DTS 6.1 to AC3 5.1 possible?

[MrNike]

Hi,

is it possible to convert DTS to DD 5.1 ?!
and if ;) are there any tool out there who do that ?!

Thx in advance !

Greets,

MrNike

[oddball]

I've been trying to transcode a 6.1 DTS file to 5.1 AC£ but cannot get it to work at all.

Here is what I have tried thus far.

azidts DTS -> AC3 with -auto6ch switch. Result. AC3 plays back channels incorrectly. All sound appears to come from center and right channel.

azidts DTS -> 6 WAV files. Can play them back but try importing them into Sonic Foundry 5.1 Soft Encode and it refuses to load them. Says they must be uncompressed PCM

Tried importing them into Sonic Foundry Vegas with Surround Sound Plugin. Try to render media and get an error about no template for AC3 rendering.

Tried to transcode using BeSweet latest GUI using list.mux file with WAV's listed in it that were from azidts output (Tried with WAV's at 48khz and downsampled to 44khz using azidts) to AC3 5.1

Playback results in the same problem as before whereby all channels are sent to center and front right channel on playback. There is a twist to this too. Sound gets garbled on top of the channel seperation problem.

Tried transcoding directly from DTS to AC3 (IN 48khz and downsampled to 44khz) using the latest BeSweet GUI. Same results.

Next. Tried Hypercube. Resulting output WAV files playback at several time the pitch they should be. Sounds like the chipmunks.

I have the correct DLL's and .AX files registered.

Anyone want to tell me why this is happening? I realise it's all work in progress.

I am going to try using Cooledit to convert the azidts 48khz WAV files next to standard Windows PCM and see what happens.

EDIT: OK there is something quirky about the files azidts outputs. When I try to open them in Cooledit 2.0 it takes AGES to open a 5 meg 1 minute test channel. ???

EDIT EDIT: WHOA! These WAV files that azidts outputs are DTS compressed or something? If I convert them to normal 44Khz Windows PCM and save them they come out HUGE! So what is occuring here? azidts is converting the DTS file to what? Demuxed DTS WAV files? Soft Encode 5.1 won't take these WAV's as they are. There seems to be some big issues when trying to transcode DTS to AC3 it would seem.

[oddball]

Right. I have this sussed now I think. The big file problem was caused by ending a transcode session part way through. I did a DVD2AVI extracting the DTS track and this time I escpaed keyed it to have a small DTS extract.

This allowed me to do a sample test and run azidts to completion without any control-break command (Bad thing to do that it screws up everything).

Anyhow now I run azidts with the following command line.

azidts -manualch -core( -input yourfile.dts -output 6wavs.wav -6ch )

This results in 6 correctly assigned to channel WAV files.

I then use BeSweet command line like so.

BeSweet.exe -core( -input list.mux -output test.ac3 ) -ac3enc( -b 384 )

This results in an AC3 file that I can mux into an avid and it plays back perfectly with correct channel seperation and audio going to the correct speakers as it should.

HOWEVER.

If I try to use azidts to transcode DIRECTLY to AC3 from DTS. It completely messes up the channel assignment. The commandline I used was thus.

C:\BeSweet>azidts -manualch -core( -input d:\rips\test.dts -output test.ac3 -6ch ) -ac3enc ( -b 384 )

I have a feeling that azidts is using the ac3enc.dll inccorrectly or that I have an ac3enc.dll that is different to the one it's expecting. Maybe my a3cenc.dll has different channel assignment to the one it's used to. BeSweet uses ac3enc.dll (At least this version) correctly.

Can someone supply a copy of ac3enc.dll that they KNOW works correctly when transcoding DTS to AC3 direct with azidts?

I'm getting there ;)

[DSPguru]

post all logfiles and attach your mux files.

[hypercube]

I read in DTS spec a stuff called "Xch",
named "Extension to more than 5.1 channels".

you should have these sync word in your .DTS file: 0x5a5a5a5a

may be, it is possible to remove this part from the stream and
produce a 5.1 DTS file from 6.1 DTS file...

[oddball]

Perhaps. But it was a 700MB file in the end and Hedit's searching was taking too long so I gave up on that. As stated. azidts to 6 WAV files outputs the correct channels. It's just when transcoding direct to AC3 that azidts messes up.

[hypercube]

this is certainly a bug.
do you know if your DTS file is DTS ES or DTS ES MATRIX ?
(see my web site "The Audio Formats Jungle" if you don't understand)
I think you have a 5.1 DTS stream...with a rear center matrixed
channel.
So you never see this channel without a DTS EXE MATRIX decoder.
So your DTS file is read as a regular 5.1 DTS stream.
So this is certainly a bug related to AC3 encoding.

:D

[Rrrough]

Very good explanation of the different formats on your site. Definetly a "must have read" for anyone interested in multichannel sound.

[hypercube]

thanks !

[oddball]

Yes it's DTS EX Matrix. Any fix for it? :)

[Wilbert]

@oddbal,

Also other people will benefit. So please "post all logfiles and attach your mux files", so that DSPGuru can see what's wrong.

[hypercube]

Yes it's DTS EX Matrix.
so your file is a regular 5.1 discrete stream.
channel 6 is produced by computation.
the pb is certainly in AC3 encoding.

it could be fun to scan a real DTS ES (not DTS ES MATRIX)
stream... to see if Xch sync word are there...

[oddball]

Oh there is two different 6.1 DTS versions? I don't know then. It's the DTS track from the R3 Spirited Away DVD. It says 6.1 on the back. Whether it is ES Matrix or not I don't know.

[hypercube]

it seems to be 6.1 ES, not 6.1 ES MATRIX.
http://miao.us/reviews/0011.php

[oddball]

Well azidts 0.1 decodes correctly to 5.1 WAV's just not AC3. When you do to 6 WAV's in azidts using the -manualch command it pops up a Intervieo iviaudio.dll box where you can select to output 5.1 audio.

Anyhow Hypercube needs to be able to handle 6.1 DTS too and the ability to transcode directly to AC3 would be desirable. However I think once that bug is resolved in azidts it will not be required (Although there is always room for more than one app doing this sort of thing of course. Not to sound mean or anything) :)

[hypercube]

this is not in my plan for instance. You can use single 5.1 WAV engine with softencode...so...there is no emergency.
44100 support as input is more needed.

[Wilbert]

Don't know whether this is usefull. Yesterday I discovered (with graphedit), that there is a filter (similar to iviaudio.ax, also from windvd) which can also decode 6.1, 7.1 and 8.1 streams. Problem is that I forgot the name of the filter (and I'm not behind my own pc).

[DSPguru]

Originally posted by oddball
If I try to use azidts to transcode DIRECTLY to AC3 from DTS. It completely messes up the channel assignment. try out BeSweet.dll v1.5b18

[oddball]

Tried that already ;)

[DSPguru]

Originally posted by oddball
Tried that already ;) that's an odd way of saying "thank you, it works!" :o

[oddball]

No it's a way of saying 'I tried it before you even suggested it and it DID NOT WORK!' ;)

[DSPguru]

Originally posted by oddball
No it's a way of saying 'I tried it before you even suggested it and it DID NOT WORK!' ;) you could not try that, because i only uploaded the binary to my website when posting.