If I'm not mistaken, Vegas still only recognizes alpha in uncompressed, png and animation codec for QT files. I haven't tried any others with V11 or 12. I know this was discussed in a thread fairly recently and someone had an "under-the-hood" mod that would allow Vegas to see alpha in other formats. Can't remember the details.

My alpha tests with DNxHD and Vegas Pro 8 worked. I'm not comfortable generalizing that to newer versions, though.

There is a mistaken impression being conveyed here. AFAIK - alpha within a mov container is never auto discovered or recognized by Vegas. First you have to identify what kind of alpha channel (if there was truly any) was created in the source - and most importantly you have to indicate in the event properties of your new project that this one event should have an alpha channel. In most cases a common straight channel will then work easily - the other types can be somewhat trickier to set properly on the timeline so that it works.

>What version of Avid LE?

musicvid, I am on the latest (afaik) release: 2.3.9.


>AFAIK - alpha within a mov container is never auto discovered or recognized by Vegas. First you have to identify what kind of alpha channel (if there was truly any) was created in the source - and most importantly you have to indicate in the event properties of your new project that this one event should have an alpha channel. In most cases a common straight channel will then work easily

videoITguy, I have definitely done the event properties, trying all three alpha channel types. How do I ensure I have identified the kind of alpha channel created in the source (which was created by Vegas12 rendering to DNxHD with settings per my 1st post)?

/jerry

>If I'm not mistaken, Vegas still only recognizes alpha in uncompressed, png and animation codec for QT files.

atom12, I just tried animation codec for QT and it does work. For now I am going to give up on DNxHD.

/jerry

"Compressed depth 32 bpp color (also tried 24 bpp),

you can have alpha channel when rendering to rec709 in DNxHD?

i thought alpha would only be for sRGB... title cards, masks, the usual post-production computer-generated images.

robwood, I just tried RGB but still no alpha channel in Vegas. As I noted before I do get the alpha in Photoshop. The Animation codec is working fine with Vegas.

/jerry

I believe that Avid NLE's handle alpha channels different than everyone else.The same is true for Mattes in Avid. Everyone uses White for print and Black for transparent and Avid uses Black for print and White for transparent in their mattes (just the opposite). You'll see that some plug-ins have special switches for Avid in case you're using them in an Avid NLE. I think Photoshop is one of those programs that has options for saving "Avid alpha" rather than regular alpha. Likewise Premiere Pro has no problem with these alpha channels.

As you might expect, the Avid DNxHD codec also handles alpha channels differently just like their NLE and apparently, Vegas Pro 12.0 can't handle that difference. I'm surprised that Vegas Pro 8.0 worked. Vegas Pro is not going to use the Avid alpha channel in DNxHD unless Sony specially adds support for it. Use the PNG or the Animation codec if you need alpha channels in a QuickTime wrapper.

~jr

jr and TeeTime,
I've rechecked my results with 2.3.9, and the DNxHD +Alpha files do not reopen with alpha in Pro 8. It may have been that way all along. They do play back with alpha in other programs. mea culpa

PNG is a viable alternative, but requires a lot more space.