MP2 Or AC3 For DVD Authoring Programs

[stanleycup]

I have some SVCDs and VCDs that I wanna convert on a DVD-R

For the audio portion, do I need the MP2 or AC3 audio file for use
in the DVD authoring program? I read some people saying you need the MP2 file and other people saying that you need the AC3 file.

I heard it's dependent on the application you use to author the DVD.

What are the advantages/disadvantages of using either the MP2 or AC3 file?

Thanks for the help

[ByronE]

The majority of programs (at least that I have used) will accept either or...if you have a 2 part stereo audio file, and your authoring program allows mp2's, than you would be better off with that. I really think the only advantage to using an ac3 would be for multi-channel stereo surround tracks...in which case, if you dont have the original multi-channel ac3, then you need something like Sonic Foundry's Soft Encode in order to convert all the seperate wavs into the multi-ac3. I've heard that ac3's can compress at a better ratio than mp2's, but have lesser quality as well. One of the major advantages of using an mp2 over ac3 is, of course, the fact that there aren't any freeware ac3 encoders available...at least that I know of.
One note, if you're using SpruceUp, rename the mp2 extension to mpa in order for spruce to recognize it.

[jdobbs]

The best advice is to stay compliant with the DVD-Video standard. Look here for what I consider to be one of the best sources:

http://www.dvddemystified.com/dvdfaq.html#1.2

From that source:

Discs containing 525/60 video (NTSC) must use PCM or Dolby Digital on at least one track. Discs containing 625/50 video (PAL/SECAM) must use PCM or MPEG audio or Dolby Digital on at least one track. Additional tracks may be in any format.

Bottom line: If you create NTSC discs you must have at least one PCM or AC-3 track. Most PAL/SECAM discs have also standardized on AC-3. There will be players that let you get away with just MPEG audio, some that won't -- but if you do it right it will ALWAYS work.

[auenf]

its not a problem to use m2a on dvds, but SVCD and VCD use 44.1khz, whereas DVDs require 48khz, which means you are going to have to convert the audio anyway, you may as well make it AC3.

all dvd players can decode m2a, ac3 and PCM, even the NTSC ones, its just the north america part of the DVD Forum doesnt like m2a at all, but it will still work.

Enf...

[Sherlock Holmes]

Well why I can't import MP2 to Scenarist ?
It doesn't allow me
:(

[jdobbs]

Where is becomes a problem is when you use digital output. Many (possibly all) players will play MPEG audio out the analog (L and R) connectors. But not all will convert the MPEG audio into a PCM stream and send it out the digital (fiber or coax) connectors. A lot of folks like to hook their system to a Dolby compatible receiver using these connectors so they can get true Dolby 5.1 output. You will find that some NTSC standalones will give you silence on an MPEG audio encoded track.

This problem has been experienced by folks who have reported it in this forum.

All manufacturers build to the standard. Some go beyond it. But, have you ever bought a commercial disc that didn't have at least one Dolby Digital track (even mono)?

[ByronE]

I resent that auenf, I'm from North America and have no problem with mpa's...and might I add that I'm a hardcore audiophile. Of, course, I havent been able to use the Digital Outputs on my Apex yet, so I don't know if it plays it through them or not...if not, then we definately have a problem....
I see what you're saying though Sherlock, I too, cannot get Scenarist to take any mp2's :confused:

[Sherlock Holmes]

to ByronE
one of my frinds told me that if i wanna using mp2 in scenarist , the imported video must be PAL. he said that if it is NTSC , i can't import mp2.
so test this and share me the result. i will test it too. but a little later , imean next weekend.
tnx

[amirkhan]

in terms of 2 channel Stereo, which is the best compression wise? between MP2 or AC3 ?

Using the same bitrate etc etc..

Amir

[ByronE]

That's odd Sherlock, my player can decode PAL, which is cool...but most of the people I make stuff for, and borrow dvd's to, cant...oh well. It dosnt take to long to convert to a PCM and then to ac3...but it is indeed annoying.

[amirkhan]

then you can be sure it'll work.

Do a search for DVD demystifed on goodle and see the excellent faq for all your answer on the "bare" minimum you need on your disc to be complient.