Interpret footage - alpha settings are grayed out, not working in after effects

[halilc85750916]

Hi! I am a windows 10 user.

I downloaded a stock video which has alpha channel option (it's written in the video description and also asked to my friend who has a Mac, he checked and confirmed that video has alpha channel)

But when I put the video into my project and open interpret footage window of it, the alpha settings are grayed out and I can't change anything.

Searched for a solution for more than 2 hours in adobe forums and all over the internet but couldn't find the solution.

Can anyone help please? Thanks in advance!

There is a short video that shows my problem:

[Rick Gerard]

Check the footage properties by selecting the footage in the Project Panel and checking the thumbnail and the data. If there is an alpha channel it will show up there:

Even high bit rate footage needs the plus sign. There is a good chance your footage looks something like this:

This info is in the User Guide and can be found in the descriptions of the various UI panels in AE.

Many times stock footage includes a black and white version of the footage that is used as a track matte to create transparency.