Merge pull request #4194 from element-hq/toger5/rtc-mode-documentation

Add docs about currently used matrixRTC mode

.github/workflows/publish-embedded-packages.yaml

@@ -9,7 +9,7 @@ on:
       - opened
       - labeled
   push:
-    branches: [livekit]
+    branches: [main]
 
 jobs:
   versioning:

.github/workflows/sync-labels.yml

@@ -4,12 +4,12 @@ on:
 
   push:
     branches:
-      - livekit
+      - main
     paths:
       - .github/labels.yml
       - .github/workflows/sync-labels.yml
 
-permissions: {} # We use ELEMENT_BOT_TOKEN instead
+permissions: {} # We use LABEL_SYNC_GITHUB_TOKEN instead
 
 jobs:
   sync-labels:
@@ -20,4 +20,4 @@ jobs:
       DELETE: true
       WET: true
     secrets:
-      ELEMENT_BOT_TOKEN: ${{ secrets.ELEMENT_BOT_TOKEN }}
+      ELEMENT_BOT_TOKEN: ${{ secrets.LABEL_SYNC_GITHUB_TOKEN }}

.github/workflows/test.yaml

@@ -2,7 +2,7 @@ name: Test
 on:
   pull_request: {}
   push:
-    branches: [livekit]
+    branches: [main]
 jobs:
   vitest:
     name: Run unit tests

.github/workflows/translations-upload.yaml

@@ -2,7 +2,7 @@ name: Upload translation files to Localazy
 on:
   push:
     branches:
-      - livekit
+      - main
     paths-ignore:
       - ".github/**"
 

.github/workflows/zizmor.yml

@@ -2,7 +2,7 @@ name: GitHub Actions Security Analysis with zizmor 🌈
 
 on:
   push:
-    branches: ["livekit", "full-mesh"]
+    branches: ["main", "full-mesh"]
   pull_request: {}
 
 permissions: {}

docker-compose-playwright.yml

@@ -13,7 +13,7 @@ services:
       - ./backend/playwright_homeserver-othersite.yaml:/data/cfg/homeserver.yaml:Z
   element-web:
     # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:f25f10f06646858a60be461ff0141992083786fcb817e3cb03521481d4d43033
+    image: ghcr.io/element-hq/element-web:develop@sha256:ee5b90cbc65f3c2f9f98629944f5712555df4ccf443597b886f70c69246f063b
   element-web-1:
     # Pin to a SHA so that upstream cannot break our tests. Renovate handles regular updates.
-    image: ghcr.io/element-hq/element-web:develop@sha256:f25f10f06646858a60be461ff0141992083786fcb817e3cb03521481d4d43033
+    image: ghcr.io/element-hq/element-web:develop@sha256:ee5b90cbc65f3c2f9f98629944f5712555df4ccf443597b886f70c69246f063b

docs/README.md

@@ -5,5 +5,6 @@ This folder contains documentation for setup, usage, and development of Element
 - [Embedded vs standalone mode](./embedded_standalone.md)
 - [Url format and parameters](./url_params.md)
 - [Global JS controls](./controls.md)
+- [MatrixRTC modes](./matrix_rtc_modes.md)
 - [Self-Hosting](./self_hosting.md)
 - [Developing with linked packages](./linking.md)

docs/matrix_rtc_modes.md

@@ -0,0 +1,60 @@
+# MatrixRTC modes
+
+Element Call is in the middle of a transition of how a call session is
+represented and how participants pick an SFU:
+
+- **Membership events**: from room _state_ events
+  (`org.matrix.msc3401.call.member`) to _sticky_ events
+  ([MSC4354](https://github.com/matrix-org/matrix-spec-proposals/pull/4354)),
+  which are a much better fit for the short lived, per-device nature of call
+  memberships.
+- **SFU selection**: from "everyone connects to the SFU of the oldest member" to
+  **multi SFU**, where each participant uses its own homeserver's SFU and the
+  SFUs interconnect.
+
+Not every homeserver supports sticky events yet. Multi SFU is supported on all current (August 2026)
+element call clients. The three MatrixRTC modes are the steps of that transition,
+so a deployment can pick the newest one its homeserver and its user base can
+handle.
+
+## The modes
+
+| Mode            | Membership events | SFU selection | JWT endpoint                 |
+| --------------- | ----------------- | ------------- | ---------------------------- |
+| `legacy`        | state events      | oldest member | legacy                       |
+| `compatibility` | state events      | multi SFU     | legacy                       |
+| `matrix_2_0`    | sticky events     | multi SFU     | Matrix 2.0 (hashed identity) |
+
+**`legacy`** — the lowest common denominator. Use it if calls need to work with
+Element Call clients older than v0.17.0, which cannot handle multi SFU calls. (unused)
+
+**`compatibility`** — multi SFU, but still state events. Use it when all Element
+Call clients are v0.17.0 or later but the homeserver does not support sticky
+events. This is the default. (default)
+
+**`matrix_2_0`** — the target state. Requires a homeserver that advertises
+MSC4354 and all clients on v0.17.0 or later. The local membership requests its
+token from the Matrix 2.0 JWT endpoint of the
+[MatrixRTC Authorization Service](https://github.com/element-hq/lk-jwt-service)
+and identifies the room by a hashed identity instead of a `livekit_alias`.
+(Remote memberships always try the new endpoint first and fall back to the
+legacy one, so remote participants can be on either.)
+
+## Selecting a mode
+
+Users can choose a mode under **Settings → Developer → MatrixRTC mode**. The
+Matrix 2.0 option is disabled if the homeserver does not support sticky events.
+
+A deployment can pin the mode for all its clients in `config.json`, which
+disables the Developer Settings choice:
+
+```json
+{
+  "matrix_rtc_mode": "compatibility"
+}
+```
+
+Valid values are `legacy`, `compatibility` and `matrix_2_0`; an invalid value is
+ignored (with a warning) and the user's choice applies. Pinning `matrix_2_0` on a
+homeserver without sticky event support makes joining fail with a "sticky events
+required" error.

docs/self_hosting.md

@@ -16,7 +16,7 @@
 The following [MSCs](https://github.com/matrix-org/matrix-spec-proposals) are
 required for Element Call to work properly:
 
-- **[MSC3266](https://github.com/deepbluev7/matrix-doc/blob/room-summaries/proposals/3266-room-summary.md):
+- **[MSC3266](https://github.com/deepbluev7/matrix-doc/blob/room-summaries/proposals/3266-room-summary.md)
   Room Summary API**: In Standalone mode Element Call is able to join rooms
   over federation using knocking. In this context MSC3266 is required as it
   allows to request a room summary of rooms you are not joined. The summary
@@ -29,19 +29,26 @@ required for Element Call to work properly:
   signalling. If disabled it is very likely that you end up with stuck calls in
   Matrix rooms.
 
+- **[MSC4519](https://github.com/matrix-org/matrix-spec-proposals/blob/travis/msc/voip-transports-registry/proposals/4519-rtc-transports-registry.md)
+  MatrixRTC Transports Registry**: Defines an endpoint that clients can use to
+  query the available MatrixRTC transports (i.e. find your LiveKit SFU).
+
 - **[MSC4222](https://github.com/matrix-org/matrix-spec-proposals/blob/erikj/sync_v2_state_after/proposals/4222-sync-v2-state-after.md)
   Adding `state_after` to sync v2**: Allow clients to opt-in to a change of the
   sync v2 API that allows them to correctly track the state of the room. This is
   required by Element Call to track room state reliably.
 
 If you're using [Synapse](https://github.com/element-hq/synapse/) as your
-homeserver, you'll need to additionally add the following config items to
-`homeserver.yaml` to comply with Element Call:
+homeserver, you can configure these features by adding the following entries to
+`homeserver.yaml`:
 
 ```yaml
 experimental_features:
   # MSC3266: Room summary API. Used for knocking over federation
   msc3266_enabled: true
+  # MSC4143: MatrixRTC. For historical reasons this flag enables the transports
+  # endpoint defined in MSC4519.
+  msc4143_enabled: true
   # MSC4222 needed for syncv2 state_after. This allow clients to
   # correctly track the state of the room.
   msc4222_enabled: true
@@ -61,6 +68,15 @@ rc_delayed_event_mgmt:
   # Currently the heart-beat is every 5 seconds which translates into a rate of 0.2Hz
   per_second: 1
   burst_count: 20
+
+matrix_rtc:
+  transports:
+    # The transport you specify will be made available to clients over the
+    # /_matrix/client/unstable/org.matrix.msc4143/rtc/transports endpoint as
+    # defined in MSC4519.
+    - type: livekit
+      # Replace this with the actual URL of your MatrixRTC Authorization Service
+      livekit_service_url: https://matrix-rtc.example.com/livekit/jwt
 ```
 
