FCP export alpha? same problem …

[Neil Ryan]

seems you can’t render the clip in the timeline which has an alpha. (I was simply using FCP to speed-up a quicktime with alpha.)
When I didn’t render the timeline, but did the export, my export worked. i.e. I got a new QT with alpha!

I trust that information is buried in the manual somewhere …

[Bret Williams]

I thought that in FCP you put it in the timeline on layer 2 or up, and turned off layer one to export with alpha intact.

Are you exporting a reference movie?

[Neil Ryan]

Thanks Bret, I tried what you said … same issue.
If the clip is rendered, it won’t output the alpha.
(this is evidenced by my sequence, which runs part of a clip as-is, then cuts to same clip with motion effect (speed) on it, then cut to original clip again with no effect. If the speed-affected clip is rendered, it doesn’t output the alpha … ie, my exported QT plays first part with alpha, middle on black, third part with alpha …)

[John Pale]

This is normal behavior if your sequence codec does not support alpha channels (most do not).

[Pol]

If you get the checkerboard in the canvas….NOT in the viewer and you set the channnel to RGB in the canvas (do NOT show the alpha channel) then it should work. I tried it today and it worked (animation codec, million+, best quality). Make sure you solo the track so that no other alphas are shown.

Good luck,