Playback of videos with alpha channel

[porg]

👉 This is a "Support data suggestion". Please add that tag. Thanks.

Information Need

• On the topic of "transparent videos" (=videos with an alpha channel) and which web browsers support them in what particular container formats and/or codecs, I only found several specifics here and there, spread over various blogs.
• But nothing holistic like an overview/comparison/compatibility matrix in a Wikipedia article or on one of the large technical documentation sites such as Mozilla Developer or Caniuse.com.
• So my first deed to improve the situation was that I added a whole new section Transparent video to the Wikipedia article HTML5 video in which I gathered the facts with proper sources.

Proposal

• It would be cool if caniuse would cover this topic.
• Caniuse already covers some particulars like https://caniuse.com/hevc or https://caniuse.com/png-alpha or https://caniuse.com/css-opacity but nothing which covers transparent videos in an overview.
• Though I would not really know how to structure/cover this properly, I hope you have some ideas.
• With my limited knowledge how Caniuse operates on the editorial side I'd propose something like this:
  • By the basic nature of how Canisue works, being "Feature X supported by browser Y since versions Z, with limitations 1, 2, 3." I assume this topic would be chunked like this:
  • Singular attributes such as alpha channel support per codec or per container format
    • so something like: VP8-alpha, VP9-alpha, MP4-alpha, WEBM-alpha, …
  • And then probably one super-set a.k.a. hyper-topic a.k.a. "Feature summary" which presents these aspects in combination.