Limit requested qualities to 4 Full / 16 Medium.

Telegram/SourceFiles/calls/group/calls_group_call.cpp

@@ -49,6 +49,8 @@ constexpr auto kUpdateSendActionEach = crl::time(500);
 constexpr auto kPlayConnectingEach = crl::time(1056) + 2 * crl::time(1000);
 constexpr auto kFixManualLargeVideoDuration = 5 * crl::time(1000);
 constexpr auto kFixSpeakingLargeVideoDuration = 3 * crl::time(1000);
+constexpr auto kFullAsMediumsCount = 4; // 1 Full is like 4 Mediums.
+constexpr auto kMaxMediumQualities = 16; // 4 Fulls or 16 Mediums.
 
 [[nodiscard]] std::unique_ptr<Webrtc::MediaDevices> CreateMediaDevices() {
 	const auto &settings = Core::App().settings();
@@ -2435,6 +2437,9 @@ void GroupCall::updateRequestedVideoChannels() {
 	channels.reserve(_activeVideoTracks.size());
 	const auto &camera = cameraSharingEndpoint();
 	const auto &screen = screenSharingEndpoint();
+	auto mediums = 0;
+	auto fullcameras = 0;
+	auto fullscreencasts = 0;
 	for (const auto &[endpoint, video] : _activeVideoTracks) {
 		const auto &endpointId = endpoint.id;
 		if (endpointId == camera || endpointId == screen) {
@@ -2447,24 +2452,74 @@ void GroupCall::updateRequestedVideoChannels() {
 		if (!params) {
 			continue;
 		}
+		const auto min = (video->quality == Group::VideoQuality::Full
+			&& endpoint.type == VideoEndpointType::Screen)
+			? Quality::Full
+			: Quality::Thumbnail;
+		const auto max = (video->quality == Group::VideoQuality::Full)
+			? Quality::Full
+			: (video->quality == Group::VideoQuality::Medium
+				&& endpoint.type != VideoEndpointType::Screen)
+			? Quality::Medium
+			: Quality::Thumbnail;
+		if (max == Quality::Full) {
+			if (endpoint.type == VideoEndpointType::Screen) {
+				++fullscreencasts;
+			} else {
+				++fullcameras;
+			}
+		} else if (max == Quality::Medium) {
+			++mediums;
+		}
 		channels.push_back({
 			.audioSsrc = participant->ssrc,
 			.endpointId = endpointId,
 			.ssrcGroups = (params->camera.endpointId == endpointId
 				? params->camera.ssrcGroups
 				: params->screen.ssrcGroups),
-			.minQuality = ((video->quality == Group::VideoQuality::Full
+			.minQuality = min,
-				&& endpoint.type == VideoEndpointType::Screen)
+			.maxQuality = max,
-				? Quality::Full
-				: Quality::Thumbnail),
-			.maxQuality = ((video->quality == Group::VideoQuality::Full)
-				? Quality::Full
-				: (video->quality == Group::VideoQuality::Medium
-					&& endpoint.type != VideoEndpointType::Screen)
-				? Quality::Medium
-				: Quality::Thumbnail),
 		});
 	}
+
+	// We limit `count(Full) * kFullAsMediumsCount + count(medium)`.
+	//
+	// Try to preserve all qualities; If not
+	// Try to preserve all screencasts as Full and cameras as Medium; If not
+	// Try to preserve all screencasts as Full; If not
+	// Try to preserve all cameras as Medium;
+	const auto mediumsCount = mediums
+		+ (fullcameras + fullscreencasts) * kFullAsMediumsCount;
+	const auto downgradeSome = (mediumsCount > kMaxMediumQualities);
+	const auto downgradeAll = (fullscreencasts * kFullAsMediumsCount)
+		> kMaxMediumQualities;
+	if (downgradeSome) {
+		for (auto &channel : channels) {
+			if (channel.maxQuality == Quality::Full) {
+				const auto camera = (channel.minQuality != Quality::Full);
+				if (camera) {
+					channel.maxQuality = Quality::Medium;
+				} else if (downgradeAll) {
+					channel.maxQuality
+						= channel.minQuality
+						= Quality::Thumbnail;
+					--fullscreencasts;
+				}
+			}
+		}
+		mediums += fullcameras;
+		fullcameras = 0;
+		if (downgradeAll) {
+			fullscreencasts = 0;
+		}
+	}
+	if (mediums > kMaxMediumQualities) {
+		for (auto &channel : channels) {
+			if (channel.maxQuality == Quality::Medium) {
+				channel.maxQuality = Quality::Thumbnail;
+			}
+		}
+	}
 	_instance->setRequestedVideoChannels(std::move(channels));
 }
 

