.mxf multitrack audio output

Apple Final Cut Pro

.mxf multitrack audio output

Posted by Mario Gaoa on March 2, 2017 at 9:32 pm

Mac Pro 2013, Sierra, FCPX 3.1

Hi every one,
i have had a look around but am still a little confused as how to achieve what I need.

Delivery to my local needs to be an interlaced .mxf with 8 track audio.

channel 1 & 2 is full mix – stereo
Channel 3 is dialogue only – mono
Channel 4 is fx – stereo
channel 5 is music – stereo
channels 6 – 8 remain empty

The order is correct, the specs I need to meet in audio are -23 to -25LUFs, now all the audio on the line has been mixed to meet this requirement. The sticky part is that all channels are playing out at the same time which obviously pushes the audio levels way over the broadcast specs. Is there a way I can have the same channel assembly, but only have channel 1 & 2 active?

The broadcaster has kicked me back twice already for sound (they have an automated system that measures loudness levels) my tests prove that removal of all other channels (so that it is only the full mix left) puts the audio back to legal range for the network.

Your thoughts and advice appreciated in advance.

Mars

Mario Gaoa replied 9 years, 2 months ago 3 Members · 4 Replies
4 Replies

Patrice Freymond
March 4, 2017 at 7:10 am

Hi,

I suspect you are delivering XDCAM, so as long as you do a mutitrack Quicktime export with the roles mapped according to the channel order you wish, and then rewrap to MXF you should be fine. We do this on a daily basis and it works.

Hope this helps,

Patrice

Patrice Freymond

Editor  Certified Trainer FCPX
Post Consultant

Always learning…
Ronny Courtens
March 4, 2017 at 9:49 am

If your delivery format is not XDCAM but AVC-Intra, ProRes, DVCPRO or Uncompressed, you can export your multitrack MXF straight from the timeline without needing to export a multitrack QT first. To do this you just need to select Share > Master File > MXF > codec of your choice and set the Roles according to the delivery specs.

As to audio compliance:

You just need to make sure that your Stereo Mix (1+2) is compliant. This is what they test at QC. To do this you disable the stems (3,4,5) on the timeline and you play the stereo mix measuring compliance.

Furthermore it’s always a good idea to make sure that the sum of your stems (3+4+5) is compliant as well. To do this you disable the stereo mix on the timeline and you play the stems measuring compliance.

If your audio has been rejected while you say that your stereo mix is fully compliant, you should contact that broadcaster and ask them how they measure compliance. Maybe they are using different compliance standards than you do.

Should they tell you that they do the QC playing all your MXF audio tracks at the same time, tell them to contact me and I will gladly teach them how to do a QC on a multitrack MXF. No-one measures compliance by playing the stereo mix together with the individual stems.

– Ronny
Mario Gaoa
March 5, 2017 at 9:22 am

Hi Ronnie,

Thanks for your help. If I disable tracks 3 – 5 and only have the stereo mix active (track 1 and 2) will the stems from the deactivated tracks still be accessible on the network end? (can they reactivate the tracks)

cheers

Mars
Mario Gaoa
March 5, 2017 at 9:26 am

Hi Patrice,

Thanks for your help. Just curious about the stereo roles (main mix, music and effects) I see they have duo mono tracks, do I need to adjust these tracks so that one is stereo left and the other right?

Mars

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