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» Film-Tech Forum   » Operations   » Digital Cinema Forum   » Blu - Ray, Scaler & Sound... (Page 1)

 
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Author Topic: Blu - Ray, Scaler & Sound...
Michael Harlow
Expert Film Handler

Posts: 170
From: Faversham, Kent, UK
Registered: Jul 2002


 - posted 02-02-2013 06:05 AM      Profile for Michael Harlow   Email Michael Harlow   Send New Private Message       Edit/Delete Post 
Hello, lovely Film-Tech members, I am after a quick piece of advice please?
We have a Barco DCP2K-19B projector, Doremi Server and so on, CP750 for the sound.
We have a Sony Blu-Ray player and a Gefen Scaler (AV Pro II), but we seem to have a sound issue...
The Blu Ray goes through the scaler and then to the projector, the sound for the blu ray goes straight from the "digital" output on the blu ray player to "input 3" on the CP750, the scaler is not looking after the sound...?
The issue we have that the Blu Ray only seems to use L and R screen channels and nothing else.. i have checked the settings of the player and it all looks ok.
Is this normal behavior..? can i get the CP750 to output all 6 channels as it does on normal film sound from the Doeremi?
Sorry for the long post, any advice, as always is welcome
Michael.

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Carsten Kurz
Film God

Posts: 4137
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 02-02-2013 06:42 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
You need to configure the BluRay Player for RAW/Bitstream Output, and the CP750 for AC3 decoding on the digital input.

Then you also need to select a multichannel track when playing the disc - usually they have a selection of stereo and multichannel tracks.

Sooner or later you could run into trouble with discs that have no AC3 tracks, as BluRays may contain different surround sound formats, but the CP750 will only decode Dolby's consumer variant.

In theory, some BluRay Players may transcode other formats to AC3/SP-DIF RAW, but it depends on the specific player and some transcodings may even be forbidden by licensing.

Which BD player are you using?

- Carsten

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Michael Harlow
Expert Film Handler

Posts: 170
From: Faversham, Kent, UK
Registered: Jul 2002


 - posted 02-02-2013 07:40 AM      Profile for Michael Harlow   Email Michael Harlow   Send New Private Message       Edit/Delete Post 
Carsten, thank you very much for taking the time to reply. I will try this when i get to the cinema, the blu-ray player we are using is a Sony BDP-S185.
Thank you for your help, will let you know how i get on later today.
Michael

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Marco Giustini
Film God

Posts: 2662
From: Reading, UK
Registered: Nov 2007


 - posted 02-02-2013 09:43 AM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
As Carsten said, you can bypass the Gefen, no problem. The upside of using the Gefen is that you then use it as a gateway for all your alternative content. Using the 750 you need to make sure you have the proper cable. Also, you have sync controls on the Gefen, while on the 750 you need to access the setup software.
Are you sure they did not connect the analog output of the Gefen to the analog input of the 750?

Besides that, it's as Carsten says, it's a BD issue. The usually decodes AC3 streams with no configuration needed.

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Dennis Benjamin
Phenomenal Film Handler

Posts: 1435
From: Denton, MD
Registered: Feb 2002


 - posted 02-02-2013 11:01 AM      Profile for Dennis Benjamin   Author's Homepage   Email Dennis Benjamin   Send New Private Message       Edit/Delete Post 
Ironic that this subject gets brought up again.

I did more testing this morning to try and figure out a way to run those Blu-Rays that have only the "DTS MASTER AUDIO" soundtracks in surround. Currently, I have to downmix them to 2.0 audio in order to play through a Dolby CP-750.

I have officially given up on this endeavor. If we happen to play a Blu-Ray that only has the "DTS MASTER AUDIO" soundtrack, then it will have to play in Stereo.

Oh well.

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Antti Nayha
Master Film Handler

Posts: 264
From: Helsinki, Finland
Registered: Oct 2008


 - posted 02-02-2013 11:13 AM      Profile for Antti Nayha   Email Antti Nayha   Send New Private Message       Edit/Delete Post 
Dennis: I’m not sure if this was already brought up, but there are Blu-Ray players which can be set to re-encode other multichannel formats to Dolby Digital.

One such player is Samsung BD-D8200N/D8500N (those may be euro-specific models, but others exist as well).

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Chris Slycord
Film God

Posts: 2986
From: 퍼항시, 경상푹도, South Korea
Registered: Mar 2007


 - posted 02-02-2013 04:28 PM      Profile for Chris Slycord   Email Chris Slycord   Send New Private Message       Edit/Delete Post 
Also, if you rip a blu-ray you could use a piece of software out there called eac3to that lets you convert the audio to your choice of ac3/dts/flac. Then you could reburn the bluray from the files left and so you'd have an ac3 bluray of the movie.

http://www.videohelp.com/tools/eac3to

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Antti Nayha
Master Film Handler

Posts: 264
From: Helsinki, Finland
Registered: Oct 2008


 - posted 02-02-2013 04:58 PM      Profile for Antti Nayha   Email Antti Nayha   Send New Private Message       Edit/Delete Post 
If you decide to go through the trouble of ripping the disc, I would suggest that you play the file instead then – either on a hardware player or a dedicated PC.

Optical media for screenings = evil.

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Marco Giustini
Film God

Posts: 2662
From: Reading, UK
Registered: Nov 2007


 - posted 02-02-2013 05:05 PM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
definitely a hardware player if you don't want the issue of vertical sync!

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Carsten Kurz
Film God

Posts: 4137
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 02-02-2013 06:27 PM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
I never came across discs with only DTS in europe, but I heard they do exist in the US.

