Blackmagic Forum

Hi All,
I am mixing 5.1 for a feature film using Fairlight. My mix sound great and all comes through the correct speakers but once rendered the resulting QuickTime file shows the 6 channels to be in the wrong place. I have tried both '5.1' and '5.1 Film'. What is happening to the order of the L,R,C,Lfe,Ls and Rs?

Please help me I'm running out of people to ask.

All The best K

(Resolve 17 Studio, Mac M1, Big Sur, Scarlett 18i20.)

CapnKarl wrote:Hi All,
I am mixing 5.1 for a feature film using Fairlight. My mix sound great and all comes through the correct speakers but once rendered the resulting QuickTime file shows the 6 channels to be in the wrong place. I have tried both '5.1' and '5.1 Film'. What is happening to the order of the L,R,C,Lfe,Ls and Rs?

Please help me I'm running out of people to ask.

All The best K

(Resolve 17 Studio, Mac M1, Big Sur, Scarlett 18i20.)

What kind of QT file? Codec? PCM audio?
Can you take a screenshot of your export settings and post?

Hi Dom, Thanks for reading. see screen shots below. Any thoughts?

AAC is a different order to film or smpte, try using linear pcm for your audio to check.

Yep, AAC has its own order.

And AC3 has a different one again!
Can't we all get along...

Andy Evans wrote:AAC is a different order to film or smpte, try using linear pcm for your audio to check.

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Andy Evans. You beauty! Thank you so much! solved. It sounds perfect now. I'm very happy and not going insane as I thought that might be the case.

I can press on with the mix knowing that it will all work out in the end. many thanks .

Nice one. From a sound perspective, we always output linear pcm for the pics master, then you do encodes to other formats from that, which will then adjust the channel order to suit the end codec.

Andy Evans wrote:Nice one. From a sound perspective, we always output linear pcm for the pics master, then you do encodes to other formats from that, which will then adjust the channel order to suit the end codec.

That's a very clever idea.

I found the same issue with my recent surround delivery. The odd thing is that I have 5.1 AAC sound in the correct order in previous exports from Resolve. I tried changing from 5.1 to 5.1 film, but that moved the center channel sound from the right speaker to the left. Is something else going on here beyond just the codec?

I've just done more testing and discovered that if I export using the PCM audio codec (which orders surround channels correctly) then use Compressor to convert the file using an AAC codec the audio channels are ordered correctly. This appears to be a bug in Resolve 17 Studio's Fairlight module. Is there anything I might be missing?

dcolacino wrote:This appears to be a bug in Resolve 17 Studio's Fairlight module. Is there anything I might be missing?

LPCM = Left, Right, Centre, LFE, Left Surround, Right Surround

AAC = Centre, Left, Right, Left Surround, Right Surround, LFE

Thanks Reynaud, however, since I didn't have this problem in prior version of Resolve, and Kompressor orders them correctly, why would there be a difference with AAC from these different renderers?

Which export mechanism is used?

Deliver page preset, custom settings on the Deliver page, or via a Quick Export preset?

I used Deliver page presets and Custom. I tried H.264 Master with both 5.1 and 5.1 Film Bus output (which is supposed to take care of the channel re-ordering as I understand it. When I use the MP4 file format the only audio option available is AAC.

Since I can play files with both AAC and LPCM audio codecs with audio coming out of the correct channels, the codecs must specify channel order for playback systems to decode them properly. Is there something I could be doing to make the channel specifications contradict their actual order in the file?

Does the H.264 Preset via the Quick Export function (File menu) produce a compliant deliverable?

No. Center comes from right speaker.

Any improvement with 17.2.2?

viewtopic.php?f=21&t=143863

Yes. 17.2.2 fixed it.

Thanks BlackMagic!

Oh boy.

Um.. sorry to bump this thread up but... no. Just no. Today I played around with 5.1. Not because I wanted to, but had to, since Resolve isn't able to... read information out of a file I guess? I don't get it and hope someone can enlighten me.

I put a capture (5.1) into the timeline and saw "5.1" in the edit page, so I thought "Cool, that's that." Then I found out that in the edit page I can't hear 5.1. So I checked and read, I have to change the MAIN output to 5.1 also. Well that's ok, even though I don't understand it. If the first/only track in Resolve is in 5.1, why would I want to hear Stereo only? Hey why not Mono? Whatever, changed it and it was fine.

And that's when I saw "5.1 film" for the first time. I was confused and read about it. Ok, it's a reordering of the audio sources/directions, why ever there is more than one standard. But that's not the fault of Resolve of course.

I started a new project and put a 5.1 test file (with visual help) in the timeline and the sound was coming from everywhere, but not the right directions. I had to play with four (!) different options to get it running for that file (AC-3). And it only worked directly in Resolve and when rendering with AAC. Not with PCM, no no no! Because then everything was completely freaked out again. What??



So when this was over, I was happy and put there a game capture with AAC 5.1 sound. Bang.. everything was crazy again. Resolve decided that the dialogue (center) will now play out on my right front speaker etc. etc. and I had to reconfigure everything again.

Em... someone really wants to tell me this is the only way this works? How ON EARTH are professionals work here with Dolby Atmos? Or are they professionals because they can? Man, this is by far the worst, if not the only, really annoying thing I've saw about Resolve in the last 5 years.

I mean even if it would work now with these kind of files for me. I would be happy if I would understand at least 50% of what I'm doing there? Checked the doc and it not even points out that there is a different order for AAC or AC3 output! And why can't Resolve read the easy information in the file itself? Every player can do it, mediainfo can do (and show the order). And even if I tell Resolve which channel is what, it doesn't get that it has to change something depending on which format I choose to export? What is going on here?

Please help me or I can't go to sleep for the next 5 days. Thank you.

i got a similar issue:
i got six mono tracks with the standard L R C LFE Ls Rs config set up.
the DCP guy wants it delivered like that, six mono tracks.
so i linked the tracks as a 5.1 group, added a 5.1 bus, assigned the tracks to the bus, selected the 5.1 bus and 'render one track per channel' on the delivery page for the export.
but the guy noted when we met after the test screening that the center channel was swapped with one (don't remember which) of the front channels.

does anyone have a clue?

should i do this instead (screenshot)?