 As a prerequisite for the
@@ -187,23 +203,6 @@ backend mxrtc_auth_backend
 
 ```
 
-#### MatrixRTC transport announcement
-
-Enable the unstable feature flag `msc4143_enabled`, and update the
-[`matrix_rtc` section](https://element-hq.github.io/synapse/latest/usage/configuration/config_documentation.html#matrix_rtc)
-of your Synapse config file:
-
-```yaml
-matrix_rtc:
-  transports:
-    - type: livekit
-      livekit_service_url: https://matrix-rtc.example.com/livekit/jwt
-```
-
-The transport you specify will be made available to clients over the
-`/_matrix/client/unstable/org.matrix.msc4143/rtc/transports` endpoint as defined
-in [MSC4143](https://github.com/matrix-org/matrix-spec-proposals/pull/4143).
-
 ## Building Element Call
 
 > [!NOTE]  

package.json

@@ -77,7 +77,7 @@
     "@typescript-eslint/utils": "^8.61.0",
     "@use-gesture/react": "^10.2.11",
     "@vector-im/compound-design-tokens": "^10.0.0",
-    "@vector-im/compound-web": "^9.3.0",
+    "@vector-im/compound-web": "^10.0.0",
     "@vitejs/plugin-react": "^6.0.2",
     "@vitest/browser-playwright": "^4.1.5",
     "@vitest/coverage-v8": "^4.0.18",

pnpm-lock.yaml

@@ -39,10 +39,10 @@ importers:
         version: 11.7.12
       '@livekit/components-core':
         specifier: ^0.12.0
-        version: 0.12.14(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
+        version: 0.12.15(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
       '@livekit/components-react':
         specifier: ^2.0.0
-        version: 2.9.23(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)
+        version: 2.9.24(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)
       '@livekit/track-processors':
         specifier: ^0.7.1
         version: 0.7.2(@types/dom-mediacapture-transform@0.1.11)(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))
@@ -134,8 +134,8 @@ importers:
         specifier: ^10.0.0
         version: 10.2.3(@types/react@19.2.17)(react@19.2.8)
       '@vector-im/compound-web':
-        specifier: ^9.3.0
-        version: 9.9.0(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.3(@types/react@19.2.17))(@types/react@19.2.17)(@vector-im/compound-design-tokens@10.2.3(@types/react@19.2.17)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
+        specifier: ^10.0.0
+        version: 10.0.1(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.3(@types/react@19.2.17))(@types/react@19.2.17)(@vector-im/compound-design-tokens@10.2.3(@types/react@19.2.17)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
       '@vitejs/plugin-react':
         specifier: ^6.0.2
         version: 6.0.5(@rolldown/plugin-babel@0.2.3(@babel/core@7.29.7(supports-color@7.2.0))(@babel/runtime@7.29.7)(rolldown@1.1.5)(vite@8.1.5(@types/node@24.13.3)(esbuild@0.28.1)(jiti@2.7.0)(sass@1.102.0)(terser@5.46.1)(yaml@2.9.0)))(babel-plugin-react-compiler@1.0.0)(vite@8.1.5(@types/node@24.13.3)(esbuild@0.28.1)(jiti@2.7.0)(sass@1.102.0)(terser@5.46.1)(yaml@2.9.0))
@@ -1159,15 +1159,15 @@ packages:
   '@jridgewell/trace-mapping@0.3.31':
     resolution: {integrity: sha512-zzNR+SdQSDJzc8joaeP8QQoCQr8NuYx2dIIytl1QeBEZHJ9uW6hebsrYgbz8hJwUQao3TWCMtmfV8Nu1twOLAw==}
 
-  '@livekit/components-core@0.12.14':
-    resolution: {integrity: sha512-6OKP/1Ok2fCZewDLKd3SzaTb7KvfZl/6hjggI+TgUdhp0Y7HBg3+tHA7YmhZRc0BO8wIyVy4VgTPn7qkLHt2nQ==}
+  '@livekit/components-core@0.12.15':
+    resolution: {integrity: sha512-bDkK+jkPMgyT4a5lZmdcuc/hZ8fZUrXW+qQPNHVeSpXCBMzk5q9QWzx+HPtTsPJ8hnncWGfoT81RnXHBsy+Z8g==}
     engines: {node: '>=18'}
     peerDependencies:
       livekit-client: ^2.20.1
       tslib: ^2.6.2
 
-  '@livekit/components-react@2.9.23':
-    resolution: {integrity: sha512-clO+0g/u3YBpuOvnAjUSAJBH/o7w+RpUAseswjiSML9rHrXlTUhwBNm8LPk+qN5GOU3A6lzsNnFYVpUHUBVOkg==}
+  '@livekit/components-react@2.9.24':
+    resolution: {integrity: sha512-qw5Oy1EfPg1f/xrKYrFielSrmtxY8BZ9mDt6299G5aikotQIztmldBfTNosrVS7VSNit7qeYfOFSyKaML20W6Q==}
     engines: {node: '>=18'}
     peerDependencies:
       '@livekit/krisp-noise-filter': ^0.2.12 || ^0.3.0 || ^0.4.0
@@ -3251,8 +3251,8 @@ packages:
       react:
         optional: true
 
-  '@vector-im/compound-web@9.9.0':
-    resolution: {integrity: sha512-GjAEhzB/mt9MA7Y1ySe6/AlW26vodDu4hvTi1ThB5rTrt4KAiHMpvk+T56KV5Lwo0VvBxAyHMtm/IY5tkyH12A==}
+  '@vector-im/compound-web@10.0.1':
+    resolution: {integrity: sha512-CT3aGMalPSf53o3JUbBF7EA10Rfp+auftIuBwOUSna+hfZ/zPxGLTFcuCuOJ7L8hrzijM+V4I8L0PUkfyOczpg==}
     peerDependencies:
       '@fontsource/inconsolata': ^5
       '@fontsource/inter': ^5
@@ -4462,6 +4462,9 @@ packages:
   jose@6.2.4:
     resolution: {integrity: sha512-N8acGzVsQy6M/fjFcxtysNc4Q379TcM5dM/qKkNtsHFji88yANnXTr7BLeP75iPnFwBfQzM/jg2BZ9+HZrHCZA==}
 
+  jose@6.2.9:
+    resolution: {integrity: sha512-XrchZOFZUl/T3vTwRe8XK+cJrGtMF4th1ARnDfwbBXFKThGhlsxEE4Zu03AD/bjJSt/9jT/mxrOCkJWOg77aPA==}
+
   js-tokens@10.0.0:
     resolution: {integrity: sha512-lM/UBzQmfJRo9ABXbPWemivdCW8V2G8FHaHdypQaIy523snUjog0W71ayWXTjiR+ixeMyVHN2XcpnTd/liPg/Q==}
 
@@ -7061,7 +7064,7 @@ snapshots:
       '@jridgewell/resolve-uri': 3.1.2
       '@jridgewell/sourcemap-codec': 1.5.5
 
-  '@livekit/components-core@0.12.14(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)':
+  '@livekit/components-core@0.12.15(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)':
     dependencies:
       '@floating-ui/dom': 1.7.6
       livekit-client: 2.21.0(@types/dom-mediacapture-record@1.0.22)
@@ -7069,12 +7072,12 @@ snapshots:
       rxjs: 7.8.2
       tslib: 2.8.1
 
-  '@livekit/components-react@2.9.23(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)':
+  '@livekit/components-react@2.9.24(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)(tslib@2.8.1)':
     dependencies:
-      '@livekit/components-core': 0.12.14(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
+      '@livekit/components-core': 0.12.15(livekit-client@2.21.0(@types/dom-mediacapture-record@1.0.22))(tslib@2.8.1)
       clsx: 2.1.1
       events: 3.3.0
-      jose: 6.2.4
+      jose: 6.2.9
       livekit-client: 2.21.0(@types/dom-mediacapture-record@1.0.22)
       react: 19.2.8
       react-dom: 19.2.8(react@19.2.8)
@@ -8713,7 +8716,7 @@ snapshots:
       '@types/react': 19.2.17
       react: 19.2.8
 
-  '@vector-im/compound-web@9.9.0(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.3(@types/react@19.2.17))(@types/react@19.2.17)(@vector-im/compound-design-tokens@10.2.3(@types/react@19.2.17)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)':
+  '@vector-im/compound-web@10.0.1(@fontsource/inconsolata@5.3.0)(@fontsource/inter@5.3.0)(@types/react-dom@19.2.3(@types/react@19.2.17))(@types/react@19.2.17)(@vector-im/compound-design-tokens@10.2.3(@types/react@19.2.17)(react@19.2.8))(react-dom@19.2.8(react@19.2.8))(react@19.2.8)':
     dependencies:
       '@floating-ui/react': 0.27.20(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
       '@floating-ui/react-dom': 2.1.9(react-dom@19.2.8(react@19.2.8))(react@19.2.8)
@@ -10052,6 +10055,8 @@ snapshots:
 
   jose@6.2.4: {}
 
+  jose@6.2.9: {}
+
   js-tokens@10.0.0: {}
 
   js-tokens@4.0.0: {}

src/components/CallFooter.stories.tsx

@@ -127,6 +127,7 @@ export const Default: Story = {
     showFooter: true,
     hideControls: false,
     asOverlay: false,
+    showModals: true,
     sharingScreen: false,
     audioOutputSwitcher: undefined,
     reactionIdentifier: undefined,

src/components/CallFooter.tsx

@@ -26,6 +26,7 @@ import {
   MediaMuteAndSwitchButton,
   type MenuOptions,
 } from "./MediaMuteAndSwitchButton";
+import { type Behavior } from "../state/Behavior";
 import { type ViewModel } from "../state/ViewModel";
 import { useBehavior } from "../useBehavior";
 import { type LayoutSwitchViewModel } from "../state/LayoutSwitchViewModel";
@@ -76,6 +77,7 @@ export interface FooterState {
   /** The footer should be used as an overlay.
    * (Over the Call Grid) This saves spaces on small screens. */
   asOverlay: boolean;
+  showModals: boolean;
 
   buttonSize: "md" | "lg";
   showLogo: boolean;
@@ -120,6 +122,7 @@ export const CallFooter: FC<FooterProps> = ({
   const asOverlay = useBehavior(vm.asOverlay$);
   const showFooter = useBehavior(vm.showFooter$);
   const hideControls = useBehavior(vm.hideControls$);
+  const showModals = useBehavior(vm.showModals$);
   const layoutSwitchVm = useBehavior(vm.layoutSwitchVm$);
   const openSettings = useBehavior(vm.openSettings$);
   const audioEnabled = useBehavior(vm.audioEnabled$);
@@ -135,7 +138,6 @@ export const CallFooter: FC<FooterProps> = ({
   const audioOutputSwitcher = useBehavior(vm.audioOutputSwitcher$);
   const hangup = useBehavior(vm.hangup$);
   const debugTileLayout = useBehavior(vm.debugTileLayout$);
-  const tileStoreGeneration = useBehavior(vm.tileStoreGeneration$);
   const videoOptions = useBehavior(vm.videoOptions$);