Some players decode DTS to 8ch LPCM and play this through HDMI. You may then try to capture the multichannel sound from the HDMI audio. There are external converter boxes that loop through the HDMI video and output audio to either multichannel analog or S/P-DIF.
Once you use one of these converters, the setup will be a lot more complicated than the plain AC3 input to the CP750. Datasats AP20 will decode dts formats as well, but it's a bit more expensive than the CP750, sure no retrofit solution for existing CP750 users.

There are boxes like this, but the specs tell you nothing about what they actually do with the different HDMI surround formats - you have to test it.

http://www.amazon.com/Vanco-280573-HDMI-Audio-Extractor/dp/B00AB40EWY/ref=sr_1_3?ie=UTF8&qid=1359851145&sr=8- 3&keywords=hdmi+deembedder

The Gefen AV Pro II has nice audiofeatures as well - but won't help you with DTS encoded audio, it will only decode Dolby surround formats, just like the CP750.

- Carsten

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Steve Guttag
We forgot the crackers Gromit!!!

Posts: 12539
From: Annapolis, MD
Registered: Dec 1999


 - posted 02-02-2013 07:04 PM      Profile for Steve Guttag   Email Steve Guttag   Send New Private Message       Edit/Delete Post 
Note...it is entirely possible that on a disc-by-disc (depending on BluRay player), you will need to select LPCM or Dolby Digital if you are using a CP750. The CP750 handles, PCM (and will perform a prologic/II matrix decode), and AC3 over the coax or Toslink inputs. if the disc does not have Dolby Digital and you select "bitstream" then you likely will not have sound. But if the disc DOES have Dolby digital, then bitstream will get you AC3 audio. Then there are those discs that have damn near every format and the player may allow you to select most/all permutations so it may take a combination of selecting what type of output you want your player to provide AND then selecting the proper track!

There is a nifty device coming out from Crestron...the HD-XSP

It is a full bore HDMI audio extractor that can handle all of the whiz-bang audio in one box and send the picture on to the projector.

If the lower bandwidth audio is sufficient, Extron has the SSP 7.1

Naturally, one can also use an A/V receiver (consumer) but the model life-times are very short and it is becoming increasingly popular to only have preamp outputs on the higher-end system.

Personally, I'm looking to go a bit more professional and reliable.

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Antti Nayha
Master Film Handler

Posts: 264
From: Helsinki, Finland
Registered: Oct 2008


 - posted 02-02-2013 07:06 PM      Profile for Antti Nayha   Email Antti Nayha   Send New Private Message       Edit/Delete Post 
quote: Carsten Kurz
I never came across discs with only DTS in europe, but I heard they do exist in the US.
Funny that it’s you who should mention that… The last two that I encountered were actually German Blu-Ray releases:
Gremlins 2
The Quiet Earth

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Carsten Kurz
Film God

Posts: 4137
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 02-02-2013 08:08 PM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
I may have just been lucky - I just found a graph showing BD audio codec distribution on titles between 2007 and 2011 - 53% DTS-HD, 19% Dolby TrueHD...

Basically, every BD player with a DTS decoder per spec should be able to send discrete multichannel audio over HDMI in LPCM. That would at least help with external HDMI audio extractors. Of course, for a CP750 with S/P-DIF in, you would still need an AC-3 transcoding (or an option to use the discrete analog inputs if not needed for other purposes).

The CP750 is simply not a good choice...

- Carsten

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Marco Giustini
Film God

Posts: 2662
From: Reading, UK
Registered: Nov 2007


 - posted 02-03-2013 03:49 AM      Profile for Marco Giustini   Email Marco Giustini   Send New Private Message       Edit/Delete Post 
Carsten,
What would you suggest instead?

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Carsten Kurz
Film God

Posts: 4137
From: Cologne, NRW, Germany
Registered: Aug 2009


 - posted 02-03-2013 06:52 AM      Profile for Carsten Kurz   Email Carsten Kurz   Send New Private Message       Edit/Delete Post 
Datasat AP20. Not only solves the DTS decoding issue, but also takes care of HDMI video switching and passthrough. It is a bit more expensive than the CP750, but for a still more flexible equivalent, the slightly cheaper 8ch version would do.

Plus, if you take a CP750 and need an auditorium level control, it will cost you something like 600US$ for a CAT 868. While the AP20 can use any of the shelf pot and cabling, like existing ones from e.g. a CP65 installation.

So, the effective price difference between a CP750 and an AP20-8ch is small. And I do not even mention that the AP20' features are way beyond the CP750.

If you're stuck with a CP750, I guess I would look into a BD-Player with internal DTS decoding and then use an external HDMI 8ch LPCM converter.
The problem is that, for general domestic use players, these features are rarely documented exactly. You simply have to do some testing. Or, through a lot more money at it, like with the EXTRON devices Steve mentioned.
But hey, this is for the occasional BluRay presentation with DTS-only soundtracks. I don't want to spend 1000-2000US$ just for that capability.

The Gefen AV Pro II can decode 8ch LPCM from HDMI. If Michael can find a BluRay Player with internal DTS decoding, it could solve the issue for less than 100US$.

BTW - Oppo has new and lower priced BluRay Players now, the 103 and 105. Unfortunately, though even the low cost model has RS232 control, they still ignore the idea of deactivating the OSD completely.

If Dennis' CP750 has the analog multichannel aux inputs unused, he could simply buy a Player (again, like the Oppo 103) with discrete multichannel analog outs and feed these to the CP750. hat would enable ALL DVD and BluRay multichannel formats for him.

- Carsten

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