TruSurround XT

[FiW]

can decode AC3 6-ch track to 2-ch WAV with TruSurround XT technology? IMHO, TruSurround XT better than Dolby Surround. graphedit & cyberlink audio effects not work :(
anyone can help me?

---
sorry, bad english :)

[MaTTeR]

Haven't heard of anyone getting these filters to work outside of PowerDVD yet. It would be a welcomed sight though.

DPLII seems to be much better than TruSurround XT by the way. Hopefully we can get that implemented soon.

[user]

Hi,

can I understand it, that somebody is working on implementing DPL2-technology into eg. azid ?
Eg. 5.1 ac3 to wav with DPL2 information ?

[DJ Bobo]

@ FiW
It would be really nice, if someone can do that. The question is: would it be TruSurrounded all the time or only with a specific filter?

@ Matter
DPL2 can't be implemented in WAV, since it's a playback-only technology.

[ChristianHJW]

Sorry for my complete ignorance on DPL2 .. i understand its an extension to old DPL and will give separated rear channels, correct ?

So, here is my question to you :

If i decode the 5.1 AC3 into DPL2 ( if Midas implements DPL2 decoding into Azid ) , will 'old' DPL equipment be able to handle it as DPL again, means, is the new DPL2 standard backwards compatible ?

[MaTTeR]

Originally posted by bobotns
@ Matter
DPL2 can't be implemented in WAV, since it's a playback-only technology.

??:confused: Have no idea where this came from. Care to expand a little? Ohhh...so your implying that Azid won't be able to use WAV as an intermediate file?

If i decode the 5.1 AC3 into DPL2 ( if Midas implements DPL2 decoding into Azid ) , will 'old' DPL equipment be able to handle it as DPL again, means, is the new DPL2 standard backwards compatible ?
I'll be taking a serious look at this now that user has uploaded some samples. I'm thinking the specs states DPII is backward compatible. The question is how will it sound on older DPL amps and then also downmixed to stereo. I hope to post my results this weekend when freee time allows.

[user]

Hi Matter and all,

yes, test it, please.

I tested the DPl2 samples on my harman kardon 5000.
That receiver has got of course not only Logic7 (like DPL2-decoder), it has an "old" DPL-mode, too, and of course pure stereo.

I put in the samples digitally in to the HK.
I would say: the DPL2 samples are very well backwards compatible, at least like DPL-stereo-waves are compatible to pure stereo.

@bobotns:
"Of course" it is possible to create stereo waves containing DPL2 information, that means separated rear channels, full frequency, (old DPL is only one rear channel (mono), cut at 7 or 8 kHz.).
Dark Avenger has proven/done it.

Everybody can download those important DA/spacer's samples (and addional high quality music DPL2-examples) at

http://www.ff123.net/samples/dpl2/

Samples are in monkeys audio, ape.

A lot music on CDDA contains DPL / DPL2 informations, that become decoded and you are able to hear it at rear speakers.

But what has surprised me most:

Even Vinyl, LP, from the very early Seventies contains excellent information for Logic7/DPL2 decoder.
Last Sunday I reactivated my Dual-player and a friend brought some vinyl.
Eg. Mahavishnu Orchestra, Deep Purple with London Symphony orchestra (original old version), Billy Cobham, all on LP !!

What does fascinate me, that clearly certain instruments are playing from the rears, or even only from rear, even from such old analogue recordings.
It is not a simple silent echo/hall from the rears !!!

BTW: that friend was first sceptical on Dolby Surround, because he knew only "old" DPL. He tells now, that DPL2/Logic7 is quite fine, even for music, not only for movie effects. Of course pure stereo for certain music and certain listeners is still more exactly regarding precision, exact wideness , placement of instruments.

Logic7/DPL2 (and probably Kenwoods Circle Surround) ROCKS !



The samples show following:

DownMix
Roll
rear-both-left-right

demonstrate, that DA has mixed some signals only at the rears, with separation of left and right rear (in Logic7/DPL2 modes).
The fronts are silent (in DPL and DPL2/Logic7 modes).

The other DPL2-samples are official-DPL2-samples, excerpts of professional hifi-music from CDDA, extracted by EAC...

[DJ Bobo]

@ Matter
I don't have a DPL2 receiver to verify this, but this what I read in PowerDVD:
"Pro Logic II is a new Dolby Laboratories technology that produces surround sound from any stereo source (e.g. 2-channels), including CDs, MP3, VCD and DVD."

And Dolby says:
"Dolby Pro Logic II is an advanced matrix decoder that derives five-channel surround (Left, Center, Right, Left Surround, and Right Surround) from any stereo program material, whether or not it has been specifically Dolby Surround encoded. On encoded material such as movie soundtracks, the sound is more like Dolby Digital 5.1 (see below), while on unencoded stereo material such as music CDs the effect is a wider, more involving soundfield. Among other improvements over Pro Logic, Pro Logic II provides two full-range surround channels, as opposed to Pro Logic’s single, limited-bandwidth surround channel"

For my understanding, this means, DPL2 is only applied when decoding.

