style(cctv): format live video integration

server/providers/cctv.js

@@ -132,7 +132,6 @@ export function cctvProxy({ sourceRoot = process.cwd() } = {}) {
   const installMiddleware = (server) => {
     server.httpServer?.on('close', () => {
       puller.shutdown();
-
     });
     server.middlewares.use('/api/cctv', async (req, res) => {
       try {
@@ -201,48 +200,112 @@ export function cctvProxy({ sourceRoot = process.cwd() } = {}) {
         }
 
         if (url.pathname.startsWith('/media/')) {
-          const match = /^\/media\/([^/]+)(?:\/(seg_(\d+)\.ts))?$/.exec(url.pathname);
-          if (!match) { res.writeHead(404); res.end(); return; }
+          const match = /^\/media\/([^/]+)(?:\/(seg_(\d+)\.ts))?$/.exec(
+            url.pathname,
+          );
+          if (!match) {
+            res.writeHead(404);
+            res.end();
+            return;
+          }
           const cameraId = decodeURIComponent(match[1]);
           const source = sourceById.get(cameraId);
           const mediaUrl = source?.url || '';
           const feedType = normalizeFeedType(source?.feedType || 'image');
           const leaseId = url.searchParams.get('lease');
-          if (feedType === 'hls' && !/^[a-f0-9-]{36}$/i.test(leaseId || '')) { res.writeHead(400); res.end(); return; }
+          if (feedType === 'hls' && !/^[a-f0-9-]{36}$/i.test(leaseId || '')) {
+            res.writeHead(400);
+            res.end();
+            return;
+          }
           if (req.method === 'DELETE') {
             if (leaseId) puller.release(cameraId, leaseId);
-            res.writeHead(204); res.end(); return;
+            res.writeHead(204);
+            res.end();
+            return;
+          }
+          if (req.method !== 'GET') {
+            res.writeHead(405);
+            res.end();
+            return;
           }
-          if (req.method !== 'GET') { res.writeHead(405); res.end(); return; }
           if (feedType === 'hls') {
-            if (!/^https?:\/\//i.test(mediaUrl) || !/\.m3u8(?:\?|$)/i.test(mediaUrl)) {
+            if (
+              !/^https?:\/\//i.test(mediaUrl) ||
+              !/\.m3u8(?:\?|$)/i.test(mediaUrl)
+            ) {
               res.writeHead(503, { 'Content-Type': 'application/json' });
-              res.end(JSON.stringify({ error: 'This stream requires an unsupported transport; use the frame fallback' }));
+              res.end(
+                JSON.stringify({
+                  error:
+                    'This stream requires an unsupported transport; use the frame fallback',
+                }),
+              );
               return;
             }
             if (match[2]) {
-              const body = puller.getSegment(cameraId, url.searchParams.get('session'), Number(match[3]), leaseId);
-              res.writeHead(body ? 200 : 404, { 'Content-Type': 'video/mp2t', 'Cache-Control': 'no-store' });
-              res.end(body || undefined); return;
+              const body = puller.getSegment(
+                cameraId,
+                url.searchParams.get('session'),
+                Number(match[3]),
+                leaseId,
+              );
+              res.writeHead(body ? 200 : 404, {
+                'Content-Type': 'video/mp2t',
+                'Cache-Control': 'no-store',
+              });
+              res.end(body || undefined);
+              return;
             }
             const downstream = watchDownstreamClose(res);
             let entry;
-            const cancelPending = () => { if (entry) puller.release(cameraId, leaseId); };
+            const cancelPending = () => {
+              if (entry) puller.release(cameraId, leaseId);
+            };
             try {
               entry = await puller.ensure(cameraId, mediaUrl, leaseId);
-              if (downstream.closed) { cancelPending(); return; }
-              downstream.signal.addEventListener('abort', cancelPending, { once: true });
-              if (!(await puller.waitReady(entry, downstream.signal))) throw new Error('Stream unavailable');
-              const playlist = await puller.buildPlaylist(entry, cameraId, leaseId);
+              if (downstream.closed) {
+                cancelPending();
+                return;
+              }
+              downstream.signal.addEventListener('abort', cancelPending, {
+                once: true,
+              });
+              if (!(await puller.waitReady(entry, downstream.signal)))
+                throw new Error('Stream unavailable');
+              const playlist = await puller.buildPlaylist(
+                entry,
+                cameraId,
+                leaseId,
+              );
               if (downstream.closed) return;
               if (!playlist) throw new Error('Stream unavailable');
-              setHealth(cameraId, { status: 'ok', sourceKind: 'live', label: source?.provider || 'Configured source', message: 'Live HLS connected' });
-              res.writeHead(200, { 'Content-Type': 'application/vnd.apple.mpegurl', 'Cache-Control': 'no-store', 'X-CCTV-Source': 'hls-pull', 'X-CCTV-Session': entry.token });
+              setHealth(cameraId, {
+                status: 'ok',
+                sourceKind: 'live',
+                label: source?.provider || 'Configured source',
+                message: 'Live HLS connected',
+              });
+              res.writeHead(200, {
+                'Content-Type': 'application/vnd.apple.mpegurl',
+                'Cache-Control': 'no-store',
+                'X-CCTV-Source': 'hls-pull',
+                'X-CCTV-Session': entry.token,
+              });
               res.end(playlist);
             } catch {
-              setHealth(cameraId, { status: 'degraded', sourceKind: 'fallback', label: source?.provider || 'Configured source', message: 'Live HLS unavailable' });
+              setHealth(cameraId, {
+                status: 'degraded',
+                sourceKind: 'fallback',
+                label: source?.provider || 'Configured source',
+                message: 'Live HLS unavailable',
+              });
               if (!downstream.closed) {
-                res.writeHead(503, { 'Content-Type': 'application/json', 'Cache-Control': 'no-store', 'Retry-After': '2' });
+                res.writeHead(503, {
+                  'Content-Type': 'application/json',
+                  'Cache-Control': 'no-store',
+                  'Retry-After': '2',
+                });
                 res.end(JSON.stringify({ error: 'Live stream unavailable' }));
               }
             } finally {
@@ -250,7 +313,11 @@ export function cctvProxy({ sourceRoot = process.cwd() } = {}) {
             }
             return;
           }
-          if (match[2] || req.method !== 'GET') { res.writeHead(404); res.end(); return; }
+          if (match[2] || req.method !== 'GET') {
+            res.writeHead(404);
+            res.end();
+            return;
+          }
 
           if (!mediaUrl || !/^https?:\/\//i.test(mediaUrl)) {
             setHealth(cameraId, {

