DVD Audio question (AC3, or PCM, or both)

[JamieM]

I've read in the forum here that to be DVD compliant there must be at least one AC3 track.

My question is: If most standalone DVD players don't have a Dolby Digital decoder in them, will having just an AC3 track not have sound when played with a simple setup? (e.g. standalone DVD player & TV, not home theater)

Related question:
Do commercial DVD's come with at least 2 tracks: AC3, and PCM? (since they can be played by even the simplest setup?) (I haven't looked at a commercial DVD with IfoEdit yet to see)

Related question 2:
If the above is true, then to make my DVD's most compatible should I also author with both AC3 & PCM tracks?

(I have noticed that some of the early Baby Einstein DVD's--yes I have a 1 year old --do not have AC3 tracks)

More information: the DVD's I am making are simple home movies captured with Instant DVD off of a Hi8 sony camcorder, and perhaps some from VHS & SVHS tapes as well.

Tools I'm using:
DVD-Lab - DVD Authoring
Windows Movie Maker - Editting and slideshow creation (I combine the captured video with slideshows from a digital camera)
TMPGenc - encoding
ffmpeggui - AC3 conversion (I found this easier to use (& it worked) than BeSweet)
Software that came with Instant DVD (I forgot the name of the tools) - conversion & some editting

(I know DVD-Lab only supports 1 audio stream, but I can use IfoEdit to create multiple stream VOB's and use them in DVD-Lab)

Sorry for the long post, but there was that topic: "How to get a question answered..."

[andydd]

Very few DVDs come with a PCM track mainly because

a). Its not surround sound, only stereo

b) It can be HUGE, almost as big as the movie.

You normally only find it on Music DVDs, as PCM is uncompressed it can deliver a better audio performance than AC3 (although AC3 has the benefit of surround sound and a seperate subwoofer channel).

[JamieM]

If that is true, then how do DVD players WITHOUT a Dolby Digital Decoder (AC3) in them output stereo analog audio? (This includes all of the el cheapo DVD players available today)

On Edit:
Or am I incorrect in assuming the DVD players do not have a DD decoder? they just don't output the 5.1 channels? is this correct?

[politiken]

I've read in the forum here that to be DVD compliant there must be at least one AC3 track.

No! - You do NOT need AC3 on the DVD - To be DVD compatible you must use one or more of the following formats:

AC3 or DTS or M2A (MP2) or PCM (LPCM)

Most DVDs today use AC3 or/and PCM.

AC3 is a compressed format, with SurroundSound and created for use in large theaters (giving you the possibility to hear whispering and bombs exploding at the same time without getting your ears damaged)

PCM is uncompressed (huge in filesize) and a better format than AC3 regarding music (i.e. opera and classical concerts)

Great, clear and detailed explanations about AC3 here:
http://forum.doom9.org/showthread.php?s=e08e78cfd0ae05291253af22d4c1c268&threadid=56020

More info here:
http://mornmist.2y.net/~blibbler/tutorial/basic/convertaudio.html
https://www.videohelp.com/forum/archive/t176533.

Pol

[Cornucopia]

I've read in the forum here that to be DVD compliant there must be at least one AC3 track.

No! - You do NOT need AC3 on the DVD - To be DVD compatible you must use one or more of the following formats:

AC3 or DTS or M2A (MP2) or PCM (LPCM)

Most DVDs today use AC3 or/and PCM.

Info here:
http://mornmist.2y.net/~blibbler/tutorial/basic/convertaudio.html
https://www.videohelp.com/forum/archive/t176533.

Pol

politiken, you've got it wrong

This topic has been done many times, but for clarity I'll say it again.

NTSC DVD's are supposed to have AT LEAST either AC3 or PCM tracks, in order to be "conformant". ADDITIONAL tracks may be more of those or MP2, DTS, or even supposedly SDDS (hasn't happened yet).

PAL DVD's are supposed to have AT LEAST AC3 or PCM or MP2 tracks to be conformant, with additional tracks being more of those or DTS, etc.

If you're non-conformant, doesn't mean it won't play anywhere, but it does mean that some players can't play it correctly (or at all). These days, with newer players, your more likely to have no problems with MP2, although you still do if all you use is DTS, but if you're not conformant, you ARE taking your chances.

On the orginal question,
You don't need BOTH PCM and AC3, just one or the other. PCM makes sense for quality, AC3 makes sense for size. More news for you people: PCM can do surround, it's just extremely rare and not very well supported on players even though it is supposed to be officially supported.
AC3, OTOH, is universally supported in all of its modes--1ch,2ch,3ch,5ch,5.1ch, etc.
Players that don't have full 5.1 output still have a decode/downmix section so that you may get a 2ch (stereo or Dolby Surround) mix to the analog audio outputs. This is REQUIRED on all DVD players, otherwise they won't be certified as true DVD players at all.
The main problem with AC3 is that there aren't many choices when it comes to encoders, especially 5.1. Not counting BeSweet, which has some known incompatibilities and probably isn't even licensed/certified by Dolby, there are NO free encoders.

Scott

[JamieM]

politiken:
Thanks for the information, I've alread read the guides & seen the info on the forums here. Heck I've known about AC3 since it first came out (I am still using my Pioneer VSX-D3S--First receiver to come out with AC3, it actually has an AC3 button *NOT* Dolby Digital, and my Clear & Present Danger laserdisc still sounds as good today as it did when I got it--First laserdisc released with AC3) I'm not slamming/flaming, just making a point

Cornucopia:
Thanks, that was what I was looking for. I wasn't sure if all DVD players could play a VOB with *only* an AC3 track and output analog audio. I guess I didn't have to make my quesiton so wordy...