♿(frontend) add keyboard navigation to screen share zoom toolbar

Arrows move between controls instead of panning, w/ en/fr/nl/de hint update.

CHANGELOG.md

@@ -8,11 +8,6 @@ and this project adheres to
 
 ## [Unreleased]
 
-### Added
-
-- ✨(frontend) add 1080p sending resolution option #1660
-- ✨(backend) add Traefik support via configurable media-auth url header #1649
-
 ### Fixed
 
 - 🐛(frontend) keep the sending resolution picked while the camera is off #1667
@@ -227,6 +222,10 @@ and this project adheres to
 - ♿️(frontend) focus side panel container on open #1452
 - 🐛(summary) whisper call error handling
 
+### Added
+
+- ✨(frontend) add screen share zoom controls #1498
+
 ## [1.23.0] - 2026-07-08
 
 ### Added

docker/dinum-frontend/Dockerfile

@@ -65,7 +65,6 @@ RUN apk update && apk upgrade  \
     musl \
     musl-utils \
     zlib>=1.3.2-r0 \
-    libexpat>=2.8.4-r0 \
     && apk del curl
 
 USER nginx

src/backend/core/api/viewsets.py

@@ -1076,10 +1076,9 @@ class RecordingViewSet(
 
     def _auth_get_original_url(self, request):
         """
-        Extracts and parses the original URL from the configured header.
+        Extracts and parses the original URL from the "HTTP_X_ORIGINAL_URL" header.
         Raises PermissionDenied if the header is missing.
-        The original url is passed by the reverse proxy in the header named by the
-        MEDIA_AUTH_ORIGINAL_URL_HEADER setting, which defaults to "HTTP_X_ORIGINAL_URL".
+        The original url is passed by nginx in the "HTTP_X_ORIGINAL_URL" header.
         See corresponding ingress configuration in Helm chart and read about the
         nginx.ingress.kubernetes.io/auth-url annotation to understand how the Nginx ingress
         is configured to do this.
@@ -1089,13 +1088,9 @@ class RecordingViewSet(
         reasons.
         """
         # Extract the original URL from the request header
-        original_url = request.META.get(settings.MEDIA_AUTH_ORIGINAL_URL_HEADER)
+        original_url = request.META.get("HTTP_X_ORIGINAL_URL")
         if not original_url:
-            logger.warning(
-                "Missing %s header in subrequest. Set MEDIA_AUTH_ORIGINAL_URL_HEADER "
-                "to the header your reverse proxy sends.",
-                settings.MEDIA_AUTH_ORIGINAL_URL_HEADER,
-            )
+            logger.warning("Missing HTTP_X_ORIGINAL_URL header in subrequest")
             raise drf_exceptions.PermissionDenied()
 
         logger.debug("Original url: '%s'", original_url)
@@ -1420,8 +1415,7 @@ class FileViewSet(
         Authorize access based on the original URL of an Nginx subrequest
         and user permissions. Returns a dictionary of URL parameters if authorized.
 
-        The original url is passed by the reverse proxy in the header named by the
-        MEDIA_AUTH_ORIGINAL_URL_HEADER setting, which defaults to "HTTP_X_ORIGINAL_URL".
+        The original url is passed by nginx in the "HTTP_X_ORIGINAL_URL" header.
         See corresponding ingress configuration in Helm chart and read about the
         nginx.ingress.kubernetes.io/auth-url annotation to understand how the Nginx ingress
         is configured to do this.
@@ -1440,13 +1434,9 @@ class FileViewSet(
         - PermissionDenied if authorization fails.
         """
         # Extract the original URL from the request header
-        original_url = request.META.get(settings.MEDIA_AUTH_ORIGINAL_URL_HEADER)
+        original_url = request.META.get("HTTP_X_ORIGINAL_URL")
         if not original_url:
-            logger.warning(
-                "Missing %s header in subrequest. Set MEDIA_AUTH_ORIGINAL_URL_HEADER "
-                "to the header your reverse proxy sends.",
-                settings.MEDIA_AUTH_ORIGINAL_URL_HEADER,
-            )
+            logger.warning("Missing HTTP_X_ORIGINAL_URL header in subrequest")
             raise drf_exceptions.PermissionDenied()
 
         parsed_url = urlparse(original_url)

src/backend/core/tests/files/test_api_files_media_auth.py

@@ -7,7 +7,6 @@ from urllib.parse import quote, urlparse
 
 from django.conf import settings
 from django.core.files.storage import default_storage
-from django.test import override_settings
 from django.utils import timezone
 
 import pytest
@@ -144,59 +143,3 @@ def test_api_files_media_auth_own_file_deleted():
     )
 
     assert response.status_code == 403
-
-
-@override_settings(MEDIA_AUTH_ORIGINAL_URL_HEADER="HTTP_X_FORWARDED_URI")
-def test_api_files_media_auth_custom_original_url_header():
-    """
-    Authorization should honour the configured original-url header.
-
-    Covers the attachment subrequest path, which resolves the header separately
-    from the recording one. Reverse proxies other than nginx-ingress use
-    different headers: Traefik's ForwardAuth sends X-Forwarded-Uri and cannot
-    emit X-Original-URL at all.
-    """
-    user = factories.UserFactory()
-
-    file = factories.FileFactory(
-        type=models.FileTypeChoices.BACKGROUND_IMAGE,
-        update_upload_state=models.FileUploadStateChoices.READY,
-        creator=user,
-    )
-
-    client = APIClient()
-    client.force_login(user)
-
-    default_storage.save(file.file_key, BytesIO(b"my prose"))
-
-    original_url = f"http://localhost/media/{file.file_key:s}"
-    response = client.get(
-        "/api/v1.0/files/media-auth/", HTTP_X_FORWARDED_URI=original_url
-    )
-
-    assert response.status_code == 200
-    assert "AWS4-HMAC-SHA256 Credential=" in response["Authorization"]
-
-
-@override_settings(MEDIA_AUTH_ORIGINAL_URL_HEADER="HTTP_X_FORWARDED_URI")
-def test_api_files_media_auth_default_header_ignored_when_reconfigured():
-    """
-    Only the configured header should be honoured, never a hardcoded fallback.
-    """
-    user = factories.UserFactory()
-
-    file = factories.FileFactory(
-        type=models.FileTypeChoices.BACKGROUND_IMAGE,
-        update_upload_state=models.FileUploadStateChoices.READY,
-        creator=user,
-    )
-
-    client = APIClient()
-    client.force_login(user)
-
-    original_url = f"http://localhost/media/{file.file_key:s}"
-    response = client.get(
-        "/api/v1.0/files/media-auth/", HTTP_X_ORIGINAL_URL=original_url
-    )
-
-    assert response.status_code == 403

src/backend/core/tests/recording/test_api_recordings_media_auth.py

@@ -8,7 +8,6 @@ from uuid import uuid4
 
 from django.conf import settings
 from django.core.files.storage import default_storage
-from django.test import override_settings
 from django.utils import timezone
 
 import pytest
@@ -283,63 +282,3 @@ def test_api_recordings_media_auth_success_administrator(mode):
         timeout=1,
     )
     assert response.content.decode("utf-8") == "my prose"
-
-
-def test_api_recordings_media_auth_missing_header():
-    """
-    Test that a subrequest without the configured original-url header is rejected.
-    """
-    user = UserFactory()
-
-    client = APIClient()
-    client.force_login(user)
-
-    response = client.get("/api/v1.0/recordings/media-auth/")
-
-    assert response.status_code == 403
-
-
-@override_settings(MEDIA_AUTH_ORIGINAL_URL_HEADER="HTTP_X_FORWARDED_URI")
-def test_api_recordings_media_auth_custom_original_url_header():
-    """
-    Test that the header carrying the original URL can be configured.
-
-    Reverse proxies other than nginx-ingress use different headers: Traefik's
-    ForwardAuth sends X-Forwarded-Uri and cannot emit X-Original-URL at all.
-    """
-    user = UserFactory()
-
-    client = APIClient()
-    client.force_login(user)
-
-    original_url = f"http://localhost/media/recordings/{uuid4()!s}.mp4"
-
-    response = client.get(
-        "/api/v1.0/recordings/media-auth/", HTTP_X_FORWARDED_URI=original_url
-    )
-
-    # The header was read and parsed: we get as far as looking the recording up,
-    # rather than being rejected for a missing header.
-    assert response.status_code == 404
-
-
-@override_settings(MEDIA_AUTH_ORIGINAL_URL_HEADER="HTTP_X_FORWARDED_URI")
-def test_api_recordings_media_auth_default_header_ignored_when_reconfigured():
-    """
-    Test that only the configured header is honoured.
-
-    Guards against the header being read from a hardcoded name in parallel with
-    the setting.
-    """
-    user = UserFactory()
-
-    client = APIClient()
-    client.force_login(user)
-
-    original_url = f"http://localhost/media/recordings/{uuid4()!s}.mp4"
-
-    response = client.get(
-        "/api/v1.0/recordings/media-auth/", HTTP_X_ORIGINAL_URL=original_url
-    )
-
-    assert response.status_code == 403

src/backend/meet/settings.py

@@ -129,15 +129,6 @@ class Base(Configuration):
     MEDIA_BASE_URL = values.Value(
         "", environ_name="MEDIA_BASE_URL", environ_prefix=None
     )
-    # Header the reverse proxy uses to pass the original request URL to the
-    # media-auth subrequest views. nginx-ingress sends X-Original-URL, which is
-    # the default. Other proxies use different headers -- Traefik's ForwardAuth,
-    # for instance, sends X-Forwarded-Uri and cannot emit X-Original-URL at all.
-    MEDIA_AUTH_ORIGINAL_URL_HEADER = values.Value(
-        default="HTTP_X_ORIGINAL_URL",
-        environ_name="MEDIA_AUTH_ORIGINAL_URL_HEADER",
-        environ_prefix=None,
-    )
 
     SITE_ID = 1
 

src/frontend/Dockerfile

@@ -53,7 +53,6 @@ RUN apk update && apk upgrade  \
     musl \
     musl-utils \
     zlib>=1.3.2-r0 \
-    libexpat>=2.8.4-r0 \
     && apk del curl
 
 USER nginx

src/frontend/src/features/analytics/exceptionFilters.ts

@@ -8,28 +8,6 @@ const IGNORED_EXCEPTION_PATTERNS = [
   // the close reason is already logged by the SDK.
   // See: https://github.com/livekit/client-sdk-js/issues/2062
   /^Event captured as exception with keys: isTrusted$/,
-  // MediaPipe's WASM writes its native logs to stderr, which Emscripten
-  // routes to console.error, which PostHog's console capture then promotes
-  // to an $exception — even though nothing was thrown. Two flavors:
-  //
-  // 1. "INFO: ..." lines are purely informational. In particular
-  //    "INFO: Created TensorFlow Lite XNNPACK delegate for CPU." is a
-  //    SUCCESS message: TFLite prints it when it lazily initializes CPU
-  //    inference on the first segmented frame. It fires on every effects
-  //    init, on every browser and delegate (the GPU delegate still
-  //    instantiates the CPU/XNNPACK delegate for non-delegated ops), so it
-  //    was our single noisiest "error" while carrying zero signal.
-  /^INFO: /,
-  //
-  // 2. absl-formatted log lines, e.g.
-  //    "E0901 19:21:45.443000 1880752 gl_graph_runner_internal.cc:260]
-  //     StartGraph failed: ..."
-  //    (severity letter E/W/I/F + MMDD + timestamp). These are the stderr
-  //    *copies* of failures that MediaPipe also raises as real JS
-  //    exceptions, which we already capture via reportError / thrown
-  //    errors. Dropping them de-duplicates each incident (previously
-  //    counted 2-3x) without losing the actual error report.
-  /^[EWIF]\d{4} \d{2}:\d{2}:\d{2}\./,
 ]
 
 const shouldIgnoreException = (value: unknown): boolean =>

src/frontend/src/features/participantTile/components/ParticipantTile.tsx

@@ -20,6 +20,7 @@ import { Track } from 'livekit-client'
 import { ParticipantPlaceholder } from './ParticipantPlaceholder'
 import { ParticipantTileFocus } from './participantTileFocus/ParticipantTileFocus'
 import { FullScreenShareWarning } from './FullScreenShareWarning'
+import { ScreenShareZoomableVideo } from '@/features/rooms/livekit/components/ScreenShareZoomableVideo'
 import { useTranslation } from 'react-i18next'
 import { getShortcutDescriptorById } from '@/features/shortcuts/catalog'
 import { formatShortcutLabel } from '@/features/shortcuts/formatLabels'
@@ -48,6 +49,8 @@ interface ParticipantTileExtendedProps extends ParticipantTileProps {
   disableTileControls?: boolean
 }
 
