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Trouble getting FCPX and/or Compressor to produce true stereo mix in resulting MXF file
Hello folks,
Using FCPX and the customizable MXF settings in Compressor, I can’t seem to figure out how to get my stereo mix out to the MXF file with having the two channels playing back straight up the middle. The choices are Discreet mono, and when re-imported into FCP and then panned again, the true stereo is there and all levels are where they should be for broadcaster. But the mxf I send to get QC’d still has Ch1 and Ch2 (the left and the right) un-panned and playing back on top of each other.
The FCPX export to MXF really doesn’t allow you to create a file where the stereo is already panned. My understanding is that Compressor allows you to customize the export to keep all the audio tracks discreet mono, whether you want 2 or 4 or 8. But even though I’ve created a single stereo track (with sub-tracks being panned LEFT and RIGHT in the project), and then I designate those two sub-tracks to the discreet mono Ch1 and Ch2, inevitably the resulting file plays everything back up the middle, making the levels seem super hot to the broadcaster’s QC tech.
On my slates I put the instruction that Ch 1 and Ch2 need to be panned to 100% left and right, which then brings all the audio back to where it should be. This workflow was sailing along fine but now the techs are failing the files for being too hot. I can easily re-import the mxf back into FCP and make the pan again (fixed), but their claim is that they shouldn’t have to touch the file. Why doesn’t the Compressor audio prefs allow one to designate stereo, or to “pan.”
Feeling I’ve missed something very simple in the workflow, but eager to find out what that might be. Maybe I can blame the broadcaster receiving the file? Shouldn’t they be able to monitor/playback those discreet mono tracks as Ch1-100% left and Ch 2-100% right?
Thanks for any insights on this.
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14 Replies
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What codec MXF?
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what Jeremy means, if it’s XDcam or alike, it’s normal behaviour and up to the playback system how to interpret the channels.
Bouke
http://www.videotoolshed.com -
XDCam HD422 (50Mbps) – 2 Discreet Channels
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Thanks for clarifying. This was my suspicion, as I could not figure out a way to force the XDCam HD 422 mxf file to playback as panned stereo, unless of course I brought it back into FCP. Any advice on how to clarify this with the broadcast group? I really can’t change my export process as they require an mxf file with the specs I mentioned, an XDCam HD422 interlaced mxf file with Ch1 and Ch2 stereo and the full mix as mono on 3 and also on 4. I can’t tell you what playback app the station uses.
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So, all is well. (In the channel department )
Now I want to know who gave you these specs. Could you share the name, or even better, send me the documents?MpegII 50 Mbit with two discrete channels is not strange, but you cannot call it XDcam, as that has 8 discrete channels (in your case, 3-8 should be silent.)
(I’m a developer who is working on QC for commercials for a huge amount of broadcasters, including the big names.)Bouke
http://www.videotoolshed.com -
I seem to have missed this post.
No worries about the playback. They will take care of it.
Do the panning yourself for your own QC, and be happy 🙂Bouke
http://www.videotoolshed.com -
Bouke’s got you covered.
FCPX makes compliant XDCam MXF files (including the 8 channels). Other codecs allow less channels.
You can set the channel assignments in Roles by assigning all roles to each track (track 1 stereo, track 2 mono, track 3 mono). Like this:
This will give you a mono L on ch 1, mono R on ch 2, mono mix on 3, and mono mix on 4. If your program has a slate, that’s what you should put on the slate, and the broadcaster will need to pan accordingly.
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Thanks so much for laying it out like that. It confirms that I was pretty much on the right path, even with the info on the slate. Spent quite a bit of time on this topic looking through other FAQ’s etc but never really finding a definitive answer; the responses here are definitely appreciated.
One follow-up regarding the video requirement that’s part of the broadcaster’s request: we’re not shooting interlaced but they want 1080i and so I was sending to Compressor’s customizable settings for XDCam mx to convert to 1080i, thinking that I could not do this conversion in the Share/Export from FCP to XDCam MXF. I didn’t see any option there (although I guess I could just convert the entire project to make a new final interlaced version of the project.) Is this the case?
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What is the format of your timeline?
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By the way, you’d get these same results with Adobe Media Encoder. Once you go over 2 channels, the file is read as all mono tracks.
Premiere can read a 2ch mxf op1a as stereo, though. FCPX defaults to dual mono which you have to change to stereo in the inspector.
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