commit cf15cb5c94fdb1abab13e048c93adf3264b78cd7
author Erik Språng <sprang@webrtc.org> Mon Dec 07 12:18:34 2020
committer Commit Bot <commit-bot@chromium.org> Mon Dec 07 13:36:03 2020
tree 2c31546461d9c608a6fccbf1f7537c16e3ea8951
parent 3ee4af45094c448f0b410fae2c9472ebeba76625

Update how FEC handles protection parameters for key vs delta frames.

This CL:
1) Updates RtpSenderVideo to actually populate the is_key_frame field
properly.

2) Updates UlpfecGenerator to:
 * Allow updating the protection parameters before adding any packet.
 * Apply keyframe protection parameter when at least one buffered
   media packet to be protected belongs to a keyframe.

Updating the parameters in the middle of a frame is allowed, at that
point they only determine how many _complete_ frames are needed in order
to trigger FEC generation. Only that requirement is met, will the
protection parameters (e.g. FEC rate and mask type) actually be applied.

This means that delta-frames adjecent to a key-frame (either ahead of
or after) may be protected in the same way as the key-frame itself.

Bug: webrtc:11340
Change-Id: Ieb84d0ae46de01c17b4ef72251a4cb37814569da
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/195620
Commit-Queue: Erik Språng <sprang@webrtc.org>
Reviewed-by: Ying Wang <yinwa@webrtc.org>
Reviewed-by: Danil Chapovalov <danilchap@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#32787}