Can I decode a single frame?

**Is your feature request related to a problem? Please describe.**
We need to decode a H265 stream which is received as individual I frames or P frames.
Is there a way to decode these individual frames via ffmpeg.wasm into image data?

**Describe the solution you'd like**
A method to decode an HVEC frame into image data (dataArray acceptable by ImageData)
https://developer.mozilla.org/en-US/docs/Web/API/ImageData/ImageData

**Describe alternatives you've considered**
We have a native ffmpeg binding that works with node, which we could call ffmpeg APIs like `av_parser_parse2` and `avcodec_send_packet`. But that doesn't work in browsers.