   const selectedVideo = useBehavior(vm.selectedVideo$);
   const audioOptions = useBehavior(vm.audioOptions$);
@@ -235,7 +237,8 @@ export const CallFooter: FC<FooterProps> = ({
     );
   }
 
-  if (reactionIdentifier && reactionData) {
+  // Reaction button contains a pretty large menu, so treat it like a modal
+  if (reactionIdentifier && reactionData && showModals) {
     buttons.push(
       <ReactionToggleButton
         size={buttonSize}
@@ -283,7 +286,9 @@ export const CallFooter: FC<FooterProps> = ({
           />
         </>
       )}
-      {debugTileLayout ? `Tiles generation: ${tileStoreGeneration}` : undefined}
+      {debugTileLayout ? (
+        <TilesDebugInfo generation$={vm.tileStoreGeneration$} />
+      ) : undefined}
     </div>
   );
 
@@ -316,3 +321,14 @@ export const CallFooter: FC<FooterProps> = ({
     </div>
   );
 };
+
+interface TilesDebugInfoProps {
+  generation$: Behavior<number | undefined>;
+}
+
+// Isolated in its own component since the layout generation updates frequently
+// and we can avoid re-rendering the footer this way
+const TilesDebugInfo: FC<TilesDebugInfoProps> = ({ generation$ }) => {
+  const generation = useBehavior(generation$);
+  return `Tiles generation: ${generation}`;
+};

src/components/CallFooterViewModel.test.ts

@@ -49,6 +49,7 @@ function buildMinimalCallViewModel(layout: Layout): CallViewModel {
     reactions$: constant({}),
     tileStoreGeneration$: constant(0),
     showFooter$: constant(true),
+    showModals$: constant(true),
     settingsOpen$: constant(false),
     setSettingsOpen$: constant(() => {}),
   } as unknown as CallViewModel;

src/components/CallFooterViewModel.tsx

@@ -161,6 +161,7 @@ export function createCallFooterViewModel(
     // candidat to move into the FooterViewModel
     showFooter$: callModel.showFooter$,
     hideControls$: constant(!showControls),
+    showModals$: callModel.showModals$,
     asOverlay$: callModel.edgeToEdge$,
     buttonSize$: scope.behavior(
       isPip$.pipe(map<boolean, "md" | "lg">((pip) => (pip ? "md" : "lg"))),
@@ -168,12 +169,12 @@ export function createCallFooterViewModel(
 
     openSettings$: scope.behavior(
       combineLatest([
-        isPip$,
+        callModel.showModals$,
         callModel.showHeader$,
         callModel.setSettingsOpen$,
       ]).pipe(
-        map(([isPip, showHeader, setSettingsOpen]) =>
-          !isPip && headerStyle !== HeaderStyle.AppBar && showControls
+        map(([showModals, showHeader, setSettingsOpen]) =>
+          showModals && headerStyle !== HeaderStyle.AppBar && showControls
             ? (): void => setSettingsOpen(true)
             : undefined,
         ),
@@ -239,6 +240,7 @@ export function createLobbyFooterViewModel(
       showLogo,
       hideControls: false,
       asOverlay: false,
+      showModals: true,
       buttonSize: "lg",
       openSettings,
       hangup,

src/config/ConfigOptions.ts

@@ -179,7 +179,8 @@ export interface ConfigOptions {
   /**
    * Pins the {@link MatrixRTCMode} for all clients on this deployment,
    * overriding any per-user choice from the Developer Settings. If unset,
-   * the user's Developer Settings choice (or its default of `Legacy`) wins.
+   * the user's Developer Settings choice (or its default of `Compatibility`)
+   * wins.
    */
   matrix_rtc_mode?: MatrixRTCMode;
 

src/graphics/desktop-gradient.svg

@@ -1,16 +0,0 @@
-<svg width="1440" height="800" viewBox="0 0 1440 800" fill="none" xmlns="http://www.w3.org/2000/svg">
-<g filter="url(#filter0_f_4162_80259)">
-<path d="M-37.0486 666.028C267.76 138.867 944.304 -46.1945 1477.05 260.929" stroke="url(#paint0_linear_4162_80259)" stroke-width="192" stroke-linecap="round"/>
-</g>
-<defs>
-<filter id="filter0_f_4162_80259" x="-333.118" y="-183.694" width="2106.24" height="1145.68" filterUnits="userSpaceOnUse" color-interpolation-filters="sRGB">
-<feFlood flood-opacity="0" result="BackgroundImageFix"/>
-<feBlend mode="normal" in="SourceGraphic" in2="BackgroundImageFix" result="shape"/>
-<feGaussianBlur stdDeviation="100" result="effect1_foregroundBlur_4162_80259"/>
-</filter>
-<linearGradient id="paint0_linear_4162_80259" x1="1255.31" y1="320.254" x2="184.899" y2="607.497" gradientUnits="userSpaceOnUse">
-<stop stop-color="#00C59E"/>
-<stop offset="0.75" stop-color="#0044A5"/>
-</linearGradient>
-</defs>
-</svg>

src/graphics/mobile-gradient.svg

@@ -1,86 +0,0 @@
-<?xml version="1.0" encoding="UTF-8" standalone="no"?>
-<svg
-   width="1200"
-   height="285"
-   viewBox="0 0 1200 285"
-   fill="none"
-   version="1.1"
-   id="svg5"
-   xmlns="http://www.w3.org/2000/svg"
-   xmlns:svg="http://www.w3.org/2000/svg">
-  <g
-     filter="url(#filter0_f_3970_9366)"
-     id="g2"
-     transform="translate(422.00201)">
-    <path
-       d="m -164.342,495.134 c 188.2881,-188.288 494.684,-190 684.684,0"
-       stroke="url(#paint0_linear_3970_9366)"
-       stroke-width="235.517"
-       stroke-linecap="round"
-       id="path1"
-       style="stroke:url(#paint0_linear_3970_9366)" />
-    <path
-       d="m -164.342,495.134 c 188.2881,-188.288 494.684,-190 684.684,0"
-       stroke="url(#paint1_linear_3970_9366)"
-       style="mix-blend-mode:overlay;stroke:url(#paint1_linear_3970_9366)"
-       stroke-width="235.517"
-       stroke-linecap="round"
-       id="path2" />
-  </g>
-  <defs
-     id="defs5">
-    <filter
-       id="filter0_f_3970_9366"
-       x="-517.617"
-       y="-0.00012207"
-       width="1391.23"
-       height="848.409"
-       filterUnits="userSpaceOnUse"
-       color-interpolation-filters="sRGB">
-      <feFlood
-         flood-opacity="0"
-         result="BackgroundImageFix"
-         id="feFlood2" />
-      <feBlend
-         mode="normal"
-         in="SourceGraphic"
-         in2="BackgroundImageFix"
-         result="shape"
-         id="feBlend2" />
-      <feGaussianBlur
-         stdDeviation="117.758"
-         result="effect1_foregroundBlur_3970_9366"
-         id="feGaussianBlur2" />
-    </filter>
-    <linearGradient
-       id="paint0_linear_3970_9366"
-       x1="349.17099"
-       y1="323.96301"
-       x2="6.82898"
-       y2="666.30499"
-       gradientUnits="userSpaceOnUse">
-      <stop
-         stop-color="#0D5CBD"
-         id="stop2" />
-      <stop
-         offset="0.730863"
-         stop-color="#0DBDA8"
-         id="stop3" />
-    </linearGradient>
-    <linearGradient
-       id="paint1_linear_3970_9366"
-       x1="349.17099"
-       y1="323.96301"
-       x2="6.82898"
-       y2="666.30499"
-       gradientUnits="userSpaceOnUse">
-      <stop
-         stop-color="#0D5CBD"
-         id="stop4" />
-      <stop
-         offset="0.730863"
-         stop-color="#0DBDA8"
-         id="stop5" />
-    </linearGradient>
-  </defs>
-</svg>

src/grid/Grid.tsx

@@ -41,6 +41,8 @@ import { TileWrapper } from "./TileWrapper";
 import { usePrefersReducedMotion } from "../usePrefersReducedMotion";
 import { useInitial } from "../useInitial";
 
+const MAX_ANIMATED_TILES = 50; // Capped for performance reasons
+
 interface Rect {
   x: number;
   y: number;
@@ -285,7 +287,6 @@ export function Grid<
   const [visibleTilesCallback, setVisibleTilesCallback] =
     useState<VisibleTilesCallback | null>(null);
   const tiles = useInitial(() => new Map<string, Tile<TileModel>>());
-  const prefersReducedMotion = usePrefersReducedMotion();
 
   const Slot: FC<SlotProps<TileModel>> = useMemo(
     () =>
@@ -372,6 +373,10 @@ export function Grid<
   // react-spring's imperative API during gestures to improve responsiveness
   const dragState = useRef<DragState | null>(null);
 
+  // If true, disables animations
+  const immediate =
+    usePrefersReducedMotion() || placedTiles.length > MAX_ANIMATED_TILES;
+
   const [tileTransitions, springRef] = useTransition(
     placedTiles,
     () => ({
@@ -389,9 +394,9 @@ export function Grid<
         y,
         width,
         height,
-        immediate: prefersReducedMotion,
+        immediate,
       }),
-      enter: { opacity: 1, scale: 1, immediate: prefersReducedMotion },
+      enter: { opacity: 1, scale: 1, immediate },
       update: ({
         id,
         x,
@@ -406,9 +411,9 @@ export function Grid<
               y,
               width,
               height,
-              immediate: prefersReducedMotion,
+              immediate,
             },
-      leave: { opacity: 0, scale: 0, immediate: prefersReducedMotion },
+      leave: { opacity: 0, scale: 0, immediate },
       config: { mass: 0.7, tension: 252, friction: 25 },
     }),
     // react-spring's types are bugged and can't infer the spring type
@@ -441,8 +446,7 @@ export function Grid<
               y: tile.y,
               width: tile.width,
               height: tile.height,
-              immediate:
-                prefersReducedMotion || ((key): boolean => key === "zIndex"),
+              immediate: immediate || ((key): boolean => key === "zIndex"),
               // Allow the tile's position to settle before pushing its
               // z-index back down
               delay: (key): number => (key === "zIndex" ? 500 : 0),
@@ -453,7 +457,7 @@ export function Grid<
               x: tileX,
               y: tileY,
               immediate:
-                prefersReducedMotion ||
+                immediate ||
                 ((key): boolean =>
                   key === "zIndex" || key === "x" || key === "y"),
             },

src/index.css

@@ -78,16 +78,19 @@ body {
   body[data-background="gradient"]::before {
     content: "";
     position: fixed;
-    inset: 0;
-    background-image: url("graphics/mobile-gradient.svg");
-    background-size: auto;
+    /* Chromium abruptly fades our images to fully transparent at the edge of
+    the element. If we just make the element a little bigger than the viewport,
+    this is no longer visible. */
+    inset: -20px;
+    background-image: url("graphics/mobile-gradient.png");
+    background-size: 1400px 305px;
     background-position: bottom;
     background-repeat: no-repeat;
   }
 
   body[data-background="gradient"][data-platform="desktop"]::before {
-    background-image: url("graphics/desktop-gradient.svg");
-    background-size: calc(max(1440px, 100vw)) calc(max(800px, 100vh));
+    background-image: url("graphics/desktop-gradient.png");
+    background-size: max(1440px, 100vw) max(1440px, 100vh);
     background-position: center;
   }
 }

src/room/GroupCallView.tsx

@@ -555,6 +555,9 @@ export const GroupCallView: FC<Props> = ({
       }}
       onError={(_error) => {
         if (rtcSession.isJoined()) onLeft("error");
+        // If there is an error we need to be able to close the widget. This is done in `onLeft` as well
+        // We need it here explicitly in case rtcSession.isJoined is false.
+        void widget?.api.setAlwaysOnScreen(false);
       }}
     >
       {body}

src/room/InCallView.tsx

@@ -261,6 +261,7 @@ export const InCallView: FC<InCallViewProps> = ({
   const overflowing = useBehavior(vm.overflowing$);
   const showNameTags = useBehavior(vm.showNameTags$);
   const showHeader = useBehavior(vm.showHeader$);
+  const showModals = useBehavior(vm.showModals$);
   const settingsOpen = useBehavior(vm.settingsOpen$);
   const setSettingsOpen = useBehavior(vm.setSettingsOpen$);
   const earpieceMode = useBehavior(vm.earpieceMode$);
@@ -622,7 +623,7 @@ export const InCallView: FC<InCallViewProps> = ({
       {earpieceOverlay}
       <ReactionsOverlay vm={vm} />
       {footer}
-      {layout.type !== "pip" && (
+      {showModals && (
         <>
           <RageshakeRequestModal {...rageshakeRequestModalProps} />
           <SettingsModal

src/room/VideoPreview.module.css

@@ -22,6 +22,9 @@ Please see LICENSE in the repository root for full details.
   height: 100%;
   object-fit: cover;
   background-color: var(--video-tile-background);
+  /* In FF if you add a transform: scale/translate/matrix filter on an element,
+  it'll ignore the parents' border-radius, so force back the radius to avoid UI glitch*/
+  border-radius: inherit;
 }
 
 video.mirror {

src/room/useLoadGroupCall.ts

@@ -280,7 +280,7 @@ export const useLoadGroupCall = (
             );
           }
           if (
-            roomSummary === undefined ||
+            roomSummary?.join_rule === undefined ||
             roomSummary.join_rule === JoinRule.Public
           ) {
             room = await client.joinRoom(roomId, {

src/state/CallViewModel/CallViewModel.ts

@@ -79,7 +79,7 @@ import {
   type ReactionInfo,
   type ReactionOption,
 } from "../../reactions";
-import { shallowEquals } from "../../utils/array";
+import { shallowEquals as shallowArrayEquals } from "../../utils/array";
 import { type MediaDevices } from "../MediaDevices";
 import { constant, type Behavior } from "../Behavior";
 import { E2eeType } from "../../e2ee/e2eeType";
@@ -89,6 +89,7 @@ import { getUrlParams, HeaderStyle } from "../../UrlParams";
 import { type ProcessorState } from "../../livekit/TrackProcessorContext";
 import { ElementWidgetActions, widget } from "../../widget";
 import {
+  layoutShallowEquals,
   type Alignment,
   type GridLayoutMedia,
   type Layout,
@@ -365,6 +366,11 @@ export interface CallViewModel {
    */
   overflowing$: Behavior<boolean>;
 
+  /**
+   * Whether modals such as settings and reactions should be accessible at all.
+   */
+  showModals$: Behavior<boolean>;
+
   settingsOpen$: Behavior<boolean>;
   setSettingsOpen$: Behavior<(open: boolean) => void>;
 
@@ -941,7 +947,7 @@ export function createCallViewModel$(
               bins.sort(([, bin1], [, bin2]) => bin1 - bin2).map(([m]) => m),
             );
       }),
-      distinctUntilChanged(shallowEquals),
+      distinctUntilChanged(shallowArrayEquals),
     ),
   );
 
@@ -1000,7 +1006,7 @@ export function createCallViewModel$(
   const spotlight$ = scope.behavior<MediaViewModel[]>(
     spotlightAndPip$.pipe(
       map(({ spotlight }) => spotlight),
-      distinctUntilChanged<MediaViewModel[]>(shallowEquals),
+      distinctUntilChanged<MediaViewModel[]>(shallowArrayEquals),
     ),
   );
 
@@ -1209,6 +1215,7 @@ export function createCallViewModel$(
         }
         return layout;
       }),
+      distinctUntilChanged(),
       scope.bind(),
     )
     .subscribe((orientation) => {
@@ -1448,6 +1455,11 @@ export function createCallViewModel$(
       map((naturallyShowFooter) => naturallyShowFooter && showFooterUrlParams),
     ),
   );
+
+  const showModals$ = scope.behavior(
+    windowMode$.pipe(map((mode) => mode !== "pip")),
+  );
+
   const settingsOpen$ = new BehaviorSubject(false);
   const setSettingsOpen$ = constant((open: boolean) => {
     settingsOpen$.next(open);
@@ -1574,7 +1586,11 @@ export function createCallViewModel$(
    * The layout of tiles in the call interface.
    */
   const layout$ = scope.behavior<Layout>(
-    layoutInternals$.pipe(map(({ layout }) => layout)),
+    layoutInternals$.pipe(
+      map(({ layout }) => layout),
+      // Drop redundant layout updates before they would hit React.
+      distinctUntilChanged<Layout>(layoutShallowEquals),
+    ),
   );
 
   const overflowing$ = scope.behavior<boolean>(
@@ -1820,6 +1836,7 @@ export function createCallViewModel$(
     showNameTags$,
     showHeader$: showHeader$,
     showFooter$: showFooter$,
+    showModals$,
     settingsOpen$: settingsOpen$,
     setSettingsOpen$: setSettingsOpen$,
     edgeToEdge$,

src/state/layout-types.test.ts

@@ -0,0 +1,74 @@
+/*
+Copyright 2026 Element Creations Ltd.
+
+SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
+Please see LICENSE in the repository root for full details.
+*/
+
+import { test, expect } from "vitest";
+import {
+  type Alignment,
+  layoutShallowEquals,
+  type Layout,
+} from "./layout-types";
+import {
+  type SpotlightTileViewModel,
+  type GridTileViewModel,
+} from "./TileViewModel";
+import { BehaviorSubject } from "rxjs";
+
+const spotlightTile = {} as unknown as SpotlightTileViewModel;
+const gridTile = {} as unknown as GridTileViewModel;
+const pipAlignment$ = new BehaviorSubject<Alignment>({
+  inline: "end",
+  block: "end",
+});
+
+const spotlightExpanded: Layout = {
+  type: "spotlight-expanded",
+  spotlight: spotlightTile,
+  pipAlignment$,
+};
+
+const spotlightPortrait: Layout = {
+  type: "spotlight-portrait",
+  spotlight: spotlightTile,
+  grid: [gridTile],
+  setVisibleTiles: () => {},
+};
+
+test("layoutShallowEquals considers a layout to be equal to its shallow clone", () =>
+  expect(layoutShallowEquals(spotlightExpanded, { ...spotlightExpanded })).toBe(
+    true,
+  ));
+
+test("layoutShallowEquals detects a missing key", () => {
+  expect(
+    layoutShallowEquals(spotlightExpanded, {
+      ...spotlightExpanded,
+      pip: gridTile,
+    }),
+  ).toBe(false);
+  expect(
+    layoutShallowEquals(
+      { ...spotlightExpanded, pip: gridTile },
+      spotlightExpanded,
+    ),
+  ).toBe(false);
+});
+
+test("layoutShallowEquals considers grid arrays with equal contents to be equal", () =>
+  expect(
+    layoutShallowEquals(spotlightPortrait, {
+      ...spotlightPortrait,
+      grid: [...spotlightPortrait.grid],
+    }),
+  ).toBe(true));
+
+test("layoutShallowEquals detects grid arrays with different contents", () =>
+  expect(
+    layoutShallowEquals(spotlightPortrait, {
+      ...spotlightPortrait,
+      grid: [...spotlightPortrait.grid, gridTile],
+    }),
+  ).toBe(false));

src/state/layout-types.ts

@@ -16,6 +16,7 @@ import {
   type SpotlightTileViewModel,
 } from "./TileViewModel.ts";
 import { type Behavior } from "./Behavior.ts";
+import { shallowEquals as arrayShallowEquals } from "../utils/array.ts";
 
