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AC-3 vs. MPEG audio?

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Apologies if this has been covered elsewhere (links appreciated if so!)

I've noticed that some authors have elected to use MPEG audio encoding on their projects, as opposed to DD.
My understanding until now has been that MPEG is the less preferable option - A, because the quality is lower at an equivalent bitrate, and B, because the format is less widely supported by DVD players (particularly in NTSC territories).

Is this not the case? You guys seem to know what you're doing, so I was hoping that someone could set me straight on this!
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I imagine that some choose MP2 because the only free AC-3 encoder (within ffmpeg) is not considered to be as high quality as commercial encoders (that pay to use the Dolby libraries). Also AC-3 encoding is a more complex process, requiring things like dialogue normalisation to be set up correctly.

There are some good open-source MP2 encoders (TooLame, MP2Enc), also some video encoders (TMPGEnc, CCE) include MP2 audio encoders.

Also note that some choose to author discs with uncompressed PCM audio, for maximum possible quality.

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Most of the material on my bonus discs is MPEG audio simply because that's how my DVD recorder encodes it from video sources. Things like WOW! and Soundtrack on my ROTJ bonus disc came out at AC-3 because I ripped them directly from another DVD and did not re-record it on the DVD recorder.
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The first DVD-authoring software I used generated MPEG audio as well. Unfortunately, my DVD player wouldn't play it, so I looked elsewhere. That's one of the reasons I decided to use Vegas.

<span class=“Italics”>MeBeJedi: Sadly, I believe the prequels are beyond repair.
<span class=“Bold”>JediRandy: They’re certainly beyond any repair you’re capable of making.</span></span>

<span class=“Italics”>MeBeJedi: You aren’t one of us.
<span class=“Bold”>Go-Mer-Tonic: I can’t say I find that very disappointing.</span></span>

<span class=“Italics”>JediRandy: I won’t suck as much as a fan edit.</span>

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PCM is easily the best quality option if you are using VHS, CD's or Laserdiscs as your audio source.
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Soooo... if you wanted to modify a 5.1 soundtrack, exported the AC3 to wavs, did your tweaks, got them to sound "perfect" on your 5.1-channel (disregarding that my sound system is neither representative nor perfect)... you'd still want a good encoder to handle the AC3 compression, then, right? (What with masking off "inaudible" sounds and all that, if I haven't screwed up the terminology).

Vegas seems to be the gold-standard. And kinda gold-priced. Is there anything cheaper that'll get the job done? Or does Dolby licensing set the price pretty high? Are there good bundles? Maybe a limited version? Does Vegas do a lot of tricks, like doing the proper phasing when you spread your additions across channels? Or... well, I don't know enough to ask the right questions, I suppose...

Come to think of it, that's off topic in this thread... so...

I've got plans for fan-edits of 48 minutes (perhaps a little more), on SL discs, would, say, Dolby 2.0 PCM fit, without a lot of video recompression? 6-channel PCM? Do players do 6-channel PCM? I'm out of my depth, here...

One day I found... 10 years had got behind me. Next day was worse.

 

Download  shows from Cable DVR (Updated! Yes, it needs a rewrite, but it's worth slogging through, anyway).

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"Or does Dolby licensing set the price pretty high?"

That's a lot of it. The AC3 plug-in doesn't work out of the box - you have to register the plug-in online first, so that's not included in the overall price. Same with the MainConcept MPEG-2 encoder.

"Does Vegas do a lot of tricks, like doing the proper phasing when you spread your additions across channels?"

Good question. I'm not sure. I'll get back to you on that one.

"6-channel PCM? Do players do 6-channel PCM? I'm out of my depth, here..."

Not to my knowledge, but considering how much space such a soundtrack would take up - WOOF! In fact, if I remember correctly, when I made a 6-channel PCM soundtrack, my computer wouldn't play it (it was an intermediate step in turning a 2-ch PCM track to a 5.1 soundtrack.)

<span class=“Italics”>MeBeJedi: Sadly, I believe the prequels are beyond repair.
<span class=“Bold”>JediRandy: They’re certainly beyond any repair you’re capable of making.</span></span>

<span class=“Italics”>MeBeJedi: You aren’t one of us.
<span class=“Bold”>Go-Mer-Tonic: I can’t say I find that very disappointing.</span></span>

<span class=“Italics”>JediRandy: I won’t suck as much as a fan edit.</span>

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Originally posted by: MeBeJedi
"Or does Dolby licensing set the price pretty high?"

That's a lot of it. The AC3 plug-in doesn't work out of the box - you have to register the plug-in online first, so that's not included in the overall price. Same with the MainConcept MPEG-2 encoder.
Ohhhh boy...

"Does Vegas do a lot of tricks, like doing the proper phasing when you spread your additions across channels?"

Good question. I'm not sure. I'll get back to you on that one.

Thanks!

"6-channel PCM? Do players do 6-channel PCM? I'm out of my depth, here..."

Not to my knowledge, but considering how much space such a soundtrack would take up - WOOF! In fact, if I remember correctly, when I made a 6-channel PCM soundtrack, my computer wouldn't play it (it was an intermediate step in turning a 2-ch PCM track to a 5.1 soundtrack.)

<self-inflicted forehead slap>

Errrr.. I, well, I, uhh was thinking of, um, BluRay, because by the time I finish, we'll all be using that. Yeah... BluRay, that's it, that's the ticket. That's what I was thinking of. Uh huh.

One day I found... 10 years had got behind me. Next day was worse.

 

Download  shows from Cable DVR (Updated! Yes, it needs a rewrite, but it's worth slogging through, anyway).

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LOL....it would certainly be interesting to see if Dolby will loosen up the compression - if any is used at all - for HD-DVD/Blu-Ray. They keep insisting that the music sounds the same at their bitrate. PCM may see a big comeback (not that it ever left, since CDs still use it.)

<span class=“Italics”>MeBeJedi: Sadly, I believe the prequels are beyond repair.
<span class=“Bold”>JediRandy: They’re certainly beyond any repair you’re capable of making.</span></span>

<span class=“Italics”>MeBeJedi: You aren’t one of us.
<span class=“Bold”>Go-Mer-Tonic: I can’t say I find that very disappointing.</span></span>

<span class=“Italics”>JediRandy: I won’t suck as much as a fan edit.</span>

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Originally posted by: Matt_Stevens
PCM is easily the best quality option if you are using VHS, CD's or Laserdiscs as your audio source.
... but it takes up a hell of a lot of space, and only those with good ears and a decent audio system can tell the difference.

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