+const MOUSE_IDLE_TIME = 3000
+
 export const ParticipantTile: (
   props: ParticipantTileExtendedProps & React.RefAttributes<HTMLDivElement>
 ) => React.ReactNode = /* @__PURE__ */ React.forwardRef<
@@ -89,6 +92,8 @@ export const ParticipantTile: (
   )
 
   const isScreenShare = trackReference.source != Track.Source.Camera
+  const isRemoteScreenShare =
+    isScreenShare && !trackReference.participant.isLocal
   const [hasKeyboardFocus, setHasKeyboardFocus] = React.useState(false)
 
   const participantColor = getParticipantColor(trackReference.participant)
@@ -98,11 +103,38 @@ export const ParticipantTile: (
   })
   const participantName = name || identity || 'Unknown'
 
+  // Hover + idle tracking for the focus overlay (pin, effects, mute buttons).
+  const [isTileHovered, setIsTileHovered] = React.useState(false)
+  const [isIdle, setIsIdle] = React.useState(false)
+  const idleTimerRef = React.useRef<number | null>(null)
+
+  const handleTileMouseMove = React.useCallback(() => {
+    if (idleTimerRef.current) window.clearTimeout(idleTimerRef.current)
+    idleTimerRef.current = window.setTimeout(
+      () => setIsIdle(true),
+      MOUSE_IDLE_TIME
+    )
+    setIsIdle(false)
+  }, [])
+
+  const isOverlayVisible = hasKeyboardFocus || (isTileHovered && !isIdle)
+
+  // tileRef: fullscreen target. setRefs merges it with the forwarded ref on the same node.
+  const tileRef = React.useRef<HTMLDivElement>(null)
+  const setRefs = React.useCallback(
+    (node: HTMLDivElement | null) => {
+      ;(tileRef as React.MutableRefObject<HTMLDivElement | null>).current = node
+      if (typeof ref === 'function') ref(node)
+      else if (ref)
+        (ref as React.MutableRefObject<HTMLDivElement | null>).current = node
+    },
+    [ref]
+  )
+
   const { t } = useTranslation('rooms', { keyPrefix: 'participantTileFocus' })
 
   const interactiveProps = {
     ...elementProps,
-    // Ensure the tile is focusable to expose contextual controls to keyboard users.
     tabIndex: 0,
     'aria-label': t('containerLabel', { name: participantName }),
     onFocus: (event: React.FocusEvent<HTMLDivElement>) => {
@@ -120,8 +152,57 @@ export const ParticipantTile: (
     },
   }
 
+  const isVideoTrack =
+    isTrackReference(trackReference) &&
+    (trackReference.publication?.kind === 'video' ||
+      trackReference.source === Track.Source.Camera ||
+      trackReference.source === Track.Source.ScreenShare)
+
+  let trackMedia: React.ReactNode = null
+  if (isVideoTrack) {
+    if (isRemoteScreenShare) {
+      trackMedia = (
+        <ScreenShareZoomableVideo
+          trackRef={trackReference}
+          tileRef={tileRef}
+          onSubscriptionStatusChanged={handleSubscribe}
+          manageSubscription={autoManageSubscription}
+        />
+      )
+    } else {
+      trackMedia = (
+        <VideoTrack
+          trackRef={trackReference}
+          onSubscriptionStatusChanged={handleSubscribe}
+          manageSubscription={autoManageSubscription}
+        />
+      )
+    }
+  } else if (isTrackReference(trackReference)) {
+    trackMedia = (
+      <AudioTrack
+        trackRef={trackReference}
+        onSubscriptionStatusChanged={handleSubscribe}
+      />
+    )
+  }
+
   return (
-    <div ref={ref} style={{ position: 'relative' }} {...interactiveProps}>
+    <div
+      ref={setRefs}
+      style={{ position: 'relative' }}
+      {...interactiveProps}
+      onMouseEnter={() => setIsTileHovered(true)}
+      onMouseLeave={() => {
+        setIsTileHovered(false)
+        setIsIdle(false)
+        if (idleTimerRef.current) {
+          window.clearTimeout(idleTimerRef.current)
+          idleTimerRef.current = null
+        }
+      }}
+      onMouseMove={handleTileMouseMove}
+    >
       <TrackRefContextIfNeeded trackRef={trackReference}>
         <ParticipantContextIfNeeded participant={trackReference.participant}>
           {trackReference.participant.isLocal && (
@@ -129,23 +210,7 @@ export const ParticipantTile: (
           )}
           {children ?? (
             <>
-              {isTrackReference(trackReference) &&
-              (trackReference.publication?.kind === 'video' ||
-                trackReference.source === Track.Source.Camera ||
-                trackReference.source === Track.Source.ScreenShare) ? (
-                <VideoTrack
-                  trackRef={trackReference}
-                  onSubscriptionStatusChanged={handleSubscribe}
-                  manageSubscription={autoManageSubscription}
-                />
-              ) : (
-                isTrackReference(trackReference) && (
-                  <AudioTrack
-                    trackRef={trackReference}
-                    onSubscriptionStatusChanged={handleSubscribe}
-                  />
-                )
-              )}
+              {trackMedia}
               <div className="lk-participant-placeholder">
                 <ParticipantPlaceholder
                   color={participantColor}
@@ -164,7 +229,7 @@ export const ParticipantTile: (
           {!disableMetadata && !disableTileControls && (
             <ParticipantTileFocus
               trackRef={trackReference}
-              hasKeyboardFocus={hasKeyboardFocus}
+              isVisible={isOverlayVisible}
             />
           )}
         </ParticipantContextIfNeeded>

src/frontend/src/features/participantTile/components/participantTileFocus/ParticipantTileFocus.tsx

@@ -1,44 +1,22 @@
 import { css } from '@/styled-system/css'
 import { HStack } from '@/styled-system/jsx'
 import { TrackReferenceOrPlaceholder } from '@livekit/components-core'
-import { ReactNode, useEffect, useRef, useState } from 'react'
+import { ReactNode } from 'react'
 import { Track } from 'livekit-client'
 import { useCanMute } from '@/features/rooms/livekit/hooks/useCanMute'
 import { FocusButton } from './FocusButton'
 import { EffectsButton } from './EffectsButton'
 import { MuteButton } from './MuteButton'
-import { ZoomButton } from './ZoomButton'
-
-const MOUSE_IDLE_TIME = 3000
 
 type FadeOverlayProps = {
   children: ReactNode
-  hasKeyboardFocus: boolean
+  isVisible: boolean
 }
 
-const FadeOverlay = ({ children, hasKeyboardFocus }: FadeOverlayProps) => {
-  const [active, setActive] = useState(false)
-  const idleTimerRef = useRef<number | null>(null)
-
-  const clearIdleTimer = () => {
-    if (idleTimerRef.current) window.clearTimeout(idleTimerRef.current)
-  }
-
-  const armIdleTimer = () => {
-    clearIdleTimer()
-    idleTimerRef.current = window.setTimeout(() => {
-      setActive(false)
-    }, MOUSE_IDLE_TIME)
-  }
-
-  const handleActivity = () => {
-    setActive(true)
-    armIdleTimer()
-  }
-
-  useEffect(() => clearIdleTimer, [])
-
-  const isVisible = hasKeyboardFocus || active
+// Pointer-events none so this overlay doesn't block the zoom surface below.
+// Hover and idle tracking therefore lives on the tile, which still receives
+// the pointer events, and comes back in as isVisible.
+const FadeOverlay = ({ children, isVisible }: FadeOverlayProps) => {
   return (
     <div
       className={css({
@@ -50,15 +28,10 @@ const FadeOverlay = ({ children, hasKeyboardFocus }: FadeOverlayProps) => {
         alignItems: 'center',
         width: '100%',
         height: '100%',
+        pointerEvents: 'none',
       })}
       data-visible={isVisible || undefined}
       aria-hidden={!isVisible}
-      onMouseEnter={handleActivity}
-      onMouseMove={handleActivity}
-      onMouseLeave={() => {
-        clearIdleTimer()
-        setActive(false)
-      }}
     >
       {isVisible && children}
     </div>
@@ -67,10 +40,10 @@ const FadeOverlay = ({ children, hasKeyboardFocus }: FadeOverlayProps) => {
 
 export const ParticipantTileFocus = ({
   trackRef,
-  hasKeyboardFocus,
+  isVisible,
 }: {
   trackRef: TrackReferenceOrPlaceholder
-  hasKeyboardFocus: boolean
+  isVisible: boolean
 }) => {
   const participant = trackRef.participant
   const isScreenShare = trackRef.source == Track.Source.ScreenShare
@@ -78,7 +51,7 @@ export const ParticipantTileFocus = ({
   const canMute = useCanMute(participant)
 
   return (
-    <FadeOverlay hasKeyboardFocus={hasKeyboardFocus}>
+    <FadeOverlay isVisible={isVisible}>
       <div
         className={css({
           backgroundColor: 'primaryDark.50',
@@ -87,6 +60,7 @@ export const ParticipantTileFocus = ({
           display: 'flex',
           opacity: 0.6,
           animation: 'overlayIn 200ms linear 300ms backwards',
+          pointerEvents: 'auto',
           _hover: {
             opacity: 0.95,
           },
@@ -94,7 +68,7 @@ export const ParticipantTileFocus = ({
       >
         <HStack gap={0.5} padding={0.5}>
           <FocusButton trackRef={trackRef} />
-          {!isScreenShare ? (
+          {!isScreenShare && (
             <>
               {isLocal ? (
                 <EffectsButton />
@@ -102,8 +76,6 @@ export const ParticipantTileFocus = ({
                 canMute && <MuteButton participant={participant} />
               )}
             </>
-          ) : (
-            !isLocal && <ZoomButton trackRef={trackRef} />
           )}
         </HStack>
       </div>

src/frontend/src/features/participantTile/components/participantTileFocus/ZoomButton.tsx

@@ -1,32 +0,0 @@
-import { TrackReferenceOrPlaceholder } from '@livekit/components-core'
-import { useTranslation } from 'react-i18next'
-import { useFullScreen } from '@/features/rooms/livekit/hooks/useFullScreen'
-import { Button } from '@/primitives'
-import { RiFullscreenLine } from '@remixicon/react'
-
-export const ZoomButton = ({
-  trackRef,
-}: {
-  trackRef: TrackReferenceOrPlaceholder
-}) => {
-  const { t } = useTranslation('rooms', { keyPrefix: 'participantTileFocus' })
-  const { toggleFullScreen, isFullscreenAvailable } = useFullScreen({
-    trackRef,
-  })
-
-  if (!isFullscreenAvailable) {
-    return
-  }
-
-  return (
-    <Button
-      size="sm"
-      variant="primaryTextDark"
-      square
-      tooltip={t('fullScreen')}
-      onPress={() => toggleFullScreen()}
-    >
-      <RiFullscreenLine />
-    </Button>
-  )
-}

src/frontend/src/features/rooms/livekit/components/ScreenShareVideoTrack.tsx

@@ -0,0 +1,26 @@
+import { VideoTrack } from '@livekit/components-react'
+import { type TrackReference } from '@livekit/components-core'
+import { memo } from 'react'
+
+interface ScreenShareVideoTrackProps {
+  trackRef: TrackReference
+  onSubscriptionStatusChanged: (subscribed: boolean) => void
+  manageSubscription?: boolean
+}
+
+// Zoom/pan updates the wrapper transform only; skip VideoTrack re-renders.
+export const ScreenShareVideoTrack = memo(
+  ({
+    trackRef,
+    onSubscriptionStatusChanged,
+    manageSubscription,
+  }: ScreenShareVideoTrackProps) => (
+    <VideoTrack
+      trackRef={trackRef}
+      onSubscriptionStatusChanged={onSubscriptionStatusChanged}
+      manageSubscription={manageSubscription}
+    />
+  )
+)
+
+ScreenShareVideoTrack.displayName = 'ScreenShareVideoTrack'

