Closed Bug 1481725 Opened 3 years ago Closed 3 years ago

re-evaluate minimum bitrate for 640xsomething resolution

Categories

(Core :: WebRTC: Audio/Video, defect, P2)

defect

Tracking

()

RESOLVED FIXED
mozilla63
Tracking Status
firefox63 --- fixed

People

(Reporter: fippo, Assigned: fippo)

References

Details

Attachments

(2 files, 1 obsolete file)

followup on https://bugzilla.mozilla.org/show_bug.cgi?id=1474661#c22

I think the minimum bitrate should not be 300kbps but 150kbps, same as in webrtc.org. Otherwise there is a gap between the maximum bitrate the 320x180 layer is going to send (150kbps) and where the 640x360 layer starts encoding.
And the maximum REMB estimate one can get from these 150kbps is around 260kbps which means one can get "stuck" in the low-resolution layer.

From what I can see this does not seem to affect non-simulcast streams, https://webrtc.github.io/samples/src/content/peerconnection/bandwidth/ works fine (when modified to use 640x360) even at 125kbps.
Attached patch minbitrate.patch (obsolete) — Splinter Review
Attachment #8998454 - Flags: review?(docfaraday)
Assignee: nobody → fippo
Status: NEW → ASSIGNED
Rank: 15
Priority: -- → P2
Comment on attachment 8998454 [details] [diff] [review]
minbitrate.patch

Review of attachment 8998454 [details] [diff] [review]:
-----------------------------------------------------------------

::: media/webrtc/signaling/src/media-conduit/VideoConduit.cpp
@@ +1634,1 @@
>    {tl::Max<MB_OF(400, 240), MB_OF(352, 288)>::value, KBPS(200), KBPS(300), KBPS(1300)}, // VGA, WVGA

The min for 480x270 is lower than the min for the next resolution down.
Attachment #8998454 - Flags: review?(docfaraday) → review-
also moved the WVGA a bit. Not sure if 125k is a good minimum bitrate but afaics the min bitrate seems unused for non-simulcast. Maybe it is only used with googSuspendBelowMinBitrate as described in http://www.rtcbits.com/2016/11/controlling-bandwidth-usage-in-webrtc.html ?
Attachment #8998779 - Flags: review?(docfaraday)
Attachment #8998454 - Attachment is obsolete: true
Comment on attachment 8998779 [details] [diff] [review]
minbitrate2.patch

Review of attachment 8998779 [details] [diff] [review]:
-----------------------------------------------------------------

This seems to work ok.
Attachment #8998779 - Flags: review?(docfaraday) → review+
bwc: can you help me land that please?
Flags: needinfo?(docfaraday)
Summary: re-evaluate simulcast bitrates for 640x360 resolution → re-evaluate minimum bitrate for 640xsomething resolution
Flags: needinfo?(docfaraday)
Keywords: checkin-needed
Pushed by apavel@mozilla.com:
https://hg.mozilla.org/integration/mozilla-inbound/rev/dc2b23ed78c7
change minimum bitrate for VGA to 150kbps r=bwc
Keywords: checkin-needed
https://hg.mozilla.org/mozilla-central/rev/dc2b23ed78c7
Status: ASSIGNED → RESOLVED
Closed: 3 years ago
Resolution: --- → FIXED
Target Milestone: --- → mozilla63
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