I think SCMPX is as good as HeadAC3he, but it's a slower encoder. Still it's excelent. :wink:

-kwag

I think SCMPX is as good as HeadAC3he, but it's a slower encoder. Still it's excelent. :wink:

Edit: Only problem is if you want "Dolby Surround 2" audio, you need to convert the AC3 audio to WAV in order to use SCMPX to encode :roll: .

-kwag

I always encode audio through TMPGEnc (external encoders), and it makes a temporary wav anyway.

But you're not retaining the dolby surround 2 mode, AKA: Dolby Prologic II. That's the beauty of HeadAC3he. It encodes the .mp2 with that feature. SCMPX doesn't do that. The sound is very close to Dolby 5.1 if you encode with this mode turned on.

-kwag

about:
"It would be useful, but I'm guessing it would be quite hard to determine borders automatically. It sounds easy but I don't think it would be . "

i post this link before,but don't remember where......
it's about autoboarder.....:
neopholus (in doom9) make a script for me to make vcds.
maybe it could help! :wink:

http://forum.doom9.org/showthread.ph...6&pagenumber=2

I've never even heard of that 8O. How does it differ from regular ProLogic? Why does resampling as PCM not retain the surround information?

It is retained. The problem is in the encoding. There is a difference between regular "Dolby Surround" and "Dolby Prologic II". I'm not sure what is the algo used, but I tested a regular WAV encoded with TMPEG at 160Kbps, and the same thing encoded with HeadAC3he as "Dolby Surround 2" and I couldn't believe the sound effects. I think it has to do with the actual separation of rear channels, where in regular surround, rear speakers are one channel. Don''t flame me here 8O . I'm no audio expert :P . This is what I've read, but my ears tell me a HUGE difference between the encodes. BTW: If you run DVD2SVCD, you'll notice that on the Audio tab and then click on the down arrow besides the little folder besides BeSweet, you get a popup dialog that let's you select "Stereo downmix type" . It defaults to "Surround." But you'll see that it has a "Surround 2" option :wink:

-kwag

Ok, so assuming I demux the AC3 with DVD2AVI as usual, what do I need to do to encode the audio with ProLogic II? I really want to try this because I have a nice surround setup and regular ProLogic just doesn't really cut it for me after AC3 ;).

Get HeadAC3he, and when you run it, select "Surround 2" on downmix type on the channel configuration screen ( At the bottom ). Also make sure you select "Dual Channel" NOT STEREO. It makes a hell of a difference on the surround signals being carried to your receiver. If you encode as "Stereo", the small adjacent channel interference from one channel to the other can dampen your dolby surround signals, and your receiver may not detect your channel separation signals correctly. When you encode as "Dual Channel" each channel is 100% independent of each other. That is, adjacent channel rejection is i believe >100db, so basically it's like two independent mono channels.

-kwag

And then just encode as mp2?

Does this only work for AC3 sources? Do all AC3 sources contain ProLogic II information, or just some? If just some, how can I tell which do and which don't? Do I need the 5.1 AC3 or can I use the 2-channel AC3, assuming the DVD contains both?

Right!What it's doing is down mixing the AC3 ( Digital 5.1 ) channels to Dolby Surround Mode 2. If your DVD has a DD 3/2 channel, use that channel. Just make sure you pick the right channel, as viewed on DVD2AVI preview. That's the channel I always convert to .mp2, usually Channel 1 :wink:

-kwag

Ok. I usually pull off just the 2-channel version if there is one, since it's smaller. But if the ProLogic II information is only in the 5.1 version then I'll make sure to get that. Maybe it's time to ask Dr Google about ProLogic II ;).

Are you saying that a 3/2 channel is better for mp2 than 5.1 channel?
It is something that I always feel… but never knew. :mrgreen:

Prologic != Prologic II :wink:

-kwag

I'll make sure I'm reading about the right version :).

No, it's not better than 5.1. That's impossible :D
But Dolby Prologic II is way better than regular surround :wink:

-kwag

I might be wrong but I assumed they were the same thing. 3 front channels, 2 rear. The only difference is that a 5.1 has a separate sub-woofer channel.

Yes, I know that 5.1 is better, but we can't have 5.1 with .mp2, can we?
So, if my DVD has both 5.1 and 3/2... Which should I choose to convert to mp2 with surround 2 downmix?