src/frontend/src/features/rooms/livekit/components/ScreenShareZoomControls.tsx

@@ -0,0 +1,223 @@
+import { css } from '@/styled-system/css'
+import { Button } from '@/primitives'
+import {
+  RiCollapseDiagonalLine,
+  RiExpandDiagonalLine,
+  RiFullscreenExitLine,
+  RiZoomInLine,
+  RiZoomOutLine,
+} from '@remixicon/react'
+import { useTranslation } from 'react-i18next'
+import { Toolbar } from 'react-aria-components'
+import { useCallback, useEffect, useRef, useState } from 'react'
+import { useScreenReaderAnnounce } from '@/hooks/useScreenReaderAnnounce'
+import { isMacintosh } from '@/utils/livekit'
+import { srOnly } from '@/styles/a11y'
+
+interface ScreenShareZoomControlsProps {
+  containerRef: React.RefObject<HTMLDivElement | null>
+  isZoomed: boolean
+  zoomPercentage: number
+  canZoomIn: boolean
+  canZoomOut: boolean
+  onZoomIn: () => void
+  onZoomOut: () => void
+  onResetZoom: () => void
+}
+
+export const ScreenShareZoomControls = ({
+  containerRef,
+  isZoomed,
+  zoomPercentage,
+  canZoomIn,
+  canZoomOut,
+  onZoomIn,
+  onZoomOut,
+  onResetZoom,
+}: ScreenShareZoomControlsProps) => {
+  const { t } = useTranslation('rooms', { keyPrefix: 'screenShareZoom' })
+  const announce = useScreenReaderAnnounce()
+
+  const zoomInButtonRef = useRef<HTMLButtonElement>(null)
+  const hadFocusInCollapsibleRef = useRef(false)
+
+  const [isFullscreen, setIsFullscreen] = useState(false)
+  // Tracks whether this tile's container triggered fullscreen (vs another share's).
+  const wasThisTileFullscreen = useRef(false)
+  const isFullscreenAvailable = document.fullscreenEnabled
+
+  // Covers Esc and browser UI exits, not just the toolbar button.
+  // Only this tile's instance announces to avoid duplicates with multiple shares.
+  useEffect(() => {
+    const onChange = () => {
+      const isThisTileFullscreen =
+        document.fullscreenElement === containerRef.current
+      setIsFullscreen(isThisTileFullscreen)
+
+      if (isThisTileFullscreen) {
+        wasThisTileFullscreen.current = true
+        announce(t('fullScreenEntered'), 'assertive')
+      } else if (wasThisTileFullscreen.current) {
+        wasThisTileFullscreen.current = false
+        announce(t('fullScreenExited'), 'assertive')
+      }
+    }
+    document.addEventListener('fullscreenchange', onChange)
+    return () => document.removeEventListener('fullscreenchange', onChange)
+  }, [announce, t, containerRef])
+
+  // Back at 100 % the collapsible controls are disabled and hidden, which drops
+  // keyboard focus on the body. Hand it to the zoom in button instead, the only
+  // control of that group still reachable.
+  useEffect(() => {
+    if (isZoomed || !hadFocusInCollapsibleRef.current) return
+    hadFocusInCollapsibleRef.current = false
+    zoomInButtonRef.current?.focus()
+  }, [isZoomed])
+
+  const toggleFullScreen = useCallback(async () => {
+    try {
+      if (document.fullscreenElement === containerRef.current) {
+        await document.exitFullscreen()
+      } else {
+        // Tile container so zoom controls stay visible in fullscreen.
+        await containerRef.current?.requestFullscreen()
+      }
+    } catch (error) {
+      console.error('Error toggling fullscreen:', error)
+    }
+  }, [containerRef])
+
+  const wheelShortcutVisual = isMacintosh() ? '⌘+scroll' : 'Ctrl+scroll'
+
+  return (
+    <div
+      className={css({
+        position: 'absolute',
+        bottom: '12px',
+        right: '12px',
+        zIndex: 2,
+        pointerEvents: 'auto',
+      })}
+    >
+      {/* react-aria Toolbar: left/right arrows move between the controls and
+          Tab leaves the group as a whole, as the toolbar role implies. */}
+      <Toolbar
+        aria-label={t('toolbarLabel')}
+        className={css({
+          display: 'flex',
+          alignItems: 'center',
+          backgroundColor: 'primaryDark.50',
+          borderRadius: '2rem',
+          padding: '0.5rem',
+          opacity: 0.7,
+          transition: 'opacity 200ms linear',
+          _hover: {
+            opacity: 0.95,
+          },
+        })}
+      >
+        <span className={srOnly}>
+          {t(isMacintosh() ? 'wheelShortcutHintMac' : 'wheelShortcutHint')}
+        </span>
+        {/* Animated wrapper: collapses to 0 when not zoomed. padding/margin
+            trick keeps overflow:hidden from clipping focus rings. */}
+        <div
+          className={css({
+            display: 'flex',
+            alignItems: 'center',
+            overflow: 'hidden',
+            transition: 'max-width 200ms ease-out, opacity 200ms ease-out',
+            padding: '3px',
+            margin: '-3px',
+          })}
+          style={{
+            maxWidth: isZoomed ? '12rem' : '0',
+            opacity: isZoomed ? 1 : 0,
+          }}
+          aria-hidden={!isZoomed}
+          onFocus={() => {
+            hadFocusInCollapsibleRef.current = true
+          }}
+          onBlur={(e) => {
+            // Disabling a focused button blurs it with no relatedTarget, so the
+            // flag must survive that case for the effect above to rescue focus.
+            if (e.relatedTarget) hadFocusInCollapsibleRef.current = false
+          }}
+        >
+          <Button
+            size="sm"
+            variant="primaryTextDark"
+            square
+            tooltip={t('fitToWindow')}
+            aria-label={t('fitToWindow')}
+            isDisabled={!isZoomed}
+            onPress={onResetZoom}
+          >
+            <RiFullscreenExitLine size={20} />
+          </Button>
+          <Button
+            size="sm"
+            variant="primaryTextDark"
+            square
+            tooltip={t('zoomOutWithShortcut', {
+              shortcut: wheelShortcutVisual,
+            })}
+            aria-label={t('zoomOut')}
+            isDisabled={!isZoomed || !canZoomOut}
+            onPress={onZoomOut}
+          >
+            <RiZoomOutLine size={20} />
+          </Button>
+          {/* Visual only - zoom level is announced via useScreenReaderAnnounce. */}
+          <span
+            aria-hidden="true"
+            className={css({
+              color: 'white',
+              fontSize: '0.8125rem',
+              fontWeight: 500,
+              minWidth: '3.25rem',
+              textAlign: 'center',
+              userSelect: 'none',
+              display: 'flex',
+              alignItems: 'center',
+              justifyContent: 'center',
+              padding: '0 0.25rem',
+              whiteSpace: 'nowrap',
+            })}
+          >
+            {zoomPercentage} %
+          </span>
+        </div>
+        <Button
+          ref={zoomInButtonRef}
+          size="sm"
+          variant="primaryTextDark"
+          square
+          tooltip={t('zoomInWithShortcut', { shortcut: wheelShortcutVisual })}
+          aria-label={t('zoomIn')}
+          isDisabled={!canZoomIn}
+          onPress={onZoomIn}
+        >
+          <RiZoomInLine size={20} />
+        </Button>
+        {isFullscreenAvailable && (
+          <Button
+            size="sm"
+            variant="primaryTextDark"
+            square
+            tooltip={isFullscreen ? t('exitFullScreen') : t('fullScreen')}
+            aria-label={isFullscreen ? t('exitFullScreen') : t('fullScreen')}
+            onPress={toggleFullScreen}
+          >
+            {isFullscreen ? (
+              <RiCollapseDiagonalLine size={20} />
+            ) : (
+              <RiExpandDiagonalLine size={20} />
+            )}
+          </Button>
+        )}
+      </Toolbar>
+    </div>
+  )
+}

src/frontend/src/features/rooms/livekit/components/ScreenShareZoomableVideo.tsx

@@ -0,0 +1,106 @@
+import { css } from '@/styled-system/css'
+import { type TrackReference } from '@livekit/components-core'
+import { useEffect, useRef } from 'react'
+import { useTranslation } from 'react-i18next'
+import { useScreenShareZoom } from '../hooks/useScreenShareZoom'
+import { useScreenReaderAnnounce } from '@/hooks/useScreenReaderAnnounce'
+import { ScreenShareZoomControls } from './ScreenShareZoomControls'
+import { ScreenShareVideoTrack } from './ScreenShareVideoTrack'
+
+interface ScreenShareZoomableVideoProps {
+  trackRef: TrackReference
+  tileRef: React.RefObject<HTMLDivElement | null>
+  onSubscriptionStatusChanged: (subscribed: boolean) => void
+  manageSubscription?: boolean
+}
+
+export const ScreenShareZoomableVideo = ({
+  trackRef,
+  tileRef,
+  onSubscriptionStatusChanged,
+  manageSubscription,
+}: ScreenShareZoomableVideoProps) => {
+  const zoom = useScreenShareZoom()
+  const { t } = useTranslation('rooms', { keyPrefix: 'screenShareZoom' })
+  const announce = useScreenReaderAnnounce()
+
+  // SR announcement: announce zoom level on change, with a one-time pan hint
+  // on the first zoom above 100 % per session.
+  const prevZoomRef = useRef(zoom.zoomPercentage)
+  const hasAnnouncedPanHint = useRef(false)
+  useEffect(() => {
+    if (prevZoomRef.current === zoom.zoomPercentage) return
+    const wasAtDefault = prevZoomRef.current <= 100
+    prevZoomRef.current = zoom.zoomPercentage
+
+    if (wasAtDefault && zoom.isZoomed && !hasAnnouncedPanHint.current) {
+      hasAnnouncedPanHint.current = true
+      announce(t('panHint', { level: zoom.zoomPercentage }), 'polite')
+    } else {
+      announce(t('currentZoomLevel', { level: zoom.zoomPercentage }), 'polite')
+    }
+
+    if (!zoom.isZoomed) hasAnnouncedPanHint.current = false
+  }, [zoom.zoomPercentage, zoom.isZoomed, announce, t])
+
+  // Attach keyboard listener on the tile container (has tabIndex=0).
+  useEffect(() => {
+    const el = tileRef.current
+    if (!el) return
+    el.addEventListener('keydown', zoom.handleKeyDown)
+    return () => el.removeEventListener('keydown', zoom.handleKeyDown)
+  }, [tileRef, zoom.handleKeyDown])
+
+  // Native wheel listener with { passive: false } so preventDefault works.
+  useEffect(() => {
+    const el = zoom.surfaceElRef.current
+    if (!el) return
+    el.addEventListener('wheel', zoom.handleWheel, { passive: false })
+    return () => el.removeEventListener('wheel', zoom.handleWheel)
+  }, [zoom.handleWheel, zoom.surfaceElRef])
+
+  return (
+    <>
+      <div
+        ref={zoom.surfaceElRef}
+        className={css({
+          width: '100%',
+          height: '100%',
+          overflow: 'hidden',
+          position: 'relative',
+          userSelect: 'none',
+          // Leaves the browser's native pinch-zoom available on touch devices
+          // while still routing single-pointer drags to useMove for panning.
+          touchAction: 'pinch-zoom',
+        })}
+        {...zoom.moveProps}
+      >
+        <div
+          ref={zoom.transformElRef}
+          style={{
+            width: '100%',
+            height: '100%',
+            pointerEvents: 'none',
+            transformOrigin: 'center center',
+          }}
+        >
+          <ScreenShareVideoTrack
+            trackRef={trackRef}
+            onSubscriptionStatusChanged={onSubscriptionStatusChanged}
+            manageSubscription={manageSubscription}
+          />
+        </div>
+      </div>
+      <ScreenShareZoomControls
+        containerRef={tileRef}
+        isZoomed={zoom.isZoomed}
+        zoomPercentage={zoom.zoomPercentage}
+        canZoomIn={zoom.canZoomIn}
+        canZoomOut={zoom.canZoomOut}
+        onZoomIn={zoom.zoomIn}
+        onZoomOut={zoom.zoomOut}
+        onResetZoom={zoom.resetZoom}
+      />
+    </>
+  )
+}

src/frontend/src/features/rooms/livekit/components/blur/BackgroundCustomProcessor.ts