server/providers/cctv/sources.js

@@ -1626,8 +1626,18 @@ export async function loadDelDOTSourcesFromOpenData() {
 
       // Prefer the catalog's HTTPS HLS transport; no subprocess is required.
       let stream;
-      try { stream = new URL(String(row?.urls?.m3u8s || '')); } catch { continue; }
-      if (stream.origin !== 'https://video.deldot.gov' || stream.username || stream.password || !/^\/live\/[A-Za-z0-9_.-]+\/playlist\.m3u8$/.test(stream.pathname)) continue;
+      try {
+        stream = new URL(String(row?.urls?.m3u8s || ''));
+      } catch {
+        continue;
+      }
+      if (
+        stream.origin !== 'https://video.deldot.gov' ||
+        stream.username ||
+        stream.password ||
+        !/^\/live\/[A-Za-z0-9_.-]+\/playlist\.m3u8$/.test(stream.pathname)
+      )
+        continue;
       const streamUrl = stream.href;
 
       const id = String(row?.id || '').trim();

server/providers/cctv/stream.js

@@ -15,7 +15,15 @@ export const HLS_LIMITS = Object.freeze({
 });
 
 /** Refuse redirects; count actual streamed bytes, including chunked responses. */
-export async function fetchHlsBytes(url, { fetchImpl = fetch, signal, maxBytes, timeoutMs = HLS_LIMITS.timeoutMs } = {}) {
+export async function fetchHlsBytes(
+  url,
+  {
+    fetchImpl = fetch,
+    signal,
+    maxBytes,
+    timeoutMs = HLS_LIMITS.timeoutMs,
+  } = {},
+) {
   const controller = new AbortController();
   const abort = () => controller.abort();
   if (signal?.aborted) controller.abort();
@@ -25,11 +33,19 @@ export async function fetchHlsBytes(url, { fetchImpl = fetch, signal, maxBytes,
   let response;
   try {
     controller.signal.throwIfAborted();
-    response = await fetchImpl(url, { redirect: 'error', signal: controller.signal,
-      headers: { 'User-Agent': 'gods-eye-view-cctv-proxy/1.0' } });
-    if (!response.ok || response.redirected || (response.url && new URL(response.url).href !== new URL(url).href))
+    response = await fetchImpl(url, {
+      redirect: 'error',
+      signal: controller.signal,
+      headers: { 'User-Agent': 'gods-eye-view-cctv-proxy/1.0' },
+    });
+    if (
+      !response.ok ||
+      response.redirected ||
+      (response.url && new URL(response.url).href !== new URL(url).href)
+    )
       throw new Error('HLS upstream refused');
-    if (Number(response.headers.get('content-length')) > maxBytes) throw new Error('HLS response too large');
+    if (Number(response.headers.get('content-length')) > maxBytes)
+      throw new Error('HLS response too large');
     reader = response.body?.getReader?.();
     if (!reader) throw new Error('HLS response is not streamable');
     const chunks = [];
@@ -56,14 +72,22 @@ export async function fetchHlsBytes(url, { fetchImpl = fetch, signal, maxBytes,
 
 export function sameOriginHlsUrl(value, base) {
   const url = new URL(value, base);
-  if (!['https:', 'http:'].includes(url.protocol) || url.origin !== new URL(base).origin || url.username || url.password)
+  if (
+    !['https:', 'http:'].includes(url.protocol) ||
+    url.origin !== new URL(base).origin ||
+    url.username ||
+    url.password
+  )
     throw new Error('HLS reference escapes registered origin');
   return url.href;
 }
 
 /** Only clear MPEG-TS media playlists: encrypted, fMP4 and byte ranges fail closed. */
 export function parseHlsMedia(text, base, limit = HLS_LIMITS.segments) {
-  if (!text.startsWith('#EXTM3U') || /#EXT-X-(?:KEY|MAP|BYTERANGE|I-FRAMES-ONLY)/.test(text))
+  if (
+    !text.startsWith('#EXTM3U') ||
+    /#EXT-X-(?:KEY|MAP|BYTERANGE|I-FRAMES-ONLY)/.test(text)
+  )
     throw new Error('Unsupported HLS playlist');
   let seq = 0;
   let duration = null;
@@ -73,16 +97,20 @@ export function parseHlsMedia(text, base, limit = HLS_LIMITS.segments) {
     const line = raw.trim();
     if (line.startsWith('#EXT-X-MEDIA-SEQUENCE:')) {
       seq = Number(line.slice(22));
-      if (!Number.isSafeInteger(seq) || seq < 0) throw new Error('Invalid media sequence');
+      if (!Number.isSafeInteger(seq) || seq < 0)
+        throw new Error('Invalid media sequence');
     } else if (line === '#EXT-X-DISCONTINUITY') {
       discontinuity = true;
     } else if (line.startsWith('#EXTINF:')) {
       duration = Number.parseFloat(line.slice(8));
-      if (!Number.isFinite(duration) || duration <= 0 || duration > 60) throw new Error('Invalid segment duration');
+      if (!Number.isFinite(duration) || duration <= 0 || duration > 60)
+        throw new Error('Invalid segment duration');
     } else if (line && !line.startsWith('#')) {
-      if (duration === null || !Number.isSafeInteger(seq)) throw new Error('Invalid HLS segment');
+      if (duration === null || !Number.isSafeInteger(seq))
+        throw new Error('Invalid HLS segment');
       const uri = sameOriginHlsUrl(line, base);
-      if (!new URL(uri).pathname.endsWith('.ts')) throw new Error('Only MPEG-TS segments are supported');
+      if (!new URL(uri).pathname.endsWith('.ts'))
+        throw new Error('Only MPEG-TS segments are supported');
       segments.push({ seq: seq++, duration, uri, discontinuity });
       discontinuity = false;
       duration = null;
@@ -91,7 +119,10 @@ export function parseHlsMedia(text, base, limit = HLS_LIMITS.segments) {
   return segments.slice(-limit);
 }
 
