LPCM To AC3

[amittzor]

Hi everybody. i ahve a big problem and i hope you can help me.

i want to rip a dvd-9 into dvd-5, but the dvd is with LPCM sound. it's the first time that i see lpcm, and i can't understand why is it taking so much space (almost 1g).

is there any program where i can convert it to ac3 so it would take less space (without ripping the audio from the DVD and re-attach it).

Thanks in advance

[mats.hogberg]

without ripping the audio from the DVD and re-attach it

No.

/Mats

[Perro Grande]

In a word, no.

LPCM is "Linear PCM" audio -- essentially an uncompressed WAV file (which is why it takes up so much space.

You must extract it as a WAV file, convert it to the compressed format of your choice (AC3, MPA), and then re-mux the files back together.

I would recommend doing this operation before any shrinking or re-authoring you plan to do. You might find that compressing the audio shrinks things enough to fit without reducing the MPEG bitrate on the video.

[amittzor]

can someone please explain to me how can i rip audio, convert it to ac3 and then reattach it?

[Faustus]

You cannot. You would have to reauthor the disc, meaning rip it to seperate video and audio streams that rebuild the DVD in an Authoring application such as DVD Maestro.

[Gregg]

Hi,

What you want is possible BUT you'll lose menus, extras, subtitles etc.
If you want the main movie only do as already suggested:

1/ Demux audio and video
2/ Convert LPCM to AC3
3/ Remux video with AC3
4/ Shrink if necessary

Enjoy!

[timmyp]

I am curious about doing the same thing and am wondering what input you all might have about this idea:

Demux VOB's
Convert audio to ac3
Remux VOB's
Use IFOEdit to change the reference of LPCM audio to ac3 audio

It's the last step that I don't know how to perform, but it seems that I read somewhere that this could be done fairly easily.

Can anyone confirm whether that can be done or not? And if so, how?

Thanks!!

[dinobike]

TMPGEnc DVD Author can re-encode lpcm to mp2 (64 ~384 kbps), and create a new menu for your dvd.

[timmyp]

Sorry. Should've been more specific. Here's what I'd like to do:

Replace the LPCM audio with AC3 audio, while keeping the structure, menus, etc. of the DVD.

So, my thought is to
1) rip the DVD to my HDD;
2) demux each vob file to a seperate folder;
3) convert the audio to ac3;
4) remux to recreate VOB;
5) paste new VOB back into DVD rip folder;
6) Use IFOEdit (or whatever tool) to change the .IFO's references of LPCM audio to ac3 audio

My question is: Would this work? Or am I losing something in the demux/remux process.

It seems I've read something about this before that seemed to indicate it was possible without a complete re-author, but I'm not sure.

Can anyone confirm one way or the other?

Thanks again.