delete one track of audio - replace in BPAV?

A

alexbklyn

Member
Just shot a few doc days on the F3 and on one of the tracks, a character's radio mic was live when it shouldn't have been - and I don't think it would be appropriate for the client to hear some of that stuff.... Is there anyway to clear that up (just leave one channel blank) and then re-create and replace the MP4 in the BPAV folder and no one would be the wiser?
(Feels like someone should have run into this before but I couldn't find any solutions on the boards...) TIA
 
How long is the clip? If it's under the 4GB file split limit, then it should be possible to import the file into an NLE, switch the track, then export back to XDCAM.

The metadata likely won't match up, but the filename should, so if there's only cursory examination of the file's naming/metadata, then it'll probably hold up.
 
Hey, I just went ahead and tested this with a small file (about 110MB) - and using FCP6 I and testing with XDCAM Browser, looks like it works perfectly - and preserves meta-data.

First thing - back up your entire folder, just incase you mess up, or it doesn't work properly.

Okay. I used the Log and Transfer plugin to pull the file into FCP.

Drop the file into a sequence, match sequence settings to XDCAM format of footage.

Also, go ahead and change sequence audio outputs to Dual Mono. It's necessary for export.

Remove the undesired audio track.

Use the voiceover tool to drop in a 48khz empty track, matching the exact duration of clip.

EXPORT>>>>Sony XDCAM

Select .mp4
Select "Current settings"
Match file name to name of file you're replacing.
Don't recompress all frames.
Execute.

Double check output file size against old file size. It should be super close, only off by a few bits.

Having made your backup, switch new .mp4 in for the old one. Make sure to use exact same file name.

Open XDCAM Browser and check your handiwork.


In theory, this would work on bridged clips as will - you would just need to process each 4GB segment separately.

Please, please, please keep a thorough backup before attempting this procedure.


That said, it should be nigh invisible for the client.
 
Thanks Viddovation - actually several folders have up to 4 sub clips. And then when you say, 'export back to XDCAM' - confused...Should I use compressor to create an MP4 since that's what I would tuck back into the BPAV? Appreciate the help!
 
alexbklyn said:
Thanks Viddovation - actually several folders have up to 4 sub clips. And then when you say, 'export back to XDCAM' - confused...Should I use compressor to create an MP4 since that's what I would tuck back into the BPAV? Appreciate the help!
Click to expand...

No, not compressor.

Once you've completed the steps in Final Cut and are ready to export, go to the FILE menu. Go to EXPORT. Select "Sony XDCAM Browser"

It will give you an export dialog with the options I gave you. You'll want .mp4 (not mxf) - and current settings (because your settings are already correct for XDCAM-EX).


As I said in my second post, the process ought to work for subclips - but I haven't tested it.

On the media cards, clips get broken up at 4GB. If you've transfered those folders into a single hard drive folder using Clip Broswer or XDCAM Browser, it automatically combines subclips for you.

Presumably, if the clips are still split up, treat them as individual clips for processing. If they've already been combined (and that's what you're sending the client) - then you can process it as one file.


Keep in mind, if a file has 4 subclips, and only one is an offender - if you only process the offending clip, and do it with a simple wipe or voiceover replace, it will create an audible bump when moving in and out of the modified segment. Anyone who isn't looking at the file forensically though, will generally ignore such things.
 
Okay- really working well with files that don't have a subclip(s) THANK YOU!!! but I'm perplexed about the files where, for example, there are 08 subclips and they only come in as 02 - each being 1h30m in length. Once I've stripped/replaced ch2, and re-output, how do you think I'd change the items in the BPAV folder to match just two long clips rather than 8 short ones? Thanks again.
 
Can you clarify? One recording is split into 8 separate .mp4 files in the BPAV folder, but on export sends back as only two separate .mp4 files?

What are the file names you start with, and how many files are returned?

Are you saying that you start with:

Sample_0056_01
Sample_0056_02
Sample_0056_03
Sample_0056_04
Sample_0056_05
Sample_0056_06
Sample_0056_07
Sample_0056_08

...and this ingests into FCP as only two files instead of eight?




I'm not 100% clear on all this.


One solution may be to import the .mp4 files directly using Cinemon .mp4 - it's a plugin with a 30 day trial that ultimately would cost you $99 - but it allows you to directly import .mp4 files.


By doing this, you could import the 4GB chunks, modify the audio track, and reexport the 4GB chunks.

Mind you, this is all extrapolation - so make sure you keep your backup copy handy.
 