-export function createHlsPuller({ fetchImpl = fetch, limits = HLS_LIMITS } = {}) {
+export function createHlsPuller({
+  fetchImpl = fetch,
+  limits = HLS_LIMITS,
+} = {}) {
   const active = new Map();
   let closed = false;
   const stop = (cameraId, token) => {
@@ -118,34 +149,50 @@ export function createHlsPuller({ fetchImpl = fetch, limits = HLS_LIMITS } = {})
   const touch = (entry, leaseId, create = false) => {
     let lease = entry.leases.get(leaseId);
     if (!lease) {
-      if (!create || entry.leases.size >= limits.leasesPerSession) throw new Error('HLS lease capacity reached');
+      if (!create || entry.leases.size >= limits.leasesPerSession)
+        throw new Error('HLS lease capacity reached');
       lease = {};
       entry.leases.set(leaseId, lease);
     }
     clearTimeout(lease.timer);
-    lease.timer = setTimeout(() => release(entry.cameraId, leaseId), limits.idleMs);
+    lease.timer = setTimeout(
+      () => release(entry.cameraId, leaseId),
+      limits.idleMs,
+    );
     lease.timer.unref?.();
   };
-  const read = (entry, url, maxBytes) => fetchHlsBytes(url, {
-    fetchImpl, signal: entry.controller.signal, maxBytes, timeoutMs: limits.timeoutMs,
-  });
+  const read = (entry, url, maxBytes) =>
+    fetchHlsBytes(url, {
+      fetchImpl,
+      signal: entry.controller.signal,
+      maxBytes,
+      timeoutMs: limits.timeoutMs,
+    });
   const poll = async (entry) => {
     try {
       let base = entry.chunklistUrl || entry.url;
-      let text = (await read(entry, base, limits.playlistBytes)).toString('utf8');
+      let text = (await read(entry, base, limits.playlistBytes)).toString(
+        'utf8',
+      );
       if (!text.includes('#EXTINF:')) {
-        const variant = text.split('\n').map((line) => line.trim()).find((line) => line && !line.startsWith('#'));
-        if (!variant || !text.includes('#EXT-X-STREAM-INF:')) throw new Error('Missing HLS variant');
+        const variant = text
+          .split('\n')
+          .map((line) => line.trim())
+          .find((line) => line && !line.startsWith('#'));
+        if (!variant || !text.includes('#EXT-X-STREAM-INF:'))
+          throw new Error('Missing HLS variant');
         base = sameOriginHlsUrl(variant, entry.url);
         text = (await read(entry, base, limits.playlistBytes)).toString('utf8');
       }
       entry.chunklistUrl = base;
       const segments = parseHlsMedia(text, base, limits.segments);
       const newest = segments.at(-1)?.seq ?? -1;
-      const restarted = newest < entry.upstreamNewest || segments.some((segment) => {
-        const prior = entry.upstream.get(segment.seq);
-        return prior && prior !== segment.uri;
-      });
+      const restarted =
+        newest < entry.upstreamNewest ||
+        segments.some((segment) => {
+          const prior = entry.upstream.get(segment.seq);
+          return prior && prior !== segment.uri;
+        });
       if (restarted) {
         entry.upstream.clear();
         entry.pendingDiscontinuity = true;
@@ -158,29 +205,45 @@ export function createHlsPuller({ fetchImpl = fetch, limits = HLS_LIMITS } = {})
         if (entry.stopping) return;
         // Evict BEFORE retaining the incoming segment. One bounded download may
         // exist in addition to the cache; no unbounded disk output is possible.
-        while (entry.segments.size && (entry.bytes + body.length > limits.sessionBytes || entry.segments.size >= limits.segments)) {
+        while (
+          entry.segments.size &&
+          (entry.bytes + body.length > limits.sessionBytes ||
+            entry.segments.size >= limits.segments)
+        ) {
           const oldest = entry.segments.keys().next().value;
           const removed = entry.segments.get(oldest);
           entry.bytes -= removed.body.length;
           if (removed.discontinuity) entry.discontinuitiesRemoved++;
           entry.segments.delete(oldest);
         }
-        if (body.length > limits.sessionBytes) throw new Error('Segment exceeds session budget');
+        if (body.length > limits.sessionBytes)
+          throw new Error('Segment exceeds session budget');
         const seq = entry.nextSeq++;
-        entry.segments.set(seq, { ...segment, seq, body, discontinuity: segment.discontinuity || entry.pendingDiscontinuity });
+        entry.segments.set(seq, {
+          ...segment,
+          seq,
+          body,
+          discontinuity: segment.discontinuity || entry.pendingDiscontinuity,
+        });
         entry.pendingDiscontinuity = false;
         entry.upstream.set(segment.seq, segment.uri);
-        while (entry.upstream.size > limits.segments * 2) entry.upstream.delete(entry.upstream.keys().next().value);
+        while (entry.upstream.size > limits.segments * 2)
+          entry.upstream.delete(entry.upstream.keys().next().value);
         entry.bytes += body.length;
       }
       entry.failures = 0;
     } catch {
       entry.chunklistUrl = null;
       entry.failures++;
-      if (entry.failures >= 3) { stop(entry.cameraId, entry.token); return; }
+      if (entry.failures >= 3) {
+        stop(entry.cameraId, entry.token);
+        return;
+      }
     } finally {
       if (!entry.stopping) {
-        entry.timer = setTimeout(() => { entry.polling = poll(entry); }, limits.pollMs);
+        entry.timer = setTimeout(() => {
+          entry.polling = poll(entry);
+        }, limits.pollMs);
         entry.timer.unref?.();
       }
     }
@@ -189,11 +252,33 @@ export function createHlsPuller({ fetchImpl = fetch, limits = HLS_LIMITS } = {})
     if (closed) throw new Error('HLS service closed');
     sameOriginHlsUrl(url, url);
     let entry = active.get(cameraId);
-    if (entry && entry.url !== url) { stop(cameraId); entry = null; }
-    if (entry) { touch(entry, leaseId, true); return entry; }
+    if (entry && entry.url !== url) {
+      stop(cameraId);
+      entry = null;
+    }
+    if (entry) {
+      touch(entry, leaseId, true);
+      return entry;
+    }
     // Reserve synchronously, before any await: concurrent creation is singleflight.
-    if (active.size >= limits.sessions) throw new Error('HLS session capacity reached');
-    entry = { cameraId, url, token: randomUUID(), controller: new AbortController(), segments: new Map(), bytes: 0, stopping: false, failures: 0, nextSeq: 0, upstream: new Map(), leases: new Map(), upstreamNewest: -1, pendingDiscontinuity: false, discontinuitiesRemoved: 0 };
+    if (active.size >= limits.sessions)
+      throw new Error('HLS session capacity reached');
+    entry = {
+      cameraId,
+      url,
+      token: randomUUID(),
+      controller: new AbortController(),
+      segments: new Map(),
+      bytes: 0,
+      stopping: false,
+      failures: 0,
+      nextSeq: 0,
+      upstream: new Map(),
+      leases: new Map(),
+      upstreamNewest: -1,
+      pendingDiscontinuity: false,
+      discontinuitiesRemoved: 0,
+    };
     active.set(cameraId, entry);
     touch(entry, leaseId, true);
     entry.polling = poll(entry);
@@ -211,18 +296,32 @@ export function createHlsPuller({ fetchImpl = fetch, limits = HLS_LIMITS } = {})
     if (entry.stopping || entry.segments.size < 2) return null;
     touch(entry, leaseId);
     const segments = [...entry.segments.values()].sort((a, b) => a.seq - b.seq);
-    const lines = ['#EXTM3U', '#EXT-X-VERSION:3', `#EXT-X-TARGETDURATION:${Math.ceil(Math.max(...segments.map((s) => s.duration)))}`, `#EXT-X-MEDIA-SEQUENCE:${segments[0].seq}`, `#EXT-X-DISCONTINUITY-SEQUENCE:${entry.discontinuitiesRemoved}`];
+    const lines = [
+      '#EXTM3U',
+      '#EXT-X-VERSION:3',
+      `#EXT-X-TARGETDURATION:${Math.ceil(Math.max(...segments.map((s) => s.duration)))}`,
+      `#EXT-X-MEDIA-SEQUENCE:${segments[0].seq}`,
+      `#EXT-X-DISCONTINUITY-SEQUENCE:${entry.discontinuitiesRemoved}`,
+    ];
     let previous;
     for (const segment of segments) {
-      if (segment.discontinuity || (previous !== undefined && segment.seq !== previous + 1)) lines.push('#EXT-X-DISCONTINUITY');
-      lines.push(`#EXTINF:${segment.duration.toFixed(3)},`, `/api/cctv/media/${encodeURIComponent(cameraId)}/seg_${segment.seq}.ts?session=${entry.token}&lease=${encodeURIComponent(leaseId)}`);
+      if (
+        segment.discontinuity ||
+        (previous !== undefined && segment.seq !== previous + 1)
+      )
+        lines.push('#EXT-X-DISCONTINUITY');
+      lines.push(
+        `#EXTINF:${segment.duration.toFixed(3)},`,
+        `/api/cctv/media/${encodeURIComponent(cameraId)}/seg_${segment.seq}.ts?session=${entry.token}&lease=${encodeURIComponent(leaseId)}`,
+      );
       previous = segment.seq;
     }
     return lines.join('\n') + '\n';
   };
   const getSegment = (cameraId, token, seq, leaseId = 'legacy') => {
     const entry = active.get(cameraId);
-    if (!entry || entry.token !== token || !entry.leases.has(leaseId)) return null;
+    if (!entry || entry.token !== token || !entry.leases.has(leaseId))
+      return null;
     const body = entry.segments.get(seq)?.body;
     if (body) touch(entry, leaseId);
     return body || null;
@@ -233,6 +332,17 @@ export function createHlsPuller({ fetchImpl = fetch, limits = HLS_LIMITS } = {})
     for (const entry of entries) stop(entry.cameraId);
     await Promise.allSettled(entries.map((entry) => entry.polling));
   };
-  return { ensure, waitReady, buildPlaylist, getSegment, stop, release, shutdown,
-    stats: () => ({ sessions: active.size, bytes: [...active.values()].reduce((total, e) => total + e.bytes, 0) }) };
+  return {
+    ensure,
+    waitReady,
+    buildPlaylist,
+    getSegment,
+    stop,
+    release,
+    shutdown,
+    stats: () => ({
+      sessions: active.size,
+      bytes: [...active.values()].reduce((total, e) => total + e.bytes, 0),
+    }),
+  };
 }

