I don't really see it as a new problem, but a long existing problem. It's often difficult to tell if a Dolby Digital 2.0 is actually Mono, Stereo, or Surround...whether it be on a DVD or Blu-ray.

Sometimes a program like DVD Audio Extractor and PowerDVD can tell you if it's "Surround" flagged, but not whether it's Stereo or Mono.

But even that can be misleading sometimes. I've seen MGM and Anchor Bay (and other studios) DVD's that flag audio tracks as "Surround" even when they are actually Mono, and stated as that on the case and set-up menu. Sometimes you just have to listen to them for channel seperation, or rip the track and use an audio program to see if there's any wave seperation in the signal.

Quoting DarklyNoon:

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Yeh well, but ripping the audio track and checking if there is a wave seperation might be a proper way to find it out, but I think this is a bit much to ask from a user, at least I think nearly none here will go this far, but I might be mistaken
Also it is very hard to proof.

Oh I fully agree, it's often hard to determine and there's really no easy way sometimes to absolutely determine what Dolby Digital 2.0 is. Generally it's accurate enough to just go by what the back cover or the Audio Set-up menu says it is.

Quoting DarklyNoon:

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P.S. the new Katatonia CD is pwnage

cheers
Donnie

Indeed, and I received my Swedish Special Edition CD in the mail today in fact!

Quoting tweeter:

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if it is a DVD i use PowerDVD to play one of the VOB files on the disc and that will distinguish between 2.0 and Surround.

Yes, but as I said previously it can sometimes give false readings if for some reason the disc was encoded with the audio track as "Surround" but it's not technically Surround with any channel seperation, but Mono. Some Studios did this a lot in the past, Anchor Bay was one.

Quoting CharlieM:

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We must rely on the DVD menu's and the program/equipment we are using.  If we make a resonable effort to give a correct answer, then I think it must be accepted.
If it is wrong, then maybe someone with better equipment/software (future) will correct this and provide his documentation.
I do not think that we can make a big deal out of this.  Get it as accurate as possible with the stuff we have.

My feelings exactly

To find out the real 2.0 sound format on a DVD or Blu-ray is not always simple. Often the producers of the discs do not know either the true format of their programs, nor do most computer programs like PowerDVD and others. That results in often misleading logos on the cover and/or display on amplifier or PC screen. There is indeed only one reliable way to find out what is really on the discs: Listen and think!

The 2.0 mono programs are quite easy to unmask. Simply activate the DOLBY ProLogic mode on your amplifier. If only the center is audible, it is definitely a mono signal. (If the signals are not splitted precisely, there may come a minimal portion of sound out of the left and right speakers but hardly audible because of the dominance of the center signal.)

If left and right speaker are obviously audible, is it either stereo or Surround. To find out which is which is a bit more tricky. That is because on their way through the ProLogic matrix all stereo signals send also sound information to the rear speakers (and to the center). Even simple stereo audio CDs send accidentally signals to the back, as soon as the ProLogic matrix is activated. From now on you have to use your brain.

Possibility 1: The template was a feature film that was originally made for cinema distribution. Then it cannot be simple two-channel-left-and-right-stereo. In cinema there was never pure two-channel-stereo! Since the invention of the talkies 1927 there was always a center channel (and still is there until today). A feature film for cinema is either in mono or has four or more sound channels.

(One exception: In the 50's there was actually a triple track format (L,C,R), which today is history. You can find it e.g. on the DVD of Billy Wilders The Seven Year Itch. A list of feature film sound formats you may find by clicking the following link: http://www.mtsu.edu/~smpte/table.html.)

Possibility 2: The program was produced directly for TV or is it a music video or music documentary or concert footage, there is indeed the chance of real two channel left-and-right stereo which should be listened to favoured in stereo mode on your ampflifier as well as it can be DOLBY SURROUND (which then normally is indicated in the titles and/or on the cover). Anyway, here you have to rely on the information on the cover, on the disc or in the titles.

Keeping that in mind, you can ascertain the following at least for cinema related features on DVD and Blu-ray when 2.0 sound is stated: Is the sound coming just out of the center (with activated ProLogic mode), it is obviously a mono program. In all other cases we have matrixed four channel sound, on DVD usually called DD 2.0 Surround. (A useful hint is also the DOLBY STEREO logo in the end credts which points to matrixed four channel Surround sound.) 2.0 stereo is only possible for not cinema related programs such as TV series or music content.

Thx for everyone answering, I also agree with most that we fill in what our own equipment tells us, makes the most sense to me

@schaumi thx a bunch, that was the best explanation I ever heard, from now on I will do it this way, and I will use your explanation as documentation if that is fine with you

cheers
Donnie

Thx to the great description schaumi gave here, I found out that alot of those commentary tracks are enterred totally wrong into the database, most are entered Dolby Digital 2-channel stereo, but they are only Dolby Digital 2-channel Mono, with the Pro Logic setting you have all the commentary just coming out of the center, so it is 2-channel Mono, curious how the reactions will be when I contribute all those changes.

A few examples are 2010, 28 days later, 28 weeks later, 3.10 to Yuma all entered as Stereo when its only Mono.

Well, at least all the commentary is only coming from the center, sometimes you hear in the far back the real sound of the movie, then the other speakers get some bits too, so if you count that in, they are all Surround, but Stereo is definitely wrong, wondring if that counts as Mono now (with the commentaries always only in the center).

Well,
cheers
Donnie

Yeh, thx for the headsup, I will go with this, then all those commentaries are Dolby Surround, as they still have the sound of the film in the background and the commentary itself from the center.

cheers
Donnie