Page 1 of 1

Audio: LFE and Center channels being switched

PostPosted: Wed Mar 18, 2015 10:45 am
by Faris Ruhi
Hey there, I have a Decklink 4k Extreme Card and I've just begun to capture games.

I've noticed that when capturing from the PS4 (using HDMI), the LFE and Center Channel seem to be switched. Now I know I can switch the channels after capturing, but the thing is the output coming from the card is also doing the same thing, meaning when I'm playing, I can't hear the stuff that should be on the center channel at all, which means all dialogue, many sound effects etc, which is a problem. If this was one of the surround channels I probably wouldn't have any issue with it, and fix it in post.

When my PS4 is connected to an AV receiver or TV, audio is perfectly fine, I can hear all the contents of the center channel, Decklink seems to be interpreting the 5.1 audio wrong. I tried capturing in stereo as well, but that doesn't fix the problem, and I've tried both the 7.1 and 5.1 options in the ps4.

This is through both Blackmagic Media Express and Adobe Premiere Pro CS 6.

I figured that maybe this was discovered already and updated, so I tried to update my desktop video version, but the thing is doing that seems to cause problems, and just shows a black screen for the ps4, but outputs the video to the tv okay.

So currently I'm using the latest version that allows me to capture video properly, which is Desktop Video 9.9.6.

So any way to adjust or fix this somehow.

Edit: Also for the heck of it, installed the new desktop video software, captured a clip (meaning a black screen) with the audio, the audio still has the same issue, LFE and Center channels are switched, and the output through Media Express also seems to have the issue since again I can't hear any dialogue (which I know is there when I can obtain it in Premiere by switching the LFE and Center channels).

Re: Audio: LFE and Center channels being switched

PostPosted: Fri Mar 20, 2015 3:24 pm
by Tony Rivera
I'd suggest sending an email to your regions support office so we can take a closer look into this.

Re: Audio: LFE and Center channels being switched

PostPosted: Thu Mar 24, 2016 2:36 am
by Rob Cork
I'm having this exact same issue while trying to capture video from my Xbox One. Center and LFE are swapped. I've emailed support and they just say that it must be coming out of the Xbox that way and my Denon receiver is somehow interpreting it correctly but the Intensity Pro 4k isn't. Seems fishy because if the Denon is hooked up to the Xbox directly, the audio is correct. If i connect the Denon to the HDMI-out of the Intensity Pro 4k, the channels are swapped. For now i'm using ffmpeg to remap the audio channels correctly but it's a pain in the process and the product should just work as advertised.

Re: Audio: LFE and Center channels being switched

PostPosted: Thu Mar 16, 2017 11:33 pm
by Erwan Robert-Thomasson
hi,
the problem is still here. i just got a 5.1 setup and can't use nor the sdi nor the hdmi audio embeded for 5.1 audio, center and lfe are swaped...
gonna have to get a dac...

Re: Audio: LFE and Center channels being switched

PostPosted: Fri Mar 17, 2017 8:42 am
by Xtreemtec
You could run it trough a decimator MD-HX. In this box you are able to swap audio channels in the hdmi or sdi..
Even can use this box to loop trough to your receiver and Go SDI Out to your decklink Card..

Re: Audio: LFE and Center channels being switched

PostPosted: Fri Mar 17, 2017 8:53 am
by Erwan Robert-Thomasson
thanks xtreemtec,
that's what i need indeed, but feel a bit pricy just to correct a bug...

Re: Audio: LFE and Center channels being switched

PostPosted: Sat Jan 19, 2019 2:29 pm
by KatieKate
I'm having the same problem with a UltraStudio 4K and Media Express 3.5.7. After much searching, I found that I can use ffmpeg to create a new file with the LFE and C channels swapped (i.e. corrected).

Code: Select all
ffmpeg -i input.mov \
-filter_complex "pan=6c|c0=c0|c1=c1|c2=c3|c3=c2|c4=c4|c5=c5[out1]" \
-map 0:0 -c:v copy \
-map [out1] -c:a pcm_s24le \
output.mov

Notes:
- The input.mov and output.mov file names must be replaced by hand in the command.
- The command assumes output written by Media Express. If the file was manipulated and written anew by Final Cut X, change the -map 0:0 to -map 0:1. This is required because ME writes audio as stream 0, whereas FCX writes video as stream 0 and audio as stream 1.
- The command assumes a 5.1 input file, and will write out a properly ordered (L, R, C, LFE, Ls, Rs) file. The actual magic happens with the c2=3|c3=2 part of the --filter_complex flag.

On macOS, ffmpeg can be installed using Homebrew.

Re: Audio: LFE and Center channels being switched

PostPosted: Thu May 02, 2019 5:10 am
by Mike Wolf
This is still an issue.

Just bought an SDI to HDMI 6G Mini Converter.

LFE and Center swapped when sending SMPTE Surround L/R/C/LFE/LS/RS.

I can route 3 to 4 and 4 to 3 in my output matrix, but that's just for monitoring/playback. Obviously need correct routing for mastering.

BMD please fix!

Re: Audio: LFE and Center channels being switched

PostPosted: Thu May 02, 2019 10:36 am
by Xtreemtec
Mike Wolf wrote:This is still an issue.

Just bought an SDI to HDMI 6G Mini Converter.

LFE and Center swapped when sending SMPTE Surround L/R/C/LFE/LS/RS.

I can route 3 to 4 and 4 to 3 in my output matrix, but that's just for monitoring/playback. Obviously need correct routing for mastering.

BMD please fix!

Send it in as a support ticket! Because this is a user forum.. Only if a lot of people have the same issues it is picked up from here. ;) But things this rare need a support ticket to get on the bugfix list.