src/data/cctvHlsStream.test.mjs

@@ -1,25 +1,77 @@
 import test from 'node:test';
 import assert from 'node:assert/strict';
-import { createHlsPuller, fetchHlsBytes, parseHlsMedia, HLS_LIMITS } from '../../server/providers/cctv/stream.js';
-const playlist = '#EXTM3U\n#EXT-X-MEDIA-SEQUENCE:12\n#EXTINF:2,\na.ts\n#EXTINF:2,\nb.ts\n#EXTINF:2,\nc.ts\n';
+import {
+  createHlsPuller,
+  fetchHlsBytes,
+  parseHlsMedia,
+  HLS_LIMITS,
+} from '../../server/providers/cctv/stream.js';
+const playlist =
+  '#EXTM3U\n#EXT-X-MEDIA-SEQUENCE:12\n#EXTINF:2,\na.ts\n#EXTINF:2,\nb.ts\n#EXTINF:2,\nc.ts\n';
 const base = 'https://camera.example/live/list.m3u8';
 
 test('playlist parser uses sequence, refuses escaping and unsupported references', () => {
-  assert.deepEqual(parseHlsMedia(playlist, base).map((s) => s.seq), [12, 13, 14]);
-  for (const bad of [playlist.replace('a.ts', 'https://evil.example/a.ts'), playlist.replace('a.ts', '//evil.example/a.ts'), '#EXTM3U\n#EXT-X-KEY:METHOD=AES-128\n' + playlist, playlist.replace('12', '-1'), playlist.replace('2,', 'Infinity,')]) assert.throws(() => parseHlsMedia(bad, base));
+  assert.deepEqual(
+    parseHlsMedia(playlist, base).map((s) => s.seq),
+    [12, 13, 14],
+  );
+  for (const bad of [
+    playlist.replace('a.ts', 'https://evil.example/a.ts'),
+    playlist.replace('a.ts', '//evil.example/a.ts'),
+    '#EXTM3U\n#EXT-X-KEY:METHOD=AES-128\n' + playlist,
+    playlist.replace('12', '-1'),
+    playlist.replace('2,', 'Infinity,'),
+  ])
+    assert.throws(() => parseHlsMedia(bad, base));
 });
 
 test('downloads reject redirect responses, oversized declared and chunked bodies', async () => {
   let init;
-  await assert.rejects(fetchHlsBytes(base, { maxBytes: 5, fetchImpl: async (_url, options) => { init = options; return new Response('', { status: 302, headers: { Location: 'https://evil.example' } }); } }));
+  await assert.rejects(
+    fetchHlsBytes(base, {
+      maxBytes: 5,
+      fetchImpl: async (_url, options) => {
+        init = options;
+        return new Response('', {
+          status: 302,
+          headers: { Location: 'https://evil.example' },
+        });
+      },
+    }),
+  );
   assert.equal(init.redirect, 'error');
-  await assert.rejects(fetchHlsBytes(base, { maxBytes: 5, fetchImpl: async () => new Response('abcdef') }));
-  await assert.rejects(fetchHlsBytes(base, { maxBytes: 5, fetchImpl: async () => new Response('a', { headers: { 'content-length': '100' } }) }));
+  await assert.rejects(
+    fetchHlsBytes(base, {
+      maxBytes: 5,
+      fetchImpl: async () => new Response('abcdef'),
+    }),
+  );
+  await assert.rejects(
+    fetchHlsBytes(base, {
+      maxBytes: 5,
+      fetchImpl: async () =>
+        new Response('a', { headers: { 'content-length': '100' } }),
+    }),
+  );
 });
 
