fix(media): "Compress image" no longer blackens transparent images or freezes animations (#331)

Compression re-encodes through a canvas to JPEG. Only PNG was skipped,
so a transparent WebP came out on a black background, and an animated
GIF or WebP became one still frame. GIF and APNG are no longer offered;
an animated WebP (VP8X animation flag) or any image with a transparent
pixel is kept as the original.

Fixes #331

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017PCb59uY3UKqDqt7B6hzd5

package-lock.json

@@ -81,7 +81,7 @@
       },
       "devDependencies": {
         "@axe-core/playwright": "4.13.0",
-        "@lotusguild/element-call-embedded": "0.25.0-lotus.22",
+        "@lotusguild/element-call-embedded": "0.25.0-lotus.23",
         "@playwright/test": "1.63.0",
         "@rollup/plugin-inject": "5.0.5",
         "@rollup/plugin-wasm": "6.2.2",
@@ -2695,9 +2695,9 @@
       "integrity": "sha512-dfLbk+PwWvFzSxwk3n5ySL0hfBog779o8h68wK/7/APo/7cgyWp5jcXockbxdk5kFRkbeXWm4Fbi9FrdN381sA=="
     },
     "node_modules/@lotusguild/element-call-embedded": {
-      "version": "0.25.0-lotus.22",
-      "resolved": "https://code.lotusguild.org/api/packages/LotusGuild/npm/%40lotusguild%2Felement-call-embedded/-/0.25.0-lotus.22/element-call-embedded-0.25.0-lotus.22.tgz",
-      "integrity": "sha512-AimDKZA4xUKEEyl2XUFUSUDl03tBKFv88T/3igKyH2VqNSPMGnqcQJC5HXIkHLTWrOmg8kLcJ//FFbqlUZiLcA==",
+      "version": "0.25.0-lotus.23",
+      "resolved": "https://code.lotusguild.org/api/packages/LotusGuild/npm/%40lotusguild%2Felement-call-embedded/-/0.25.0-lotus.23/element-call-embedded-0.25.0-lotus.23.tgz",
+      "integrity": "sha512-vRmcWeJcU0Accyl2x3mqNEzrIe8djE5BekyYbYOSCsMflC98rZgD1mO7KOe7bA1cX7gparRf6sAt1fotHoU+bA==",
       "dev": true
     },
     "node_modules/@matrix-org/matrix-sdk-crypto-wasm": {

package.json

@@ -108,7 +108,7 @@
   },
   "devDependencies": {
     "@axe-core/playwright": "4.13.0",
-    "@lotusguild/element-call-embedded": "0.25.0-lotus.22",
+    "@lotusguild/element-call-embedded": "0.25.0-lotus.23",
     "@playwright/test": "1.63.0",
     "@rollup/plugin-inject": "5.0.5",
     "@rollup/plugin-wasm": "6.2.2",

src/app/components/CallEmbedProvider.tsx

@@ -111,8 +111,6 @@ type IncomingCallInfo = {
   intent?: string;
   notificationType: RTCNotificationType;
   refEventId: string;
-  /** [Gitea #313] The rtc.notification event itself: what a decline must reference (MSC4310). */
-  notificationEventId?: string;
 };
 type IncomingCallProps = {
   dm: boolean;
@@ -285,9 +283,7 @@ function IncomingCall({ dm, info, onIgnore, onAnswer, onReject }: IncomingCallPr
                   fill="Soft"
                   size="400"
                   radii="400"
-                  onClick={() =>
-                    dm ? onReject(room, info.notificationEventId ?? info.refEventId) : onIgnore()
-                  }
+                  onClick={() => (dm ? onReject(room, info.refEventId) : onIgnore())}
                   before={<Icon size="200" src={Icons.Cross} filled />}
                 >
                   <Text as="span" size="B400">
@@ -459,9 +455,7 @@ function IncomingCallBanner({ dm, info, onIgnore, onAnswer, onReject }: Incoming
           size="300"
           radii="300"
           outlined
-          onClick={() =>
-            dm ? onReject(room, info.notificationEventId ?? info.refEventId) : onIgnore()
-          }
+          onClick={() => (dm ? onReject(room, info.refEventId) : onIgnore())}
           before={<Icon size="100" src={Icons.Cross} filled />}
         >
           <Text as="span" size="B300">
@@ -602,7 +596,6 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
             : undefined,
         notificationType,
         refEventId,
-        notificationEventId: event.getId(),
       };
 
