Converting 5.1 Wavfiles to AC3 without loosing Multichannel?

[g.henk]

Hi,

I´m just authoring a demo dvd to show the potential of a good Dolby Digital Hifi System.

On the DVD I have some Trailers and Musicvideos in DD 5.1 and DTS.

Because I also want my audience to just listen to the effects without being disturbed by the effects on the screen I also want to add some audio only tracks.

I have some cd´s and wav files that are 5.1 oder DTS. I was trying to convert them from 44Khz multichannel wav to 48KHz Ac3.
But no matter what I do, I always loose my multichannel sound.

Tools like the pegasys plugin or besweet just rip tehm down to 2.0 AC3 files because they are inteded to integrate mp3 or wav stereofiles in homevideo projects.

But what can I do to get my 5.1 wav/cd´s files to real 5.1 AC3 files or even VOBs or something.

I just tried the maven3D demo but that software doen not recognize multichannel sound in wav files

Please help I have to finish my project to present to the customer on monday!

Finest regards

Gabriel

[zagortenej]

You can make audio-only DVD tracks with DD or DTS audio files as well. Instead of mpeg video as your main video track simply use black jpeg file and couple it with whatever DD 5.1 or DTS audio file. When you play it, the only thing you'll see on yout TV is blank (black) screen and you won't have any video-effect distractions while listening to your audio. It's simpler and faster than what you are trying to do and the end result is what you want.

[Cornucopia]

I just tried the maven3D demo but that software doen not recognize multichannel sound in wav files

Gabriel

Maven 3d Pro specifically touts itself as being able to handle multichannel files, so maybe it's just the demo.

Soundforge(edit-oops) SoftEncode used to be able to do this, but is no longer available as such. Try Vegas...

Scott

[g.henk]

simply use black jpeg file and couple it with whatever DD 5.1 or DTS audio file

That is right as long as the audio files is already in a format that is compliant with a DVD. I could do if my files would be already .ac3 files.

But they are wav files and also have only 44KHz. Any athoring tools would refuse them if I would just try to drag them as they are.

Moongate

[g.henk]

Maven 3d Pro specifically touts itself as being able to handle multichannel files, so maybe it's just the demo.
Scott

No its not the demo, the tool can´t handle the multich-annel wavs only other multi-channel files. But those work very fine...but not as a solution for me!



Moongate

[Cornucopia]

Don't know if it'l help, but you could try Hypercube Transcoder.

Scott

[Cornucopia]

You know what, I'll bet you actually don't have a multichannel "WAV". If you got them from a rip off of an AC3 (DD) or DTS Multichannel CD, what you have is an AC3-encapsulated within a WAV (or DTS encapsulated w/in a WAV). That is a different beast altogether.

You might get away with simply decoding them 1st

#1-rename your WAV's to .AC3.
#2-use Hypercube transcoder to convert to either multichannel wav or multiple separate file mono waves. Or use a similar AC3 demuxer/decoder tool (there are a number that work alone or in conjunction with DVD extraction/decryption.
#3-now you have LPCM WAVEs that can be Sample Rate converted from 44.1 to 48k
#4-then re-encode to the multichannel format you desire--AC3 or DTS or MP2

If you can't get away with simply decoding, you'll need to take the 5 channels out from your receiver (analog) and re-digitize them. Heck, you might as well do it at 48k at that point. Save some time later.

HTH,
Scott

[g.henk]

I can surely tell you that I now what I have and I have multi-channel wav files.
It is not a ripoff and if it is burned onto an audio cd it will play in a dvd player as a dolby digital file right away.

Those kinds of files can be downloaded here for free:

http://www.sr.se/multikanal/english/e_index.stm

Moongate

[guns1inger]

They are AC3 in a wav package, but tuned for CD. I have a number of DTS ones myself.

Another suggestion, just to keep you moving forward, would be to create blank video for some existing AC3 5.1 tracks you may have on DVD. Something like Shrink could do this very easily by changing the compression type to still image, and loading a black bitmap.

[Cornucopia]

I can surely tell you that I now what I have and I have multi-channel wav files.
It is not a ripoff and if it is burned onto an audio cd it will play in a dvd player as a dolby digital file right away.

