Missing HD Audio Formats on Blu-Ray Discs...

[david_tring]

I've recently purchased a UK copy of "Blade Runner" on Blu-Ray. This states on the packaging notes that the main-feature audio is in PCM English 5.1 and Dolby Digital 5.1 formats.

On playing the disc the audio defaults to Dolby True HD - a format that isn't mentioned on the packaging. There seems to be an option within the disc's "Languages" menu to select ordinary Dolby Digital, which is of course a non-HD format. However, there is no apparent way to select the multi-channel PCM soundtrack promised on the packaging.

This is the second Blu-ray I've had with audio tracks that seem to differ on the disc from what is quoted on the box - given that I haven't seen all that many Blu-Ray discs this is a worrying average. I've played millions of old-style DVDs over many years and never had a single one that differed!

So two questions fellow forum members - firstly has anyone else found this general problem and secondly any ideas on how to get to the PCM sound track on Blade Runner (if in fact it exists)?

Regards - David

 

[Anonymous]

PCM is uncompressed, which is essentially describing "true HD" sound in another way.
As your compressed option is "Dolby 5.1", then it follows the PCM is the uncompressed Dolby: i.e. Dolby true HD.

What more do you want? The packaging doesn't mention DTS so I'm unsure what you are thinking you may have?

 

[mattjax05]

I think he is confused with LPCM and Dolby True HD, in this case both are the same.

 

[Anonymous]

As I just said?

 

[mattjax05]

SAP7 - I wasn't duplicating what you said just agreeing!

 

[david_tring]

Thank you for your replies gentlemen but I must disagree - PCM is uncompressed audio (the highest quality) whereas all Dolby/DTS formats are compressed.

The only differences between the various Dolby and DTS formats relates to how much compression is applied, DTS is normally "better" in this regard. See "What Hi-Fi" November 2007 page 68 for a very informative chart showing the compression rates.

A music CD is (uncompressed) PCM at 44.1KHz sample rate. PCM from a Blu-Ray is sampled at an even higher rate, so is sometimes described as "better than CD quality". So my "Bladerunner" audio in Dolby format is not as good as the promised PCM and certainly not the same thing unfortunately.

 

[Anonymous]

david_tring:Thank you for your replies gentlemen but I must disagree - PCM is uncompressed audio (the highest quality) whereas all Dolby/DTS formats are compressed.

The only differences between the various Dolby and DTS formats relates to how much compression is applied,

It depends which Dolby and DTS you're talking about. As you state, LPCM is uncompressed audio, and the Dolby and DTS tracks (from DVD days) used a lossy compression algorithm.

Dolby TrueHD and DTS-HD Master Audio are compressed, but it's a lossless algorithm, so effectively the end result will be the same as LPCM (because it's bit-for-bit reproduction - it's just there to reduce the usage on disk space, and possibly datarate, should that be an issue). I believe TrueHD uses Meridian Lossless Packing, but I'm not sure about DTS-HD.

 

[Gerrardasnails]

david_tring:Thank you for your replies gentlemen but I must disagree - PCM is uncompressed audio (the highest quality) whereas all Dolby/DTS formats are compressed.

The only differences between the various Dolby and DTS formats relates to how much compression is applied, DTS is normally "better" in this regard. See "What Hi-Fi" November 2007 page 68 for a very informative chart showing the compression rates.

A music CD is (uncompressed) PCM at 44.1KHz sample rate. PCM from a Blu-Ray is sampled at an even higher rate, so is sometimes described as "better than CD quality". So my "Bladerunner" audio in Dolby format is not as good as the promised PCM and certainly not the same thing unfortunately.

Here you go. Packaging is wrong if it says there is PCM audio on the disc.

http://bluray.highdefdigest.com/1039/bladerunner_cce.html

 

[david_tring]

Thanks Gerard, at least it's good to know I'm not cracking up....!

I've e-mailed Warner Bros UK so will see what they say. I guess that ultimately if it's a print mistake then all the complaining in the world won't produce a PCM sound track if none actually exists.

But,as I mentioned in my original post, this makes 2 Blu-Ray out of the relatively small number I wathced that had "wrong" info. Given that I've never found a single DVD with this type of mistake, it seems bizarre that suddenly the production process within studios seems to have gone wrong in this way.

 

[Anonymous]

I do sympathise with you on this one - I've found that some versions of Cyberlink's PowerDVD will downmix TrueHD tracks to two channels (it appears that DTS-HD Master Audio and LPCM are OK).

This shouldn't be a problem, as TrueHD is an optional format, and the discs are supposed to contain one of the mandotory formats too. It appears that some (e.g. Spiderman 3) do this properly - having TrueHD and LPCM, and some (Iron Man) only have a TrueHD track. The only reason I can think they they're getting away with it is that foreign language streams for the movie are present (in other formats). However, it strikes me as a bit of a con, as it means the only English track is in TrueHD.

Then there are the discs that just contain a "5.1 surround track" without telling you what format is present!

Oh, and then there's all this BD-Live stuff, and having to update even standalone players to cope with new features. Sometimes I've no idea how the average Joe is supposed to work out what's going on.

 

[Anonymous]

Loads of DVDs have incorrect labelling on the packaging - it happens. Blu-ray is no different. The Canadian Blu-ray releases of Sin City and From Dusk Till Dawn are also mislabelled as DTS 5.1, but in those cases they're actually DTS-HD Master Audio 5.1.

 

[Clare Newsome]

Mentasm:Loads of DVDs have incorrect labelling on the packaging - it happens. Blu-ray is no different.

Absolutely - and DVDs were particularly bad in their relative infancy, as Blu-rays are now. It'll settle down.

 

[Anonymous]

I certainly hope it will. I think we need a bit of stability with all the new features coming out on Blu-ray discs.

Should it be useful to anyone - the problems I mentioned with PowerDVD appear to be down to some OEM versions that are packaged with Blu-ray drives. I managed to get a reasonably priced upgrade from Cyberlink, and can confirm that the full version of PowerDVD 8 Ultra will play TrueHD in surround, and give an analogue output from the soundcard. Let's hope we don't get yet more audio formats appearing on discs, and requiring yet another software update!

 

[Anonymous]

They're not going to change the spec after it's been finalised. There's really no need for different formats on current hardware - lossless is lossless.