.MPA or AC3?

[fsuorange]

Hello, I am currently working on a dvd but have questions as to what audio type I should choose.

What is the difference between mpa and ac3 and which should I choose for dvd? Or is there no noticeable differece? If I should choose ac3 would you please tell me how to convert mpa audio to ac3 audio.


Thanks

[fsuorange]

or should I choose pcm?

[SimonH]

If your audio is already mpa, I'd leave it as that.

The advantage of AC3 is that you can have DD 5.1 surround sound and all that jazz, but unless you already have this in AC3 format, there's no way you can create it from anything alse AFAIK.

The other advantage is that AC3 is slightly more compatible with standalone DVD players when compared to MP2 (which is probably what your MPA file is), although personally, i've never come across a player that wouldn't play MP2 audio on a DVD, they do exist - see the DVD Players list.

[awlchu]

Who is your target audience? Family, friends, commerical?

There is a trade off between video and audio. PCM, in the USA, is very compatible but takes ~7x the space (over AC3) leaving less room for video. MPA (MP2 audio) works well for PAL lands, but only has a ~80% hit rate within the US.

AC3 is nice and compact and is compatible (I believe) in all areas. But, unless you're will to invest into a commerical AC3 encoder ($300US +), your only choice is besweet or ffgmpeg (sp?). Compatibility *might* be an issue. Try it and see!

Now I have heard some nice things about TMPGenc DVD creator and it's new AC3 encoder. For $90US, it might be you fastest way to complete your project and not bust the budget!

Charge on! (I do not work for VISA! )

[FT Shark]

From what it sounds you already have the audio in mpeg format. This format is already compressed; converting it to PCM will not help gain any quality. Converting to AC3 now will not compress it much more and will more than likely reduce the quality. Stick with mpeg audio; most DVD players will accept it.

[SimonH]

I agree with FT Shark.

Converting to PCM may gain you a little more compatibility with standalone's, but at the cost of considerable disk space, and that's it.

[vhelp]

.
.
and if I can add..

correct me if I'm wrong, but if your audio source originates from an .avi
file (ie, DV like advc) you have 48k auido, and is as good (or best) to convert
to AC3 in this stage, then author to DVD :P

But, if your source is .avi and you convert/encode to an .mpa/.mp2 source,
and THEN convert to AC3, as FT Shark put it, ..is not a good idea due to the
re-converting again, to even lesser audio quality sound.

So, if your source is .avi and has 48k audio, that's when you want to convert
to AC3 first, then encode/author to DVD.

-vhelp

[SLK001]

MPA audio is NOT MP2 audio. It is MPEG 1, Layer II audio. Most US players have no problem with MPA audio, but MP2 audio is NOT part of the NTSC DVD spec, so not many players handle it.

Your best bet (and by far the most compatible format) is AC3.

[SimonH]

MPA audio is NOT MP2 audio. It is MPEG 1, Layer II audio

My bad - you're absolutely right.

Just replace MP2 with MPA in my post, and the points still stand

[Baldrick]

some tools(Tmpgenc) use the extension mp2 for mpeg1 layer 2.