Do not try to manually adjust SVC layers based off target resolution (#…

…2920)
aws · Jul 8, 2024 · e12a7ab · e12a7ab
1 parent 706a3b5
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Showing 4 changed files with 5 additions and 37 deletions.
diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Removed
 
 ### Changed
+- Do not try to manually adjust SVC layers based off target resolution, as this may lead to an unnecessarily high minimum bitrate to subscribe to all remote videos. Instead rely on browser logic which drops any layers below around 135p.
 
 ### Fixed
 

diff --git a/docs/classes/nscalevideouplinkbandwidthpolicy.html b/docs/classes/nscalevideouplinkbandwidthpolicy.html
@@ -415,7 +415,7 @@ <h3>set<wbr>Meeting<wbr>Supported<wbr>Video<wbr>Send<wbr>Codecs</h3>
 							<aside class="tsd-sources">
 								<p>Implementation of <a href="../interfaces/videouplinkbandwidthpolicy.html">VideoUplinkBandwidthPolicy</a>.<a href="../interfaces/videouplinkbandwidthpolicy.html#setmeetingsupportedvideosendcodecs">setMeetingSupportedVideoSendCodecs</a></p>
 								<ul>
-									<li>Defined in <a href="https://github.com/aws/amazon-chime-sdk-js/blob/main/src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts#L303">src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts:303</a></li>
+									<li>Defined in <a href="https://github.com/aws/amazon-chime-sdk-js/blob/main/src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts#L304">src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts:304</a></li>
 								</ul>
 							</aside>
 							<div class="tsd-comment tsd-typography">
@@ -622,7 +622,7 @@ <h3>wants<wbr>Video<wbr>Dependency<wbr>Descriptor<wbr>Rtp<wbr>Header<wbr>Extensi
 							<aside class="tsd-sources">
 								<p>Implementation of <a href="../interfaces/videouplinkbandwidthpolicy.html">VideoUplinkBandwidthPolicy</a>.<a href="../interfaces/videouplinkbandwidthpolicy.html#wantsvideodependencydescriptorrtpheaderextension">wantsVideoDependencyDescriptorRtpHeaderExtension</a></p>
 								<ul>
-									<li>Defined in <a href="https://github.com/aws/amazon-chime-sdk-js/blob/main/src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts#L299">src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts:299</a></li>
+									<li>Defined in <a href="https://github.com/aws/amazon-chime-sdk-js/blob/main/src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts#L300">src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts:300</a></li>
 								</ul>
 							</aside>
 							<div class="tsd-comment tsd-typography">

diff --git a/src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts b/src/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.ts
@@ -264,7 +264,8 @@ export default class NScaleVideoUplinkBandwidthPolicy implements VideoUplinkBand
       if ((this.numParticipants >= 0 && this.numParticipants < 3) || !this.isUsingSVCCodec) {
         scalabilityMode = 'L1T1';
       } else {
-        scalabilityMode = targetHeight >= 720 ? 'L3T3' : targetHeight >= 360 ? 'L2T3' : 'L1T3';
+        // We do not limit the number of layers depending on input resolution, however Chrome will drop anything below around 135p.
+        scalabilityMode = 'L3T3';
       }
       this.logger?.info(
         `calculateEncodingParameters: SVC: ${this.enableSVC}    participants: ${

diff --git a/test/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.test.ts b/test/videouplinkbandwidthpolicy/NScaleVideoUplinkBandwidthPolicy.test.ts
@@ -898,40 +898,6 @@ describe('NScaleVideoUplinkBandwidthPolicy', () => {
       expect(policy.optimalParameters.isSVCEncoding()).to.be.true;
     });
 
-    it('Degrade to L2T3 scalability mode if target height is between 360 and 720', () => {
-      policy.setTransceiverController(transceiverController);
-      // @ts-ignore
-      policy.isUsingSVCCodec = false;
-      // @ts-ignore
-      policy.numParticipants = 10;
-      // @ts-ignore
-      policy.numberOfPublishedVideoSources = 8;
-      policy.setSVCEnabled(true);
-      policy.setMeetingSupportedVideoSendCodecs(
-        [VideoCodecCapability.vp9Profile0()],
-        [VideoCodecCapability.vp9Profile0(), VideoCodecCapability.h264ConstrainedBaselineProfile()]
-      );
-      // @ts-ignore
-      expect(policy.optimalParameters.isSVCEncoding()).to.be.true;
-    });
-
-    it('Degrade to L1T3 scalability mode if target height is below 360', () => {
-      policy.setTransceiverController(transceiverController);
-      // @ts-ignore
-      policy.isUsingSVCCodec = false;
-      // @ts-ignore
-      policy.numParticipants = 16;
-      // @ts-ignore
-      policy.numberOfPublishedVideoSources = 14;
-      policy.setSVCEnabled(true);
-      policy.setMeetingSupportedVideoSendCodecs(
-        [VideoCodecCapability.vp9Profile0()],
-        [VideoCodecCapability.vp9Profile0(), VideoCodecCapability.h264ConstrainedBaselineProfile()]
-      );
-      // @ts-ignore
-      expect(policy.optimalParameters.isSVCEncoding()).to.be.true;
-    });
-
     it('Enables SVC when SVC is enabled, even if logger is not defined', () => {
       policy = new NScaleVideoUplinkBandwidthPolicy(selfAttendeeId, true);
       policy.setTransceiverController(transceiverController);