Alpha channel from Premiere to Final Cut doesnt work

[Jeff Pulera]

Well, this is a bit embarrassing, and I do apologize… but apparently Avid DNxHD does NOT support an embedded alpha channel! Not that I can see anyway, and I also Googled it and that appears to be the case.

Besides that little issue, the idea was that since FCP is so old, I didn’t know if it would support the .mxf flavor of DNxHD which is included in Premiere export settings, so I had you download the QuickTime codecs which would give you a more standard .mov file to share with the editor.

So at top of exporter under FORMAT (1), you’d choose QUICKTIME, then go down to VIDEO tab, and under VIDEO CODEC (2) select DNxHD, then under RESOLUTION (3) choose a quality level. Based on your source, 8-bit would likely be suitable rather than 10-bit.

Perhaps go back to the other plan of providing editor with source video clip, along with the Matte version, but use this codec for the matte? See (4) and there is an option to Render Alpha Channel Only. When you check that box, it changes the keyed image to a black and white matte for export.

Sorry for the error – who builds a really great codec, then doesn’t offer alpha channel support??!

Thanks

Jeff Pulera
Safe Harbor Computers

[Jeff Pulera]

PS – in my screen shot example I’d selected a 10-bit “resolution” but given that your source video is 8-bit, then 8-bit is likely a better choice to make smaller files. Definitely 8-bit for the Alpha Channel export since that is just black and white and would not benefit from 10-bit color fidelity!

Thanks

Jeff Pulera
Safe Harbor Computers