So, yes, it's as you say - with actually 7 successive files under one main string which comes into FCP as 2 long files. I just tried to change the audio track "right" by using the Cinemon plug in, opening the file directly in quicktime and changing the setting for the right track to "unused", then saving (which only wanted to save as an .mov and herein lies part of the problem I think). I processed all the related mp4 files and tried to see what they would sound like when bringing then in through Log & Transfer but it was a bust - error message and wouldn't import. Not to mention, even while the saved .mov file (which I overwrote the suffix to .mp4) played fine in QT (ie: the offending track was silent), I could just go back and select "right" in the pulldown and it was all there again... Importing the "processed" file directly into FCP yielded the same result meaning the erased track was there again. Puzzling. Thank you for staying with me through this.
 
alexbklyn said:
So, yes, it's as you say - with actually 7 successive files under one main string which comes into FCP as 2 long files. I just tried to change the audio track "right" by using the Cinemon plug in, opening the file directly in quicktime and changing the setting for the right track to "unused", then saving (which only wanted to save as an .mov and herein lies part of the problem I think). I processed all the related mp4 files and tried to see what they would sound like when bringing then in through Log & Transfer but it was a bust - error message and wouldn't import. Not to mention, even while the saved .mov file (which I overwrote the suffix to .mp4) played fine in QT (ie: the offending track was silent), I could just go back and select "right" in the pulldown and it was all there again... Importing the "processed" file directly into FCP yielded the same result meaning the erased track was there again. Puzzling. Thank you for staying with me through this.
Click to expand...

Where in the process are you saving these with a .mov extension and changing that to a .mp4 extension by hand? That's *not* in my instructions.

After importing the file and switching the audio tracks it uses in the sequence you do not do a standard save or export.

You go:

FILE>>>>EXPORT>>>>Sony XDCAM Browser

You need to have XDCAM Browser installed

And you select to export as a .mp4 - with current settings. It should export as a .mp4 - not an .mov
 
Yes - for the shots that don't have split files, I am doing it within in the FCP workflow exactly as you suggested and it works nicely.
The problem comes when there are more dependent files that then come in already grouped. I can still replace track 2 with nothing but don't know what to do in terms of re-inserting these newly wrapped files into the BPAV folder that holds the several splits. This is where I understood Cinemon would come in bc I'd be able to intervene just accessing the MP4 in Quicktime ONE 13min file at a time to replace in the splits _02, _03, _04 etc... But I'm clearly doing something wrong since a) it can only save changes as an .mov in QT and b) because the re-assigning of the track as "unused" doesn't seem to stick....
 
alexbklyn said:
Yes - for the shots that don't have split files, I am doing it within in the FCP workflow exactly as you suggested and it works nicely.
The problem comes when there are more dependent files that then come in already grouped. I can still replace track 2 with nothing but don't know what to do in terms of re-inserting these newly wrapped files into the BPAV folder that holds the several splits. This is where I understood Cinemon would come in bc I'd be able to intervene just accessing the MP4 in Quicktime ONE 13min file at a time to replace in the splits _02, _03, _04 etc... But I'm clearly doing something wrong since a) it can only save changes as an .mov in QT and b) because the re-assigning of the track as "unused" doesn't seem to stick....
Click to expand...

Huh?

Why can it only save changes as an .mov in QT? Why aren't you using the Sony XDCAM Browser export .mp4? If you are using the export feature as directed, at exactly what step does it prevent you from exporting an .mp4?

When dealing with technical computer issues, you need to provide precise explanations of the issue, or it's impossible for anyone not at your workstation to understand what went wrong.


And why make the track "unused" - why not drop in a blank voiceover? Remember, it can't not have the second audio track - it's going to be required - you just can change the audio so it sounds as if the no mic was attached.
 
No - I've got that part down, the workflow once I'm in FCP, stripping the track and exporting. All that's good. The trouble comes with longer files with several dependent clips. This is when I understood Cinemon would come in handy since I'd be able to intervene in the individual 13min clips instead of the hour+ ones that it combines them into once I have imported into FCP. (I can't then seamlessly export two hour+ clips into the 7 separate folders belonging to that single clip).
 
Perhaps I'm not using Cinemon correctly but what I tried to do was go into the Properties info, scroll down to Sound Track and re-assign ch 2, or "Right" to "Unused". When I play it back, it seems to have worked. But it won't save it, and it won't HOLD the change if I do export or save as...
 
What I'm instructing you to do with Cinemon is -

Install Cinemon .mp4 Assuming that's already done by now.

Make sure you have your BPAV folder backed up.

In Final Cut, go to the Import File dialog (or, Import Folder works).

Import the desired .mp4 files. If you inadvertently also imported .smi files, either ignore or remove them from the Final Cut project.

Now, for each .mp4 file separately -

do what we did with the .mov files that worked before.

make a sequence.
drop in the .mp4 file
delete the undesired audio track
record a blank voiceover track in it's place. needs to be exact length of video.
make sure sequence is set to dual mono.
FILE>>>EXPORT>>>Sony XDCAM Browser
use the .mp4 and current settings option.
name it the same as file it's replacing.
switch it out for the old file.

mind you - i haven't tested this on a bridged clip, but that's the workflow i'm proposing.


i know nothing about setting properties or whatever you're doing.
 
Ooooh, simpler than I was making it. Trying with series of bridged clips now - getting called away to shoot but this should work the same way as the non-bridged clips. Thank you so very much - lifesaver!
 
First long clip modified, exported, re-ingested, and rebuilt in FCP as one hour+ take. PERFECT! Problem solved - Thank you again!!!
 
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