dnxhd alpha

[chriss0212]

hi all

the dnxhd codec is supporting alpha channel and ventuz should be able to play int incl. alpha but if i encode a png encoded mov or a png image sequence with quicktime pro to dnxhd i am missing the alpha channel.

any idear or tipp how i get the alpha channel?

thx and greetz

chriss

[SamTheSwede]

I have done this a lot before, not using QuickTime Pro though. I've made DNxHD clips with After Effects with the attached settings and played them in Ventuz with alpha. However, I tried a clip just now and it seems to ignore the alphachannel. I brought the file into after-effects again to verify that the alpha channel is in fact present in the clip, and it is.

Something happened in one of the latest releases?

All the best,

Sam

[chriss0212]

hi sam

thx for answer! so it realy seems, that i am doing everything right and there is a problem in ventuz?!

greetz

chriss

[joysprod]

Hi guys. I did ask a similar question related to the advanced movie node some months ago. http://forum-archive.ventuz.com/forums/ ... wPost.aspx

I'm not certain where we stand with future updates of Codecs being available to us? Apparently not as easy as just adding a new codec to the folder. Maybe someone at Ventuz can give us an idea for future support, roadmap, time frame for - Dnx including alpha, Pro Res etc if ever?

Regards

Peter

[Christian Krix Schmidt]

Which node are you using in Ventuz to play back the clip? The new Advanced Movie Node uses an implementation of ffmpeg to decode movies. Maybe ffmpeg does not support alpha channel of the dnxhd codec. Have a look here: http://en.wikipedia.org/wiki/DNxHD_codec

Alternatively you can always use the Quicktime Animation codec to play back RGBA footage.

Chris

[Karol]

So you say that the dnxhd codec with alpha worked correctly in some previous versions of Ventuz but it does not work with with the latest version!?
And you used the Quicktime Movie node for playback?

Cheers
Karol

[chriss0212]

hi karol

from my side i can say: i think (i am not 100% sure) that i allready tested dnxhd with alpha withe the new mf node and i think it worked...but i am realy not sure! i think i am loosing my brain with my hair color

wikipedia say that alpha should be possible

so do you have any experience regarding dnxhd and alpha?

i know i can use qt animation codec.....but my client dont want to use it

greetz

chriss

[SamTheSwede]

Karol, I'm sure I've used DNxHD codec with alpha before, however it was on my 32-bit system (that I no longer have available).
And I'm not entierly sure, but I think it was under the Quicktime node I used it... sorry for the bad info!

Maybe we have to be sure we have the same version of the Codec-package from Avid as FFMPeg is using?

All the best from Stockholm,

Sam

[chriss0212]

hi krix

i tested the dnxhd file with alphe in ae. there i can see the alpha! so dnxhd definitly supports alpha!

greetz to dubai

chriss

[Christian Krix Schmidt]

chriss, i meant to say that ffmpeg maybe does not support the alpha channel.
it is a bit funny, weird and sad at the same time that your client does not want to use QT animation.

sam, if you used the quicktime node before than it is a whole different story. don't count on the advanced movie node to be able to play back the same codecs. it is not quicktime. if you were to use the 32bit version of ventuz than you can use the quicktime nodes again and the dnxhd codec as before.