 test('one session is reserved before await; disk-free cache and capacity remain bounded', async () => {
-  const manager = createHlsPuller({ limits: { ...HLS_LIMITS, sessions: 1, segmentBytes: 4, sessionBytes: 6, segments: 2, pollMs: 100000 }, fetchImpl: async (url) => new Response(url.endsWith('.m3u8') ? playlist : 'abc') });
-  const [a, b] = await Promise.all([manager.ensure('a', base), manager.ensure('a', base)]);
+  const manager = createHlsPuller({
+    limits: {
+      ...HLS_LIMITS,
+      sessions: 1,
+      segmentBytes: 4,
+      sessionBytes: 6,
+      segments: 2,
+      pollMs: 100000,
+    },
+    fetchImpl: async (url) =>
+      new Response(url.endsWith('.m3u8') ? playlist : 'abc'),
+  });
+  const [a, b] = await Promise.all([
+    manager.ensure('a', base),
+    manager.ensure('a', base),
+  ]);
   assert.equal(a, b);
   await assert.rejects(manager.ensure('b', base));
   assert.equal(await manager.waitReady(a), true);
@@ -37,7 +89,16 @@ test('one session is reserved before await; disk-free cache and capacity remain
 
 test('shutdown cancels in-flight downloads and late responses cannot refill cache', async () => {
   let observed;
-  const manager = createHlsPuller({ fetchImpl: async (_url, { signal }) => { observed = signal; return new Promise((resolve, reject) => signal.addEventListener('abort', () => reject(new Error('cancelled')), { once: true })); } });
+  const manager = createHlsPuller({
+    fetchImpl: async (_url, { signal }) => {
+      observed = signal;
+      return new Promise((resolve, reject) =>
+        signal.addEventListener('abort', () => reject(new Error('cancelled')), {
+          once: true,
+        }),
+      );
+    },
+  });
   const entry = await manager.ensure('a', base);
   await manager.shutdown();
   assert.equal(observed.aborted, true);
@@ -48,7 +109,13 @@ test('shutdown cancels in-flight downloads and late responses cannot refill cach
 
 test('idle cleanup stops all polling without a background sweep', async () => {
   let calls = 0;
-  const manager = createHlsPuller({ limits: { ...HLS_LIMITS, idleMs: 15, pollMs: 100000 }, fetchImpl: async (url) => { calls++; return new Response(url.endsWith('.m3u8') ? playlist : 'abc'); } });
+  const manager = createHlsPuller({
+    limits: { ...HLS_LIMITS, idleMs: 15, pollMs: 100000 },
+    fetchImpl: async (url) => {
+      calls++;
+      return new Response(url.endsWith('.m3u8') ? playlist : 'abc');
+    },
+  });
   await manager.ensure('a', base);
   await new Promise((r) => setTimeout(r, 50));
   assert.deepEqual(manager.stats(), { sessions: 0, bytes: 0 });
@@ -60,7 +127,11 @@ test('idle cleanup stops all polling without a background sweep', async () => {
 
 test('agency sequence rollback creates a monotonic local discontinuity', async () => {
   let current = playlist;
-  const manager = createHlsPuller({ limits: { ...HLS_LIMITS, pollMs: 5 }, fetchImpl: async (url) => new Response(url.endsWith('.m3u8') ? current : 'abc') });
+  const manager = createHlsPuller({
+    limits: { ...HLS_LIMITS, pollMs: 5 },
+    fetchImpl: async (url) =>
+      new Response(url.endsWith('.m3u8') ? current : 'abc'),
+  });
   const entry = await manager.ensure('a', base);
   await manager.waitReady(entry);
   const before = await manager.buildPlaylist(entry, 'a');
@@ -68,34 +139,53 @@ test('agency sequence rollback creates a monotonic local discontinuity', async (
   current = playlist.replace('SEQUENCE:12', 'SEQUENCE:0');
   await new Promise((r) => setTimeout(r, 30));
   const after = await manager.buildPlaylist(entry, 'a');
-  assert.match(after, /#EXT-X-DISCONTINUITY\n#EXTINF:2\.000,\n\/api\/cctv\/media\/a\/seg_3\.ts/);
+  assert.match(
+    after,
+    /#EXT-X-DISCONTINUITY\n#EXTINF:2\.000,\n\/api\/cctv\/media\/a\/seg_3\.ts/,
+  );
   await manager.shutdown();
 });
 
 test('upstream discontinuity tags survive the media parser', () => {
-  const parsed = parseHlsMedia(playlist.replace('a.ts', 'a.ts\n#EXT-X-DISCONTINUITY'), base);
+  const parsed = parseHlsMedia(
+    playlist.replace('a.ts', 'a.ts\n#EXT-X-DISCONTINUITY'),
+    base,
+  );
   assert.equal(parsed[0].discontinuity, false);
   assert.equal(parsed[1].discontinuity, true);
 });
 
 test('a reused agency sequence with changed segment URI cannot remain stale', async () => {
   let current = playlist;
-  const manager = createHlsPuller({ limits: { ...HLS_LIMITS, pollMs: 5 }, fetchImpl: async (url) => new Response(url.endsWith('.m3u8') ? current : 'abc') });
+  const manager = createHlsPuller({
+    limits: { ...HLS_LIMITS, pollMs: 5 },
+    fetchImpl: async (url) =>
+      new Response(url.endsWith('.m3u8') ? current : 'abc'),
+  });
   const entry = await manager.ensure('a', base);
   await manager.waitReady(entry);
   current = playlist.replaceAll('.ts', '.ts?generation=2');
   await new Promise((r) => setTimeout(r, 30));
-  assert.match(await manager.buildPlaylist(entry, 'a'), /#EXT-X-DISCONTINUITY\n#EXTINF:2\.000,\n\/api\/cctv\/media\/a\/seg_3\.ts/);
+  assert.match(
+    await manager.buildPlaylist(entry, 'a'),
+    /#EXT-X-DISCONTINUITY\n#EXTINF:2\.000,\n\/api\/cctv\/media\/a\/seg_3\.ts/,
+  );
   await manager.shutdown();
 });
 
