Fix quality issues with SVC screenshares. #1077
Merged
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
When we munged SDP to set bitrate, it was set on the codec's fmtp line. The codec and its fmtp is shared across media tracks. So if a user is sharing a camera and screenshare tracks, both tracks will be published at the same bitrate (typically the user's camera track). This leads to blurry screenshares. Additionally, screenshares cannot be encoded in VP9 with L3T3_KEY. Chrome degrades quality aggressively whenever L1T3 isn't used.
🦋 Changeset detectedLatest commit: da7e6ee The changes in this PR will be included in the next version bump. This PR includes changesets to release 1 package
Not sure what this means? Click here to learn what changesets are. Click here if you're a maintainer who wants to add another changeset to this PR |
size-limit report 📦
|
|
nice findings! |
lukasIO
approved these changes
Mar 15, 2024
Merged
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
When we munged SDP to set bitrate, it was set on the codec's fmtp line.
The codec and its fmtp is shared across media tracks. So if a user is sharing
a camera and screenshare tracks, both tracks will be published at the
same bitrate (typically the user's camera track). This leads to blurry
screenshares.
Previously this was set because AV1 took a long time to start up. So we are
keeping that behavior only for AV1. I've confirmed that VP9 does not suffer
from the slow-start.
Additionally, screenshares cannot be encoded in SVC with L3T3_KEY. Chrome
degrades quality aggressively whenever L1T3 isn't used.