start of fix

Overlord-Client/cmd/agent/capture/capture.go

@@ -110,10 +110,9 @@ func CaptureAndSend(ctx context.Context, env *rt.Env) error {
 
 	if frame, captureDur, encodeDur, used, err := tryBuildDirectH264Frame(display); used {
 		if err != nil {
-			consecutiveCaptureFails.Add(1)
+			suppressDesktopHardwareH264(err)
-			log.Printf("capture: direct video capture failed: %v (sending black frame, consecutive=%d)", err, consecutiveCaptureFails.Load())
+			log.Printf("capture: direct video encode failed: %v; falling back to the software H.264 path", err)
-			return sendBlackFrame(ctx, env)
+		} else {
-		}
 			emitDesktopCursor(ctx, env, display, frame.Header.Width, frame.Header.Height)
 			if len(frame.Data) == 0 {
 				consecutiveCaptureFails.Store(0)
@@ -122,6 +121,7 @@ func CaptureAndSend(ctx context.Context, env *rt.Env) error {
 			consecutiveCaptureFails.Store(0)
 			return sendCompletedFrame(ctx, env, frame, display, t0, captureDur, encodeDur)
 		}
+	}
 
 	img, err := safeCaptureDisplay(display)
 	if err != nil {
@@ -145,7 +145,7 @@ func CaptureAndSend(ctx context.Context, env *rt.Env) error {
 	consecutiveCaptureFails.Store(0)
 	captureDur := time.Since(t0)
 
-	willSendViaWebRTC := blockCodec() == "h264" && webrtcpub.IsActive(webrtcpub.KindDesktop)
+	willSendViaWebRTC := desktopCodec() == "h264" && webrtcpub.IsActive(webrtcpub.KindDesktop)
 	var slotAcquired bool
 	if !willSendViaWebRTC {
 		if !AcquireFrameSlot() {
@@ -157,7 +157,7 @@ func CaptureAndSend(ctx context.Context, env *rt.Env) error {
 
 	frameWidth := img.Bounds().Dx()
 	frameHeight := img.Bounds().Dy()
-	quality := jpegQuality()
+	quality := desktopJPEGQuality()
 	frame, encodeDur, err := buildFrame(img, display, quality)
 	PutRGBA(img)
 	img = nil
@@ -413,7 +413,7 @@ func captureAllDisplaysAndSend(ctx context.Context, env *rt.Env) error {
 		PutRGBA(part.img)
 	}
 
-	quality := jpegQuality()
+	quality := desktopJPEGQuality()
 	frame, _, err := buildFrame(canvas, 0, quality)
 	canvasW, canvasH := canvas.Rect.Dx(), canvas.Rect.Dy()
 	PutRGBA(canvas)
@@ -482,6 +482,8 @@ func MonitorCount() int {
 
 const frameLogInterval = 5 * time.Second
 
+const desktopHardwareH264FallbackCooldown = 30 * time.Second
+
 var consecutiveCaptureFails atomic.Int64
 
 var (
@@ -511,10 +513,14 @@ var (
 	statBlockFallbacks  atomic.Int64
 	statFrameSlotSkips  atomic.Int64
 
-	overrideQuality     atomic.Int64
+	desktopOverrideQuality       atomic.Int64
-	overrideCodec       atomic.Value
+	backstageOverrideQuality     atomic.Int64
+	desktopOverrideCodec         atomic.Value
+	backstageOverrideCodec       atomic.Value
 	desktopSoftwareH264          atomic.Bool
+	desktopHardwareFallbackUntil atomic.Int64
 	h264WarnOnce                 sync.Once
+	backstageH264WarnOnce        sync.Once
 	hevcWarnOnce                 sync.Once
 	codecLogOnce                 sync.Once
 
@@ -645,7 +651,7 @@ func ResetPrevbackstage() {
 
 func RequestDesktopFullFrame() {
 	requestFullFrames(2)
-	webrtcpub.RequestKeyframe()
+	webrtcpub.RequestKeyframe(webrtcpub.KindDesktop)
 	RequestDesktopH264Keyframe()
 }
 