@@ -17,7 +17,7 @@ import {
   type ProcessorType,
   MEDIAPIPE_PATH_WASM,
 } from '.'
-import { captureEvent, reportError } from '@/features/analytics/telemetry'
+import { captureEvent } from '@/features/analytics/telemetry.ts'
 
 const PROCESSING_WIDTH = 256
 const PROCESSING_HEIGHT = 144
@@ -26,40 +26,6 @@ const SEGMENTATION_MASK_CANVAS_ID = 'background-blur-local-segmentation'
 const BLUR_CANVAS_ID = 'background-blur-local'
 
 const DEFAULT_BLUR = '10'
-const CONCEALING_BLUR = '25'
-const FRAME_INTERVAL_MS = 1000 / 30
-
-// After this many consecutive failed frames, stop segmenting and fall back to
-// publishing a fully blurred frame: the user keeps a live camera instead of a
-// frozen one, without ever exposing the surroundings they chose to conceal.
-const MAX_CONSECUTIVE_ERRORS = 5
-
-let webgl2Supported: boolean | undefined
-
-/**
- * MediaPipe's ImageSegmenter requires a WebGL2 context on the web even with
- * `delegate: 'CPU'` (only inference runs on CPU; the mask post-processing in
- * TensorsToSegmentationCalculator is GL-based). Without this check, machines
- * with WebGL disabled or blocklisted fail at StartGraph with
- * `emscripten_webgl_create_context() returned error 0`.
- *
- * The result is cached and the probe context is explicitly released so that
- * repeated support checks do not count against the browser's limit on live
- * WebGL contexts.
- */
-const isWebGL2Supported = () => {
-  if (webgl2Supported === undefined) {
-    try {
-      const canvas = document.createElement('canvas')
-      const gl = canvas.getContext('webgl2')
-      webgl2Supported = !!gl
-      gl?.getExtension('WEBGL_lose_context')?.loseContext()
-    } catch {
-      webgl2Supported = false
-    }
-  }
-  return webgl2Supported
-}
 
 /**
  * This implementation of video blurring is made to be run on CPU for browser that are
@@ -76,12 +42,14 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
   source?: MediaStreamTrack
   sourceSettings?: MediaTrackSettings
   videoElement?: HTMLVideoElement
+  videoElementLoaded?: boolean
 
   // Canvas containing the video processing result, of which we extract as stream.
   outputCanvas?: HTMLCanvasElement
   outputCanvasCtx?: CanvasRenderingContext2D
 
   imageSegmenter?: ImageSegmenter
+  imageSegmenterResult?: ImageSegmenterResult
 
   // Canvas used for resizing video source and projecting mask.
   segmentationMaskCanvas?: HTMLCanvasElement
@@ -98,13 +66,6 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
   type: ProcessorType
   virtualBackgroundImage?: HTMLImageElement
 
-  private virtualBackgroundImagePath?: string
-  private destroyed = false
-  private degraded = false
-  private consecutiveErrors = 0
-  private processing?: Promise<void>
-  private onVideoLoaded?: () => void
-
   constructor(opts: ProcessorConfig) {
     this.name = 'blur'
     this.options = opts
@@ -112,10 +73,7 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
   }
 
   static get isSupported() {
-    return (
-      navigator.userAgent.toLowerCase().includes('firefox') &&
-      isWebGL2Supported()
-    )
+    return navigator.userAgent.toLowerCase().includes('firefox')
   }
 
   async init(opts: ProcessorOptions<Track.Kind>) {
@@ -123,10 +81,6 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
       throw new Error('Element is required for processing')
     }
 
-    this.destroyed = false
-    this.degraded = false
-    this.consecutiveErrors = 0
-
     this.source = opts.track as MediaStreamTrack
     this.sourceSettings = this.source!.getSettings()
     this.videoElement = opts.element as HTMLVideoElement
@@ -143,56 +97,26 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
     this.processedTrack = tracks[0]
 
     this.segmentationMask = new ImageData(PROCESSING_WIDTH, PROCESSING_HEIGHT)
-
-    const t0 = performance.now()
     await this.initSegmenter()
-    const segmenterInitMs = Math.round(performance.now() - t0)
-
     this._initWorker()
 
-    captureEvent('legacy-background-processor', {
-      effect_type: this.options.type,
-      hw_concurrency: navigator.hardwareConcurrency,
-      video_width: this.videoElement?.videoWidth,
-      video_height: this.videoElement?.videoHeight,
-      segmenter_init_ms: segmenterInitMs,
-    })
+    captureEvent('firefox-blurring-init', {})
   }
 
   _initVirtualBackgroundImage() {
-    if (this.options.type !== 'virtual' || !this.options.imagePath) {
+    if (this.options.type !== 'virtual') {
       return
     }
 
-    if (
+    const needsUpdate =
+      this.options.imagePath &&
       this.virtualBackgroundImage &&
-      this.virtualBackgroundImagePath === this.options.imagePath
-    ) {
-      return
+      this.virtualBackgroundImage.src !== this.options.imagePath
+    if (this.options.imagePath || needsUpdate) {
+      this.virtualBackgroundImage = document.createElement('img')
+      this.virtualBackgroundImage.crossOrigin = 'anonymous'
+      this.virtualBackgroundImage.src = this.options.imagePath!
     }
-
-    const image = document.createElement('img')
-    image.crossOrigin = 'anonymous'
-    image.src = this.options.imagePath
-    // Surface load failures once instead of letting drawImage throw on a
-    // broken image inside the processing loop.
-    image.decode().catch((error) => {
-      reportError('effects_processor_failure', error, {
-        context: 'Failed to load virtual background image',
-        image_path:
-          this.options.type === 'virtual' ? this.options.imagePath : undefined,
-      })
-    })
-    this.virtualBackgroundImage = image
-    this.virtualBackgroundImagePath = this.options.imagePath
-  }
-
-  _isVirtualBackgroundImageReady() {
-    return (
-      !!this.virtualBackgroundImage &&
-      this.virtualBackgroundImage.complete &&
-      this.virtualBackgroundImage.naturalWidth > 0
-    )
   }
 
   async update(opts: ProcessorConfig): Promise<void> {
@@ -205,26 +129,26 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
       name: 'Blurring',
     })
     this.timerWorker.onmessage = (data) => this.onTimerMessage(data)
-
-    const startLoop = () => {
-      this.onVideoLoaded = undefined
-      this._syncOutputCanvasSize()
-      this._scheduleNextFrame()
-    }
-    
-    if (this.videoElement!.readyState >= HTMLMediaElement.HAVE_CURRENT_DATA) {
-      startLoop()
-    } else {
-      this.onVideoLoaded = startLoop
-      this.videoElement!.addEventListener('loadeddata', this.onVideoLoaded, {
-        once: true,
+    // When hiding camera then showing it again, the onloadeddata callback is not fired again.
+    if (this.videoElementLoaded) {
+      this.timerWorker!.postMessage({
+        id: SET_TIMEOUT,
+        timeMs: 1000 / 30,
       })
+    } else {
+      this.videoElement!.onloadeddata = () => {
+        this.videoElementLoaded = true
+        this.timerWorker!.postMessage({
+          id: SET_TIMEOUT,
+          timeMs: 1000 / 30,
+        })
+      }
     }
   }
 
   onTimerMessage(response: { data: { id: number } }) {
     if (response.data.id === TIMEOUT_TICK) {
-      this.processing = this.process()
+      this.process()
     }
   }
 
@@ -270,47 +194,30 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
    */
   async segment() {
     const startTimeMs = performance.now()
-    return new Promise<void>((resolve, reject) => {
-      try {
-        this.imageSegmenter!.segmentForVideo(
-          this.sourceImageData!,
-          startTimeMs,
-          (result: ImageSegmenterResult) => {
-            try {
-              // The mask is only valid for the duration of this callback:
-              // MediaPipe frees the underlying WASM memory as soon as it
-              // returns, so the data must be copied out synchronously here.
-              this._applyMaskToAlphaChannel(result)
-              resolve()
-            } catch (error) {
-              reject(error)
-            }
-          }
-        )
-      } catch (error) {
-        reject(error)
-      }
+    return new Promise<void>((resolve) => {
+      this.imageSegmenter!.segmentForVideo(
+        this.sourceImageData!,
+        startTimeMs,
+        (result: ImageSegmenterResult) => {
+          this.imageSegmenterResult = result
+          resolve()
+        }
+      )
     })
   }
 
-  _applyMaskToAlphaChannel(result: ImageSegmenterResult) {
-    const categoryMask = result.categoryMask
-    if (!categoryMask) {
-      return
-    }
-    const mask = categoryMask.getAsUint8Array()
-    const alpha = this.segmentationMask!.data
-    const length = Math.min(mask.length, alpha.length / 4)
-    for (let i = 0; i < length; ++i) {
-      alpha[i * 4 + 3] = 255 - mask[i]
-    }
-  }
-
   /**
-   * Composite the segmentation mask over the output canvas: mask first, then
-   * the clear body, leaving the background to be filled by the caller.
+   * TODO: future improvement with WebGL.
    */
-  _compositeMaskAndBody() {
+  async blur() {
+    if (this.options.type !== 'blur') {
+      throw new Error('Blurring is only supported for blur background')
+    }
+    const mask = this.imageSegmenterResult!.categoryMask!.getAsUint8Array()
+    for (let i = 0; i < mask.length; ++i) {
+      this.segmentationMask!.data[i * 4 + 3] = 255 - mask[i]
+    }
+
     this.segmentationMaskCanvasCtx!.putImageData(this.segmentationMask!, 0, 0)
 
     this.outputCanvasCtx!.globalCompositeOperation = 'copy'
@@ -333,16 +240,6 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
     this.outputCanvasCtx!.globalCompositeOperation = 'source-in'
     this.outputCanvasCtx!.filter = 'none'
     this.outputCanvasCtx!.drawImage(this.videoElement!, 0, 0)
-  }
-
-  /**
-   * TODO: future improvement with WebGL.
-   */
-  async blur() {
-    if (this.options.type !== 'blur') {
-      throw new Error('Blurring is only supported for blur background')
-    }
-    this._compositeMaskAndBody()
 
     // Draw blurry background.
     this.outputCanvasCtx!.globalCompositeOperation = 'destination-over'
@@ -354,150 +251,87 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
    * TODO: future improvement with WebGL.
    */
   async drawVirtualBackground() {
-    this._compositeMaskAndBody()
-
-    this.outputCanvasCtx!.globalCompositeOperation = 'destination-over'
-    this.outputCanvasCtx!.filter = 'none'
-    if (this._isVirtualBackgroundImageReady()) {
-      // Draw virtual background.
-      this.outputCanvasCtx!.drawImage(
-        this.virtualBackgroundImage!,
-        0,
-        0,
-        this.outputCanvas!.width,
-        this.outputCanvas!.height
-      )
-    } else {
-      // Image not decoded (yet, or failed to load): fill the background with
-      // a heavy blur instead. Never fall back to the raw video here — the
-      // user selected this effect to conceal their surroundings, so the
-      // fallback must keep concealing them.
-      this.outputCanvasCtx!.filter = `blur(${CONCEALING_BLUR}px)`
-      this.outputCanvasCtx!.drawImage(this.videoElement!, 0, 0)
+    const mask = this.imageSegmenterResult!.categoryMask!.getAsUint8Array()
+    for (let i = 0; i < mask.length; ++i) {
+      this.segmentationMask!.data[i * 4 + 3] = 255 - mask[i]
     }
-  }
 
