, or backing up? It should present you with a list of audio streams, and the only one there should be 2-channel MPEG audio. If it isn't selected (checked), then DVD Shrink would strip out the audio.
tonyjer
Posts: 196
Joined: Thu Mar 03, 2005 12:41 pm

mpeg audio problem

Post by tonyjer »

Soory to be dumb Torsten but whats the difference between reauthoring and backing up in the context of DVD Shrink?

Antonio, Anna y Eduardo Felipe
Antonio y Anna
THoff

Post by THoff »

Backing up takes the entire DVD with all scenes, angels, subtitles, audio tracks, menus and makes a copy by simply lowering the bitrate of the video (the largest chunk of the DVD). It's fully functional but otherwise identical to the source DVD.

Reauthoring allows you to select items that you wish to exclude from the copy. If you don't need multiple audio languages, director's comments, previews of other movies, subtitles, or 5.1 surround sound, you can reauthor and exclude the unwanted items.

So with reauthoring, there is the potential of unintentionally dropping the only audio track you have. I don't know if DVD Shrink would display a warning or error dialog in this case, I haven't tried it.
tonyjer
Posts: 196
Joined: Thu Mar 03, 2005 12:41 pm

Thanks Torsten

Post by tonyjer »

Many thanks for the explanation

Antonio, Anna y Eduardo Felipe
Antonio y Anna
kcorth

Post by kcorth »

You say you combined the two TS into one, did you use DVDShrink to do that or something else? If you used DVD Shrink then you used Reauthor, in which case you probably didn't set the default audio streem on the MPEG section.

Going from memory here:
To do this, open the movie in DVDShrink, click the reauthor tab, drag the main video file into the pane on the left. Click the Compression tab, make sure the audio source is checked in the right pane. In the left pane right click the title and select Set Default Stream. There you can set the audio stream you want to use for that portion of the movie.

Kevin
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