1909373 - Improve VideoFrame.copyTo performance

Status: NEW

(Core :: Audio/Video: Web Codecs, enhancement, P3)

Description

[C.M.Chang[:chunmin]]

Chrome's VideoFrame copyTo is way faster than Firefox. Here: https://chunminchang.github.io/playground/webcodecs/videoFrame-copyTo-performance.html is a test page showing the time that VideoFrames' copyTo take to convert from RGBX/A and I420(A) to RGBA/X with different color space settings. Currently, on MacOS, Chrome only takes 0.1 ms to convert I420 to RGBA, while my Nightly takes 3 ms to do the same job. For plain copy (unchecked the "set options" in the test page), Chrome takes 0.3 ms to copy RGBA, while my Nightly takes 1 ms.

There are two main tasks:

1. Find a better solution to convert the YUV to RGBA (Bug 1906717),
2. Speed up the plain RGBA copy (shuffle the channels if needed)

Maybe we could do the YUV-to-RGBA conversion by GPU and copy the data in paralle threads like what Chrome does.