 export interface GridLayoutMedia {
   type: "grid";
@@ -140,3 +141,30 @@ export type Layout =
   | OneOnOneDesktopLayout
   | OneOnOneMobileLayout
   | PipLayout;
+
+/**
+ * Tests whether the top-level properties and array elements of layout `a` are
+ * equal to those of layout `b`. Useful for deduping redundant layout updates.
+ */
+export function layoutShallowEquals(a: Layout, b: Layout): boolean {
+  // If a and b have the same number of keys and every key in a is also in b,
+  // then they have the same keys.
+  const aKeys = Object.keys(a);
+  const bKeys = Object.keys(b);
+  if (aKeys.length !== bKeys.length) return false;
+
+  for (const key of aKeys) {
+    if (!(key in b)) return false;
+
+    // Now check that they have the same values.
+    const aValue = (a as any)[key];
+    const bValue = (b as any)[key];
+    if (Array.isArray(aValue) && Array.isArray(bValue)) {
+      // Special case for arrays so we can detect when the grid tiles arrays are
+      // essentially the same.
+      if (!arrayShallowEquals(aValue, bValue)) return false;
+    } else if (aValue !== bValue) return false;
+  }
+
+  return true;
+}

src/state/media/UserMediaViewModel.ts

@@ -33,7 +33,6 @@ import { type RemoteUserMediaViewModel } from "./RemoteUserMediaViewModel";
 import { type ObservableScope } from "../ObservableScope";
 import { showConnectionStats } from "../../settings/settings";
 import { observeRtpStreamStats$ } from "./observeRtpStreamStats";
-import { videoFit$, videoSizeFromParticipant$ } from "../../utils/videoFit.ts";
 
 /**
  * A participant's user media (i.e. their microphone and camera feed).
@@ -47,7 +46,6 @@ export interface BaseUserMediaViewModel extends BaseMemberMediaViewModel {
   speaking$: Behavior<boolean>;
   audioEnabled$: Behavior<boolean>;
   videoEnabled$: Behavior<boolean>;
-  videoFit$: Behavior<"cover" | "contain">;
   videoOrientation$: Behavior<"landscape" | "portrait">;
   toggleCropVideo: () => void;
   /**
@@ -63,12 +61,9 @@ export interface BaseUserMediaViewModel extends BaseMemberMediaViewModel {
     RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats | undefined
   >;
   /**
-   * Set the target dimensions of the HTML element (final dimension after anim).
-   * This can be used to determine the best video fit (fit to frame / keep ratio).
-   * @param targetWidth - The target width of the HTML element displaying the video.
-   * @param targetHeight - The target height of the HTML element displaying the video.
+   * Set the aspect ratio of the video track to determine the orientation.
    */
-  setTargetDimensions: (targetWidth: number, targetHeight: number) => void;
+  setVideoAspectRatio: (ratio: number) => void;
 }
 
 export interface BaseUserMediaInputs extends Omit<
@@ -98,14 +93,8 @@ export function createBaseUserMedia(
     ),
   );
   const toggleCropVideo$ = new Subject<void>();
+  const videoAspectRatio$ = new BehaviorSubject(NaN);
 
-  // The target size of the video element, used to determine the best video fit.
-  // The target size is the final size of the HTML element after any animations have completed.
-  const targetSize$ = new BehaviorSubject<
-    { width: number; height: number } | undefined
-  >(undefined);
-
-  const videoSize$ = videoSizeFromParticipant$(participant$);
   return {
     ...createMemberMedia(scope, {
       ...inputs,
@@ -132,13 +121,11 @@ export function createBaseUserMedia(
       media$.pipe(map((m) => m?.cameraTrack?.isMuted === false)),
     ),
     videoOrientation$: scope.behavior(
-      videoSize$.pipe(
-        map((s) => (s ? s.width / s.height : 1)),
+      videoAspectRatio$.pipe(
         map((aspect) => (aspect > 1 ? "landscape" : "portrait")),
       ),
       "portrait",
     ),
-    videoFit$: videoFit$(scope, videoSize$, targetSize$),
     toggleCropVideo: () => toggleCropVideo$.next(),
     rtcBackendIdentity,
     handRaised$,
@@ -162,8 +149,6 @@ export function createBaseUserMedia(
         return observeRtpStreamStats$(p, Track.Source.Camera, statsType);
       }),
     ),
-    setTargetDimensions: (targetWidth: number, targetHeight: number): void => {
-      targetSize$.next({ width: targetWidth, height: targetHeight });
-    },
+    setVideoAspectRatio: (ratio) => videoAspectRatio$.next(ratio),
   };
 }

src/state/media/observeRtpStreamStats.ts

@@ -19,10 +19,15 @@ import {
   startWith,
   switchMap,
   map,
+  share,
 } from "rxjs";
 
 import { observeTrackReference$ } from "../observeTrackReference";
 
+// Use a shared timer for all the stats observers so that we don't clog up the
+// event loop with hundreds of timers in large calls
+const refreshStats$ = interval(1000).pipe(share());
+
 export function observeRtpStreamStats$(
   participant: Participant,
   source: Track.Source,
@@ -32,9 +37,7 @@ export function observeRtpStreamStats$(
 > {
   return combineLatest([
     observeTrackReference$(participant, source),
-    // The update frequency is high because we use this value to update the PiP orientation and the fit/fill video tile props based on that
-    // We want it to be responsive. For just the debug tools 1s would be sufficient.
-    interval(350).pipe(startWith(0)),
+    refreshStats$.pipe(startWith(0)),
   ]).pipe(
     switchMap(async ([trackReference]) => {
       const track = trackReference?.publication?.track;
@@ -69,12 +72,3 @@ export function observeInboundRtpStreamStats$(
     map((x) => x as RTCInboundRtpStreamStats | undefined),
   );
 }
-
-export function observeOutboundRtpStreamStats$(
-  participant: Participant,
-  source: Track.Source,
-): Observable<RTCOutboundRtpStreamStats | undefined> {
-  return observeRtpStreamStats$(participant, source, "outbound-rtp").pipe(
-    map((x) => x as RTCOutboundRtpStreamStats | undefined),
-  );
-}

src/tile/GridTile.test.tsx

@@ -5,7 +5,10 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { type RemoteTrackPublication } from "livekit-client";
+import {
+  type LocalTrackPublication,
+  type RemoteTrackPublication,
+} from "livekit-client";
 import { test, expect } from "vitest";
 import { act, render, screen } from "@testing-library/react";
 import { axe } from "vitest-axe";
@@ -17,6 +20,9 @@ import {
   mockRtcMembership,
   mockRemoteMedia,
   mockRemoteParticipant,
+  mockLocalMedia,
+  mockLocalParticipant,
+  mockMediaDevices,
 } from "../utils/test";
 import { GridTileViewModel } from "../state/TileViewModel";
 import { ReactionsSenderProvider } from "../reactions/useReactionsSender";
@@ -54,7 +60,7 @@ const callVm = {
   handsRaised$: constant({}),
 } as Partial<CallViewModel> as CallViewModel;
 
-test("GridTile is accessible", async () => {
+test("GridTile displays remote media", async () => {
   const vm = mockRemoteMedia(
     mockRtcMembership("@alice:example.org", "AAAA"),
     {
@@ -88,6 +94,40 @@ test("GridTile is accessible", async () => {
   screen.getByText("Alice");
 });
 
+test("GridTile displays local media", async () => {
+  const vm = mockLocalMedia(
+    mockRtcMembership("@alice:example.org", "AAAA"),
+    {
+      rawDisplayName: "Alice",
+      getMxcAvatarUrl: () => "mxc://adfsg",
+    },
+    mockLocalParticipant({
+      getTrackPublication: () =>
+        ({}) as Partial<LocalTrackPublication> as LocalTrackPublication,
+    }),
+    mockMediaDevices({}),
+  );
+
+  const { container } = render(
+    <ReactionsSenderProvider vm={callVm} rtcSession={fakeRtcSession}>
+      <GridTile
+        vm={new GridTileViewModel(constant(vm))}
+        onOpenProfile={() => {}}
+        targetWidth={300}
+        targetHeight={200}
+        showSpeakingIndicators
+        showNameTags
+        showRingingStatus
+        showOutline
+        focusable
+      />
+    </ReactionsSenderProvider>,
+  );
+  expect(await axe(container)).toHaveNoViolations();
+  // Name should be visible
+  screen.getByText("Alice");
+});
+
 test("GridTile displays ringing media", async () => {
   const pickupState$ = new BehaviorSubject<
     RingingMediaViewModel["pickupState$"]["value"]

src/tile/GridTile.tsx

@@ -11,9 +11,9 @@ import {
   type ReactNode,
   type Ref,
   useCallback,
-  useEffect,
   useRef,
   useState,
+  useMemo,
 } from "react";
 import { type animated } from "@react-spring/web";
 import classNames from "classnames";
@@ -91,7 +91,6 @@ const RingingMediaTile: FC<RingingMediaTileProps> = ({
       }
       avatarStyle="translucent"
       videoEnabled={false}
-      videoFit="cover"
       mirror={false}
       {...props}
     />
@@ -105,20 +104,22 @@ interface UserMediaTileProps extends TileProps {
   playbackMuted: boolean;
   waitingForMedia?: boolean;
   primaryButton?: ReactNode;
-  menuStart?: ReactNode;
-  menuEnd?: ReactNode;
   focusUrl: string | undefined;
 }
 
-const UserMediaTile: FC<UserMediaTileProps> = ({
+/**