@@ -653,13 +659,27 @@ func SetDesktopSoftwareH264(enabled bool) {
 	if desktopSoftwareH264.Swap(enabled) == enabled {
 		return
 	}
+	desktopHardwareFallbackUntil.Store(0)
 	resetH264Encoder()
 	requestFullFrames(2)
 	log.Printf("capture: desktop software h264 %v", enabled)
 }
 
 func useDesktopSoftwareH264() bool {
-	return desktopSoftwareH264.Load()
+	if desktopSoftwareH264.Load() {
+		return true
+	}
+	until := desktopHardwareFallbackUntil.Load()
+	return until > 0 && time.Now().UnixNano() < until
+}
+
+func suppressDesktopHardwareH264(err error) {
+	until := time.Now().Add(desktopHardwareH264FallbackCooldown).UnixNano()
+	previous := desktopHardwareFallbackUntil.Swap(until)
+	resetH264Encoder()
+	if previous < time.Now().UnixNano() {
+		log.Printf("capture: hardware H.264 temporarily unavailable (%v); using software H.264 for %s", err, desktopHardwareH264FallbackCooldown)
+	}
 }
 
 func RequestbackstageFullFrame() {
@@ -667,12 +687,19 @@ func RequestbackstageFullFrame() {
 	backstagePrevFrame = nil
 	backstagePrevMu.Unlock()
 	backstageLastKeyframe.Store(0)
-	resetH264Encoderbackstage()
+	RequestBackstageH264Keyframe()
 }
 
-func jpegQuality() int {
+func desktopJPEGQuality() int {
+	return streamJPEGQuality(&desktopOverrideQuality)
+}
 
-	if q := overrideQuality.Load(); q > 0 {
+func backstageJPEGQuality() int {
+	return streamJPEGQuality(&backstageOverrideQuality)
+}
+
+func streamJPEGQuality(override *atomic.Int64) int {
+	if q := override.Load(); q > 0 {
 		return int(q)
 	}
 	q := int(loadOnceInt(&cachedJPEGQuality, 95))
@@ -761,13 +788,13 @@ func buildFrame(img *image.RGBA, display int, quality int) (wire.Frame, time.Dur
 	height := img.Bounds().Dy()
 	full := false
 	now := time.Now()
-	codec := blockCodec()
+	codec := desktopCodec()
 	if codec == "hevc" {
 		if width%2 != 0 || height%2 != 0 {
 			log.Printf("capture: hevc skipped for odd dimensions (%dx%d), falling back to h264/jpeg", width, height)
 			codec = "h264"
 		} else {
-			if webrtcpub.ConsumeKeyframeRequest() {
+			if webrtcpub.ConsumeKeyframeRequest(webrtcpub.KindDesktop) {
 				resetHEVCEncoder()
 			}
 			hevcBytes, err := encodeHEVCFrame(img)
@@ -782,10 +809,10 @@ func buildFrame(img *image.RGBA, display int, quality int) (wire.Frame, time.Dur
 			resetHEVCEncoder()
 			if h264Available() {
 				codec = "h264"
-				overrideCodec.Store("h264")
+				desktopOverrideCodec.Store("h264")
 			} else {
 				codec = "jpeg"
-				overrideCodec.Store("jpeg")
+				desktopOverrideCodec.Store("jpeg")
 			}
 		}
 	}
@@ -795,7 +822,7 @@ func buildFrame(img *image.RGBA, display int, quality int) (wire.Frame, time.Dur
 			log.Printf("capture: h264 skipped for odd dimensions (%dx%d), falling back to jpeg", width, height)
 			codec = "jpeg"
 		} else {
-			if webrtcpub.ConsumeKeyframeRequest() {
+			if webrtcpub.ConsumeKeyframeRequest(webrtcpub.KindDesktop) {
 				resetH264Encoder()
 			}
 			h264Bytes, err := encodeH264Frame(img)
@@ -892,7 +919,7 @@ func buildFramebackstage(img *image.RGBA, display int, quality int) (wire.Frame,
 	encStart := time.Now()
 	width := img.Bounds().Dx()
 	height := img.Bounds().Dy()
-	codec := blockCodec()
+	codec := backstageCodec()
 