 test('two consumers share downloads but release and abandoned expiry are independent', async () => {
   let downloads = 0;
-  const manager = createHlsPuller({ limits: { ...HLS_LIMITS, pollMs: 100000, leasesPerSession: 2 }, fetchImpl: async (url) => {
-    downloads++;
-    return new Response(url.endsWith('.m3u8') ? playlist : 'abc');
-  } });
-  const [a, b] = await Promise.all([manager.ensure('camera', base, 'viewer-a'), manager.ensure('camera', base, 'viewer-b')]);
+  const manager = createHlsPuller({
+    limits: { ...HLS_LIMITS, pollMs: 100000, leasesPerSession: 2 },
+    fetchImpl: async (url) => {
+      downloads++;
+      return new Response(url.endsWith('.m3u8') ? playlist : 'abc');
+    },
+  });
+  const [a, b] = await Promise.all([
+    manager.ensure('camera', base, 'viewer-a'),
+    manager.ensure('camera', base, 'viewer-b'),
+  ]);
   assert.equal(a, b);
   await manager.waitReady(a);
   assert.equal(downloads, 4); // One manifest and three segments, not per consumer.
@@ -105,7 +195,10 @@ test('two consumers share downloads but release and abandoned expiry are indepen
   assert.equal(manager.stats().sessions, 1);
   assert.equal(manager.getSegment('camera', a.token, 0, 'viewer-a'), null);
   assert.equal(manager.getSegment('camera', a.token, 0, 'viewer-b').length, 3);
-  assert.match(await manager.buildPlaylist(b, 'camera', 'viewer-b'), /lease=viewer-b/);
+  assert.match(
+    await manager.buildPlaylist(b, 'camera', 'viewer-b'),
+    /lease=viewer-b/,
+  );
   manager.release('camera', 'viewer-a'); // Duplicate/late release cannot stop B.
   assert.equal(b.controller.signal.aborted, false);
   manager.release('camera', 'viewer-b');
@@ -115,7 +208,11 @@ test('two consumers share downloads but release and abandoned expiry are indepen
 });
 
 test('an abandoned consumer expires while a renewed consumer keeps the session', async () => {
-  const manager = createHlsPuller({ limits: { ...HLS_LIMITS, idleMs: 80, pollMs: 100000 }, fetchImpl: async (url) => new Response(url.endsWith('.m3u8') ? playlist : 'abc') });
+  const manager = createHlsPuller({
+    limits: { ...HLS_LIMITS, idleMs: 80, pollMs: 100000 },
+    fetchImpl: async (url) =>
+      new Response(url.endsWith('.m3u8') ? playlist : 'abc'),
+  });
   const entry = await manager.ensure('camera', base, 'abandoned');
   await manager.ensure('camera', base, 'active');
   await new Promise((r) => setTimeout(r, 50));

src/layers/cctv/presentation.js

@@ -83,7 +83,9 @@ export function createPresentation({
       mountHeightM: camera.mountHeightM,
       active: isActive,
       feedType: camera.feedType,
-      isVideo: parts.model.isVideoFeedType(camera.feedType) && record.projection?.mode !== 'image',
+      isVideo:
+        parts.model.isVideoFeedType(camera.feedType) &&
+        record.projection?.mode !== 'image',
       sourceKind:
         health?.sourceKind ||
         camera.sourceKind ||

src/layers/cctv/projection.js

@@ -233,20 +233,32 @@ export function createProjection({
       video.addEventListener('loadedmetadata', bindVideoTexture);
       video.addEventListener('resize', bindVideoTexture);
       runtime.video = video;
-      runtime.playback = attachCctvVideo(video, parts.frames.mediaUrlFor(record.camera), feedType, {
-        onFailure: () => {
-          if (runtime.disposed) return;
-          runtime.video = null;
-          runtime.mode = 'image';
-          runtime.image = new Image();
-          runtime.image.decoding = 'async';
-          runtime.image.onload = () => { runtime.imageLoading = false; runtime.imageReady = true; runtime.imageStamp = Date.now(); };
-          runtime.image.onerror = () => { runtime.imageLoading = false; runtime.imageReady = false; };
-          runtime.planeMaterial.image = runtime.canvas;
-          parts.frames.refreshProjectionImage(record, true);
-          parts.presentation.notifyListeners();
+      runtime.playback = attachCctvVideo(
+        video,
+        parts.frames.mediaUrlFor(record.camera),
+        feedType,
+        {
+          onFailure: () => {
+            if (runtime.disposed) return;
+            runtime.video = null;
+            runtime.mode = 'image';
+            runtime.image = new Image();
+            runtime.image.decoding = 'async';
+            runtime.image.onload = () => {
+              runtime.imageLoading = false;
+              runtime.imageReady = true;
+              runtime.imageStamp = Date.now();
+            };
+            runtime.image.onerror = () => {
+              runtime.imageLoading = false;
+              runtime.imageReady = false;
+            };
+            runtime.planeMaterial.image = runtime.canvas;
+            parts.frames.refreshProjectionImage(record, true);
+            parts.presentation.notifyListeners();
+          },
         },
-      });
+      );
     } else {
       const img = new Image();
       img.decoding = 'async';
@@ -294,7 +306,8 @@ export function createProjection({
 
   function ensureProjectionRuntime(record) {
     if (!record) return null;
-    if (record.projection && !record.projection.disposed) return record.projection;
+    if (record.projection && !record.projection.disposed)
+      return record.projection;
     const runtime = createProjectionRuntime(record);
     record.projection = runtime;
     if (runtime) {
@@ -314,7 +327,11 @@ export function createProjection({
     runtime.disposed = true;
     runtime.playback?.dispose();
     runtime.playback = null;
-    if (runtime.image) { runtime.image.onload = null; runtime.image.onerror = null; runtime.image.src = ''; }
+    if (runtime.image) {
+      runtime.image.onload = null;
+      runtime.image.onerror = null;
+      runtime.image.src = '';
+    }
     if (runtime.video) {
       runtime.video.pause();
       runtime.video.removeAttribute('src');
@@ -392,16 +409,15 @@ export function createProjection({
   function pauseInactiveProjectionFeeds(activeId) {
     for (const record of layerState._records) {
       if (!record.projection?.video) continue;
-      if (
-        record.camera.id === activeId &&
-        layerState._enabled
-      ) {
+      if (record.camera.id === activeId && layerState._enabled) {
         record.projection.video.play().catch(() => {});
       } else {
         const runtime = record.projection;
         destroyProjectionRuntime(runtime);
         record.projection = null;
-        layerState._projectionEntities = layerState._projectionEntities.filter((entry) => entry !== runtime);
+        layerState._projectionEntities = layerState._projectionEntities.filter(
+          (entry) => entry !== runtime,
+        );
       }
     }
   }

src/layers/cctv/rendering.js

@@ -215,7 +215,12 @@ export function createRendering({
         // (set at creation) — see the field-test far-zoom submerge fix there.
       }
 