And then user has come, claiming having DPL2 encoded WAVs.
Well, I'm short circuited! I don't know any more!

[MaTTeR]

bobotns,

It's possible;) I'm downloading user's samples as I type this message. Try them for yourself and then give us some feedback.

[DSPguru]

DPL2 Iz mainly a decoder, and it will create 5.1 track out of a stereo track.
in case the track was encoded as dpl, the decoded track should sound like the original.
in case the track is a plain stereo, the decoding process will end with an interpolated 5.1 track, that should give you a feeling of a surroud sound. (that's a by-product of the dpl2 decoding algorithm)

either way,
the dpl2 decoder ALWAYS do the same thing.

[DJ Bobo]

@ DSPguru
So you are of my opinion that DPL2 can't be implemented in WAV?

@ Matter
As said, I don't have the proper equipment to test the files

[DarkAvenger]

DPL (old and II) are *decoding* techniques.

But as I posted in the other thread:

I found out how to control DPL2's behaviour, at least I am pretty sure about it. I am waiting for Midas to mail out some test versions, as I really don't understand what makes him take so long.

If anyone is interested, you can have a modified version of DSEnc to create test "DS2" downmixes. I hope you still know how to use DSEnc...

[user]

Decoder
stereo-Waves can become decoded to "independent, full frequency, 5-channel" surround by:

Logic7 (trademark of Harman Kardon or related daughter company)
Circle Surround (trademark of Kenwood)
DPL2 = Dolby Pro Logic 2 (trademark of Dolby labs)

Why have I chosen this ranking ?

Because as I remember, Logic7 and Circle have been earlier sold than DPL2.
In fact, Dolby was slow. Just because there is the name "Dolby" it is more popular.
"Independent" very well known German hifi-magazine Stereoplay has tested and published one month ago, that decoding by Logic7 sounds even slightly better than decoding by DPL2.
They compared the new HK AVR 5500 against each other, one time with setting Logic7, then with DPL2.
Because I own for 3/4 year a HK5000, I telephoned to HK-Germany and asked their opinion about difference or not between Logic7 and DPl2, because they have added DPL2 to their new models, in spite of the fact, that they have Logic7. I suggested the man on telephone, that I would sell my HK5000 and would buy a new 5500, if DPL2 would be better than Logic7.
But the man told me:
HK has added to new models DPL2 additional to Logic7, because: People who buy amps/receivers at the moment, are asking for DPL2, just because from past the name Dolby is well known.
So because HK does not want to lose buyers (who look just for the name Dolby, not the true content !), they have added DPL2 additional to Logic7.
And this fact gave testers of big hifi-magazine the possibility to check DPL2 against Logic7 as decoder with the result that Logic sounds a little bit better.
But of course we all know that such tests are not always the truth, but that hifi-magazine performs its tests normally very well and their results I could confirm for myself, if I performed tests, if I have been lucky to have similar equipment.


Encoder

so, are there existing special DPL2-waves ?

I tell: yes.

A long time before the HK5500 test with Logic7 against DPL2 has been published (this March or April, I remember),
the same very well known hifi-magazine in germany (Stereoplay) added a promo - CDDA to its January release with about 40 minutes music, new recordings.
Some excerpts you can download at ff123's DPL2...
This CDDA was labelled in big letters:
DPL2
They described exactly the surround sound, effects. It was very clear that this CDDA should promote the new models of amps/receivers, like HK5000/5500, Denon 1802 (sic !) and so on....
With several hifi-shops distributed over whole Germany, they selected demo-hifi-surround-components, so that everybody could listen in the shops to that DPl2 examples via very well (but affordable) hifi-components, over all Germany the same components in different shops.

And since 3/4 of a year I am listening to my old CDDA's/mp3/mp2 music/movies.
And recordings are different:
Some music does not result to exciting surround, That I would describe like "old DPL" surround effects/sounding-quality (but with this I describe music, that does not contain DPL/DPL2-code).

1.
Music without surround information results to some "hall/echo" from rear speakers, decoded by Logic7/DPL2.

2.
Music with DPL information (as you know by azid: DPL is coded into stereo wave...)
results to very well surrounding decoded by Logic7/DPL2.
This sounds much better than decoding the same music by DPL-mode !!!!

3.
These new DPL2 samples from that CDDA sound very well decoded by Logic7/DPL2.
They sound like normal DPL surround if decoded by DPL.
Of course you can play DPL2-music in pure stereo.
These samples sound amazing, fantastic, even in pure stereo.
This has been reported not only by me, there were printed reactions of people in germany in that magazine, one or two months later.

Then my experiences with Dark Avengers test samples.
DA has not owned a Logic7/DPL2 amp/decoder/receiver. So he asked in www.dvdboard.de or such a kind of group, who already ownes a DPL2-decoder.
I mailed him , that I would do some test for him, if he sends waves to me.
The first sample showed immediately separation of rear left against rear right.
Perhaps the second sample was not so well separated.
The third sample had very clear separation between rears left and right.
These last mixes with very clean separation you can download at ff123's DPl2 section.