-  /**
-   * Draw the whole frame heavily blurred (person included). Used when
-   * segmentation is broken: the outgoing video keeps flowing instead of
-   * freezing on a stale frame, while the surroundings the user chose to
-   * conceal stay concealed. Requires no segmenter, only one filtered draw.
-   */
-  _drawDegradedFrame() {
+    this.segmentationMaskCanvasCtx!.putImageData(this.segmentationMask!, 0, 0)
+
     this.outputCanvasCtx!.globalCompositeOperation = 'copy'
-    this.outputCanvasCtx!.filter = `blur(${CONCEALING_BLUR}px)`
-    this.outputCanvasCtx!.drawImage(this.videoElement!, 0, 0)
+    this.outputCanvasCtx!.filter = 'blur(8px)'
+
+    // Put opacity mask.
+    this.outputCanvasCtx!.drawImage(
+      this.segmentationMaskCanvas!,
+      0,
+      0,
+      PROCESSING_WIDTH,
+      PROCESSING_HEIGHT,
+      0,
+      0,
+      this.videoElement!.videoWidth,
+      this.videoElement!.videoHeight
+    )
+
+    // Draw clear body.
+    this.outputCanvasCtx!.globalCompositeOperation = 'source-in'
     this.outputCanvasCtx!.filter = 'none'
+    this.outputCanvasCtx!.drawImage(this.videoElement!, 0, 0)
+
+    // Draw virtual background.
+    this.outputCanvasCtx!.globalCompositeOperation = 'destination-over'
+    this.outputCanvasCtx!.drawImage(
+      this.virtualBackgroundImage!,
+      0,
+      0,
+      this.outputCanvas!.width,
+      this.outputCanvas!.height
+    )
   }
 
   async process() {
-    if (this.destroyed) {
-      return
+    await this.sizeSource()
+    await this.segment()
+
+    if (this.options.type === 'blur') {
+      await this.blur()
+    } else {
+      await this.drawVirtualBackground()
     }
-    try {
-      this._syncOutputCanvasSize()
-      // No decoded frame available (e.g. right after a device switch): skip
-      // this tick rather than processing a 0x0 source.
-      if (
-        !this.videoElement ||
-        this.videoElement.videoWidth === 0 ||
-        this.videoElement.videoHeight === 0
-      ) {
-        this._scheduleNextFrame()
-        return
-      }
-
-      if (this.degraded) {
-        this._drawDegradedFrame()
-        this._scheduleNextFrame()
-        return
-      }
-
-      await this.sizeSource()
-      await this.segment()
-
-      if (this.destroyed) {
-        return
-      }
-
-      if (this.options.type === 'blur') {
-        await this.blur()
-      } else {
-        await this.drawVirtualBackground()
-      }
-      this.consecutiveErrors = 0
-    } catch (error) {
-      if (this.destroyed) {
-        return
-      }
-      this.consecutiveErrors += 1
-      if (this.consecutiveErrors >= MAX_CONSECUTIVE_ERRORS) {
-        // Degrade to a fully blurred frame: a live camera beats a frozen
-        // one, and concealment must survive the failure.
-        this.degraded = true
-        reportError('effects_processor_failure', error, {
-          context:
-            'Background processing failed repeatedly, falling back to fully blurred video',
-          consecutive_errors: this.consecutiveErrors,
-        })
-        this.imageSegmenter?.close()
-        this.imageSegmenter = undefined
-      }
-    }
-    this._scheduleNextFrame()
-  }
-
-  _scheduleNextFrame() {
-    if (this.destroyed) {
-      return
-    }
-    this.timerWorker?.postMessage({
+    this.timerWorker!.postMessage({
       id: SET_TIMEOUT,
-      timeMs: FRAME_INTERVAL_MS,
+      timeMs: 1000 / 30,
     })
   }
 
-  /**
-   * Keep the output canvas in sync with the actual decoded video dimensions.
-   * `MediaStreamTrack.getSettings()` can be incomplete or stale on Firefox,
-   * so the video element is the source of truth.
-   */
-  _syncOutputCanvasSize() {
-    const width = this.videoElement?.videoWidth
-    const height = this.videoElement?.videoHeight
-    if (!width || !height || !this.outputCanvas) {
-      return
-    }
-    if (
-      this.outputCanvas.width !== width ||
-      this.outputCanvas.height !== height
-    ) {
-      this.outputCanvas.width = width
-      this.outputCanvas.height = height
-    }
-  }
-
   _createMainCanvas() {
-    const width =
-      this.sourceSettings?.width || this.videoElement?.videoWidth || 1280
-    const height =
-      this.sourceSettings?.height || this.videoElement?.videoHeight || 720
-    this.outputCanvas = this._createCanvas(BLUR_CANVAS_ID, width, height)
+    this.outputCanvas = document.querySelector(
+      'canvas#background-blur-local'
+    ) as HTMLCanvasElement
+    if (!this.outputCanvas) {
+      this.outputCanvas = this._createCanvas(
+        BLUR_CANVAS_ID,
+        this.sourceSettings!.width!,
+        this.sourceSettings!.height!
+      )
+    }
     this.outputCanvasCtx = this.outputCanvas.getContext('2d')!
   }
 
   _createMaskCanvas() {
-    this.segmentationMaskCanvas = this._createCanvas(
-      SEGMENTATION_MASK_CANVAS_ID,
-      PROCESSING_WIDTH,
-      PROCESSING_HEIGHT
-    )
-    // getImageData is called on this canvas 30 times per second: opt out of
-    // GPU backing to avoid a costly readback on every frame.
-    this.segmentationMaskCanvasCtx = this.segmentationMaskCanvas.getContext(
-      '2d',
-      { willReadFrequently: true }
-    )!
+    this.segmentationMaskCanvas = document.querySelector(
+      `#${SEGMENTATION_MASK_CANVAS_ID}`
+    ) as HTMLCanvasElement
+    if (!this.segmentationMaskCanvas) {
+      this.segmentationMaskCanvas = this._createCanvas(
+        SEGMENTATION_MASK_CANVAS_ID,
+        PROCESSING_WIDTH,
+        PROCESSING_HEIGHT
+      )
+    }
+    this.segmentationMaskCanvasCtx =
+      this.segmentationMaskCanvas.getContext('2d')!
   }
 
   _createCanvas(id: string, width: number, height: number) {
@@ -514,39 +348,11 @@ export class BackgroundCustomProcessor implements BackgroundProcessorInterface {
   }
 
   async destroy() {
-    this.destroyed = true
-
     this.timerWorker?.postMessage({
       id: CLEAR_TIMEOUT,
     })
 
-    // Let any in-flight frame finish before releasing the resources it uses,
-    // so segmentForVideo is never called on a closed segmenter.
-    try {
-      await this.processing
-    } catch {
-      // Failures are already handled inside process().
-    }
-    this.processing = undefined
-
-    if (this.onVideoLoaded && this.videoElement) {
-      this.videoElement.removeEventListener('loadeddata', this.onVideoLoaded)
-    }
-    this.onVideoLoaded = undefined
-
     this.timerWorker?.terminate()
-    this.timerWorker = undefined
-
     this.imageSegmenter?.close()
-    this.imageSegmenter = undefined
-
-    this.processedTrack?.stop()
-    this.processedTrack = undefined
-
-    this.outputCanvas = undefined
-    this.outputCanvasCtx = undefined
-    this.segmentationMaskCanvas = undefined
-    this.segmentationMaskCanvasCtx = undefined
-    this.sourceImageData = undefined
   }
 }

src/frontend/src/features/rooms/livekit/components/blur/index.ts

@@ -6,7 +6,6 @@ import type { Track, TrackProcessor } from 'livekit-client'
 import { BackgroundCustomProcessor } from './BackgroundCustomProcessor'
 import { UnifiedBackgroundTrackProcessor } from './UnifiedBackgroundTrackProcessor'
 import { FaceLandmarksOptions } from './FaceLandmarksProcessor'
-import { captureEvent } from '@/features/analytics/telemetry'
 
 export const SELFIE_SEGMENTER_MODEL_PATH =
   '/assets/mediapipe/models/selfie_segmenter_landscape.tflite'
@@ -32,29 +31,15 @@ export interface BackgroundProcessorInterface extends TrackProcessor<Track.Kind>
   options: ProcessorConfig
 }
 
-let unsupportedReported = false
-
 export class BackgroundProcessorFactory {
-  private static _isSupported?: boolean
-
   static hasModernApiSupport() {
     return ProcessorWrapper.hasModernApiSupport
   }
 
   static isSupported() {
-    if (this._isSupported === undefined) {
-      this._isSupported =
-        supportsBackgroundProcessors() || BackgroundCustomProcessor.isSupported
-    }
-
-    if (!this._isSupported && !unsupportedReported) {
-      unsupportedReported = true
-      captureEvent('background-processor-unsupported', {
-        path: 'isSupported',
-      })
-    }
-
-    return this._isSupported
+    return (
+      supportsBackgroundProcessors() || BackgroundCustomProcessor.isSupported
+    )
   }
 
   static getProcessor(
@@ -63,8 +48,6 @@ export class BackgroundProcessorFactory {
     const isBlur = config.type === ProcessorType.BLUR
     const isVirtual = config.type === ProcessorType.VIRTUAL
 
-    return new BackgroundCustomProcessor(config)
-
     if (!isBlur && !isVirtual) return undefined
 
     if (supportsBackgroundProcessors()) {
@@ -75,12 +58,6 @@ export class BackgroundProcessorFactory {
       return new BackgroundCustomProcessor(config)
     }
 
-    if (!unsupportedReported) {
-      captureEvent('background-processor-unsupported', {
-        path: 'getProcessor',
-      })
-    }
-
     return undefined
   }
 

src/frontend/src/features/rooms/livekit/components/effects/EffectsConfiguration.tsx

@@ -25,11 +25,7 @@ import {
 } from '@/features/files/api/listFiles.ts'
 import { useCreateFile } from '@/features/files/api/createFile.ts'
 import { FileTrigger } from 'react-aria-components'
-import {
-  RiDeleteBinLine,
-  RiImageAddFill,
-  RiProhibitedLine,
-} from '@remixicon/react'
+import { RiDeleteBinLine, RiImageAddFill } from '@remixicon/react'
 import { useDeleteFile } from '@/features/files/api/deleteFile.ts'
 import { useUser } from '@/features/auth/api/useUser'
 import { ApiFileItem } from '@/features/files/api/types.ts'
@@ -201,23 +197,10 @@ export const EffectsConfiguration = ({
          *
          * We arrive in this condition when we enter the room with the camera already off.
          */
-        try {
-          const newProcessorTmp =
-            BackgroundProcessorFactory.getProcessor(config)!
-          await toggle(true, {
-            processor: newProcessorTmp,
-          })
-        } catch (error) {
-          reportError('effects_processor_failure', error, {
-            context: 'Error applying effect while enabling camera:',
-          })
-          saveProcessorConfig(undefined)
-          try {
-            await toggle(true)
-          } catch {
-            // Camera errors are handled by the toggle's own error path.
-          }
-        }
+        const newProcessorTmp = BackgroundProcessorFactory.getProcessor(config)!
+        await toggle(true, {
+          processor: newProcessorTmp,
+        })
         setTimeout(() => setProcessorPending(false))
         return
       }
@@ -259,14 +242,6 @@ export const EffectsConfiguration = ({
         reportError('effects_processor_failure', error, {
           context: 'Error applying effect:',
         })
-        try {
-          if (videoTrack.getProcessor()) {
-            await videoTrack.stopProcessor()
-          }
-        } catch {
-          // Best effort: the processor may already be broken.
-        }
-        saveProcessorConfig(undefined)
       } finally {
         // Without setTimeout the DOM is not refreshing when updating the options.
         setTimeout(() => setProcessorPending(false))
@@ -275,24 +250,6 @@ export const EffectsConfiguration = ({
     [enabled, selectedId, toggle, updateEffectStatusMessage, videoTrack]
   )
 
-  const clearEffect = useCallback(async () => {
-    if (selectedId === 'none') return
-    setProcessorPending(true)
-    try {
-      if (videoTrack?.getProcessor()) {
-        await videoTrack.stopProcessor()
-      }
-      saveProcessorConfig(undefined)
-      announceEffectStatusMessage(t('blur.status.none'))
-    } catch (error) {
-      reportError('effects_processor_failure', error, {
-        context: 'Error clearing effect:',
-      })
-    } finally {
-      setTimeout(() => setProcessorPending(false))
-    }
-  }, [announceEffectStatusMessage, selectedId, t, videoTrack])
-
   const { data: appConfig } = useConfig()
   const { isLoggedIn } = useUser()
   const canUploadBackground =
@@ -690,17 +647,6 @@ export const EffectsConfiguration = ({
                     gap: '1.25rem',
                   })}
                 >
-                  <ToggleButton
-                    variant="bigSquare"
-                    aria-label={t('clear')}
-                    tooltip={t('clear')}
-                    isDisabled={processorOptions.isDisabled}
-                    onChange={clearEffect}
-                    isSelected={selectedId === 'none'}
-                    data-attr="toggle-effect-none"
-                  >
-                    <RiProhibitedLine />
-                  </ToggleButton>
                   {processorOptions.blurBased.map(({ Icon, ...option }) => (
                     <ToggleButton
                       key={option.id}

src/frontend/src/features/rooms/livekit/hooks/useJoinTracks.ts

@@ -22,12 +22,10 @@ import { VOICE_AUDIO_CONSTRAINTS } from '../utils/constants'
 import {
   saveAudioInputDeviceId,
   saveAudioInputEnabled,
-  saveProcessorConfig,
   saveVideoInputDeviceId,
   saveVideoInputEnabled,
   userChoicesStore,
 } from '@/stores/userChoices'
-import { reportError } from '@/features/analytics/telemetry'
 import { useSyncTrackDeviceId } from './useSyncTrackDeviceId'
 