       // [Gitea #312] Don't ring for a call that is already over or handled: after
@@ -611,10 +604,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       // stale RTC session). The caller's membership can arrive just after the
       // ring, so an absent one gets a short grace period before giving up.
       const myUserId = mx.getSafeUserId();
-      if (
-        declinedRing(room, [refEventId, event.getId()], myUserId) ||
-        hasActiveCallMembership(room, myUserId)
-      ) {
+      if (declinedRing(room, refEventId, myUserId) || hasActiveCallMembership(room, myUserId)) {
         return;
       }
       if (hasActiveCallMembership(room, sender)) {
@@ -623,10 +613,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       }
       setTimeout(() => {
         if (Date.now() >= senderTs + lifetime) return;
-        if (
-          declinedRing(room, [refEventId, event.getId()], myUserId) ||
-          hasActiveCallMembership(room, myUserId)
-        ) {
+        if (declinedRing(room, refEventId, myUserId) || hasActiveCallMembership(room, myUserId)) {
           return;
         }
         if (hasActiveCallMembership(room, sender)) setCallInfo(info);
@@ -698,10 +685,7 @@ function IncomingCallListener({ callEmbed, joined }: IncomingCallListenerProps)
       if (eventRoom?.roomId !== room.roomId || !data.liveEvent) return;
       if (event.getType() === EventType.RTCDecline && event.getSender() === myUserId) {
         const related = event.getRelation()?.event_id;
-        // [Gitea #313] Correct clients reference the notification; older Lotus
-        // builds referenced the call membership. Accept both.
-        if (!related || related === refEventId || related === callInfo.notificationEventId)
-          dismiss(); // declined elsewhere
+        if (!related || related === refEventId) dismiss(); // declined elsewhere
       }
     };
     session.on(MatrixRTCSessionEvent.MembershipsChanged, checkMemberships);

src/app/components/create-room/utils.ts

@@ -139,8 +139,11 @@ export const createRoom = async (mx: MatrixClient, data: CreateRoomData): Promis
       data.allowFederation,
       data.additionalCreators,
     ),
-    power_level_content_override:
-      data.type === RoomType.Call ? createVoiceRoomPowerLevelsOverride() : undefined,
+    // [Gitea #328] Every non-space room gets call.member at user level, not just
+    // voice rooms: the call button is shown in private group rooms too, and with
+    // Synapse's state_default (50) only admins could start or join a call there
+    // ("You don't have permission to join!").
+    power_level_content_override: createVoiceRoomPowerLevelsOverride(),
     initial_state: initialState,
   };
 

src/app/features/room/RoomTimeline.tsx

@@ -138,7 +138,7 @@ import { useMediaAuthentication } from '../../hooks/useMediaAuthentication';
 import { useIgnoredUsers } from '../../hooks/useIgnoredUsers';
 import { useImagePackRooms } from '../../hooks/useImagePackRooms';
 import { useIsDirectRoom } from '../../hooks/useRoom';
-import { declinedRing, isRingableRoom } from '../../utils/callRing';
+import { isRingableRoom } from '../../utils/callRing';
 import { useOpenUserRoomProfile } from '../../state/hooks/userRoomProfile';
 import { useSpaceOptionally } from '../../hooks/useSpace';
 import { useRoomCreators } from '../../hooks/useRoomCreators';
@@ -2037,9 +2037,6 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
         // Same rule as ringing: no "Missed call" in voice rooms or space
         // channels, where starting a call is just joining the channel.
         if (!isRingableRoom(room, direct)) return null;
-        // [Gitea #313] A call we declined isn't a missed call.
-        const ringRef = mEvent.getRelation()?.event_id;
-        if (declinedRing(room, [mEventId, ringRef], mx.getSafeUserId())) return null;
         const content = mEvent.getContent();
         const mention =
           content['m.mentions']?.room ||