+ * A user media tile without a context menu.
+ */
+// The context menu is kept separate from this component for performance
+// reasons (c.f. UserMediaTile)
+const UserMediaTileInner: FC<UserMediaTileProps & { menu: ReactNode }> = ({
   ref,
   vm,
   showSpeakingIndicators,
   playbackMuted,
   waitingForMedia,
   primaryButton,
-  menuStart,
-  menuEnd,
+  menu,
   className,
   focusUrl,
   displayName,
@@ -141,19 +142,11 @@ const UserMediaTile: FC<UserMediaTileProps> = ({
   const audioEnabled = useBehavior(vm.audioEnabled$);
   const videoEnabled = useBehavior(vm.videoEnabled$);
   const speaking = useBehavior(vm.speaking$);
-  const videoFit = useBehavior(vm.videoFit$);
 
   const rtcBackendIdentity = vm.rtcBackendIdentity;
   const handRaised = useBehavior(vm.handRaised$);
   const reaction = useBehavior(vm.reaction$);
 
-  // Whenever bounds change, inform the viewModel
-  useEffect(() => {
-    if (targetWidth > 0 && targetHeight > 0) {
-      vm.setTargetDimensions(targetWidth, targetHeight);
-    }
-  }, [targetWidth, targetHeight, vm]);
-
   const AudioIcon = playbackMuted
     ? VolumeOffSolidIcon
     : audioEnabled
@@ -166,31 +159,32 @@ const UserMediaTile: FC<UserMediaTileProps> = ({
       : t("microphone_off");
 
   const [menuOpen, setMenuOpen] = useState(false);
-  const menu = (
-    <>
-      {menuStart}
-      {/*
-       No additional menu item (used to be the manual fit to frame.
-       Placeholder for future menu items that should be placed here.
-       */}
-      {menuEnd}
-    </>
+  const menuTrigger = useMemo(
+    () => (
+      <button
+        aria-label={t("common.options")}
+        tabIndex={focusable ? undefined : -1}
+      >
+        <OverflowHorizontalIcon aria-hidden width={20} height={20} />
+      </button>
+    ),
+    [t, focusable],
   );
 
-  const raisedHandOnClick = vm.local
-    ? (): void => void toggleRaisedHand()
-    : undefined;
+  const raisedHandOnClick = useMemo(
+    () => (vm.local ? (): void => void toggleRaisedHand() : undefined),
+    [vm.local, toggleRaisedHand],
+  );
 
   const showSpeaking = showSpeakingIndicators && speaking;
 
-  const tile = (
+  return (
     <MediaView
       ref={ref}
       video={video}
       userId={vm.userId}
       unencryptedWarning={unencryptedWarning}
       videoEnabled={videoEnabled}
-      videoFit={videoFit}
       className={classNames(className, styles.tile, {
         [styles.speaking]: showSpeaking,
         [styles.handRaised]: !showSpeaking && handRaised,
@@ -213,14 +207,7 @@ const UserMediaTile: FC<UserMediaTileProps> = ({
             open={menuOpen}
             onOpenChange={setMenuOpen}
             title={displayName}
-            trigger={
-              <button
-                aria-label={t("common.options")}
-                tabIndex={focusable ? undefined : -1}
-              >
-                <OverflowHorizontalIcon aria-hidden width={20} height={20} />
-              </button>
-            }
+            trigger={menuTrigger}
             side="left"
             align="start"
           >
@@ -233,6 +220,7 @@ const UserMediaTile: FC<UserMediaTileProps> = ({
       raisedHandOnClick={raisedHandOnClick}
       waitingForMedia={waitingForMedia}
       focusUrl={focusUrl}
+      setVideoAspectRatio={vm.setVideoAspectRatio}
       audioStreamStats={audioStreamStats}
       videoStreamStats={videoStreamStats}
       rtcBackendIdentity={rtcBackendIdentity}
@@ -241,9 +229,37 @@ const UserMediaTile: FC<UserMediaTileProps> = ({
       {...props}
     />
   );
+};
 
+/**
+ * A user media tile enhanced with a context menu.
+ */
+const UserMediaTile: FC<
+  UserMediaTileProps & { menuStart?: ReactNode; menuEnd?: ReactNode }
+> = ({ menuStart, menuEnd, ...props }) => {
+  const menu = useMemo(
+    () => (
+      <>
+        {menuStart}
+        {/*
+       No additional menu item (used to be the manual fit to frame.
+       Placeholder for future menu items that should be placed here.
+       */}
+        {menuEnd}
+      </>
+    ),
+    [menuStart, menuEnd],
+  );
+
+  // ContextMenu is expensive to render, so we avoid subscribing to any
+  // frequently-changing behaviors here and instead keep them isolated in the
+  // UserMediaTileInner component
   return (
-    <ContextMenu title={displayName} trigger={tile} hasAccessibleAlternative>
+    <ContextMenu
+      title={props.displayName}
+      trigger={<UserMediaTileInner {...props} menu={menu} />}
+      hasAccessibleAlternative
+    >
       {menu}
     </ContextMenu>
   );
@@ -279,6 +295,29 @@ const LocalUserMediaTile: FC<LocalUserMediaTileProps> = ({
     [vm, latestAlwaysShow],
   );
 
+  const menuStart = useMemo(
+    () => (
+      <ToggleMenuItem
+        Icon={VisibilityOnIcon}
+        label={t("video_tile.always_show")}
+        checked={alwaysShow}
+        onSelect={onSelectAlwaysShow}
+      />
+    ),
+    [t, alwaysShow, onSelectAlwaysShow],
+  );
+  const menuEnd = useMemo(
+    () =>
+      onOpenProfile && (
+        <MenuItem
+          Icon={UserProfileIcon}
+          label={t("common.profile")}
+          onSelect={onOpenProfile}
+        />
+      ),
+    [t, onOpenProfile],
+  );
+
   return (
     <UserMediaTile
       ref={ref}
@@ -297,23 +336,8 @@ const LocalUserMediaTile: FC<LocalUserMediaTileProps> = ({
           </button>
         )
       }
-      menuStart={
-        <ToggleMenuItem
-          Icon={VisibilityOnIcon}
-          label={t("video_tile.always_show")}
-          checked={alwaysShow}
-          onSelect={onSelectAlwaysShow}
-        />
-      }
-      menuEnd={
-        onOpenProfile && (
-          <MenuItem
-            Icon={UserProfileIcon}
-            label={t("common.profile")}
-            onSelect={onOpenProfile}
-          />
-        )
-      }
+      menuStart={menuStart}
+      menuEnd={menuEnd}
       focusable={focusable}
       focusUrl={focusUrl}
       {...props}

src/tile/MediaView.test.tsx

@@ -33,7 +33,6 @@ describe("MediaView", () => {
   const baseProps: ComponentProps<typeof MediaView> = {
     displayName: "some name",
     videoEnabled: true,
-    videoFit: "contain",
     targetWidth: 300,
     targetHeight: 200,
     mirror: false,

src/tile/MediaView.tsx

@@ -7,7 +7,13 @@ Please see LICENSE in the repository root for full details.
 
 import { type TrackReferenceOrPlaceholder } from "@livekit/components-core";
 import { animated } from "@react-spring/web";
-import { type FC, type ComponentProps, type ReactNode } from "react";
+import {
+  type FC,
+  type ComponentProps,
+  type ReactNode,
+  type SyntheticEvent,
+  useState,
+} from "react";
 import { useTranslation } from "react-i18next";
 import classNames from "classnames";
 import { VideoTrack } from "@livekit/components-react";
@@ -26,6 +32,7 @@ import { type ReactionOption } from "../reactions";
 import { ReactionIndicator } from "../reactions/ReactionIndicator";
 import { RTCConnectionStats } from "../RTCConnectionStats";
 import videoPlaceholder from "../graphics/video-placeholder.gif";
+import { autoVideoFit } from "../utils/videoFit";
 
 interface Props extends ComponentProps<typeof animated.div> {
   className?: string;
@@ -33,7 +40,11 @@ interface Props extends ComponentProps<typeof animated.div> {
   targetWidth: number;
   targetHeight: number;
   video: TrackReferenceOrPlaceholder | undefined;
-  videoFit: "cover" | "contain";
+  /**
+   * How to fit the video content inside the tile. When undefined, MediaView
+   * chooses a smart default based on the aspect ratios of the tile and video.
+   */
+  videoFit?: "cover" | "contain";
   mirror: boolean;
   soundWaves?: boolean;
   userId: string;
@@ -55,8 +66,15 @@ interface Props extends ComponentProps<typeof animated.div> {
   audioStreamStats?: RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats;
   videoStreamStats?: RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats;
   rtcBackendIdentity?: string;
-  // The focus url, mainly for debugging purposes
+  /**
+   * The focus url, mainly for debugging purposes.
+   */
   focusUrl?: string;
+  /**
+   * Called whenever the aspect ratio of the video content becomes known or
+   * otherwise changes.
+   */
+  setVideoAspectRatio?: (ratio: number) => void;
 }
 
 export const MediaView: FC<Props> = ({
@@ -89,6 +107,7 @@ export const MediaView: FC<Props> = ({
   videoStreamStats,
   rtcBackendIdentity,
   focusUrl,
+  setVideoAspectRatio: setTheirVideoAspectRatio,
   ...props
 }) => {
   const { t } = useTranslation();
@@ -100,6 +119,22 @@ export const MediaView: FC<Props> = ({
       (soundWaves === undefined ? 0.5 : 0.38),
   );
 
+  const [videoAspectRatio, setOurVideoAspectRatio] = useState<number>(NaN);
+  const tileAspectRatio = targetWidth / targetHeight;
+
+  // Propagate video dimensions
+  const setVideoAspectRatio = (ratio: number) => {
+    setOurVideoAspectRatio(ratio);