 // Module-level: effect dependencies, must be referentially stable.
@@ -223,32 +221,15 @@ export function useJoinTracks(): {
     [audioDeviceId]
   )
 
-  const createVideo = useCallback(async () => {
-    const processor =
-      BackgroundProcessorFactory.fromProcessorConfig(processorConfig)
-    if (!processor) {
-      return createLocalVideoTrack({ deviceId: videoDeviceId })
-    }
-    try {
-      return await createLocalVideoTrack({
+  const createVideo = useCallback(
+    () =>
+      createLocalVideoTrack({
         deviceId: videoDeviceId,
-        processor,
-      })
-    } catch (error) {
-      // A camera problem (permission, device missing/busy) is not the
-      // effect's fault: let the normal media error handling deal with it
-      // without touching the user's saved effect.
-      const e = getMediaDeviceFailure(error as Error)
-      if (e !== MediaDeviceFailure.Other && !!e) {
-        throw error
-      }
-      reportError('effects_processor_failure', error, {
-        context: 'Restoring saved effect failed, retrying without it',
-      })
-      saveProcessorConfig(undefined)
-      return createLocalVideoTrack({ deviceId: videoDeviceId })
-    }
-  }, [videoDeviceId, processorConfig])
+        processor:
+          BackgroundProcessorFactory.fromProcessorConfig(processorConfig),
+      }),
+    [videoDeviceId, processorConfig]
+  )
 
   const audioTrack = useLocalTrack({
     ready: audioReady,

src/frontend/src/features/rooms/livekit/hooks/useScreenShareZoom.ts

@@ -0,0 +1,284 @@
+import { useCallback, useRef, useSyncExternalStore } from 'react'
+import { useMove } from 'react-aria'
+import type { MoveMoveEvent } from '@react-types/shared'
+import {
+  FULL_PICTURE_RATIO,
+  MIN_ZOOM,
+  PAN_STEP,
+  WHEEL_ZOOM_SPEED,
+  ZOOM_STEP,
+  type PanOffset,
+  type ZoomSnapshot,
+  buildZoomSnapshot,
+  clampPan,
+  clampZoom,
+  getCursorFromZoomState,
+  getCursorPercentsFromWheelEvent,
+  getPanDeltaPercentsFromMove,
+  getPictureRatio,
+  getWheelPanOffset,
+  getZoomTransform,
+} from '../utils/screenShareZoom'
+
+/**
+ * Manages zoom and pan state for a remote screen share.
+ *
+ * Performance: zoom/pan live in refs and are applied imperatively to the DOM
+ * (via transformElRef / surfaceElRef) so the hot path (drag, wheel) never
+ * triggers a React re-render. A useSyncExternalStore snapshot is flushed only
+ * when the toolbar UI needs to update (zoom level change, drag end).
+ *
+ * Drag/touch panning is handled by react-aria's useMove (moveProps).
+ * Ctrl/Cmd + wheel zoom is a native listener (must be non-passive to
+ * preventDefault and block browser page zoom).
+ * Arrow key panning and +/-/0 zoom are on a keydown listener attached to the
+ * tile container (which has tabIndex=0 and focus).
+ */
+export const useScreenShareZoom = () => {
+  const zoomRef = useRef(MIN_ZOOM)
+  const panRef = useRef<PanOffset>({ x: 0, y: 0 })
+  const draggingRef = useRef(false)
+
+  // The consumer binds these to the inner transform div and the outer drag surface.
+  const transformElRef = useRef<HTMLDivElement | null>(null)
+  const surfaceElRef = useRef<HTMLDivElement | null>(null)
+
+  // Snapshot store: subscribers are notified only on explicit flush() calls.
+  const snapshotRef = useRef<ZoomSnapshot>(
+    buildZoomSnapshot(MIN_ZOOM, { x: 0, y: 0 }, false)
+  )
+  const listenersRef = useRef(new Set<() => void>())
+
+  const subscribe = useCallback((cb: () => void) => {
+    listenersRef.current.add(cb)
+    return () => {
+      listenersRef.current.delete(cb)
+    }
+  }, [])
+
+  const getSnapshot = useCallback(() => snapshotRef.current, [])
+
+  const snapshot = useSyncExternalStore(subscribe, getSnapshot, getSnapshot)
+
+  const flush = useCallback(() => {
+    snapshotRef.current = buildZoomSnapshot(
+      zoomRef.current,
+      panRef.current,
+      draggingRef.current
+    )
+    listenersRef.current.forEach((cb) => cb())
+  }, [])
+
+  const applyTransform = useCallback(() => {
+    const el = transformElRef.current
+    if (!el) return
+    el.style.transform = getZoomTransform(zoomRef.current, panRef.current)
+  }, [])
+
+  // The video is letterboxed inside the surface by object-fit: contain, so the
+  // pan bounds depend on how much of the surface the picture actually covers.
+  // Read live rather than cached: both the tile and the shared resolution can
+  // change at any time.
+  const readPictureRatio = useCallback(() => {
+    const surface = surfaceElRef.current
+    const video = transformElRef.current?.querySelector('video')
+    if (!surface || !video) return FULL_PICTURE_RATIO
+    return getPictureRatio(
+      surface.clientWidth,
+      surface.clientHeight,
+      video.videoWidth,
+      video.videoHeight
+    )
+  }, [])
+
+  const applyCursor = useCallback(() => {
+    const el = surfaceElRef.current
+    if (!el) return
+    el.style.cursor = getCursorFromZoomState(
+      zoomRef.current,
+      draggingRef.current
+    )
+  }, [])
+
+  const zoomIn = useCallback(() => {
+    const next = clampZoom(zoomRef.current + ZOOM_STEP)
+    zoomRef.current = next
+    panRef.current = clampPan(panRef.current, next, readPictureRatio())
+    applyTransform()
+    applyCursor()
+    flush()
+  }, [applyTransform, applyCursor, flush, readPictureRatio])
+
+  const zoomOut = useCallback(() => {
+    const next = clampZoom(zoomRef.current - ZOOM_STEP)
+    zoomRef.current = next
+    panRef.current =
+      next <= MIN_ZOOM
+        ? { x: 0, y: 0 }
+        : clampPan(panRef.current, next, readPictureRatio())
+    applyTransform()
+    applyCursor()
+    flush()
+  }, [applyTransform, applyCursor, flush, readPictureRatio])
+
+  const resetZoom = useCallback(() => {
+    zoomRef.current = MIN_ZOOM
+    panRef.current = { x: 0, y: 0 }
+    applyTransform()
+    applyCursor()
+    flush()
+  }, [applyTransform, applyCursor, flush])
+
+  // Must be attached with { passive: false } so preventDefault() blocks
+  // the browser's native Ctrl+scroll page zoom.
+  const handleWheel = useCallback(
+    (e: WheelEvent) => {
+      if (!e.ctrlKey && !e.metaKey) return
+
+      e.preventDefault()
+      e.stopPropagation()
+
+      const target = e.currentTarget as HTMLElement
+      const prev = zoomRef.current
+      const delta = -e.deltaY * WHEEL_ZOOM_SPEED
+      const next = clampZoom(prev + delta)
+
+      if (next <= MIN_ZOOM) {
+        zoomRef.current = MIN_ZOOM
+        panRef.current = { x: 0, y: 0 }
+      } else {
+        const { cursorXPercent, cursorYPercent } =
+          getCursorPercentsFromWheelEvent(e, target)
+        zoomRef.current = next
+        panRef.current = getWheelPanOffset({
+          pan: panRef.current,
+          prevZoom: prev,
+          nextZoom: next,
+          cursorXPercent,
+          cursorYPercent,
+          ratio: readPictureRatio(),
+        })
+      }
+
+      applyTransform()
+      applyCursor()
+      flush()
+    },
+    [applyTransform, applyCursor, flush, readPictureRatio]
+  )
+
+  // useMove handles mouse drag + touch pan. Keyboard arrows are not handled
+  // here because moveProps is on the zoom surface, while focus is on the tile
+  // container, see handleKeyDown below.
+  const { moveProps } = useMove({
+    onMoveStart() {
+      if (zoomRef.current <= MIN_ZOOM) return
+      draggingRef.current = true
+      applyCursor()
+      flush()
+    },
+    onMove(e: MoveMoveEvent) {
+      if (zoomRef.current <= MIN_ZOOM) return
+
+      const el = surfaceElRef.current
+      if (!el) return
+
+      const { deltaXPercent, deltaYPercent } = getPanDeltaPercentsFromMove(
+        e.deltaX,
+        e.deltaY,
+        el
+      )
+
+      panRef.current = clampPan(
+        {
+          x: panRef.current.x + deltaXPercent,
+          y: panRef.current.y + deltaYPercent,
+        },
+        zoomRef.current,
+        readPictureRatio()
+      )
+
+      applyTransform()
+      // Mouse drag: skip flush (imperative-only) to avoid re-renders per frame.
+      // Keyboard: flush so the toolbar reflects the updated position.
+      if (e.pointerType === 'keyboard') {
+        flush()
+      }
+    },
+    onMoveEnd() {
+      draggingRef.current = false
+      applyTransform()
+      applyCursor()
+      flush()
+    },
+  })
+
+  const panBy = useCallback(
+    (dx: number, dy: number) => {
+      panRef.current = clampPan(
+        { x: panRef.current.x + dx, y: panRef.current.y + dy },
+        zoomRef.current,
+        readPictureRatio()
+      )
+      applyTransform()
+      flush()
+    },
+    [applyTransform, flush, readPictureRatio]
+  )
+
+  // Attached to the tile container (not the zoom surface) where keyboard
+  // focus lives. Arrows pan, +/-/0 zoom.
+  const handleKeyDown = useCallback(
+    (e: KeyboardEvent) => {
+      const isZoomed = zoomRef.current > MIN_ZOOM
+      if (!isZoomed && e.key !== '+' && e.key !== '=') return
+
+      if (e.key.startsWith('Arrow') && e.target !== e.currentTarget) return
+
+      switch (e.key) {
+        case 'ArrowLeft':
+          e.preventDefault()
+          panBy(PAN_STEP, 0)
+          break
+        case 'ArrowRight':
+          e.preventDefault()
+          panBy(-PAN_STEP, 0)
+          break
+        case 'ArrowUp':
+          e.preventDefault()
+          panBy(0, PAN_STEP)
+          break
+        case 'ArrowDown':
+          e.preventDefault()
+          panBy(0, -PAN_STEP)
+          break
+        case '+':
+        case '=':
+          e.preventDefault()
+          zoomIn()
+          break
+        case '-':
+          e.preventDefault()
+          zoomOut()
+          break
+        case '0':
+          e.preventDefault()
+          resetZoom()
+          break
+      }
+    },
+    [panBy, zoomIn, zoomOut, resetZoom]
+  )
+
+  return {
+    ...snapshot,
+    transformElRef,
+    surfaceElRef,
+    moveProps,
+    zoomIn,
+    zoomOut,
+    resetZoom,
+    handleWheel,
+    handleKeyDown,
+  }
+}

