FCP alpha channel help needed

Scott F

Scott F

Pug Life
Help out an idiot on a deadline here. I just purchased a lower 3rd quicktime file from pond 5. In the description, it claimed the video was rendered with an alpha channel and should be keyable over footage. the movie file is a .mov

I am just getting the black screen behind it. How can I remove it? I have tried going into "item properties" and changing the alpha to straight, black and white. No luck. I admit, I don't know what to do.
My sequence is 1920X1080 23.98fps.

I'm looking for assistance from the Hawk Teflons of the world. Help a brother out!

I also have After Effects if that can be used.

thanks,
Scott
 
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Hey Scott, drop the mov into the project pane of FCP. Control click on it > Item properties > look down left column
The two rows you want to check are called compressor (tells you the codec) and alpha (tells you if it has an alpa channel)
does it have an alpha channel? what codec?
 
the compressor is PNG

and the alpha is currently in none/ignore with the option to switch it to straight, black or white. But doing the switch has done nothing so far.

thanks.
 
Basically there are two main commonly used codecs that support alpha's and they are prores4444 (not the other prores's) and animation.

If it is one of these codecs and the alpha column says yes then you should be able to drop the file onto your timeline on the top layer and the unwanted areas of the screen will be translucent.

If it does not have an alpha then use a luma key effect to remove the black. To do this drop the clip onto the timeline Effects > Video Filters > Key > Luma Key
Double click the clip so it opens to the viewer window off the timeline. Click the filters inspection tab. Change key mode to key out darker. Change View to Final, Adjust your threshold
 
no, it's a movie.

i'm currently working in a prores 422 timeline. not 444 like you mentioned. maybe that's it?

the luma filter is working as a stop-gap solution. since i have to kick this video out, i will probably just go that route.

otherwise, maybe i could transcode the file as animation? i don't know. i just figured i would drop it on the timeline and be good to go. frustrating.

thanks for the help though, jhoe.
 
Prores 422 timeline doesn't matter - you can drop a prores4444 with alpha onto it and it works fine.

Judging by the pic you posted the luma key should work just fine. Kick the job out the door.

I forgot about PNG as movie as it is not commonly used. PNG can carry alpha.
 
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yeah, it's working, looks pretty good. thanks again for the insight.

plus this is a corporate vid, will probably ultimately end up as a windows movie or something blown up on a projection screen. : )
 
Aha, I found the culprit. The seller was accidentally selling the clip w/o an alpha.

All's well that ends well, he sent me the correct format.

Thanks for your help Jhoe, we will work on a project together someday I'm sure. :thumbsup:
 
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