All my MP4 videos are getting black bars on the sides when viewed in Storyline
MP4s are supposed to be natively supported in Storyline, but I am running into a consistent issue with them: Every mp4 I bring into Storyline gets a black bar on either side of the video. You can see in the attached .story file and in the attached screenshot. I've put two versions of the same video on a single slide. The top video (the one with the black bars) is the MP4. The bottom video is the AVI (no black bars).
I'd like to know how to prevent these black bars from showing up. I am seeing them in preview mode, and web mode for both Chrome and Firefox. It might be showing up in other publishing formats, though I haven't checked. Thank you for your help with this!