Render w/alpha channel

[Sherman]

720p-30 greenscreen footage rendered to .avi.
Will render out to mp4 before sending by ftp.
Client specifies an alpha channel.
Can this be accomplished in Vegas, or do I need to use Handbrake, Super of some other third party program.
Thanks

 

[milksac]

MP4 files don't have embedded alpha channels. You'll need to either render out the alpha channel as a separate clip or use another codec such as PNG.

 

[JeganRX]

I strongly recommend NOT using .mp4 in this case. I assume this means you're using the H264 codec, correct? If so, this means no alpha support, and the best option you probably have is the PNG format. It's very large, but it's lossless and supports alpha (and is QT compatible).

There are other lossless formats that support alpha channels but many of them are windows-only.

 

[Demistate]

You can render out alpha channel videos as a seperate video (black and white only). I still would not render this out in a h.264 since the color space is 4:2:0 and you will loose chroma resolution.

PNG sequences are a very good way to render out alpha channels, keep in mind you are converting a (most likely) REC.709 video source to RGB when you do it this way unless your export software allows you to export REC.709 color space within a PNG sequence.

You also have to be able to read it as a REC.709 color space at the other end. After effects supports this through color management.

 

[Sherman]

Rendered to PNG, as for some reason my NLE, Vegas Pro 9, refuses to render to .MOV.

 

[Sherman]

So I rendered to PNG.
Got, I think it's 15 thousand stills.
Chose the wrong option in Vegas methinks.
Help!

 

[milksac]

15,000 frames at 30fps is a around 8 minutes. Is this correct, is your clip about 8min? At 720p resolution that's a ton of data to attempt to send via ftp. Can you toss it on a thumb drive and mail it?

You rendered out a PNG sequence, which as you found out renders out the individual frames. You should be able to select Quicktime export and then select PNG as the codec. This will render out a self contained movie. As to why your system won't export QT I don't know.