Add a speaking indicator

Signed-off-by: Šimon Brandner <simon.bra.ag@gmail.com>

res/css/views/voip/_CallView.scss

@@ -74,9 +74,9 @@ limitations under the License.
     > .mx_VideoFeed {
         width: 100%;
         height: 100%;
+        border-width: 0 !important; // Override mx_VideoFeed_speaking
 
         &.mx_VideoFeed_voice {
-            background-color: $inverted-bg-color;
             display: flex;
             justify-content: center;
             align-items: center;

res/css/views/voip/_VideoFeed.scss

@@ -17,12 +17,17 @@ limitations under the License.
 .mx_VideoFeed {
     overflow: hidden;
     position: relative;
+    box-sizing: border-box;
 
     &.mx_VideoFeed_voice {
         background-color: $inverted-bg-color;
         aspect-ratio: 16 / 9;
     }
 
+    &.mx_VideoFeed_speaking {
+        border: $accent-color 2px solid;
+    }
+
     .mx_VideoFeed_video {
         width: 100%;
         background-color: transparent;

src/components/views/voip/VideoFeed.tsx

@@ -24,6 +24,8 @@ import MemberAvatar from "../avatars/MemberAvatar";
 import { replaceableComponent } from "../../../utils/replaceableComponent";
 import { SDPStreamMetadataPurpose } from 'matrix-js-sdk/src/webrtc/callEventTypes';
 
+const SPEAKING_THRESHOLD = -60;
+
 interface IProps {
     call: MatrixCall;
 
@@ -45,6 +47,7 @@ interface IProps {
 interface IState {
     audioMuted: boolean;
     videoMuted: boolean;
+    speaking: boolean;
 }
 
 @replaceableComponent("views.voip.VideoFeed")
@@ -57,6 +60,7 @@ export default class VideoFeed extends React.PureComponent<IProps, IState> {
         this.state = {
             audioMuted: this.props.feed.isAudioMuted(),
             videoMuted: this.props.feed.isVideoMuted(),
+            speaking: false,
         };
     }
 
@@ -103,11 +107,19 @@ export default class VideoFeed extends React.PureComponent<IProps, IState> {
         if (oldFeed) {
             this.props.feed.removeListener(CallFeedEvent.NewStream, this.onNewStream);
             this.props.feed.removeListener(CallFeedEvent.MuteStateChanged, this.onMuteStateChanged);
+            if (this.props.feed.purpose === SDPStreamMetadataPurpose.Usermedia) {
+                this.props.feed.removeListener(CallFeedEvent.VolumeChanged, this.onVolumeChanged);
+                this.props.feed.measureVolumeActivity(false);
+            }
             this.stopMedia();
         }
         if (newFeed) {
             this.props.feed.addListener(CallFeedEvent.NewStream, this.onNewStream);
             this.props.feed.addListener(CallFeedEvent.MuteStateChanged, this.onMuteStateChanged);
+            if (this.props.feed.purpose === SDPStreamMetadataPurpose.Usermedia) {
+                this.props.feed.addListener(CallFeedEvent.VolumeChanged, this.onVolumeChanged);
+                this.props.feed.measureVolumeActivity(true);
+            }
             this.playMedia();
         }
     }
@@ -162,6 +174,10 @@ export default class VideoFeed extends React.PureComponent<IProps, IState> {
         });
     };
 
+    private onVolumeChanged = (volume: number): void => {
+        this.setState({ speaking: volume > SPEAKING_THRESHOLD });
+    };
+
     private onResize = (e) => {
         if (this.props.onResize && !this.props.feed.isLocal()) {
             this.props.onResize(e);
@@ -173,6 +189,7 @@ export default class VideoFeed extends React.PureComponent<IProps, IState> {
 
         const wrapperClasses = classnames("mx_VideoFeed", {
             mx_VideoFeed_voice: this.state.videoMuted,
+            mx_VideoFeed_speaking: this.state.speaking,
         });
         const micIconClasses = classnames("mx_VideoFeed_mic", {
             mx_VideoFeed_mic_muted: this.state.audioMuted,