src/frontend/src/features/rooms/livekit/utils/screenShareZoom.ts

@@ -0,0 +1,154 @@
+export const MIN_ZOOM = 1
+export const MAX_ZOOM = 4
+export const ZOOM_STEP = 0.1
+export const WHEEL_ZOOM_SPEED = 0.002
+export const PAN_STEP = 5
+
+// Half of a 100 % axis. Geometry, not a tunable: it is both the centre the
+// cursor offset is measured from and the half extent the pan is clamped
+// against, so the two stay consistent by construction.
+export const HALF_EXTENT_PERCENT = 50
+
+export interface PanOffset {
+  x: number
+  y: number
+}
+
+// Fraction of the surface each axis of the picture covers, in [0, 1].
+export interface PictureRatio {
+  x: number
+  y: number
+}
+
+export const FULL_PICTURE_RATIO: PictureRatio = { x: 1, y: 1 }
+
+export interface ZoomSnapshot {
+  zoomLevel: number
+  zoomPercentage: number
+  panOffset: PanOffset
+  isZoomed: boolean
+  isDragging: boolean
+  canZoomIn: boolean
+  canZoomOut: boolean
+}
+
+export const clampZoom = (value: number) => {
+  return Math.max(MIN_ZOOM, Math.min(MAX_ZOOM, value))
+}
+
+// Restrict pan so the picture always covers the view. Pan is a % of the
+// surface, in which object-fit: contain letterboxes the picture: its half
+// extent is `ratio * 50` against a view half extent of 50, and scaling by
+// `zoom` must keep `zoom * (ratio * 50 - |pan|) >= 50`. An axis whose picture
+// is still smaller than the view is pinned to 0, keeping the bars symmetric.
+export const clampPan = (
+  pan: PanOffset,
+  zoom: number,
+  ratio: PictureRatio
+): PanOffset => {
+  const maxPanX = Math.max(0, (ratio.x - 1 / zoom) * HALF_EXTENT_PERCENT)
+  const maxPanY = Math.max(0, (ratio.y - 1 / zoom) * HALF_EXTENT_PERCENT)
+  return {
+    x: Math.max(-maxPanX, Math.min(maxPanX, pan.x)),
+    y: Math.max(-maxPanY, Math.min(maxPanY, pan.y)),
+  }
+}
+
+// Per-axis fraction of the surface covered by an object-fit: contain picture.
+export const getPictureRatio = (
+  surfaceWidth: number,
+  surfaceHeight: number,
+  videoWidth: number,
+  videoHeight: number
+): PictureRatio => {
+  if (!surfaceWidth || !surfaceHeight || !videoWidth || !videoHeight) {
+    return FULL_PICTURE_RATIO
+  }
+  const surfaceRatio = surfaceWidth / surfaceHeight
+  const videoRatio = videoWidth / videoHeight
+  return surfaceRatio > videoRatio
+    ? { x: videoRatio / surfaceRatio, y: 1 }
+    : { x: 1, y: surfaceRatio / videoRatio }
+}
+
+export const buildZoomSnapshot = (
+  zoom: number,
+  pan: PanOffset,
+  dragging: boolean
+): ZoomSnapshot => {
+  return {
+    zoomLevel: zoom,
+    zoomPercentage: Math.round(zoom * 100),
+    panOffset: pan,
+    isZoomed: zoom > MIN_ZOOM,
+    isDragging: dragging,
+    canZoomIn: zoom < MAX_ZOOM,
+    canZoomOut: zoom > MIN_ZOOM,
+  }
+}
+
+export const getZoomTransform = (zoom: number, pan: PanOffset) => {
+  return `scale(${zoom}) translate(${pan.x}%, ${pan.y}%)`
+}
+
+export const getCursorFromZoomState = (zoom: number, dragging: boolean) => {
+  if (zoom <= MIN_ZOOM) return 'default'
+  return dragging ? 'grabbing' : 'grab'
+}
+
+// Keep the content point under the cursor anchored while zooming. With
+// `scale(z) translate(pan%)`, a point at `offset` from the center renders at
+// `z * (offset + pan)`, so holding it still gives:
+// pan' = pan + cursor * (1 / zoom' - 1 / zoom).
+export const getWheelPanOffset = ({
+  pan,
+  prevZoom,
+  nextZoom,
+  cursorXPercent,
+  cursorYPercent,
+  ratio,
+}: {
+  pan: PanOffset
+  prevZoom: number
+  nextZoom: number
+  cursorXPercent: number
+  cursorYPercent: number
+  ratio: PictureRatio
+}): PanOffset => {
+  const panShift = 1 / nextZoom - 1 / prevZoom
+  return clampPan(
+    {
+      x: pan.x + cursorXPercent * panShift,
+      y: pan.y + cursorYPercent * panShift,
+    },
+    nextZoom,
+    ratio
+  )
+}
+
+// Convert cursor pixel position to a % offset from the surface center.
+export const getCursorPercentsFromWheelEvent = (
+  e: WheelEvent,
+  target: HTMLElement
+) => {
+  const rect = target.getBoundingClientRect()
+  return {
+    cursorXPercent:
+      ((e.clientX - rect.left) / rect.width) * 100 - HALF_EXTENT_PERCENT,
+    cursorYPercent:
+      ((e.clientY - rect.top) / rect.height) * 100 - HALF_EXTENT_PERCENT,
+  }
+}
+
+// Convert useMove pixel deltas to % of the surface dimensions.
+export const getPanDeltaPercentsFromMove = (
+  deltaX: number,
+  deltaY: number,
+  surface: HTMLElement
+) => {
+  const rect = surface.getBoundingClientRect()
+  return {
+    deltaXPercent: (deltaX / rect.width) * 100,
+    deltaYPercent: (deltaY / rect.height) * 100,
+  }
+}

src/frontend/src/features/settings/components/tabs/VideoTab.tsx

@@ -18,7 +18,6 @@ import {
   saveVideoPublishResolution,
   saveVideoSubscribeQuality,
   userChoicesStore,
-  VIDEO_RESOLUTIONS,
   VideoResolution,
 } from '@/stores/userChoices'
 import { RowWrapper } from './layout/RowWrapper'
@@ -71,7 +70,7 @@ export const VideoTab = ({ id }: VideoTabProps) => {
         isDisabled: true,
       }
 
-  const handleVideoResolutionChange = async (key: VideoResolution) => {
+  const handleVideoResolutionChange = async (key: 'h720' | 'h360' | 'h180') => {
     saveVideoPublishResolution(key)
     const videoTrack = localParticipant.getTrackPublication(
       Track.Source.Camera
@@ -125,13 +124,20 @@ export const VideoTab = ({ id }: VideoTabProps) => {
   }, [videoDeviceId, videoElement])
 
   const resolutionItems = useMemo(() => {
-    const labels: Record<VideoResolution, string> = {
-      h1080: `${t('resolution.publish.items.veryHigh')} (1080p)`,
-      h720: `${t('resolution.publish.items.high')} (720p)`,
-      h360: `${t('resolution.publish.items.medium')} (360p)`,
-      h180: `${t('resolution.publish.items.low')} (180p)`,
-    }
-    return VIDEO_RESOLUTIONS.map((value) => ({ value, label: labels[value] }))
+    return [
+      {
+        value: 'h720',
+        label: `${t('resolution.publish.items.high')} (720p)`,
+      },
+      {
+        value: 'h360',
+        label: `${t('resolution.publish.items.medium')} (360p)`,
+      },
+      {
+        value: 'h180',
+        label: `${t('resolution.publish.items.low')} (180p)`,
+      },
+    ]
   }, [t])
 
   const videoQualityItems = useMemo(() => {

src/frontend/src/features/shortcuts/catalog.ts

@@ -16,6 +16,10 @@ export type ShortcutId =
   | 'recording'
   | 'reaction'
   | 'fullscreen'
+  | 'zoom-in'
+  | 'zoom-out'
+  | 'zoom-reset'
+  | 'zoom-pan'
 
 export const getShortcutDescriptorById = (id: ShortcutId) =>
   shortcutCatalog.find((item) => item.id === id)
@@ -24,7 +28,7 @@ export type ShortcutDescriptor = {
   id: ShortcutId
   category: ShortcutCategory
   shortcut?: Shortcut
-  kind?: 'press' | 'longPress'
+  kind?: 'press' | 'longPress' | 'arrows'
   code?: string // used when kind === 'longPress' (KeyboardEvent.code)
   description?: string
 }
@@ -86,4 +90,27 @@ export const shortcutCatalog: ShortcutDescriptor[] = [
     category: 'interaction',
     shortcut: { key: 'P', ctrlKey: true, shiftKey: true },
   },
+  // Screen share zoom keys are unmodified, so they are bound on the focused
+  // tile instead of being registered globally. They are listed here so the
+  // shortcuts panel stays exhaustive.
+  {
+    id: 'zoom-in',
+    category: 'interaction',
+    shortcut: { key: '+' },
+  },
+  {
+    id: 'zoom-out',
+    category: 'interaction',
+    shortcut: { key: '-' },
+  },
+  {
+    id: 'zoom-reset',
+    category: 'interaction',
+    shortcut: { key: '0' },
+  },
+  {
+    id: 'zoom-pan',
+    category: 'interaction',
+    kind: 'arrows',
+  },
 ]

src/frontend/src/features/shortcuts/formatLabels.ts

@@ -25,6 +25,7 @@ export const formatShortcutLabelForSR = (
     shiftLabel,
     plusLabel,
     noShortcutLabel,
+    keyLabels,
   }: {
     controlLabel: string
     commandLabel: string
@@ -33,10 +34,12 @@ export const formatShortcutLabelForSR = (
     shiftLabel: string
     plusLabel: string
     noShortcutLabel: string
+    // Spelled-out names for keys screen readers may skip or mispronounce.
+    keyLabels?: Record<string, string>
   }
 ) => {
   if (!shortcut) return noShortcutLabel
-  const key = shortcut.key?.toUpperCase()
+  const key = keyLabels?.[shortcut.key] ?? shortcut.key?.toUpperCase()
   if (!key) return noShortcutLabel
   const ctrlWord = isMacintosh() ? commandLabel : controlLabel
   const altWord = isMacintosh() ? optionLabel : altLabel

src/frontend/src/features/shortcuts/hooks/useShortcutFormatting.ts

@@ -12,6 +12,9 @@ export const useShortcutFormatting = () => {
 
   const formatVisual = useCallback(
     (shortcut?: Shortcut, code?: string, kind?: string) => {
+      if (kind === 'arrows') {
+        return t('shortcutsPanel.visual.arrows')
+      }
       if (code && kind === 'longPress') {
         const label = getKeyLabelFromCode(code)
         return t('shortcutsPanel.visual.hold', { key: label || '?' })
@@ -23,6 +26,9 @@ export const useShortcutFormatting = () => {
 
   const formatForSR = useCallback(
     (shortcut?: Shortcut, code?: string, kind?: string) => {
+      if (kind === 'arrows') {
+        return t('shortcutsPanel.sr.arrows')
+      }
       if (code && kind === 'longPress') {
         const label = getKeyLabelFromCode(code)
         return t('shortcutsPanel.sr.hold', { key: label || '?' })
@@ -35,6 +41,10 @@ export const useShortcutFormatting = () => {
         shiftLabel: t('shortcutsPanel.sr.shift'),
         plusLabel: t('shortcutsPanel.sr.plus'),
         noShortcutLabel: t('shortcutsPanel.sr.noShortcut'),
+        keyLabels: {
+          '+': t('shortcutsPanel.sr.plusKey'),
+          '-': t('shortcutsPanel.sr.minusKey'),
+        },
       })
     },
     [t]

src/frontend/src/locales/de/rooms.json

@@ -756,6 +756,24 @@
     "muteParticipant": "{{name}} stummschalten",
     "fullScreen": "Vollbild"
   },
+  "screenShareZoom": {
+    "toolbarLabel": "Zoom-Steuerung für Bildschirmfreigabe",
+    "zoomIn": "Vergrößern",
+    "zoomInWithShortcut": "Vergrößern ({{shortcut}})",
+    "zoomOut": "Verkleinern",
+    "zoomOutWithShortcut": "Verkleinern ({{shortcut}})",
+    "wheelShortcut": "Steuerung plus Mausrad",
+    "wheelShortcutMac": "Befehl plus Mausrad",
+    "wheelShortcutHint": "Tastenkürzel: Steuerung plus Mausrad zum Vergrößern oder Verkleinern.",
+    "wheelShortcutHintMac": "Tastenkürzel: Befehl plus Mausrad zum Vergrößern oder Verkleinern.",
+    "fitToWindow": "An Fenster anpassen",
+    "fullScreen": "Vollbild",
+    "exitFullScreen": "Vollbild beenden",
+    "currentZoomLevel": "Zoom {{level}} %",
+    "panHint": "Zoom {{level}} %. Mit der Maus ziehen oder den Fokus zurück auf die Bildschirmfreigabe setzen und mit den Pfeiltasten im Bild navigieren.",
+    "fullScreenEntered": "Vollbild aktiviert",
+    "fullScreenExited": "Vollbild deaktiviert"
+  },
   "shortcutsPanel": {
     "title": "Tastenkürzel",
     "categories": {
@@ -775,7 +793,11 @@
       "raise-hand": "Hand heben oder senken",
       "toggle-chat": "Chat anzeigen/ausblenden",
       "toggle-participants": "Teilnehmende anzeigen/ausblenden",
-      "open-shortcuts-settings": "Tastenkürzel-Einstellungen öffnen"
+      "open-shortcuts-settings": "Tastenkürzel-Einstellungen öffnen",
+      "zoom-in": "In einen geteilten Bildschirm hineinzoomen",
+      "zoom-out": "Aus einem geteilten Bildschirm herauszoomen",
+      "zoom-reset": "Zoom des geteilten Bildschirms zurücksetzen",
+      "zoom-pan": "Im gezoomten geteilten Bildschirm navigieren"
     },
     "sr": {
       "control": "Steuerung",
@@ -785,10 +807,14 @@
       "shift": "Umschalt",
       "plus": "plus",
       "hold": "Halte {{key}} gedrückt",
+      "arrows": "Pfeiltasten",
+      "plusKey": "Plus-Taste",
+      "minusKey": "Minus-Taste",
       "noShortcut": "Kein Tastenkürzel"
     },
     "visual": {
-      "hold": "Halte {{key}} gedrückt"
+      "hold": "Halte {{key}} gedrückt",
+      "arrows": "↑ ↓ ← →"
     }
   },
   "fullScreenWarning": {

