Prores w/ alpha issues with FCP and compressor

[Rafael Amador]

If you want Compressor keeps the Alpha, you needs to send something with Alpha.
If you let your sequence as XDCAM, there is no Alpha going to Compressor.
You need to set your sequence with a codec supporting Alpha, even if the rendering is done in Compressor.
If you are going to Proress 4444, make sure that you set “Render YUV in High Precision’.
Rafael

http://www.nagavideo.com

[Jeremy Garchow]

I assume by Quicktime compression, you mean Quicktime Conversion? Yeah, QT Conversion is really no good.

So you are keying in FCP and want to export and preserve the alpha channel? Is that what I’m hearing?

[Alex Ezorsky]

Hello,

first of all I would like to correct a typo. My source footage is 1080p24 not 1080i. Also I recently tried changing the sequence to match my desired output rather than the source footage because I read in another post that compressor just renders the timeline using the timeline settings rather than starting with the raw footage.

So I changed my sequence to prores4444 and exported with compressor. The result was great for two reasons and sucked for one.

The imported footage had correct brightness and the key was perfect. BUT now the quality was a bit iffy and it seemed as though there was some problem with the interlacing because every once and a while there was a slight flicker. Also there are two very thin vertical blue lines about a third and two thirds across the screen.

This is also what I see after the timeline is rendered.

man nothing is easy is it.

[Alex Ezorsky]

Thanks for your help guys.

In reply to Rafael. Yes I recently came to the realization that I needed to change my timeline to prores… and that is how I got my first successful results. However as I mentioned in the previous post, this prores timeline exported to prores gave me footage that has iffy quality and vertical lines. I tried removing the key to see if that changed things but what it did is make it really obvious that prores export is giving me vertical lines (see image).

Just as a test I tried turning my timeline back into XDCAM but sending to compressor while caps lock was on. The file actually worked, as in the key and color were good, but the lines were still there. As a wild test I then tried exporting the XDCAM timeline to compressor with capslock off, which is essentially where I started and so I expected the result to be unkeyed and dark….But lo and behold I got the same result. Things are starting to make less and less sense.

So technically I have tried the following:

XDCAM timeline to prores – Result: unkeyed and dark
Prores timeline to prores -Result: keyed and correct gamma but with lines
XDCAM timeline to prores capslock on – Result: keyed and correct gamma but with lines
XDCAM timeline to prores capslock off – Result: keyed and correct gamma but with lines (SAME AS FIRST ONE BUT WITH DIFFERENT RESULTS?!?!?)
XDCAM timeline (rendered) to prores capslock off – Result: keyed and correct gamma but with lines (now I really have no idea what is going on)
XDCAM timeline with YUV set to high precision – Result: keyed and correct gamma but with lines
Prores timeline with YUV set to high precision – Result: keyed and correct gamma but with lines

I would reallllly like to use prores but it looks like it will have to be animation.

Any more assistance would be a lifesaver.

Thanks

[Alex Ezorsky]

Sorry here is that photo of the lines I get when I export to prores from, as it seems, anything with any setting. The chroma key is off

thanks again

[Jeremy Garchow]

Did you change the ‘Depth’ to million of colors+ like this?

Jeremy

[Rafael Amador]

Are you playing the clip at full size?
rafael

http://www.nagavideo.com

[Alex Ezorsky]

Great suggestions but yes and yes.

I FIGURED IT OUT!!!!!!!!!

As a chromakeyer I usually apply the 4:2:2 color smoother to footage taken from anything that isnt 4:2:2 which is the case since I am using XDCAM 4:2:0. The smoother does make a minor positive effect on the key.

BUT! Pushing the video to 4:2:2 adds false information which the Prores render miscalculates when creating a 4:4:4:4 video!

I took the filter out and WAM problem solved.

I am still curious about why my XDCAM timeline sometimes made keyed exports and sometimes didn’t. I started a new XDCAM timeline and exported it as prores and the key once again didn’t work. Then I did it with the sequence set as prores and it didn’t work. Then I tried again with capslock on and it worked. Then I did it again with it off and it worked.

1 problem solved! still one to go and I am a happppppy camper.

Thanks for all your help

[Rafael Amador]

[alex ezorsky] “As a chromakeyer I usually apply the 4:2:2 color smoother to footage taken from anything that isnt 4:2:2 which is the case since I am using XDCAM 4:2:0. The smoother does make a minor positive effect on the key. “
I don’t know which Croma Smoother filter are you applying, but you don’t have to apply 422 but 420, as your footage is.
rafael

http://www.nagavideo.com