As I have understood DA, he changed some db - levels of the channels in the mix.

Probably it is done like DPL coding:
phase shifts, and the decoder recognizes the phase differences. Eg, if some music signals have this special phase, then they are forwarded to eg. rear channel or to center.
Remember:
DPL had 4 channels: front right and left, center, one ! rear channel (only up to 7 or 8 kHz) !
So the "degrees" between one and the next channel have been much, big difference, so it was easy to decode it, at that time, the technical possibilities.

Now DPL2:
5 channels: front left and right, center, rear left and right, all independet, all full frequency up to 20 kHz.
That means, that phase differences between neighboured channels are somewhat smaller than compared with DPL.
But today the decoders are able to manage it, to recognize smaller differences of phases/phase shifts, so more information is hided in phase shifts.

(all my suggestion, how it *COULD* work)
Perhaps not exactly, but at least it is a methapher, how it could work.


And I tell it again:
The most amazing/fantastic surprise:
That Logic7/DPL2 decoder decodes SOMETIMES unbelievable surround even from early seventies/sixties/eighties waves (digital or/and !!analogue sources) !!!
AFAIK DPL coded music exists since the Nineties (BTW: that magazine stereoplay has published a bonus-CD at one month with exciting music coded in DPL, some years ago, I own that CDDA, too).
DPL2 coded music will be coming more and more in this decade, I guess. BTW: On your music - CDDA's, is there written: this contains DPL-signals ! ?
No, this is very rare. I guess, music industry does not label its CDDA's with DPL or now with DPL2, because: 1. then they would have to pay licence fees to Dolby labs , 2. they do not want to irritate buyers of their CDDA's with a lot of formats....

DPL2 is a big advance over DPL, just like stereo over 2 mono-speakers.

And so my conclusion:
As we have a lot quite well sounding 5.1 ac3's, why should not we perform a stereo-DPL2/Logic7-compatible downmix, since Dark Avenger has found a method (by trying out) to do it.
I think, that the finished program, probably "azid2.exe" offers you to select, if you want pure stereo; DPL; or DPL2 downmix.

Of course advertisements tell, that DPL2/Logic7 decodes surround even from old pure stereo sources.
This is, because they make the big money with new amps/receivers, they want to sell.
Music-CDDA's they sell anyway, you buy your music-CDDA's independent of "DPL, DPL2, HDCD", you buy normally your preffered music reagarding the artists name, not the name Dolby1/2/HDCD and so on...

[Spawn]

DarkAveneger,

Ahh the old DSEnc days, seems to long ago now .. ;-). But yes, I'll give it a shot. I have a friend with a DPL2 capable receiver, I can test it on.

Email it to paul_arola@hotmail.com/

Thanks,

[DSPguru]

Originally posted by bobotns
@ DSPguru
So you are of my opinion that DPL2 can't be implemented in WAV?dpl decoder wiLl interpolate wav to 5.1 surround track, even if the wav wasn't encoded as dpl.

[DarkAvenger]

@Spawn

I need another address:

I'm afraid I wasn't able to deliver your message to the following addresses.
This is a permanent error; I've given up. Sorry it didn't work out.

<paul-arola@hotmail.com>:
[censored]_does_not_like_recipient./Remote_host_said:_550_Requested_action_not_taken:_mailbox_unavailable/Giving_up_on_[censored]/

[Spawn]

Sorry I accidently put in my email with a dash instead of an underscore. This is the correct address:
paul_arola@hotmail.com

Thanks again,

[MaTTeR]

I finally got around to listening to the DPLII samples today on my DPL amp (Sony:( )

I must say they sounded really well, more specifically the stereo image and sepration was exceptional. The surround effects are a little difficult to judge with the music samples though. Do we have any way of getting a clip from a movie source? I suppose not:rolleyes:

Has anyone heard from Midas yet in regards to him supporting DPLII?

[ChAoS Overlord]

Is there some directshow filter than that can decode (as it is primarily a decoding technique) DPL(II)? Because right now when playing back in mediaplayer, bsplayer,... movies with MP3 just get played back as pure stereo.

[MaTTeR]

@ChAoS Overlord

I don't know of a DSF that will allow the decoding except for Cyberlink's filter which I've yet to make work in any other application. I've played some MP3 files with PowerDVD using DPLII and it sounded really cool, espcially to the normal stereo mode.

If your watching your movies through an external amp then just switch your amp to DPL mode. It really is much better IMO than watching the movies in stereo.

[ChAoS Overlord]

Well I've been using Powerdvd too, the strange thing is: I can hear sound of dvd's & audio cd's, but not of mp3's and/or divxes with mp3 sound... I have the latest build tho!

[MaTTeR]

Well I don't have any Divx files to test here, just Xvid and Vorbis. I'm just playing raw MP3 files in media mode though and toggling between stereo mode and TruSurroundXT. With headphones you can hear that TruSurroundXT prvoides a much more rich sound(especially bass). I also went in the advanced dialog and turned off all options except DPLII/Music mode.

I'd expect this to work for an AVI file with embedded audio as well.