Movie Transparent Alpha Channel

Jul 19, 2012

OK, let me make sure I have this straight, perhaps the community can enlighten me.

-- If I import a .mov movie that has a clear alpha channel into Storyline it will encode it into an .mp4 and I will loose the alpha channel.

-- If I import a .flv that has a clear alpha channel it will keep it unless an HTML 5 request comes and then Storyline will encode it into a .mp4 and loose the alpha channel.

--If I import a .mp4 with a clear alpha channel Storyline will re-encode it and wipe out my alpha channel.

So, the best approach appears to be to forget about movies with clear alpha channels if you suspect that any of your clients don't like Flash. And only .flv works.

34 Replies
Alexandra Beaumont-Marrow

Hi, I'm being provided an alpha channel transparency video from a colleague for import into Storyline. It's an .flv, but when I import it (just over a gradient to test for now), I'm still getting a black background (see attached). I'm trying it both in Storyline 1 and 2, but having the same issue. Is this typical? Or is is an issue with the video file?



Ashley Terwilliger-Pollard

Hi Alexandra, 

FLV videos with alpha channel transparency are supported in Articulate Storyline's Flash and Articulate Mobile Player (AMP) output. See this article for a comparison of Flash, HTML5, and AMP features.

There was an issue in earlier builds of Storyline where alpha channel transparency wasn't working as expected in published courses. This issue was corrected in Update 5 for Storyline 2. To take advantage of the new features and fixes, install the latest version from the link in your product confirmation email or download it here.

After installing the latest software update, delete the affected FLV videos from your project file, then insert them again and republish your course.

It should work in Storyline 1 as described here. 

Alexandra Beaumont-Marrow


Thanks for the quick response, but that doesn't necessarily clarify my issue.

I've already upgraded my version of Storyline 2, so that shouldn't be a problem. My question is, should I still see a black background in the video once I import it into the course I'm working on? I've also tried publishing to see if the background only goes away after publishing, but that didn't work either - still have the black background.

Should the video appear in the project file in Storyline with a transparent background upon import? If it's not (as in my case - still has black background), am I to assume that there's something wrong with the file itself?



Alexandra Beaumont-Marrow

Thanks so much for your help, Ashley.

Please see the attached.

The person providing the files is frustrated by the FLV limitation - apparently many Adobe video editing software products do not support FLV any longer, so she's having to try and convert.

I couldn't even find an FLV stock video clip to test, because FLV seems to be really outside of the norm (another person on our media team reiterated that as well). It would be cool if Storyline could expand their alpha channel acceptance to other, more commonly used file types....I hate to bump into this each time we need to use a transparent background video.

Could you recommend some programs that would naturally export to FLV with alpha channel? I'd be glad to be able to offer my video gal an alternative solution.

Thanks again for your help,


Steve Flowers

Adobe removed the FLV export from recent versions but AfterEffects CC 12 can still do it. She'd need to install this version to have the option. 

Unfortunately, MP4 playback in the browser doesn't support alpha channel. It's also an oddball encoding so I'm not confident that Articulate would consider adding this feature. 

Ashley Terwilliger-Pollard

Hi Alexandra, 

I'm glad Steve was able to share an option with you here - as I don't know much about other ways to ensure there is alpha channel. I did share your FLV file with a colleague, and he shared that all video with alpha channels must be 32-bit and all 32-bit videos have an alpha channel. Taking a look at your file, it seems to be 8-bit and it would see that this .flv file does not contain transparency. 

Alexandra Beaumont-Marrow

Hi Again!

So it looks like my internal video asset is not able to prep the files appropriately for use in Storyline - a big bummer.

I'm now contacting post-production studios to try and salvage our footage. However they're asking for full specs on the files they need to deliver - for example compression, etc....

What are the optimal video specs for an FLV with alpha channel for use in Storyline????

Thanks for your help!


Tim Shelton

I know this might sound stupid but why dont you add your background into the video file. Video rendering software uses Alpha for importing other video clips or files which may have transparent elements i.e. from a 3D software or an animation.

It is not meant for rendering a video to then sit on a background element in a different software and be transparent (like a window video on a picture jpg). SWFs and Flash can do this but again its not the best idea it makes sense to use whatever backdrop in the file and then export a whole video/swf.

Make sense?


Tim Shelton

Depending on the content of said video you could build it in storyline and have it play on the timeline if it is a series of text and images. I have done this for clients who werent fond of paying for videos or custom animation work.

Also the players will likely not read the alpha channel even if its there as they have no way of displaying it so they will show black.

Heather Jones

Do you guys have any plans up updating other file imports other than flv since that is no longer supported by adobe and several companies are moving away from flash?

We have a chromakey file we are trying to  import where the green screen has already been removed but its .mov and the black background wont  go away.  is there anyway storyline will acknowledge the aplha channel on an .flv file. I do have the upgraded version

Leslie McKerchie

Hi Heather!

FLV videos with alpha channel transparency are supported in Articulate Storyline's Flash and Articulate Mobile Player (AMP) output. There was an issue in earlier builds of Storyline where alpha channel transparency wasn't working as expected in published courses. This issue was fixed in Update 5. See this article for details.

I am not sure of any future support details, but if you have a suggestion, you are welcome to share your thoughts with our product development team here.

Leslie McKerchie

Hi Heather!

Duplicating my response in your other post here.

Are you utilizing the latest update as explained in this article? Keep in mind that this will not work in the HTML5 output.

If you are still having difficulty and need us to take a look at your .story file, you can share your file here with our team.

Heather Jones

Hello Steve,


I apologize for the delay in getting back to you.

Since me last post our video editor went and got Adobe After Effects  CS6.

When I drop the FLV file in, our talent still has black around her- it appears that the alpha channel is still not being recognized.

He created the chroma key using Keylight 1.2 in AE

The file was exported using the FLV with Alpha option 
The Channels were set to RGB + Alpha

Any suggestions/thoughts on what we could be doing wrong?


I've attached the FLV test file he provided.

Thank you for your help


Tim Shelton

If you could be more specific as to how the 2 are meant to interact I may
be able to be more specific but I have detailed some thoughts below:

Having an alpha channel will not solve this issue you would not be able to
click through the video to hit anything on the background it will treat the
whole iframe as the video. So unless the video is cropped to the talking
head it would play pause the video. A much simpler solution would be to
have the talent in a coloured box to match the template much like a mini
window. This whole object could then move around the screen as needed.

Examples of this kind of talking head can be found on video
streams or many content formats on youtube.

Trying to preserve the alpha channel in the way your describing is unlikely
to work and overly complicated.