Silent video transcripts

I am working to optimize my project's accessibility features.  Several slides have short videos with no audio.  The video includes characters speaking in speech bubbles, and the action is important to the context of the learning experience.  Since transcripts are only generated by closed captioning, which would only be distracting to the learners in this case, the best option I can find is to type out the entire transcript in the alt text option.  Is there a better solution to this?