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Author Topic: Wrong audio tracks on HDMI input Joost Vandertogt Film Handler Posts: 8 From: Zoetermeer, ZH, The Netherlands Registered: May 2016 posted 05-31-2016 08:12 AM                     Hello all, I'm pretty new in this bussiness. Originally I'm a sound engineer in a theatre (in the Netherlands) and since november last year we have a DC setup in our small stage. The setup is: Doremi DCP-server Doremi IMB Barco DP2k-15C Datasat AP20 Audio from IMB to AP20 is AES. On the IMB, there's a HDMI input, which we would like to use for viewings outside of the usual screenings. When I last connected a MacBook, the picture was fine, but there's something odd with the audio tracks. When viewing a video with 5.1 sound, the center channel was missing. When putting just audio from iTunes, the audio came on input 3 and 4 on the AP20 (center and sub). Now my question is: what's going wrong and where can I (if possible) correct it? Later I'll try with a DVD/Blue-ray, but we're a little busy at the moment... If the solution is above my head, I'll ask DCinex when they come for maintenance in November. Thanks in advance! Kind regards Joost  |  IP: Logged Dave Macaulay Film God Posts: 2321 From: Toronto, Canada Registered: Apr 2001 posted 05-31-2016 02:22 PM                     The HDMI sound processing in the IMB is mysterious, I have tried to get details from Doremi without success. Some sources give 5.1 sound and some don't. Some come out as L/R (AES pair 1) which can be decoded with ProLogic to whatever that gives (4.1?). Apple have their own impenetrable secrets, no clue what is happening there. Try a standard DVD player with HDMI output and see what you get out of the IMB. Generally I find it better to strip out the digital audio signal from HDMI and deal with it in an outboard processor, where non-DCP content playback is required. It just makes everything simpler especially with BluRay where there are so many audio options. If you strip out HDMI digital audio and send it to an AP20 SPDIF input you should have better results.  |  IP: Logged Sascha F. Roll Expert Film Handler Posts: 140 From: Berlin, Berlin / Germany Registered: Sep 2015 posted 05-31-2016 02:28 PM                     Never had any serious issues with the HDMI audio de-embedding in the AP20. It just works. And is easy to configure. Just connect your HDMI source to the AP20 HDMI inputs 1-4 und send the "picture" stream to your IMB and everything should work fine. /Edit: The only thing that didn't work for me was Copying the Side Surrounds to the Back Surrounds (on a DS7.1 channel layout) when using DTS NEO6 Matrix Decoding.  |  IP: Logged Joost Vandertogt Film Handler Posts: 8 From: Zoetermeer, ZH, The Netherlands Registered: May 2016 posted 05-31-2016 03:03 PM                     Thanks for the answers. Sascha, I'm using the HDMI input on the IMB in the projector. The AP20 gets its AEB audio signal by about 35 meters of Shielded CAT6 cable, because all the amps (and AP20) are in a room with all other amps of tha hall, so using the HDMI input of the AP20 is not quite an option, because the HDMI signal has to travel the same distance back to the projector (or we have to use 2 HDMI ports on the source). Dave, I'll soon try with an ordinary DVD-player and maybe a Windows notebook, to see if it reacts different then Mac. And offcourse I'll post my findings  |  IP: Logged Sascha F. Roll Expert Film Handler Posts: 140 From: Berlin, Berlin / Germany Registered: Sep 2015 posted 05-31-2016 03:10 PM                     Maybe this discussion here might be interesting for you as well? http://www.film-tech.com/ubb/f16/t002689.html  |  IP: Logged Joost Vandertogt Film Handler Posts: 8 From: Zoetermeer, ZH, The Netherlands Registered: May 2016 posted 05-31-2016 03:34 PM                     Yeah, I went through that post already, but thanks for the heads up!  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 05-31-2016 07:18 PM                     Joost - the Doremi IMB is very poor in decoding most popular HDMI audio formats. I suggest you feed HDMI sources to the AP20 4/1 switcher and use a HDMI extender from there. The AP20 is the only cinema processor with all the necessary audio format decoding. Besides that, the Mac has a full audio routing feature in audio setup in the utilities folder. - Carsten  |  IP: Logged Peter Castle Expert Film Handler Posts: 220 From: Wollongong University, NSW ,Australia Registered: Oct 2003 posted 05-31-2016 10:07 PM                     Some time back I encountered a similar (perhaps the same) problem in making a DCP from a 6-channel quicktime movie. The six channels were in one order, while the DCP wants Windows WMA(?) order. I can't remember the workaround but I seem to recall a PC program that allowed the shuffling of the channels.  |  IP: Logged Joost Vandertogt Film Handler Posts: 8 From: Zoetermeer, ZH, The Netherlands Registered: May 2016 posted 08-11-2016 07:15 AM                     Today I finally found some time to do some tests... All without succes... Even from a DVD-player the sound wasn't routed correct from IMB to AP20. I even tried using other audio settings in Doremi (not sure if they effect the IMB or just the Doremi/DCP). So next step is to contact the supplier, see if they know some way to get it to work correctly. If not I guess we have to spend some money to get some very good HDMI extenders...  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 08-11-2016 11:54 AM                     Maybe you have a non-standard AES-Routing and audio routing table setup in the Doremi to the AP20. There is actually not much to do about the HDMI-AES mapping in the Doremi, it is 1:1. Doremi has a techdoc dealing with adjusting the mapping for different SDI and HDMI mappings on a per-CPL basis. I don't know if you have access to http://support.doremitechno.org/index.php/faq/digital-cinema-player/set-up/499-imb-audio-channel-3-4-swapped-when-switching-sdi-to-hdmi If not, pm me, and I will help you out. You'd certainly be better of feeding the HDMI to the AP20 directly. Put some money on the HDMI extender, but you will have no HDMI/audio trouble afterwards, no matter what BluRay player you connect or what disc you play. You WILL certainly have trouble when you keep feeding the audio to the IMB HDMI input. - Carsten  |  IP: Logged Marco Giustini Film God Posts: 2713 From: Reading, UK Registered: Nov 2007 posted 08-11-2016 01:59 PM                     Joost, what Carsten said: take the HDMI to the AP20 *FIRST*, then to the IMB. The AP20 will take care of the sound just fine.  |  IP: Logged Joost Vandertogt Film Handler Posts: 8 From: Zoetermeer, ZH, The Netherlands Registered: May 2016 posted 08-11-2016 02:07 PM                     Hi Carsten, Thanx for the link. Unfortunately I do not have access to that site...  |  IP: Logged Carsten Kurz Film God Posts: 4340 From: Cologne, NRW, Germany Registered: Aug 2009 posted 08-11-2016 02:47 PM                     Check your profile for pm... - Carsten  |  IP: Logged Joost Vandertogt Film Handler Posts: 8 From: Zoetermeer, ZH, The Netherlands Registered: May 2016 posted 08-11-2016 02:53 PM                     Thanx a lot, I'll try next week and let you know the result!  |  IP: Logged Joost Vandertogt Film Handler Posts: 8 From: Zoetermeer, ZH, The Netherlands Registered: May 2016 posted 08-15-2016 03:01 AM                     Just tried with the CPL, even after rebooting the whole set-up a couple of times no result, so I'll contact the supplier, hope they can help with it, or just go with the HDMI-extender sollution... Thanx fot the help though  |  IP: Logged

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