+    setTheirVideoAspectRatio?.(ratio);
+  };
+  const videoRef = (el: HTMLVideoElement | null) => {
+    if (el !== null) setVideoAspectRatio(el.videoWidth / el.videoHeight);
+  };
+  const onResize = (ev: SyntheticEvent<HTMLVideoElement>) =>
+    setVideoAspectRatio(
+      ev.currentTarget.videoWidth / ev.currentTarget.videoHeight,
+    );
+
   const warnings = unencryptedWarning && (
     <Tooltip
       label={t("common.unencrypted")}
@@ -126,7 +161,9 @@ export const MediaView: FC<Props> = ({
       ref={ref}
       data-testid="videoTile"
       data-video-enabled={video && videoEnabled}
-      data-video-fit={videoFit}
+      data-video-fit={
+        videoFit ?? autoVideoFit(videoAspectRatio, tileAspectRatio)
+      }
       data-background={background}
       {...props}
     >
@@ -158,6 +195,8 @@ export const MediaView: FC<Props> = ({
             // Set the placeholder to a small transparent image. (On Android web
             // views the default poster image is particularly ugly.)
             poster={videoPlaceholder}
+            ref={videoRef}
+            onResize={onResize}
           />
         )}
       </div>

src/tile/SpotlightTile.tsx

@@ -68,6 +68,7 @@ interface SpotlightItemBaseProps {
   background: "solid" | "transparent";
   focusable: boolean;
   "aria-hidden"?: boolean;
+  setVideoAspectRatio?: (ratio: number) => void;
 }
 
 interface SpotlightMemberMediaItemBaseProps extends SpotlightItemBaseProps {
@@ -77,7 +78,6 @@ interface SpotlightMemberMediaItemBaseProps extends SpotlightItemBaseProps {
 }
 
 interface SpotlightUserMediaItemBaseProps extends SpotlightMemberMediaItemBaseProps {
-  videoFit: "contain" | "cover";
   videoEnabled: boolean;
   soundWaves: boolean | undefined;
 }
@@ -120,20 +120,12 @@ const SpotlightUserMediaItem: FC<SpotlightUserMediaItemProps> = ({
   targetHeight,
   ...props
 }) => {
-  const videoFit = useBehavior(vm.videoFit$);
   const videoEnabled = useBehavior(vm.videoEnabled$);
   const speaking = useBehavior(vm.speaking$);
 
-  // Whenever target bounds change, inform the viewModel
-  useEffect(() => {
-    if (targetWidth > 0 && targetHeight > 0) {
-      vm.setTargetDimensions(targetWidth, targetHeight);
-    }
-  }, [targetWidth, targetHeight, vm]);
-
   const baseProps: SpotlightUserMediaItemBaseProps &
     RefAttributes<HTMLDivElement> = {
-    videoFit,
+    setVideoAspectRatio: vm.setVideoAspectRatio,
     videoEnabled,
     soundWaves: props.background === "transparent" ? speaking : undefined,
     targetWidth,
@@ -227,7 +219,6 @@ const SpotlightRingingMediaItem: FC<SpotlightRingingMediaItemProps> = ({
       }
       avatarStyle="translucent"
       videoEnabled={false}
-      videoFit="cover"
       mirror={false}
       {...props}
     />

src/utils/videoFit.test.ts

@@ -5,259 +5,106 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { describe, expect, test, vi } from "vitest";
-import {
-  LocalTrack,
-  type LocalTrackPublication,
-  type RemoteTrackPublication,
-  Track,
-} from "livekit-client";
+import { describe, expect, test } from "vitest";
 
-import { ObservableScope } from "../state/ObservableScope";
-import { videoFit$, videoSizeFromParticipant$ } from "./videoFit";
-import { constant } from "../state/Behavior";
-import {
-  flushPromises,
-  mockLocalParticipant,
-  mockRemoteParticipant,
-} from "./test";
+import { autoVideoFit } from "./videoFit";
 
 describe("videoFit$ defaults", () => {
   test.each([
     {
-      videoSize: { width: 1920, height: 1080 },
-      tileSize: undefined,
+      videoAspectRatio: 1920 / 1080,
+      tileAspectRatio: NaN,
     },
     {
-      videoSize: { width: 1080, height: 1920 },
-      tileSize: undefined,
+      videoAspectRatio: 1080 / 1920,
+      tileAspectRatio: NaN,
     },
     {
-      videoSize: undefined,
-      tileSize: { width: 1920, height: 1080 },
+      videoAspectRatio: NaN,
+      tileAspectRatio: 1920 / 1080,
     },
     {
-      videoSize: undefined,
-      tileSize: { width: 1080, height: 1920 },
+      videoAspectRatio: NaN,
+      tileAspectRatio: 1080 / 1920,
     },
   ])(
-    "videoFit$ returns `cover` when videoSize is $videoSize and tileSize is $tileSize",
-    ({ videoSize, tileSize }) => {
-      const scope = new ObservableScope();
-      const videoSize$ = constant(videoSize);
-      const tileSize$ = constant(tileSize);
-
-      const fit = videoFit$(scope, videoSize$, tileSize$);
-      expect(fit.value).toBe("cover");
-    },
+    "videoFit$ returns `cover` when videoAspectRatio is $videoAspectRatio and tileAspectRatio is $tileAspectRatio",
+    ({ videoAspectRatio, tileAspectRatio }) =>
+      expect(autoVideoFit(videoAspectRatio, tileAspectRatio)).toBe("cover"),
   );
 });
 
-const VIDEO_480_L = { width: 640, height: 480 };
-const VIDEO_720_L = { width: 1280, height: 720 };
-const VIDEO_1080_L = { width: 1920, height: 1080 };
+const VIDEO_480_L = 640 / 480;
+const VIDEO_720_L = 1280 / 720;
+const VIDEO_1080_L = 1920 / 1080;
 
 // Some sizes from real world testing, which don't match the standard video sizes exactly
-const TILE_SIZE_1_L = { width: 180, height: 135 };
-const TILE_SIZE_3_P = { width: 379, height: 542 };
-const TILE_SIZE_4_L = { width: 957, height: 542 };
+const TILE_SIZE_1_L = 180 / 135;
+const TILE_SIZE_3_P = 379 / 542;
+const TILE_SIZE_4_L = 957 / 542;
 // This is the size of an iPhone Xr in portrait mode
-const TILE_SIZE_5_P = { width: 414, height: 896 };
+const TILE_SIZE_5_P = 414 / 896;
 
-export function invertSize(size: { width: number; height: number }): {
-  width: number;
-  height: number;
-} {
-  return {
-    width: size.height,
-    height: size.width,
-  };
+function inverse(ratio: number): number {
+  return 1 / ratio;
 }
 
 test.each([
   {
-    videoSize: VIDEO_480_L,
-    tileSize: TILE_SIZE_1_L,
+    videoAspectRatio: VIDEO_480_L,
+    tileAspectRatio: TILE_SIZE_1_L,
     expected: "cover",
   },
   {
-    videoSize: invertSize(VIDEO_480_L),
-    tileSize: TILE_SIZE_1_L,
+    videoAspectRatio: inverse(VIDEO_480_L),
+    tileAspectRatio: TILE_SIZE_1_L,
     expected: "contain",
   },
   {
-    videoSize: VIDEO_720_L,
-    tileSize: TILE_SIZE_4_L,
+    videoAspectRatio: VIDEO_720_L,
+    tileAspectRatio: TILE_SIZE_4_L,
     expected: "cover",
   },
   {
-    videoSize: invertSize(VIDEO_720_L),
-    tileSize: TILE_SIZE_4_L,
+    videoAspectRatio: inverse(VIDEO_720_L),
+    tileAspectRatio: TILE_SIZE_4_L,
     expected: "contain",
   },
   {
-    videoSize: invertSize(VIDEO_1080_L),
-    tileSize: TILE_SIZE_3_P,
+    videoAspectRatio: inverse(VIDEO_1080_L),
+    tileAspectRatio: TILE_SIZE_3_P,
     expected: "cover",
   },
   {
-    videoSize: VIDEO_1080_L,
-    tileSize: TILE_SIZE_5_P,
+    videoAspectRatio: VIDEO_1080_L,
+    tileAspectRatio: TILE_SIZE_5_P,
     expected: "contain",
   },
   {
-    videoSize: invertSize(VIDEO_1080_L),
-    tileSize: TILE_SIZE_5_P,
+    videoAspectRatio: inverse(VIDEO_1080_L),
+    tileAspectRatio: TILE_SIZE_5_P,
     expected: "cover",
   },
   {
     // square video
-    videoSize: { width: 400, height: 400 },
-    tileSize: VIDEO_480_L,
+    videoAspectRatio: 400 / 400,
+    tileAspectRatio: VIDEO_480_L,
     expected: "contain",
   },
   {
     // Should default to cover if the initial size is 0:0.
     // Or else it will cause a flash of "contain" mode until the real size is loaded, which can be jarring.
-    videoSize: VIDEO_480_L,
-    tileSize: { width: 0, height: 0 },
+    videoAspectRatio: VIDEO_480_L,
+    tileAspectRatio: 0 / 0,
     expected: "cover",
   },
   {
-    videoSize: { width: 0, height: 0 },
-    tileSize: VIDEO_480_L,
+    videoAspectRatio: 0 / 0,
+    tileAspectRatio: VIDEO_480_L,
     expected: "cover",
   },
 ])(
-  "videoFit$ returns $expected when videoSize is $videoSize and tileSize is $tileSize",
-  ({ videoSize, tileSize, expected }) => {
-    const scope = new ObservableScope();
-    const videoSize$ = constant(videoSize);
-    const tileSize$ = constant(tileSize);
-
-    const fit = videoFit$(scope, videoSize$, tileSize$);
-    expect(fit.value).toBe(expected);
-  },
+  "videoFit$ returns $expected when videoAspectRatio is $videoAspectRatio and tileAspectRatio is $tileAspectRatio",
+  ({ videoAspectRatio, tileAspectRatio, expected }) =>
+    expect(autoVideoFit(videoAspectRatio, tileAspectRatio)).toBe(expected),
 );
-
-describe("extracting video size from participant stats", () => {
-  function createMockRtpStats(
-    isInbound: boolean,
-    props: Partial<RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats> = {},
-  ): RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats {
-    const baseStats = {
-      id: "mock-stats-id",
-      timestamp: Date.now(),
-      type: isInbound ? "inbound-rtp" : "outbound-rtp",
-      kind: "video",
-      ...props,
-    };
-
