From 98fa41dcf08320c860c636d687ec5ff173c0d917 Mon Sep 17 00:00:00 2001
From: Hampus <hampus@fluxer.app>
Date: Fri, 2 Oct 2026 22:52:03 +0200
Subject: [PATCH] fix(voice): avoid capped software h264 for auto screen shares
 (#3139)

---
 .../voice/utils/CodecCapabilityDetector.ts         |  3 ++-
 .../voice/utils/ScreenShareCodecSelection.ts       | 14 ++++++++++----
 .../src/features/voice/utils/ScreenShareOptions.ts |  7 +++++--
 3 files changed, 17 insertions(+), 7 deletions(-)

diff --git a/fluxer_app/src/features/voice/utils/CodecCapabilityDetector.ts b/fluxer_app/src/features/voice/utils/CodecCapabilityDetector.ts
index 99aa131a6..50f6f1abd 100644
--- a/fluxer_app/src/features/voice/utils/CodecCapabilityDetector.ts
+++ b/fluxer_app/src/features/voice/utils/CodecCapabilityDetector.ts
@@ -24,7 +24,7 @@ import {
 	type ScreenShareCodecProfileEntry,
 	type ScreenShareCodecRanking,
 } from '@app/features/voice/utils/ScreenShareCodecSelection';
-import {normaliseStreamingModeForContext} from '@app/features/voice/utils/ScreenShareOptions';
+import {isH264SoftwareClamped, normaliseStreamingModeForContext} from '@app/features/voice/utils/ScreenShareOptions';
 import {getProbedVideoDecoderExclusionsSync} from '@app/features/voice/utils/VideoDecoderCapabilities';
 import type {TrackPublishDefaults, TrackPublishOptions} from 'livekit-client';
 import {BackupCodecPolicy, supportsVideoCodec, type VideoCodec, type VideoEncoding} from 'livekit-client';
@@ -410,6 +410,7 @@ export function buildScreenShareCodecProfile(): ScreenShareCodecProfile {
 			h265: entry('h265'),
 			av1: entry('av1'),
 		},
+		h264SoftwareClamped: isH264SoftwareClamped(),
 	};
 }
 
diff --git a/fluxer_app/src/features/voice/utils/ScreenShareCodecSelection.ts b/fluxer_app/src/features/voice/utils/ScreenShareCodecSelection.ts
index 198eabde5..b9c431e21 100644
--- a/fluxer_app/src/features/voice/utils/ScreenShareCodecSelection.ts
+++ b/fluxer_app/src/features/voice/utils/ScreenShareCodecSelection.ts
@@ -5,6 +5,7 @@ import type {VideoCodec} from 'livekit-client';
 
 export const CODEC_PREFERENCE: ReadonlyArray<VideoCodec> = ['av1', 'h265', 'h264', 'vp9', 'vp8'];
 const SOFTWARE_H264_CODEC_PREFERENCE: ReadonlyArray<VideoCodec> = ['av1', 'h265', 'vp9', 'h264', 'vp8'];
+const CLAMPED_H264_CODEC_PREFERENCE: ReadonlyArray<VideoCodec> = ['av1', 'h265', 'vp9', 'vp8', 'h264'];
 const GECKO_CODEC_PREFERENCE: ReadonlyArray<VideoCodec> = ['vp8', 'h264'];
 const COMPATIBILITY_CODECS: ReadonlySet<VideoCodec> = new Set(['h264', 'vp9', 'vp8']);
 export const LAST_RESORT_VIDEO_CODEC: VideoCodec = 'vp8';
@@ -79,6 +80,7 @@ export interface ScreenShareCodecProfile {
 	browser: ScreenShareCodecBrowser;
 	desktop: boolean;
 	codecs: Record<VideoCodec, ScreenShareCodecProfileEntry>;
+	h264SoftwareClamped?: boolean;
 }
 
 export interface ScreenShareCodecRankingInput {
@@ -94,7 +96,9 @@ export interface ScreenShareCodecRanking {
 
 export function rankScreenShareCodecs(input: ScreenShareCodecRankingInput): ScreenShareCodecRanking {
 	const {codecs} = input.profile;
-	const isHardware = (codec: VideoCodec): boolean => codecs[codec].supported && codecs[codec].hardware;
+	const h264Clamped = input.profile.h264SoftwareClamped === true;
+	const isHardware = (codec: VideoCodec): boolean =>
+		codecs[codec].supported && codecs[codec].hardware && !(codec === 'h264' && h264Clamped);
 	const hardwareAvailable = CODEC_PREFERENCE.some((codec) => isHardware(codec));
 	const pin = input.pin !== 'auto' && codecs[input.pin].allowed && codecs[input.pin].supported ? input.pin : null;
 	const baselineOnly =
@@ -108,9 +112,11 @@ export function rankScreenShareCodecs(input: ScreenShareCodecRankingInput): Scre
 	const preference =
 		input.profile.browser === 'firefox'
 			? GECKO_CODEC_PREFERENCE
-			: isHardware('h264')
-				? CODEC_PREFERENCE
-				: SOFTWARE_H264_CODEC_PREFERENCE;
+			: h264Clamped
+				? CLAMPED_H264_CODEC_PREFERENCE
+				: isHardware('h264')
+					? CODEC_PREFERENCE
+					: SOFTWARE_H264_CODEC_PREFERENCE;
 	const survivors = preference.filter(survives);
 	const ranked =
 		input.encoderModeSetting === 'software'
diff --git a/fluxer_app/src/features/voice/utils/ScreenShareOptions.ts b/fluxer_app/src/features/voice/utils/ScreenShareOptions.ts
index 36682260d..8da8e2f78 100644
--- a/fluxer_app/src/features/voice/utils/ScreenShareOptions.ts
+++ b/fluxer_app/src/features/voice/utils/ScreenShareOptions.ts
@@ -330,11 +330,14 @@ export function resolveScreenShareDegradationPreference(
 	return 'maintain-framerate';
 }
 
-function shouldClampToSoftwareH264(codec: VideoCodec | undefined): boolean {
-	if (codec !== 'h264') return false;
+export function isH264SoftwareClamped(): boolean {
 	return getH264HardwareProfilesSync()?.profiles.size === 0;
 }
 
+function shouldClampToSoftwareH264(codec: VideoCodec | undefined): boolean {
+	return codec === 'h264' && isH264SoftwareClamped();
+}
+
 function clampToSoftwareH264Budget(quality: {
 	mode: StreamingMode;
 	resolution: ScreenshareResolution;