Telegram/SourceFiles/calls/group/calls_group_viewport.cpp

@@ -191,7 +191,7 @@ void Viewport::updateSelected(QPoint position) {
 		return;
 	}
 	for (const auto &tile : _tiles) {
-		const auto geometry = tile->shown()
+		const auto geometry = tile->visible()
 			? tile->geometry()
 			: QRect();
 		if (geometry.contains(position)) {
@@ -763,7 +763,11 @@ void Viewport::setTileGeometry(not_null<VideoTile*> tile, QRect geometry) {
 	const auto kMedium = style::ConvertScale(540);
 	const auto kSmall = style::ConvertScale(240);
 	const auto &endpoint = tile->endpoint();
-	const auto quality = (min >= kMedium)
+	const auto forceThumbnailQuality = !wide()
+		&& (ranges::count(_tiles, false, &VideoTile::hidden) > 1);
+	const auto quality = forceThumbnailQuality
+		? VideoQuality::Thumbnail
+		: (min >= kMedium)
 		? VideoQuality::Full
 		: (min >= kSmall)
 		? VideoQuality::Medium

Telegram/SourceFiles/calls/group/calls_group_viewport_opengl.cpp

@@ -439,7 +439,7 @@ void Viewport::RendererGL::paint(
 	validateDatas();
 	auto index = 0;
 	for (const auto &tile : _owner->_tiles) {
-		if (!tile->shown()) {
+		if (!tile->visible()) {
 			index++;
 			continue;
 		}

Telegram/SourceFiles/calls/group/calls_group_viewport_raster.cpp

@@ -45,7 +45,7 @@ void Viewport::RendererSW::paintFallback(
 		tileData.stale = true;
 	}
 	for (const auto &tile : _owner->_tiles) {
-		if (!tile->shown()) {
+		if (!tile->visible()) {
 			continue;
 		}
 		paintTile(p, tile.get(), bounding, bg);

Telegram/SourceFiles/calls/group/calls_group_viewport_tile.cpp

@@ -82,14 +82,14 @@ bool Viewport::VideoTile::screencast() const {
 void Viewport::VideoTile::setGeometry(
 		QRect geometry,
 		TileAnimation animation) {
-	_shown = true;
+	_hidden = false;
 	_geometry = geometry;
 	_animation = animation;
 	updateTopControlsPosition();
 }
 
 void Viewport::VideoTile::hide() {
-	_shown = false;
+	_hidden = true;
 	_quality = std::nullopt;
 }
 
@@ -106,7 +106,7 @@ void Viewport::VideoTile::toggleTopControlsShown(bool shown) {
 }
 
 bool Viewport::VideoTile::updateRequestedQuality(VideoQuality quality) {
-	if (!_shown) {
+	if (_hidden) {
 		_quality = std::nullopt;
 		return false;
 	} else if (_quality && *_quality == quality) {
@@ -249,7 +249,7 @@ void Viewport::VideoTile::setup(rpl::producer<bool> pinned) {
 	}) | rpl::start_with_next([=](bool pinned) {
 		_pinned = pinned;
 		updateTopControlsSize();
-		if (_shown) {
+		if (!_hidden) {
 			updateTopControlsPosition();
 			_update();
 		}

Telegram/SourceFiles/calls/group/calls_group_viewport_tile.h

@@ -45,8 +45,11 @@ public:
 	[[nodiscard]] bool pinned() const {
 		return _pinned;
 	}
-	[[nodiscard]] bool shown() const {
+	[[nodiscard]] bool hidden() const {
-		return _shown && !_geometry.isEmpty();
+		return _hidden;
+	}
+	[[nodiscard]] bool visible() const {
+		return !_hidden && !_geometry.isEmpty();
 	}
 	[[nodiscard]] QRect pinOuter() const;
 	[[nodiscard]] QRect pinInner() const;
@@ -115,7 +118,7 @@ private:
 	Ui::Animations::Simple _topControlsShownAnimation;
 	bool _topControlsShown = false;
 	bool _pinned = false;
-	bool _shown = false;
+	bool _hidden = true;
 	std::optional<VideoQuality> _quality;
 
 	rpl::lifetime _lifetime;