Audio Channel Routing Issue in 7.1 DCP Playback .(Movie Smile 2)

[Shibu Paul]

Dear All,
We are encountering an audio routing issue with the 7.1 DCP of the movie "Smile 2 ."
The HI-VI narration is playing from the back right surround channel, while the center stage sound is being routed to the back left rear surround channel. This issue is observed when using both GDC SR1000 and Dolby IMS3000 servers, where the audio is connected via a single LAN cable. However, there is no issue when playing the 5.1 version or when the sound processor is set to 5.1 while using the 7.1 DCP.
The CPL ID for the DCP is: Smile2_FTR-CSR_F-200_EN-EN-OCAP_IN_71-HI-VI_2K_PC_20241016_PXU_SMPTE_VF.
Can you please provide guidance on what might be causing this misrouting in the 7.1 configuration and any steps we can take to resolve it ?.

Thanks in Advance.

[Steve Guttag]

You can only have 7.1 with HI and VI with two cables. You have 10-channels to contend with. If you do not want/need HI/VI, then you can handle 7.1 on just one cable by having the server re-route the Lrs and Rrs surrounds to channels 7 and 8.

If you need HI/VI...then you can only have 5.1 on a single cable. The default channel configuration is to have HI/VI on channels 7 and 8 (pair 4) on the AES3 cable.

[Dave Macaulay]

Playing 7.1 with a single "network" cable will have HI on rear left and VI on rear right. The HI channel is often just the centre channel with music and effects removed to make dialog more understandable. VI is descriptive speech like "Bond shoots Professor Dent".
So you're apparently getting exactly what is expected with channels 1-8 going to a processor playing 7/8 as rear surrounds.
I don't know about GDC but you should be able to reroute LSS and RSS to channels 7 & 8 in audio configuration in an IMS3000.
What sound processor do you use?
With a CP950 (with default 7.1configuration) you would get silence at rear as it expects the rear surround on channels 11 and 12, and would not be playing HI/VI back there.
Other processors, particularly with DB25 inputs, can use a channel switch board like Odyssey/Dargco have, or pin up an RJ45 to DB25 adapter to suit the channel reassignment.

[Harold Hallikainen]

Agree with the above comments. Most cinema sound processors can generate HI from an LCR mix. Of course, they cannot generate VI. In the US, theaters are required to make VI audio available if it is in the DCP. I don't know what the disability requirements are in India. If there is no requirement for VI, you SHOULD be able to change the routing of the DCP mainsound channels 11 and 12 to AES channels 7 and 8 to get 7.1 sound with the single four pair cable. For channel assignments in the DCP, see https://files.isdcf.com/papers/ISDCF...mendations.pdf .

Good luck!

[Carsten Kurz]

The issue is probably that you never played a 7.1 DCP including HI/VI-N before. As others have noted, you need to transmit 10 channels, using two LAN cables in order to do that properly. Using a single LAN cable and serverside channel routing, you can only either play 7.1 OR 5.1+HI/VI-N.