OGG 6Ch --> AC 5.1

[ChAoS Overlord]

I have a movie backup that I made previously as an experiment to try out OGG 6CH. Now I want to repack my original 6CH .ogm backup in an .avi, compatible with my standalone player.

Therefore I have to reconvert the ogg stream to AC3.

Which is the most appropriate way to transcode everything?
Thank you very much for your insight in this.

[ChAoS Overlord]

Absolutely nobody who's able to help me with this? I've tried out several things with besweet, but none of them work (or even produce a file).

[KpeX]

I'd recommend doing this in a two step process, first decoding the 5.1 vorbis to six-channel wav and then encoding to AC3.

Graphedit can be used to convert the vorbis to 5.1 wav. Basically you'll need to connect a 'wav dest' and file writer to the decoded 5.1 ogg stream.

BeSweet or any AC3 encoder can then be used to convert six channel wav to AC3.

[ChAoS Overlord]

OK, I got a 32bit 6channel wave of about 2.82 GB in size, but every time I use besweet from this wave file I get:

BeSweet v1.5b26 by DSPguru.
--------------------------
Error 58: Error : Unknown Input-File Format : "d:\TLU1.wav".
Quiting...
[00:00:00:000] Conversion Completed !

Logging ends : 04/25/04 , 22:35:25.

What's the deal? :(

[KpeX]

Looks like an invalid wav file. Try running it through a wav editor such as audacity.

[ChAoS Overlord]

OK, I forgot setting the output of the ogg decoder to 16bit. I corrected that now. Still, I get the same error with besweet(GUI) again. Even though I can open it in both Audacity and winamp (which I couldn't do with the 32bit version.) Saving it again in Audacity is also not an option, since it only saves to two channel wavs.

[tiki4]

AFAIK the WAV Dest filter always adds a strange header to the WAV file (I guess you never get 6 channel, take a look on properties in Windows explorer)...

Try to convert the 6ch Ogg in Winamp directly with the Diskwriter plugin. If you feel advanced enough, then go for foobar2000 directly, a little bit more difficult, but gives you lots of choice.

tiki4

[ChAoS Overlord]

Explorer tells me it's a 6 channel 16bit wave file, as does audacity.

[KpeX]

Well if explorer or audacity will let you convert to six channel AC3 than you're in business. Since they don't you'll have to consider one of the choices tiki4 presented you with. Give foobar2000 a shot, it's very versatile.

[ChAoS Overlord]

OK, I ran it through foobar, the resulting wav file also works fine, this time also in besweet. After encoding it to AC3 5.1 (448 kbit) it seems that the a lot of the dialog has migrated to the right channel! So it's very annoying to hear people talking from the right.

What could be the cause of this problem? :confused:

[tiki4]

Did you pay attention to the right channel order? 6 channel Ogg Vorbis has a different channel order than AC3 (at least I think so). Take a look at the audio FAQ linked in KpeX signature. You may correct for that with the help of .lst files in BeSweet.

tiki4

[ChAoS Overlord]

I've been looking for info on that subject indeed, but I didn't find it... It's going from the .wav file to the .ac3 that gives me problems.

[hans-jürgen]

Originally posted by ChAoS Overlord
What could be the cause of this problem? :confused: Somewhere down the line the channel order gets mixed up, e.g. in the Vorbis decoder of foobar2000 if it doesn't use the standard 5.1 WAV format at its output like foo_ac3.dll does. Normally Vorbis and AC-3 multichannel layouts are the same, so you would have to correct this (if it's really the case) in the resulting WAV file manually, before you encode it with your AC-3 encoder.

[ChAoS Overlord]

It's very strange. When I play back the resulting wave, the sound IS coming from the correct channels. :confused:

[ChAoS Overlord]

Nobody who can help me get settings with a correct channel mapping? :( It's the final step that I have to take.

[ChAoS Overlord]

Is there really nobody who can help me further?
Upon opening it in audicity I get

left
right
mono (center?)
mono (LFE?)
mono (Surround left?)
mono (Surround right?)

why won't it map correctly in my AC3 file? :(:(

[tiki4]

Dunno, how do you encode to AC3?

tiki4

[ChAoS Overlord]

This is the commandline as given to me by besweetGUI.

"c:\Program Files\Besweet\BeSweet.exe" -core( -input "d:\001 TLU1.wav" -output "d:\001 TLU1.ac3" -logfile "C:\Program Files\Besweet\BeSweet.log" ) -ac3enc( -b 448 -6ch )

[tiki4]

If you have a 6 channel WAV file, you can demux that in BeSweet with the following command line:

besweet -core( -input in.wav -output out.wav -6ch )

After that you get 6 mono WAV files that are named outC.wav, outLF.wav and so on.

Now put the names of the files into a so called .mux file. Just open Notepad, enter the filenames in the right order of your channels and save as input.mux. Then:

besweet -core( -input input.mux -output out.ac3 ) -ac3enc( -b 448 )

That should do. Unfortunately you have to experiment with the right channel order (although I think that BeSweet should not mix them up).

Check the AC3 FAQ, or search the forums for the right channel order in AC3, I cannot remember right now.

tiki4

EDIT: It is .mux and not .lst, my bad. Anyway, please consult BeSweet FAQ question 31.

[ChAoS Overlord]

Thank you very much! I'm now going through the final step, and everything seems to be working! I'm off to bed now, I'll check up on it in the morning.