Compressor vs FCP for QT with 5.1 Surround

[Daniel Raim]

Update: Our distributor is requesting a QT movie file. These are the specs:

Video:
ProRes 422 (HQ)

Audio:
Multi-channel AES3 LPCM (302m) – minimum 16bit, 48kHz:
Ch. 1 – Left , Ch. 2 – Right, Ch. 3 – Center, Ch. 4 – LFE, Ch. 5 – Left Surround, Ch. 6 – Right Surround, Ch. 7 – Left Total, Ch. 8 – Right Total

I think I’m on track now but I still have a couple work flow questions. I have 8 audio tracks on the timeline. Ch 7 and 8 is the stereo mix. I unlinked the stereo mix and hard panned Ch7 left and Ch 8 is hard panned right.

I’m still not sure about the down mix db….Do I need to down mix to -3db (in the Audio Output Tab) or leave it at 0db?

Any help would be greatly appreciated!
Dan

[Mark Spano]

To avoid confusion, I would output the audio from your mix as separate files, rather than grouping it in with the QuickTime. Make a video-only ProRes HQ QuickTime, and send along your mix as eight separate WAV files, all with the exact same starting point as your QT. This way you can label each one with the channel designation, and there will be no chance for them to be laid out incorrectly.

If you still want to output the QT with the audio tracks, line them up exactly as they asked for them (L/R/C/LFE/Ls/Rs/Lt/Rt). In your Sequence Settings / Audio Outputs tab, choose 8 outputs, all dual mono, don’t worry about downmix. Right click on each track in the Audio Mixer and designate it to the proper output (A1 goes to 1, A2 goes to 2, etc.). Now when you export your Quicktime file, it will have eight mono channels, in the order you arranged them in FCP.

[Daniel Raim]

Thanks so much for the feedback, Mark!

Another quick quick questions: with all tracks set to dual mono I should set the Config to: Discrete Channels?

And what if I decide to to pair track 7&8 as “Stereo” – do I still set Config to: Discrete Channels or Channel Grouped?

Thanks again!

[Mark Spano]

[Daniel Raim] “with all tracks set to dual mono I should set the Config to: Discrete Channels?”

No – leave that at Grouped. Discrete is usually fine, but harder to test in QuickTime Player, so I leave it set to Grouped.

[Daniel Raim] “And what if I decide to to pair track 7&8 as “Stereo””

Don’t bother pairing track outputs. When you’re outputting QuickTimes it is best to leave them all set to Dual Mono, that way they can be recovered in the correct order at the destination.

[Daniel Raim]

Thank again, Mark. Just tested the QuickTime and everything seems to work great!

[Andrew Hecker]

Let me re-address this. I’m doing virtually the same thing, FCP 7 timeline @ 24fps (let me be clear, its 24, not 23.98, nothing has 23.98 in any setting anywhere I can find) ProRes 422 1920×1080.

I’ve exported a .mov without audio I exported, first .aif files (my timeline mix has groups of discrete tracks for each level of the mix–I mute the ones not needed for each purpose track). I first a surround window in compressor. I started with the .mov file and “add surround sound” ended up with all the activity on a separate track. Frustrated with getting a new window, I tried to link the video back to that track “add video” but it would not accept the .mov file because it didn’t have audio. For some reason its not as basic as it looks and I don’t know why. So I came here.

So this recommends exporting .wav files and doing it in FCP. So I put the .mov into a FCP timeline. I let it use settings that match the clip. First I dropped in an .aif file. Funny, the .aif, made from the same time line DOES NOT sync with video. I have sync marks at the start and end, the audio is short by 5:12 over (slightly over) an hour and a half program. The video file matches the length of the original file exactly. .wav files created from the same timeline do the same thing and needless to say, the resultant lipsync is gone. I haven’t even gotten to trying to make 5.1 with this craziness happening.

[Subrata Sen]

This craziness keeps on happening to me all the time, and I have to stretch the sound by slowing it to 99.9% and only then it matches. Any plausible reason from anybody?

[Subrata Sen]

This craziness keeps on happening to me all the time, and I have to stretch the sound by slowing it to 99.9% and only then it matches. This 99.9% thing

[Andrew Hecker]

99.9% or whatever estimate you make to this is not mathematically accurate for syncing 5.1 sound with lipsync. This stuff should be an exact frame accurate match. That’s technically how all sound works, two files, the video frame sequence @ frame rate, displayed with a sound file at whatever data/sampling rate.

By the way, the only solution I found to this sync issue was to export each track with a video track tied to it. For 5.1 that was two stereo pairs and two mono tracks. That will copy and paste directly into the timeline in sync. Once I assembled the tracks I was able to export the .mov file with 5.1 in tact.

Curiously, even after creating a proper audio track tied to video, you cannot separate the two, like extracting or copying and pasting. That will result in a 23.98 audio track again. So to me, this seems like a flaw in the QT time flag–a design error.

[Michael Gissing]

Once again the FCP frame rate stamp feature bug is biting. Once you pull a wav or aif file into FCP it stamps a frame rate based on your current Easy Setup NOT your sequence settings. This sync bug is so common that it often comes up here a few time each week so search for Matt Lyon’s tutorial on how to fix or prevent the bug biting.

If the aim is a quicktime with picture married to the PCM tracks then you have to use FCP or Quicktime Pro to marry the audio tracks with a quicktime video without audio