Please help - ac3 issue with AC3machine

[dosser]

is there any way I can encode a ac3 2ch to virtua dolby digital for surround dvd. Any info would be welcomed cheers

[DSPguru]

are you interested in going from 2.0ac3 to 5.1ac3 ?
it's pointless..


can't your authoring program accept 2.0AC3 streams ?

[dosser]

Why is it point besweet author I am designing a promo dvd for work, and to save time I recorded from source on dmre20 2ch then I use maestro to author. 6ch sound or 5.1 would be wicked does besweet have any options to do this

[DSPguru]

"dmre20 2ch" - is that AC3 2.0 ?
if it does, it was probably downmixes as Dolby Surround and that means that any Amplifier that supports Dolby ProLogic deocding can produce a virtual surround out of it.
now, your idea won't add extra information, 'cause the best thing you could do is :
- take the 2ch source file and decode it
- run somekind of virtual surround effect on the decoded result to generate a 6ch signal from it.
- encode this 6ch into 5.1AC3
and now ask yourself what would sound better ? the original 2.0AC3 that was decoded using Dolby ProLogic decoder or a 5.1AC3 that was decoded+encoded+decoded ?
in the worst case - they would have equal quality, but i bet that in 99.9% of the cases - the original soundtrack would win.

[DSPguru]

Originally posted by dosser
does besweet have any options to do this no, but if you feel like doing this, i would suggest that you look here :
http://forum.doom9.org/showthread.php?s=&threadid=29277

[dosser]

I will take your advice its just that I heard of a guy on another forum advertising to make virtua dolby digital from a 2ch source thanx for your expert help.

[imel6]

Pleeeeeeeeeeaaaaaaaaaaaaaaassssse help! I am at my wits end. When trying to encode 6 channel audio (ac3), ac3machine routinely encodes with 2 channels. Channels mode is set to 5.1. I am using Ac3machine .41 and Besweet 1b4. My log file is below (and it indicates 2 channel mode). Thanks in advance.

BeSweet v1.4 by DSPguru.
--------------------------
Using Shibatch.dll v0.2 by Naoki Shibata & DSPguru (shibatch.sourceforge.net).
Using AC3enc.dll v0.2 by Gerard Lantau & Dg (http://ffmpeg.org).
Manual Dynamic-Compression algorithm by LigH (author of WaveBooster).

Logging start : 01/07/03 , 21:58:00.

D:\soft\multimedia\BeSweetv1.4\BeSweet.exe -core( -input E:\temp\battlestar theme.wav -output E:\temp\squad1-.ac3 -logfile D:\soft\multimedia\BeSweetv1.4\AC3Machinev0.41\BeSweet.log ) -ssrc( --rate 48000 --att 20 ) -ota( -d -66 ) -boost( /b=1db ) -ac3enc( -b 384 ) -profile( The AC3Machine v0.4 )

[00:00:00:000] +------- BeSweet -----
[00:00:00:000] | Input : E:\temp\battlestar theme.wav
[00:00:00:000] | Output: E:\temp\squad1-.ac3
[00:00:00:000] | Floating-Point Process: No
[00:00:00:-66] | Source Sample-Rate: 48.0KHz
[00:00:00:-66] +-------- BOOST ------
[00:00:00:-66] | Algorithm by : LigH
[00:00:00:-66] | Boost Factor : 1.1
[00:00:00:-66] | Limit Factor : 0.99
[00:00:00:-66] +------- AC3ENC ------
[00:00:00:-66] | Bitrate method : CBR
[00:00:00:-66] | AC3 bitrate : 384
[00:00:00:-66] | Channels Mode : 2.0
[00:00:00:-66] | Error Protection: Yes
[00:00:00:-66] +---------------------
[00:01:07:006] Conversion Completed !
[00:01:07:006] Actual Avg. Bitrate : 383kbps
[00:00:05:000] <-- Transcoding Duration
Logging ends : 01/07/03 , 21:58:05.

[DSPguru]

what can you tell us about your wave file ? is it stereo ?

[imel6]

It is a normal stereo file. Thanks for the reply

[DSPguru]

i'm afraid that currently BeSweet will only create 5.1ac3 out of a 6ch source.