src/app/features/room/message/Reactions.tsx

@@ -69,8 +69,15 @@ export const Reactions = as<'div', ReactionsProps>(
     const measure = useCallback(() => {
       const container = containerRef.current;
       if (!container) return;
-      const rowWidth = container.getBoundingClientRect().width;
-      const gap = parseFloat(getComputedStyle(container).columnGap) || 8;
+      // [Gitea #305] The width the chips actually get (content box). The border
+      // box grows by 4 px while collapsed (margin -2 / padding 2), and measuring
+      // it made a row within 4 px of fitting flip collapsed↔expanded every frame.
+      const cs = getComputedStyle(container);
+      const rowWidth =
+        container.clientWidth -
+        (parseFloat(cs.paddingLeft) || 0) -
+        (parseFloat(cs.paddingRight) || 0);
+      const gap = parseFloat(cs.columnGap) || 8;
       const chips = keys ? keys.split('\u0000').map((k) => chipRefs.current.get(k)) : [];
       const widths = chips.map((el) => el?.getBoundingClientRect().width ?? 0);
       const moreWidth = moreRef.current?.getBoundingClientRect().width ?? 48;
@@ -110,8 +117,21 @@ export const Reactions = as<'div', ReactionsProps>(
         style={{
           ...props.style,
           ...(collapsed && rowHeight
-            ? // 2px breathing room so row-1 focus outlines are not clipped.
-              { maxHeight: rowHeight + 4, overflow: 'hidden', padding: 2, margin: -2 }
+            ? // 2px breathing room so row-1 focus outlines are not clipped. Longhand
+              // margins so the timeline's marginTop survives (Gitea #305: the
+              // `margin` shorthand overrode it and, once removed, cleared it).
+              {
+                maxHeight: rowHeight + 4,
+                overflow: 'hidden',
+                padding: 2,
+                marginLeft: -2,
+                marginRight: -2,
+                marginBottom: -2,
+                marginTop:
+                  props.style?.marginTop !== undefined
+                    ? `calc(${typeof props.style.marginTop === 'number' ? `${props.style.marginTop}px` : props.style.marginTop} - 2px)`
+                    : -2,
+              }
             : {}),
         }}
         ref={(el) => {

src/app/plugins/call/CallEmbed.ts

@@ -31,6 +31,7 @@ import { verifyDenoiseAssets } from './denoiseSmokeCheck';
 import { canDelegateCapability } from './utils';
 import { getCallPageUrl } from './callPageUrl';
 import { restrictWidgetMessages } from '../widgetTransport';
+import { isRingableRoom } from '../../utils/callRing';
 
 // Maximum time to wait for the embedded Element Call iframe to progress from
 // initial load to a ready/joined state. If it hasn't by then, we assume the
@@ -251,8 +252,18 @@ export class CallEmbed {
       verifyDenoiseAssets(denoiseModel).catch(() => undefined);
     }
 
+    // [Gitea #295] Only ask Element Call to notify where a call can ring at all
+    // (DMs, invite-only groups outside a space). In a voice channel or space
+    // room the notification carries an @room mention, so every member got a
+    // highlighted ping (and phone push) whenever a moderator hopped in, and
+    // other clients showed it as a missed call.
+    // `none` needs element-call-embedded ≥ 0.25.0-lotus.23 (older builds ignore it).
     if (CallEmbed.startingCall(intent)) {
-      params.append('sendNotificationType', CallEmbed.dmCall(intent) ? 'ring' : 'notification');
+      let notify = 'none';
+      if (isRingableRoom(room, CallEmbed.dmCall(intent))) {
+        notify = CallEmbed.dmCall(intent) ? 'ring' : 'notification';
+      }
+      params.append('sendNotificationType', notify);
     }
 
     // [Gitea #43] On its own origin when config.json sets elementCallUrl.

src/app/utils/callRing.test.ts

@@ -67,18 +67,3 @@ test('declinedRing finds our own decline of that ring only (#312)', () => {
   assert.equal(declinedRing(room, '$ring2', '@me:x'), false, "someone else's decline");
   assert.equal(declinedRing(room, '$ring3', '@me:x'), false);
 });
-
-test('declinedRing matches a decline of the notification or of the membership (#313)', () => {
-  const decline = (rel: string) => ({
-    getType: () => 'org.matrix.msc4310.rtc.decline',
-    getSender: () => '@me:x',
-    getRelation: () => ({ event_id: rel }),
-  });
-  const room = stateRoom([], [decline('$notification')]);
-  assert.equal(declinedRing(room, ['$membership', '$notification'], '@me:x'), true);
-  assert.equal(declinedRing(room, ['$membership'], '@me:x'), false);
-  assert.equal(
-    declinedRing(stateRoom([], [decline('$membership')]), ['$membership', undefined], '@me:x'),
-    true,
-  );
-});

