From 7d792c33bf5c0a65056e1e4ab17a328d358663cc Mon Sep 17 00:00:00 2001
From: Lotus CI <ci@lotusguild.org>
Date: Mon, 29 Jun 2026 23:38:45 -0400
Subject: [PATCH] lotus(#7): fix screenshare cap per review

- Apply the encoding patch to ALL simulcast layers, not just encodings[0]:
  screenshare publishes simulcast (VP8), so the full-res layer (the real
  bandwidth hog) was left uncapped (CRITICAL).
- Re-apply on TrackUnmuted/restart + a 500ms settle, since LiveKit's
  refreshSenderEncodings() overwrites our caps on replaceTrack (device/
  source switch, processor toggle) without firing LocalTrackPublished (HIGH).
- Clamp values to sane ranges so a typo can't brick the encoder (MED).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/lotus/lotusQuality.ts | 49 +++++++++++++++++++++++++--------------
 1 file changed, 32 insertions(+), 17 deletions(-)

diff --git a/src/lotus/lotusQuality.ts b/src/lotus/lotusQuality.ts
index d35d604c..5fcea4ce 100644
--- a/src/lotus/lotusQuality.ts
+++ b/src/lotus/lotusQuality.ts
@@ -89,17 +89,24 @@ export function startLotusQuality(vm: CallViewModel): () => void {
     // Add listeners for new rooms + apply current settings to them.
     for (const room of next) {
       if (!roomListeners.has(room)) {
-        const onPublished = (): void => applyToRoom(room);
-        room.localParticipant.on(
+        // Re-apply on (re)publish AND unmute/track-restart: LiveKit's
+        // refreshSenderEncodings() overwrites maxBitrate/maxFramerate from the
+        // publish presets on replaceTrack (device/source switch, processor
+        // toggle, restart-on-unmute), and those paths don't emit
+        // LocalTrackPublished. The settle re-apply lands after LiveKit's async
+        // recompute so our cap wins.
+        const reapply = (): void => {
+          applyToRoom(room);
+          setTimeout(() => applyToRoom(room), 500);
+        };
+        const events = [
           ParticipantEvent.LocalTrackPublished,
-          onPublished,
-        );
-        roomListeners.set(room, () =>
-          room.localParticipant.off(
-            ParticipantEvent.LocalTrackPublished,
-            onPublished,
-          ),
-        );
+          ParticipantEvent.TrackUnmuted,
+        ] as const;
+        for (const e of events) room.localParticipant.on(e, reapply);
+        roomListeners.set(room, () => {
+          for (const e of events) room.localParticipant.off(e, reapply);
+        });
         applyToRoom(room);
       }
     }
@@ -109,14 +116,19 @@ export function startLotusQuality(vm: CallViewModel): () => void {
     void w.api.transport.reply(ev.detail, {});
     const data = ev.detail.data as Record<string, unknown> | undefined;
     if (!data) return;
-    for (const key of [
-      "audioMaxBitrate",
-      "screenshareMaxBitrate",
-      "screenshareMaxFramerate",
-    ] as const) {
+    // Clamp to sane ranges so a typo can't brick the encoder (e.g. a 1 bps mic).
+    const ranges: Record<keyof QualitySettings, [number, number]> = {
+      audioMaxBitrate: [6_000, 510_000],
+      screenshareMaxBitrate: [50_000, 20_000_000],
+      screenshareMaxFramerate: [1, 60],
+    };
+    for (const key of Object.keys(ranges) as (keyof QualitySettings)[]) {
       const v = data[key];
       if (v === null) settings[key] = undefined;
-      else if (typeof v === "number" && v > 0) settings[key] = v;
+      else if (typeof v === "number" && Number.isFinite(v)) {
+        const [lo, hi] = ranges[key];
+        settings[key] = Math.min(hi, Math.max(lo, v));
+      }
     }
     applyToAll();
   };
@@ -139,7 +151,10 @@ async function patchSender(
     const params = sender.getParameters();
     if (!params.encodings || params.encodings.length === 0)
       params.encodings = [{}];
-    Object.assign(params.encodings[0], patch);
+    // Apply to EVERY encoding, not just encodings[0]: screenshare publishes
+    // with simulcast (VP8), so encodings[0] is the small layer and the
+    // full-resolution layer — the real bandwidth hog — is a later encoding.
+    for (const enc of params.encodings) Object.assign(enc, patch);
     await sender.setParameters(params);
   } catch (e) {
     logger.warn("[lotus] set_quality: setParameters failed", e);