-    return baseStats as RTCInboundRtpStreamStats | RTCOutboundRtpStreamStats;
-  }
-
-  test("get stats for local user", async () => {
-    const localParticipant = mockLocalParticipant({
-      identity: "@local:example.org:AAAAAA",
-    });
-
-    const mockReport: RTCStatsReport = new Map([
-      [
-        "OT01V639885149",
-        createMockRtpStats(false, {
-          frameWidth: 1280,
-          frameHeight: 720,
-        }),
-      ],
-    ]);
-
-    const track = {
-      source: Track.Source.Camera,
-      getRTCStatsReport: vi
-        .fn()
-        .mockImplementation(async () => Promise.resolve(mockReport)),
-    } as Partial<LocalTrack> as LocalTrack;
-
-    // Set up the prototype chain (there is an instanceof check in getRTCStatsReport)
-    Object.setPrototypeOf(track, LocalTrack.prototype);
-
-    localParticipant.getTrackPublication = vi
-      .fn()
-      .mockImplementation((source: Track.Source) => {
-        if (source === Track.Source.Camera) {
-          return {
-            track,
-          } as unknown as LocalTrackPublication;
-        } else {
-          return undefined;
-        }
-      });
-
-    const videoDimensions$ = videoSizeFromParticipant$(
-      constant(localParticipant),
-    );
-
-    const publishedDimensions: { width: number; height: number }[] = [];
-    videoDimensions$.subscribe((dimensions) => {
-      if (dimensions) publishedDimensions.push(dimensions);
-    });
-
-    await flushPromises();
-
-    const dimension = publishedDimensions.pop();
-    expect(dimension).toEqual({ width: 1280, height: 720 });
-  });
-
-  test("get stats for remote user", async () => {
-    // vi.useFakeTimers()
-    const remoteParticipant = mockRemoteParticipant({
-      identity: "@bob:example.org:AAAAAA",
-    });
-
-    const mockReport: RTCStatsReport = new Map([
-      [
-        "OT01V639885149",
-        createMockRtpStats(true, {
-          frameWidth: 480,
-          frameHeight: 640,
-        }),
-      ],
-    ]);
-
-    const track = {
-      source: Track.Source.Camera,
-      getRTCStatsReport: vi
-        .fn()
-        .mockImplementation(async () => Promise.resolve(mockReport)),
-    } as Partial<LocalTrack> as LocalTrack;
-
-    // Set up the prototype chain (there is an instanceof check in getRTCStatsReport)
-    Object.setPrototypeOf(track, LocalTrack.prototype);
-
-    remoteParticipant.getTrackPublication = vi
-      .fn()
-      .mockImplementation((source: Track.Source) => {
-        if (source === Track.Source.Camera) {
-          return {
-            track,
-          } as unknown as RemoteTrackPublication;
-        } else {
-          return undefined;
-        }
-      });
-
-    const videoDimensions$ = videoSizeFromParticipant$(
-      constant(remoteParticipant),
-    );
-
-    const publishedDimensions: { width: number; height: number }[] = [];
-    videoDimensions$.subscribe((dimensions) => {
-      if (dimensions) publishedDimensions.push(dimensions);
-    });
-
-    await flushPromises();
-
-    const dimension = publishedDimensions.pop();
-    expect(dimension).toEqual({ width: 480, height: 640 });
-  });
-});

src/utils/videoFit.ts

@@ -5,107 +5,27 @@ SPDX-License-Identifier: AGPL-3.0-only OR LicenseRef-Element-Commercial
 Please see LICENSE in the repository root for full details.
 */
 
-import { combineLatest, map, type Observable, of, switchMap } from "rxjs";
-import {
-  type LocalParticipant,
-  type RemoteParticipant,
-  Track,
-} from "livekit-client";
-
-import { type ObservableScope } from "../state/ObservableScope.ts";
-import { type Behavior } from "../state/Behavior.ts";
-import {
-  observeInboundRtpStreamStats$,
-  observeOutboundRtpStreamStats$,
-} from "../state/media/observeRtpStreamStats";
-
-type Size = {
-  width: number;
-  height: number;
-};
-
 /**
  * Computes the appropriate video fit mode ("cover" or "contain") based on the aspect ratios of the video and the tile.
  * - If the video and tile have the same orientation (both landscape or both portrait), we use "cover" to fill the tile, even if it means cropping.
  * - If the video and tile have different orientations, we use "contain" to ensure the entire video is visible, even if it means letterboxing (black bars).
- * @param scope - the ObservableScope to create the Behavior in
- * @param videoSize$ - an Observable of the video size (width and height) or undefined if the size is not yet known (no data yet received).
- * @param tileSize$ - an Observable of the tile size (width and height) or undefined if the size is not yet known (not yet rendered).
  */
-export function videoFit$(
-  scope: ObservableScope,
-  videoSize$: Observable<Size | undefined>,
-  tileSize$: Observable<Size | undefined>,
-): Behavior<"cover" | "contain"> {
-  const fit$ = combineLatest([videoSize$, tileSize$]).pipe(
-    map(([videoSize, tileSize]) => {
-      if (!videoSize || !tileSize) {
-        // If we don't have the sizes, default to cover to avoid black bars.
-        // This is a reasonable default as it will ensure the video fills the tile, even if it means cropping.
-        return "cover";
-      }
-      if (
-        videoSize.width === 0 ||
-        videoSize.height === 0 ||
-        tileSize.width === 0 ||
-        tileSize.height === 0
-      ) {
-        // If we have invalid sizes (e.g. width or height is 0), default to cover to avoid black bars.
-        return "cover";
-      }
-      const videoAspectRatio = videoSize.width / videoSize.height;
-      const tileAspectRatio = tileSize.width / tileSize.height;
+export function autoVideoFit(
+  videoAspectRatio: number,
+  tileAspectRatio: number,
+): "cover" | "contain" {
+  if (Number.isNaN(videoAspectRatio) || Number.isNaN(tileAspectRatio)) {
+    // If we have invalid sizes (e.g. useMeasure returns 0×0 on an initial render),
+    // default to cover to avoid black bars.
+    return "cover";
+  }
 
-      // If video is landscape (ratio > 1) and tile is portrait (ratio < 1) or vice versa,
-      // we want to use "contain" (fit) mode to avoid excessive cropping
-      const videoIsLandscape = videoAspectRatio > 1;
-      const tileIsLandscape = tileAspectRatio > 1;
+  // If video is landscape (ratio > 1) and tile is portrait (ratio < 1) or vice versa,
+  // we want to use "contain" (fit) mode to avoid excessive cropping
+  const videoIsLandscape = videoAspectRatio > 1;
+  const tileIsLandscape = tileAspectRatio > 1;
 
-      // If the orientations are the same, use the cover mode (Preserves the aspect ratio, and the image fills the container.)
-      // If they're not the same orientation, use the contain mode (Preserves the aspect ratio, but the image is letterboxed - black bars- to fit within the container.)
-      return videoIsLandscape === tileIsLandscape ? "cover" : "contain";
-    }),
-  );
-
-  return scope.behavior(fit$, "cover");
-}
-
-/**
- * Helper function to get the video size from a participant.
- * It observes the participant's video track stats and extracts the frame width and height.
- * @param participant$ - an Observable of a LocalParticipant or RemoteParticipant, or null if no participant is selected.
- * @returns an Observable of the video size (width and height) or undefined if the size cannot be determined.
- */
-export function videoSizeFromParticipant$(
-  participant$: Observable<LocalParticipant | RemoteParticipant | null>,
-): Observable<{ width: number; height: number } | undefined> {
-  return participant$
-    .pipe(
-      // If we have a participant, observe their video track stats. If not, return undefined.
-      switchMap((p) => {
-        if (!p) return of(undefined);
-        if (p.isLocal) {
-          return observeOutboundRtpStreamStats$(p, Track.Source.Camera);
-        } else {
-          return observeInboundRtpStreamStats$(p, Track.Source.Camera);
-        }
-      }),
-    )
-    .pipe(
-      // Extract the frame width and height from the stats. If we don't have valid stats, return undefined.
-      map((stats) => {
-        if (!stats) return undefined;
-        if (
-          // For video tracks, frameWidth and frameHeight should be numbers. If they're not, we can't determine the size.
-          typeof stats.frameWidth !== "number" ||
-          typeof stats.frameHeight !== "number"
-        ) {
-          return undefined;
-        }
-        return {
-          width: stats.frameWidth,
-          height: stats.frameHeight,
-        };
-      }),
-    );
+  // If the orientations are the same, use the cover mode (Preserves the aspect ratio, and the image fills the container.)
+  // If they're not the same orientation, use the contain mode (Preserves the aspect ratio, but the image is letterboxed - black bars- to fit within the container.)
+  return videoIsLandscape === tileIsLandscape ? "cover" : "contain";
 }