src/app/utils/callRing.ts

@@ -40,18 +40,7 @@ export const hasActiveCallMembership = (room: Room, userId: string): boolean =>
  * declined it (our own RTCDecline relates to it) — e.g. replayed together with
  * the ring in the first sync after a restart, before any dismiss listener.
  */
-export const declinedRing = (
-  room: Room,
-  ringIds: string | Array<string | undefined>,
-  myUserId: string,
-): boolean => {
-  // [Gitea #313] A decline references the notification event (MSC4310); older
-  // Lotus builds referenced the call membership instead. Match either.
-  const ids = new Set((Array.isArray(ringIds) ? ringIds : [ringIds]).filter(Boolean));
-  return declinedAny(room, ids, myUserId);
-};
-
-const declinedAny = (room: Room, ids: Set<string | undefined>, myUserId: string): boolean =>
+export const declinedRing = (room: Room, refEventId: string, myUserId: string): boolean =>
   room
     .getLiveTimeline()
     .getEvents()
@@ -59,5 +48,5 @@ const declinedAny = (room: Room, ids: Set<string | undefined>, myUserId: string)
       (ev) =>
         ev.getType() === 'org.matrix.msc4310.rtc.decline' &&
         ev.getSender() === myUserId &&
-        ids.has(ev.getRelation()?.event_id),
+        ev.getRelation()?.event_id === refEventId,
     );

src/app/utils/imageCompression.test.ts

@@ -1,6 +1,11 @@
 import { test } from 'node:test';
 import assert from 'node:assert/strict';
-import { formatFileSize, isCompressible } from './imageCompression';
+import {
+  formatFileSize,
+  hasTransparency,
+  isAnimatedWebp,
+  isCompressible,
+} from './imageCompression';
 
 test('formatFileSize formats bytes below 1KB as B', () => {
   assert.equal(formatFileSize(0), '0 B');
@@ -25,14 +30,38 @@ test('formatFileSize formats values in the MB range', () => {
 test('isCompressible accepts raster image types', () => {
   assert.equal(isCompressible({ type: 'image/png' } as Blob), true);
   assert.equal(isCompressible({ type: 'image/jpeg' } as Blob), true);
-  assert.equal(isCompressible({ type: 'image/gif' } as Blob), true);
   assert.equal(isCompressible({ type: 'image/webp' } as Blob), true);
 });
 
 test('isCompressible rejects svg, empty type, and non-images', () => {
   assert.equal(isCompressible({ type: 'image/svg+xml' } as Blob), false);
+  // [Gitea #331] usually animated; a canvas keeps one frame
+  assert.equal(isCompressible({ type: 'image/gif' } as Blob), false);
+  assert.equal(isCompressible({ type: 'image/apng' } as Blob), false);
   assert.equal(isCompressible({ type: '' } as Blob), false);
   assert.equal(isCompressible({ type: 'application/pdf' } as Blob), false);
   assert.equal(isCompressible({ type: 'text/plain' } as Blob), false);
   assert.equal(isCompressible({ type: 'video/mp4' } as Blob), false);
 });
+
+const webpHeader = (chunk: string, flags = 0) => {
+  const b = new Uint8Array(32);
+  const put = (at: number, str: string) => b.set(new TextEncoder().encode(str), at);
+  put(0, 'RIFF');
+  put(8, 'WEBP');
+  put(12, chunk);
+  b[20] = flags;
+  return b;
+};
+
+test('isAnimatedWebp: VP8X with the animation flag (#331)', () => {
+  assert.equal(isAnimatedWebp(webpHeader('VP8X', 0x02)), true);
+  assert.equal(isAnimatedWebp(webpHeader('VP8X', 0x10)), false, 'alpha flag only');
+  assert.equal(isAnimatedWebp(webpHeader('VP8 ')), false, 'simple lossy');
+  assert.equal(isAnimatedWebp(new Uint8Array(8)), false);
+});
+
+test('hasTransparency (#331)', () => {
+  assert.equal(hasTransparency(new Uint8ClampedArray([1, 2, 3, 255, 4, 5, 6, 255])), false);
+  assert.equal(hasTransparency(new Uint8ClampedArray([1, 2, 3, 255, 0, 0, 0, 0])), true);
+});

src/app/utils/imageCompression.ts

@@ -8,11 +8,32 @@ export type CompressionResult = {
   height: number;
 };
 