-      if (layerState._enabled && isActive && (layerState._showProjection || parts.model.isVideoFeedType(record.camera.feedType))) {
+      if (
+        layerState._enabled &&
+        isActive &&
+        (layerState._showProjection ||
+          parts.model.isVideoFeedType(record.camera.feedType))
+      ) {
         parts.projection.ensureProjectionRuntime(record);
       }
       // One live plane in the world at a time (§2c): only the active camera's

src/layers/cctv/videoPlayback.js

@@ -1,20 +1,30 @@
 /** One decoder per active camera; both surfaces consume this video element. */
-export function attachCctvVideo(video, url, feedType, {
-  loadHls = () => import('hls.js'),
-  onFailure = () => {},
-  fetchImpl = globalThis.fetch,
-} = {}) {
+export function attachCctvVideo(
+  video,
+  url,
+  feedType,
+  {
+    loadHls = () => import('hls.js'),
+    onFailure = () => {},
+    fetchImpl = globalThis.fetch,
+  } = {},
+) {
   let disposed = false;
   let hls = null;
   const leaseId = feedType === 'hls' ? globalThis.crypto.randomUUID() : null;
-  const mediaUrl = feedType === 'hls' ? `${url}${url.includes('?') ? '&' : '?'}lease=${leaseId}` : url;
+  const mediaUrl =
+    feedType === 'hls'
+      ? `${url}${url.includes('?') ? '&' : '?'}lease=${leaseId}`
+      : url;
   let timer = null;
   let startup = null;
   let governor = null;
   let retries = 0;
   const release = () => {
     if (feedType === 'hls') {
-      void fetchImpl?.(mediaUrl, { method: 'DELETE', keepalive: true }).catch(() => {});
+      void fetchImpl?.(mediaUrl, { method: 'DELETE', keepalive: true }).catch(
+        () => {},
+      );
     }
   };
   const dispose = () => {
@@ -46,19 +56,33 @@ export function attachCctvVideo(video, url, feedType, {
   video.addEventListener('error', fail);
   startup = setTimeout(fail, 30000);
   const ready = (async () => {
-    if (feedType !== 'hls') { video.src = mediaUrl; return; }
+    if (feedType !== 'hls') {
+      video.src = mediaUrl;
+      return;
+    }
     try {
       const { default: Hls } = await loadHls();
       if (disposed) return;
       if (!Hls.isSupported()) {
-        if (video.canPlayType('application/vnd.apple.mpegurl')) video.src = mediaUrl;
+        if (video.canPlayType('application/vnd.apple.mpegurl'))
+          video.src = mediaUrl;
         else fail();
         return;
       }
-      hls = new Hls({ enableWorker: true, maxBufferLength: 24, maxMaxBufferLength: 30, backBufferLength: 0, maxBufferSize: 16 * 1024 * 1024, liveSyncDurationCount: 3 });
+      hls = new Hls({
+        enableWorker: true,
+        maxBufferLength: 24,
+        maxMaxBufferLength: 30,
+        backBufferLength: 0,
+        maxBufferSize: 16 * 1024 * 1024,
+        liveSyncDurationCount: 3,
+      });
       hls.on(Hls.Events.ERROR, (_event, data) => {
         if (disposed || !data?.fatal) return;
-        if (++retries > 2) { fail(); return; }
+        if (++retries > 2) {
+          fail();
+          return;
+        }
         clearTimeout(timer);
         timer = setTimeout(() => {
           if (disposed) return;
@@ -68,14 +92,18 @@ export function attachCctvVideo(video, url, feedType, {
       });
       governor = setInterval(() => {
         if (disposed || !video.buffered?.length) return;
-        const ahead = video.buffered.end(video.buffered.length - 1) - video.currentTime;
+        const ahead =
+          video.buffered.end(video.buffered.length - 1) - video.currentTime;
         // Some agency encoders publish less media time than wall time. Bound
         // correction rather than repeatedly draining the live buffer at 1x.
-        video.playbackRate = ahead < 6 ? 0.8 : ahead < 12 ? 0.9 : ahead > 24 ? 1.05 : 1;
+        video.playbackRate =
+          ahead < 6 ? 0.8 : ahead < 12 ? 0.9 : ahead > 24 ? 1.05 : 1;
       }, 1000);
       hls.attachMedia(video);
       hls.loadSource(mediaUrl);
-    } catch { fail(); }
+    } catch {
+      fail();
+    }
   })();
   return { dispose, ready };
 }

src/layers/cctv/videoPlayback.test.mjs

@@ -3,15 +3,33 @@ import assert from 'node:assert/strict';
 import { attachCctvVideo } from './videoPlayback.js';
 function video() {
   const v = new EventTarget();
-  Object.assign(v, { src: '', pause() {}, load() {}, removeAttribute() {}, play: () => Promise.resolve() });
+  Object.assign(v, {
+    src: '',
+    pause() {},
+    load() {},
+    removeAttribute() {},
+    play: () => Promise.resolve(),
+  });
   return v;
 }
 test('switch during lazy import never starts the stale decoder', async () => {
   let resolve;
   let constructed = 0;
-  class Hls { constructor() { constructed++; } static isSupported() { return true; } }
+  class Hls {
+    constructor() {
+      constructed++;
+    }
+    static isSupported() {
+      return true;
+    }
+  }
   const source = video();
-  const playback = attachCctvVideo(source, '/api/cctv/media/a', 'hls', { loadHls: () => new Promise((r) => { resolve = r; }) });
+  const playback = attachCctvVideo(source, '/api/cctv/media/a', 'hls', {
+    loadHls: () =>
+      new Promise((r) => {
+        resolve = r;
+      }),
+  });
   playback.dispose();
   resolve({ default: Hls });
   await playback.ready;
@@ -20,7 +38,12 @@ test('switch during lazy import never starts the stale decoder', async () => {
 });
 test('missing decoder uses honest failure fallback once', async () => {
   let failures = 0;
-  const playback = attachCctvVideo(video(), '/api/cctv/media/a', 'hls', { loadHls: async () => { throw new Error('unavailable'); }, onFailure: () => failures++ });
+  const playback = attachCctvVideo(video(), '/api/cctv/media/a', 'hls', {
+    loadHls: async () => {
+      throw new Error('unavailable');
+    },
+    onFailure: () => failures++,
+  });
   await playback.ready;
   playback.dispose();
   assert.equal(failures, 1);
@@ -32,7 +55,9 @@ test('native HLS releases its client lease without response-header access', asyn
   const releases = [];
   const playback = attachCctvVideo(source, '/api/cctv/media/a', 'hls', {
     loadHls: async () => ({ default: { isSupported: () => false } }),
-    fetchImpl: async (url, init) => { releases.push({ url, init }); },
+    fetchImpl: async (url, init) => {
+      releases.push({ url, init });
+    },
   });
   await playback.ready;
   assert.match(source.src, /\/api\/cctv\/media\/a\?lease=[a-f0-9-]{36}$/);

