This changes the libvpx VP9 encoder to generate the scalability mode based on the current encoding parameters when using layer activation.
Tested: Ran with L3T3_KEY reduced to L2T3_KEY and L1T3 due to bandwidth or layer activation. Added unit tests.
Bug: webrtc:15892
Change-Id: Iaedca4ea5fc3a692996666ceaf0d6aa03fb058a1
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/344760
Commit-Queue: Evan Shrubsole <eshr@google.com>
Reviewed-by: Ilya Nikolaevskiy <ilnik@webrtc.org>
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#42007}