Alpha channel in a MOV file?

Is it possible to maintain the alpha channel of, say, a rendered sequence of PNG files when sequencing them into a Quicktime MOV file? I’ve heard that the animation codec in Quicktime allows for this. I don’t have the Pro version, but am willing to purchase it if this is necessary. My client needs to composite my animation over other footage and is having problems using the PNG sequence himself. Not sure what software he’s using on his end. Anyone attempted or have thots? TIA!

Format tab, select quicktime and a settings window will popup where you can select the animation codec. Be sure that you have RGBA enabled. It’s 8BPC RGBA. Quicktime holds alphas as premultiplied so be sure that you’re not using a straight alpha. Animation codec provides minor lossless compression.

If you open the PNG sequence in Quicktime using the open image sequence option and just save, it puts all the PNGs into a .mov. That should be supported in any compositing program but I guess if he doesn’t have Quicktime installed he may have issues. It could be the PNG format, you can save as a tiff sequence too.

Animation format as mentioned should work fine and is a popular format for compositing. I’ve had some glitches appear in animation format so I tend to use tiff image sequences. They load faster in compositors too but they take up a lot of space.

If you need to send an avi, MPEG Streamclip can convert a .mov container into a .avi container.

It’s good to see you around again mzungu, I remember you from a while back.

or use this:
better compression than qt Animation and its also free
supports RGBA

Thanks for this info, guys! wiki updated

Technically Quicktime isn’t a codec. Lagarith is though. Quicktime is merely a container for codec formats.

Quicktime codecs that support alpha include:




Pixlet (developed by Pixar)

It’s the same as saying .avi is a format but AVI can contain Indeo video, DivX, MS-MPEG4 and so on.

MP4 is another container that contains MPEG4 variants - H264 being the most popular and it’s derived from the Quicktime container.

You can actually put the same mpeg4 compressed video inside .avi, .mp4 and .mov.

ok, thx OSX. yes, my QT has 9 codecs to choose from, i realize that now.

Did you update the wiki?

I thought I had a login setup but it’s not the same as my BA one. You can edit it if you like, you’ve done a good job already.

Just change Quicktime to the 4 codecs I mentioned - I think they’re the only Quicktime codecs that support RGBA though they’re not limited to quicktime containers. For Blender though, that’s how they are accessed.

If you say something like:

codecs that support RGBA:

animation (quicktime)
PNG (quicktime)
TIFF (quicktime)
Pixlet (quicktime) - note, not lossless.

Also, Pixlet might be a Mac-only deal, I’m not sure if the Windows version of Quicktime supports it.

ok. i am sick of updating this page. all for now. have to move on to the other 100 pages that are waiting.

Thanks, gents, for the replies. I’ve tinkered with this some more using the alpha’d PNGs that I’ve already rendered with little success. I don’t own Quicktime Pro, so osxrules, I’m not able to render out one like you’ve mentioned within Quicktime (I’m on windblows.) Thanks for the tip on MPEG Streamclip. Looks like a very handy little app. (And, hey, I’ve been skulking around the forum all along… mostly looking out for CAD-related threads and trying not to be corrupted by your cult-of-OSX gospel/propoganda :D;))

So, does this mean that I’ll have to re-render with premul turned on and directly into the MOV? (don’t know if it was on when I ran these PNGs…) Also, the depth setting under the animation codec that I was told to use was “millions of colors+”. Is this correct?

Once again, much appreciated, y’all.:slight_smile:

If you have the pngs you should be able to put those in the sequencer and from there render it out into a mov with the codec. I don’t know if the sequencer is capable of premultiplying the pngs before rendering them into the mov.

Presently the SVN version of Blender 2.45.12, on windows is broken for output.

There is a bug in the system where the FPS is calculated incorrectly. The FPS is divided by 10 in the final MOV file. So you can not use quicktime output with the SVN version of blender.

virtualdub might work for you on windows. It seems to work with image sequences. You should never render animations direct to a movie format. Always as an image sequence and then join it into a movie. It just gives you a backup if there’s a crash or whatever.

Haha, you will succumb one day. You all will muahahaha. :yes: :RocknRoll:

I’ve been considering changing my name for ages but I can’t decide on what to go with. It’s between P.Brain to match my avatar/sig and intellectual capacity, and bowlcut to match my hairstyle. :wink:

Yeah, I love virtualdub and have used it for years. Prob is, its mostly an AVI tool and for alpha channel support, the codecs of AVI are pretty scarce-to-nonexistant. Also, this customer is used to Quicktime, it seems.

I’ve always liked “IDtenT” (you have to write it out with the number to see it) or “ÜberGoober”, but then those may be too obvious.