src/frontend/src/locales/de/settings.json

@@ -56,7 +56,6 @@
       "publish": {
         "label": "Wähle die maximale Auflösung beim Senden",
         "items": {
-          "veryHigh": "Sehr hohe Auflösung",
           "high": "Hohe Auflösung",
           "medium": "Mittlere Auflösung",
           "low": "Niedrige Auflösung"

src/frontend/src/locales/en/rooms.json

@@ -756,6 +756,24 @@
     "muteParticipant": "Mute {{name}}",
     "fullScreen": "Full screen"
   },
+  "screenShareZoom": {
+    "toolbarLabel": "Screen share zoom controls",
+    "zoomIn": "Zoom in",
+    "zoomInWithShortcut": "Zoom in ({{shortcut}})",
+    "zoomOut": "Zoom out",
+    "zoomOutWithShortcut": "Zoom out ({{shortcut}})",
+    "wheelShortcut": "Control plus scroll wheel",
+    "wheelShortcutMac": "Command plus scroll wheel",
+    "wheelShortcutHint": "Shortcut: Control plus scroll wheel to zoom in or out.",
+    "wheelShortcutHintMac": "Shortcut: Command plus scroll wheel to zoom in or out.",
+    "fitToWindow": "Fit to window",
+    "fullScreen": "Full screen",
+    "exitFullScreen": "Exit full screen",
+    "currentZoomLevel": "Zoom {{level}} %",
+    "panHint": "Zoom {{level}} %. Drag with mouse, or move focus back to the screen share and use arrow keys to navigate the picture.",
+    "fullScreenEntered": "Full screen enabled",
+    "fullScreenExited": "Full screen disabled"
+  },
   "shortcutsPanel": {
     "title": "Keyboard shortcuts",
     "categories": {
@@ -775,7 +793,11 @@
       "raise-hand": "Raise or lower hand",
       "toggle-chat": "Toggle chat",
       "toggle-participants": "Toggle participants",
-      "open-shortcuts-settings": "Open shortcuts settings"
+      "open-shortcuts-settings": "Open shortcuts settings",
+      "zoom-in": "Zoom in on a shared screen",
+      "zoom-out": "Zoom out on a shared screen",
+      "zoom-reset": "Reset the shared screen zoom",
+      "zoom-pan": "Move around a zoomed shared screen"
     },
     "sr": {
       "control": "Control",
@@ -785,10 +807,14 @@
       "shift": "Shift",
       "plus": "plus",
       "hold": "Hold {{key}}",
+      "arrows": "Arrow keys",
+      "plusKey": "Plus key",
+      "minusKey": "Minus key",
       "noShortcut": "No shortcut"
     },
     "visual": {
-      "hold": "Hold {{key}}"
+      "hold": "Hold {{key}}",
+      "arrows": "↑ ↓ ← →"
     }
   },
   "fullScreenWarning": {

src/frontend/src/locales/en/settings.json

@@ -56,7 +56,6 @@
       "publish": {
         "label": "Select your sending resolution (max.)",
         "items": {
-          "veryHigh": "Very high definition",
           "high": "High definition",
           "medium": "Standard definition",
           "low": "Low definition"

src/frontend/src/locales/es/settings.json

@@ -56,7 +56,6 @@
       "publish": {
         "label": "Selecciona tu resolución de envío (máx.)",
         "items": {
-          "veryHigh": "Muy alta definición",
           "high": "Alta definición",
           "medium": "Definición estándar",
           "low": "Baja definición"

src/frontend/src/locales/fr/rooms.json

@@ -756,6 +756,24 @@
     "muteParticipant": "Couper le micro de {{name}}",
     "fullScreen": "Plein écran"
   },
+  "screenShareZoom": {
+    "toolbarLabel": "Contrôles de zoom du partage d'écran",
+    "zoomIn": "Zoomer",
+    "zoomInWithShortcut": "Zoomer ({{shortcut}})",
+    "zoomOut": "Dézoomer",
+    "zoomOutWithShortcut": "Dézoomer ({{shortcut}})",
+    "wheelShortcut": "Contrôle plus molette",
+    "wheelShortcutMac": "Commande plus molette",
+    "wheelShortcutHint": "Raccourci : Contrôle plus molette pour zoomer ou dézoomer.",
+    "wheelShortcutHintMac": "Raccourci : Commande plus molette pour zoomer ou dézoomer.",
+    "fitToWindow": "Ajuster à la fenêtre",
+    "fullScreen": "Plein écran",
+    "exitFullScreen": "Quitter le plein écran",
+    "currentZoomLevel": "Zoom {{level}} %",
+    "panHint": "Zoom {{level}} %. Glissez avec la souris, ou revenez sur le partage d'écran et utilisez les touches fléchées pour naviguer dans l'image.",
+    "fullScreenEntered": "Plein écran activé",
+    "fullScreenExited": "Plein écran désactivé"
+  },
   "shortcutsPanel": {
     "title": "Raccourcis clavier",
     "categories": {
@@ -775,7 +793,11 @@
       "raise-hand": "Lever ou baisser la main",
       "toggle-chat": "Afficher/Masquer le chat",
       "toggle-participants": "Afficher/Masquer les participants",
-      "open-shortcuts-settings": "Ouvrir les réglages des raccourcis"
+      "open-shortcuts-settings": "Ouvrir les réglages des raccourcis",
+      "zoom-in": "Zoomer sur un écran partagé",
+      "zoom-out": "Dézoomer sur un écran partagé",
+      "zoom-reset": "Réinitialiser le zoom de l’écran partagé",
+      "zoom-pan": "Se déplacer dans un écran partagé zoomé"
     },
     "sr": {
       "control": "Contrôle",
@@ -785,10 +807,14 @@
       "shift": "Majuscule",
       "plus": "plus",
       "hold": "Maintenir {{key}}",
+      "arrows": "Touches fléchées",
+      "plusKey": "Touche plus",
+      "minusKey": "Touche moins",
       "noShortcut": "Aucun raccourci"
     },
     "visual": {
-      "hold": "Maintenir {{key}}"
+      "hold": "Maintenir {{key}}",
+      "arrows": "↑ ↓ ← →"
     }
   },
   "fullScreenWarning": {

src/frontend/src/locales/fr/settings.json

@@ -56,7 +56,6 @@
       "publish": {
         "label": "Sélectionner votre résolution d'envoi (max.)",
         "items": {
-          "veryHigh": "Très haute définition",
           "high": "Haute définition",
           "medium": "Définition standard",
           "low": "Basse définition"

src/frontend/src/locales/nl/rooms.json

@@ -756,6 +756,24 @@
     "muteParticipant": "Demp {{name}}",
     "fullScreen": "Volledig scherm"
   },
+  "screenShareZoom": {
+    "toolbarLabel": "Zoombediening voor schermdeling",
+    "zoomIn": "Inzoomen",
+    "zoomInWithShortcut": "Inzoomen ({{shortcut}})",
+    "zoomOut": "Uitzoomen",
+    "zoomOutWithShortcut": "Uitzoomen ({{shortcut}})",
+    "wheelShortcut": "Control plus scrollwiel",
+    "wheelShortcutMac": "Command plus scrollwiel",
+    "wheelShortcutHint": "Sneltoets: Control plus scrollwiel om in of uit te zoomen.",
+    "wheelShortcutHintMac": "Sneltoets: Command plus scrollwiel om in of uit te zoomen.",
+    "fitToWindow": "Aanpassen aan venster",
+    "fullScreen": "Volledig scherm",
+    "exitFullScreen": "Volledig scherm verlaten",
+    "currentZoomLevel": "Zoom {{level}} %",
+    "panHint": "Zoom {{level}} %. Sleep met de muis, of zet de focus terug op de schermdeling en gebruik de pijltjestoetsen om door het beeld te navigeren.",
+    "fullScreenEntered": "Volledig scherm ingeschakeld",
+    "fullScreenExited": "Volledig scherm uitgeschakeld"
+  },
   "shortcutsPanel": {
     "title": "Sneltoetsen",
     "categories": {
@@ -775,7 +793,11 @@
       "raise-hand": "Hand opsteken of laten zakken",
       "toggle-chat": "Chat tonen/verbergen",
       "toggle-participants": "Deelnemers tonen/verbergen",
-      "open-shortcuts-settings": "Sneltoets-instellingen openen"
+      "open-shortcuts-settings": "Sneltoets-instellingen openen",
+      "zoom-in": "Inzoomen op een gedeeld scherm",
+      "zoom-out": "Uitzoomen op een gedeeld scherm",
+      "zoom-reset": "Zoom van het gedeelde scherm herstellen",
+      "zoom-pan": "Navigeren in een ingezoomd gedeeld scherm"
     },
     "sr": {
       "control": "Control",
@@ -785,10 +807,14 @@
       "shift": "Shift",
       "plus": "plus",
       "hold": "Houd {{key}} ingedrukt",
+      "arrows": "Pijltoetsen",
+      "plusKey": "Plus-toets",
+      "minusKey": "Min-toets",
       "noShortcut": "Geen sneltoets"
     },
     "visual": {
-      "hold": "Houd {{key}} ingedrukt"
+      "hold": "Houd {{key}} ingedrukt",
+      "arrows": "↑ ↓ ← →"
     }
   },
   "fullScreenWarning": {

src/frontend/src/locales/nl/settings.json

@@ -56,7 +56,6 @@
       "publish": {
         "label": "Selecteer uw verzendresolutie (max.)",
         "items": {
-          "veryHigh": "Zeer hoge definitie",
           "high": "Hoge definitie",
           "medium": "Standaarddefinitie",
           "low": "Lage definitie"

src/frontend/src/stores/userChoices.ts

@@ -10,12 +10,7 @@ import {
 } from '@livekit/components-core'
 import { VideoQuality } from 'livekit-client'
 
-export const VIDEO_RESOLUTIONS = ['h1080', 'h720', 'h360', 'h180'] as const
-
-export type VideoResolution = (typeof VIDEO_RESOLUTIONS)[number]
-
-const isVideoResolution = (value: unknown): value is VideoResolution =>
-  VIDEO_RESOLUTIONS.includes(value as VideoResolution)
+export type VideoResolution = 'h720' | 'h360' | 'h180'
 
 export type LocalUserChoices = Omit<LocalUserChoicesLK, 'username'> & {
   processorConfig?: ProcessorConfig
@@ -26,17 +21,13 @@ export type LocalUserChoices = Omit<LocalUserChoicesLK, 'username'> & {
 }
 
 function getUserChoicesState(): LocalUserChoices {
-  const stored: LocalUserChoices = {
+  return {
     noiseReductionEnabled: false,
     audioOutputDeviceId: 'default', // Use 'default' to match LiveKit's standard device selection behavior
     videoPublishResolution: 'h720',
     videoSubscribeQuality: VideoQuality.HIGH,
     ...loadUserChoices(),
   }
-  if (!isVideoResolution(stored.videoPublishResolution)) {
-    stored.videoPublishResolution = 'h720'
-  }
-  return stored
 }
 
 export const userChoicesStore = proxy<LocalUserChoices>(getUserChoicesState())