-// Any raster image the browser can render to canvas can be compressed to JPEG.
-// SVG is vector and must stay as-is; GIF animation is lost on canvas but static
-// frames compress fine. Empty type string (undetected MIME) is excluded.
+// Raster images the browser can render to canvas can be compressed to JPEG.
+// SVG is vector and must stay as-is. [Gitea #331] GIF and APNG are usually
+// animated, and a canvas keeps only the first frame, so they aren't offered.
+// Empty type string (undetected MIME) is excluded.
+const NOT_COMPRESSIBLE = new Set(['image/svg+xml', 'image/gif', 'image/apng']);
 const isCompressibleType = (type: string): boolean =>
-  type.startsWith('image/') && type !== 'image/svg+xml' && type !== '';
+  type.startsWith('image/') && !NOT_COMPRESSIBLE.has(type);
+
+/**
+ * Pure: whether a WebP file is animated. An animated WebP is a VP8X file
+ * whose header has the animation flag (byte 20, bit 0x02) and an ANIM chunk.
+ */
+export function isAnimatedWebp(bytes: Uint8Array): boolean {
+  const ascii = (at: number, len: number) => String.fromCharCode(...bytes.subarray(at, at + len));
+  if (bytes.length < 21 || ascii(0, 4) !== 'RIFF' || ascii(8, 4) !== 'WEBP') return false;
+  // Bit 0x02 of the VP8X flags byte (no-bitwise: test it arithmetically).
+  return ascii(12, 4) === 'VP8X' && Math.floor(bytes[20] / 2) % 2 === 1;
+}
+
+/** Pure: whether RGBA pixel data has any pixel that isn't fully opaque. */
+export function hasTransparency(rgba: Uint8ClampedArray): boolean {
+  for (let i = 3; i < rgba.length; i += 4) {
+    if (rgba[i] !== 255) return true;
+  }
+  return false;
+}
 
 /** Returns true if this file can be compressed via canvas (any raster image type). */
 export function isCompressible(file: File | Blob): boolean {
@@ -28,7 +49,8 @@ const JPEG_OUTPUT_TYPE = 'image/jpeg';
  *
  * PNG is skipped entirely: it may carry an alpha channel, and re-encoding to
  * JPEG composites transparency onto an opaque (black) background, corrupting the
- * image. Returning null makes callers fall back to uploading the lossless
+ * image. Any other image with transparent pixels, and animated WebP, are left
+ * alone for the same reason (#331). Returning null makes callers fall back to uploading the lossless
  * original. The image is decoded with `imageOrientation: 'from-image'` so any
  * EXIF orientation is baked into the pixels instead of being silently dropped.
  */
@@ -39,6 +61,15 @@ export async function compressImage(
   if (!isCompressibleType(file.type)) return null;
   // Skip PNG (potential alpha) — re-encoding to JPEG would flatten transparency.
   if (file.type === 'image/png') return null;
+  // [Gitea #331] An animated WebP would become a single still frame.
+  if (file.type === 'image/webp') {
+    try {
+      const head = new Uint8Array(await file.slice(0, 32).arrayBuffer());
+      if (isAnimatedWebp(head)) return null;
+    } catch {
+      return null;
+    }
+  }
 
   let bitmap: ImageBitmap;
   try {
@@ -60,6 +91,13 @@ export async function compressImage(
   }
   ctx.drawImage(bitmap, 0, 0);
   bitmap.close();
+  // [Gitea #331] JPEG has no alpha: a transparent WebP (sticker, logo) came out
+  // with a black background. Keep any image with transparency as the original.
+  try {
+    if (hasTransparency(ctx.getImageData(0, 0, width, height).data)) return null;
+  } catch {
+    return null;
+  }
 
   return new Promise((resolve) => {
     canvas.toBlob(