RGBA rendering

Hi !

I saw a .mov file that had an alpha layer (It was edited with After effects. Video Codec : Run-length encoding / FFQTRLE).
It was working well in the Kdenlive's time line with composite transition.
Is there a way to exporte a movie with a RGBA type of file with KDEnLive ?
It should be realy great for simplify composite work !

Thank You


I have learned here :
that it's possible to export to .png sequence, but it's png without alpha...
Do you know if this fonction will be added in KDEnLive ?

**EDITED** My initial reply. Yes RGBA out from RGBA source files would be useful.

Ffmpeg (which provides codecs for Kdenlive) seems to support a few RGB codecs, but as far as I can see here:


they don't include alpha.

Ffmpeg also supports at least one codec with alpha:

AYUV X X Microsoft uncompressed packed 4:4:4:4

or posibly one more:

v408 QuickTime uncompressed 4:4:4:4 X X

Note that both are uncompressed, so get a big disk :-)

I saw those formats in your link, but nothing is writed about an alpha layer.

The only one is
PAM X X PAM is a PNM extension with alpha support.
(for encoding and decoding)

Is there a way to exporte a file in PNM format with KDEnLive ?

Thank you

This capability was only recently added to MLT:

You will need to use a daily build or the build script and adjust (or create) your render profile per the commit comment.

I'm sorry for my poor knowledge. :-(
I am not able to make a script.
May be it would be nice if a real specialist add it to the (so desired) V1.0 of Kdenlive.

If you know one, you should indicate me a tutorial to make a MLT scrip and I will try anyway...