src/ui/cctvControls.js

@@ -39,9 +39,17 @@ export class CctvControls {
     this._actionGeneration = 0;
     this._initCctvPanel();
     if (this._cctvVideo && typeof MutationObserver !== 'undefined') {
-      this._videoVisibilityObserver = new MutationObserver(() => this._renderCctvState(this._cctvState));
-      if (this._cctvPanel) this._videoVisibilityObserver.observe(this._cctvPanel, { attributes: true, attributeFilter: ['class', 'hidden'] });
-      this.listen(document, 'visibilitychange', () => this._renderCctvState(this._cctvState));
+      this._videoVisibilityObserver = new MutationObserver(() =>
+        this._renderCctvState(this._cctvState),
+      );
+      if (this._cctvPanel)
+        this._videoVisibilityObserver.observe(this._cctvPanel, {
+          attributes: true,
+          attributeFilter: ['class', 'hidden'],
+        });
+      this.listen(document, 'visibilitychange', () =>
+        this._renderCctvState(this._cctvState),
+      );
     }
   }
   listen(target, type, handler, options = {}) {

src/ui/cctvPresentation.js

@@ -169,14 +169,19 @@ export function _renderCctvState(state) {
   if (this._cctvVideo) {
     this._cctvVideo.hidden = !liveIntent;
     if (this._cctvFrame) this._cctvFrame.hidden = liveIntent;
-    const visible = liveIntent && !document.hidden && !this._cctvPanel?.classList.contains('collapsed');
+    const visible =
+      liveIntent &&
+      !document.hidden &&
+      !this._cctvPanel?.classList.contains('collapsed');
     if (!visible || this._cctvVideoCameraId !== activeId) {
       this._cctvVideoSurface?.stop();
       this._cctvVideoSurface = null;
     }
     this._cctvVideoCameraId = activeId;
     if (visible && !this._cctvVideoSurface) {
-      this._cctvVideoSurface = createCctvVideoSurface(this._cctvVideo, () => this.cctv.getActiveVideoElement?.());
+      this._cctvVideoSurface = createCctvVideoSurface(this._cctvVideo, () =>
+        this.cctv.getActiveVideoElement?.(),
+      );
     }
   }
 

src/ui/cctvVideo.js

@@ -1,5 +1,12 @@
 /** Paint a second surface from the projection decoder, bounded to 640px/15 fps. */
-export function createCctvVideoSurface(canvas, getVideo, { requestFrame = requestAnimationFrame, cancelFrame = cancelAnimationFrame } = {}) {
+export function createCctvVideoSurface(
+  canvas,
+  getVideo,
+  {
+    requestFrame = requestAnimationFrame,
+    cancelFrame = cancelAnimationFrame,
+  } = {},
+) {
   const ctx = canvas.getContext('2d');
   let handle = 0;
   let stopped = false;
@@ -14,18 +21,39 @@ export function createCctvVideoSurface(canvas, getVideo, { requestFrame = reques
       previous = video;
       previousTime = -1;
     }
-    if (ctx && video?.readyState >= 2 && video.videoWidth > 0 && video.videoHeight > 0 && now - paintedAt >= 1000 / 15 && video.currentTime !== previousTime) {
+    if (
+      ctx &&
+      video?.readyState >= 2 &&
+      video.videoWidth > 0 &&
+      video.videoHeight > 0 &&
+      now - paintedAt >= 1000 / 15 &&
+      video.currentTime !== previousTime
+    ) {
       const width = Math.min(640, video.videoWidth);
-      const height = Math.max(1, Math.round(width * video.videoHeight / video.videoWidth));
-      if (canvas.width !== width || canvas.height !== height) { canvas.width = width; canvas.height = height; }
+      const height = Math.max(
+        1,
+        Math.round((width * video.videoHeight) / video.videoWidth),
+      );
+      if (canvas.width !== width || canvas.height !== height) {
+        canvas.width = width;
+        canvas.height = height;
+      }
       try {
         ctx.drawImage(video, 0, 0, width, height);
         previousTime = video.currentTime;
         paintedAt = now;
-      } catch { /* A resolution/decode transition retries on the next frame. */ }
+      } catch {
+        /* A resolution/decode transition retries on the next frame. */
+      }
     }
     handle = requestFrame(paint);
   };
   handle = requestFrame(paint);
-  return { stop() { stopped = true; cancelFrame(handle); ctx?.clearRect(0, 0, canvas.width, canvas.height); } };
+  return {
+    stop() {
+      stopped = true;
+      cancelFrame(handle);
+      ctx?.clearRect(0, 0, canvas.width, canvas.height);
+    },
+  };
 }

src/ui/cctvVideo.test.mjs

@@ -6,16 +6,35 @@ test('second surface uses shared decoder, caps draws, clears switch and cancels
   let draws = 0;
   let clears = 0;
   let cancelled = 0;
-  const canvas = { width: 1, height: 1, getContext: () => ({ drawImage: () => draws++, clearRect: () => clears++ }) };
-  let v = { readyState: 2, videoWidth: 1920, videoHeight: 1080, currentTime: 1 };
-  const surface = createCctvVideoSurface(canvas, () => v, { requestFrame: (fn) => { callback = fn; return 1; }, cancelFrame: () => cancelled++ });
-  callback(0); callback(20); callback(80);
+  const canvas = {
+    width: 1,
+    height: 1,
+    getContext: () => ({ drawImage: () => draws++, clearRect: () => clears++ }),
+  };
+  let v = {
+    readyState: 2,
+    videoWidth: 1920,
+    videoHeight: 1080,
+    currentTime: 1,
+  };
+  const surface = createCctvVideoSurface(canvas, () => v, {
+    requestFrame: (fn) => {
+      callback = fn;
+      return 1;
+    },
+    cancelFrame: () => cancelled++,
+  });
+  callback(0);
+  callback(20);
+  callback(80);
   assert.equal(draws, 1);
   assert.equal(canvas.width, 640);
-  v = { ...v }; callback(160);
+  v = { ...v };
+  callback(160);
   assert.equal(draws, 2);
   assert.equal(clears, 2);
-  surface.stop(); callback(200);
+  surface.stop();
+  callback(200);
   assert.equal(cancelled, 1);
   assert.equal(draws, 2);
 });