Blackmagic Forum

I have an H264 mp4 video with embedded 5.1. The video was rendered from Resolve. Opening it in Quicktime shows a channel layout of C L R Ls Rs LFE (no way to set/change this in Resolve, even though I had the layout in Resolve set to L R C LFE Ls Rs). When I put the clip on a 5.1 timeline and a 5.1 track I can see waveforms in the edit page, but the Fairlight page does show the 6 audio channels/tracks. When playback I can only get audio through the 3 audio channel in the meters. I've tried all the patching options I could and still can't get it to play through the correct audio channels. How can I get this to work? I need to bring it back in to make sure plays correctly.

Keep clip as 5.1 mapping but change the channel order.
Your order: C L R Ls Rs LFE
Required: L R C LFE Ls Rs
An Example Mapping: (I've made a mistake on the LFE in this, but it's easier to get an idea from)



Please remember to set your Main bus -> 5.1 too

Yes, I did all that and it still only plays to Channel 3.

Ok I just tried it again with a new file render and I'm getting waveforms and audio playback through speakers. The channel config is all messed up though. Here's what I see in Quicktime for the channel layout:



And here's what I set it to in Resolve:



What I end up with now is:

Center channel playing on the center channel
Either Ls or Rs playing on Ls
Either Ls or Rs playing on Front Left
Either Front Left or Front Right playing on Front Right
Either Front Left or Front Right playing on LFE
LFE playing on Rs

Totally messed up.

Trying to figure out the right channels through trial and error, and it's impossible. The waveforms are actually wrong. Some channels seems to have been combined in the render of the mp4 with embedded 5.1 from Resolve or something. Definitely an issue with the Resolve's handling or rendering out a 5.1 audio track.

Here's the original timeline with the separate 5.1 WAVs:


And here's the Resolve rendered mp4 with the 5.1 audio track:

I reset the channel layout to the default for this.

More testing... If I link group to 5.1 and render the mp4 with the 5.1 audio, there is no sound in channel 4 at all. I did get this layout:

1 = L
2 = R
3 = C
4 = nothing even though a waveform shows in Fairlight, no meter action
5 = Ls
6 = LFE (shows what I believe is the Rs waveform, but is actually the LFE channel?)

I brought the file into Premiere Pro and here is what Premiere Pro shows for the waveforms:



Premiere Pro shows channel 5 as the empty channel instead of channel 4. I get no audio from channel 4 in Resolve during playback of each channel separately (muting other tracks). If I playback channel 5 on its own in Resolve (by setting all other channels to mute) I do get sound.

I also found that the order of the tracks is completely different in Premiere Pro than Resolve too.

1= R
2= C
3= L
4 = LFE
5 = Empty
6 = Ls

Could you post a sample clip for the original h.264 mp4 file Mike? The one with the (C L R Ls Rs LFE) order?

Thanks
Shrinivas

unfortuantly totaly typical of the train wreck audio mapping has become after v12.5....

and what works one day will not work the next...

what is needed is the routeing from 12.5 brought back

Shrinivas Ramani wrote:Could you post a sample clip for the original h.264 mp4 file Mike? The one with the (C L R Ls Rs LFE) order?

Thanks
Shrinivas

Happy to send it to you, but I can’t post it online in this forum. Is there another way to get it to you?

Put it on a cloud service and give them the link with a single space in the URL.

Uli Plank wrote:Put it on a cloud service and give them the link with a single space in the URL.

That doesn’t help. Anyone can copy the link and remove the space to use it.

Then PM.