Those kinds of files can be downloaded here for free:

http://www.sr.se/multikanal/english/e_index.stm

Moongate

Without realizing it, you just supported my arguement. What you have is DTS-WAV or AC3-WAV, which is DTS or AC3 (at 44.1kHz sampling rate) that has additional padding and WAV headers--so it'll look like a WAV to an Audio CD burning program and be passed for burning.

Only program I know that had specific support for importing or exporting this was Sonic Foundry's SoftEncode. You should be able to get that same functionality with (now) Sony's Vegas.

BTW, I said --RIP--OFF--OF--A--CD, not RIPOFF.

Scott

[Abond]

I think they are realy wav files - bitrate reported by GSpot is 1400 kbps - somewhat too high for ac3.

[Cornucopia]

That's why I said "padding & WAV headers to make it look like a WAV file". This necessitates upping the perceived bitrate (but not the true AC3 compressed bitrate).

These files are not a method to take files and make them smaller to fit more on disc, they are a method to take surround and fit them on std 2-ch AudioCD. As such, they should be equivalent to stereo LPCM WAV bitrates/sizes.

Scott

[Abond]

22 MB for 2 min playing time - do you want to say the headers also trick Window explorer and adjust the file duration or maybe they affect the calculator (regular)?
Ah I see - padding.
But then how you can say they are ac3, how you found they are ac3?

[Cornucopia]

Take a look at http://www.kellyindustries.com/diy_5_1.html and it might help you understand what we're talking about.

Scott

[Abond]

Well,yes, I see. The site says it is AC3. There is no way to prove they are - every application will recognize it as wav.
I found it. In the latest GSpot the AC3.wav file I downloaded from the link you posted is shown as 384 kb/s total 4 channels. No doubt it is AC3. However the file I have down loaded from the site g.henk has posted is shown with 1411 kbps 2 channels. So make your conclusions.

[Cornucopia]

Here's a clue--true AC3 bitrates don't go higher than 640kbps (at least that's as high as all the encoders I've tested will let you go).

Look at the site mentioned by g.henk--it's probably the DTS-wav and not the AC3-wav.

Do you have a DTS decoder? Tools for converting DTS are less available than those for converting AC3, but for a start, I'd check out Minnetonka's Surcode series.

Scott

[Abond]

Well, the file I have downloaded has a name SURROUNDTEST_DD_640.zip. Seems like right one.
BTW I wanted only to found the answer: Are the Dolby Digital files at the site g.henk posted multichannel wav files, or ac3 files with wav header? For me at least the file I have downloaded is real wav file.
About the audio encoding AC3Machine and BeSweetGUI are everything what I need. Thanks for the links.

[Cornucopia]

Answer: The file "SURROUNDTEST_DD_640.zip" (and prob all the other DD files listed there) IS an AC3 w/ WAV header/padding file, NOT a multichannel WAV file.
I downloaded it myself and tested it and analyzed it.

Did you try playing the file w/Windows Media Player?
The AC3-WAV will be rhythmic, spitting/hissing garbage sound.

Scott

[Abond]

Well, you will stay with your opinion, I will stay with mine. Your statement is not convincing. Bye.

[g.henk]

@Cornucopia and @Abond

Windows Mediaplayer ist not able to play multichannel wav files. for that you will need the vlc player. even if you find mediaplayer not playing the files and you might think you are missing a codec, if you have windvd or powerdvd installed using vlc will do the job.

that is because mediaplayer can only play real ac3 files and not multichannel wav files.

ciao

gabriel

[Cornucopia]

Multichannel WAV is playing in my WMP (both 6.4 and 7,8,9,10) right now. I have both Morgan Stream switcher and Moonlight Odio Dekoda installed--not sure which is helping out, but that's about it for additional codecs/plugins.

I specifically used a reference 6-channel file from the web. Properties in WMP 6.4 say "#Channels: 6". Also created on from scratch with audio workstation. Same thing.

This set of tools may help you: http://www.bath.ac.uk/~masrwd/mctools.html

Scott