 	now := time.Now()
 	if codec == "h264" {
@@ -900,7 +927,7 @@ func buildFramebackstage(img *image.RGBA, display int, quality int) (wire.Frame,
 			log.Printf("backstage capture: h264 skipped for odd dimensions (%dx%d), falling back to jpeg", width, height)
 			codec = "jpeg"
 		} else {
-			if webrtcpub.ConsumeKeyframeRequest() {
+			if webrtcpub.ConsumeKeyframeRequest(webrtcpub.Kindbackstage) {
 				resetH264Encoderbackstage()
 			}
 			h264Bytes, err := encodeH264Framebackstage(img)
@@ -910,7 +937,7 @@ func buildFramebackstage(img *image.RGBA, display int, quality int) (wire.Frame,
 				frame := wire.Frame{Type: "frame", Header: wire.FrameHeader{Monitor: display, FPS: 0, Format: "h264", Backstage: true}, Data: h264Bytes}
 				return frame, time.Since(encStart), nil
 			}
-			h264WarnOnce.Do(func() {
+			backstageH264WarnOnce.Do(func() {
 				detail := h264AvailabilityDetail()
 				if detail != "" {
 					log.Printf("backstage capture: h264 encode unavailable, falling back to jpeg: %v (%s)", err, detail)
@@ -1589,12 +1616,7 @@ func encodeBlockRaw(img *image.RGBA, x, y, w, h int) []byte {
 	return buf
 }
 
-func blockCodec() string {
+func defaultCodec() string {
-	if v := overrideCodec.Load(); v != nil {
-		if s, ok := v.(string); ok && s != "" {
-			return s
-		}
-	}
 	blockCodecOnce.Do(func() {
 		codec := strings.ToLower(os.Getenv(blockCodecEnv))
 		switch codec {
@@ -1613,12 +1635,33 @@ func blockCodec() string {
 	return cachedBlockCodec
 }
 
-func SetQualityAndCodec(quality int, codec string) {
+func selectedCodec(override *atomic.Value) string {
+	if v := override.Load(); v != nil {
+		if s, ok := v.(string); ok && s != "" {
+			return s
+		}
+	}
+	return defaultCodec()
+}
+
+func desktopCodec() string {
+	return selectedCodec(&desktopOverrideCodec)
+}
+
+func backstageCodec() string {
+	codec := selectedCodec(&backstageOverrideCodec)
+	if codec == "hevc" {
+		return "jpeg"
+	}
+	return codec
+}
+
+func SetDesktopQualityAndCodec(quality int, codec string) {
 	if quality > 0 {
 		if quality > 100 {
 			quality = 100
 		}
-		overrideQuality.Store(int64(quality))
+		desktopOverrideQuality.Store(int64(quality))
 	}
 	s := strings.ToLower(strings.TrimSpace(codec))
 	if s == "h265" {
@@ -1630,40 +1673,60 @@ func SetQualityAndCodec(quality int, codec string) {
 		if h264Available() {
 			fallback = "h264"
 		}
-		log.Printf("capture: requested codec=hevc but unavailable (%s); forcing codec=%s", detail, fallback)
+		log.Printf("capture: requested desktop codec=hevc but unavailable (%s); forcing codec=%s", detail, fallback)
 		s = fallback
 	}
 	if s == "h264" && !h264Available() {
 		detail := h264AvailabilityDetail()
-		if detail != "" {
+		log.Printf("capture: requested desktop codec=h264 but unavailable (%s); forcing codec=jpeg", detail)
-			log.Printf("capture: requested codec=h264 but unavailable (%s); forcing codec=jpeg", detail)
-		} else {
-			log.Printf("capture: requested codec=h264 but unavailable; forcing codec=jpeg")
-		}
 		s = "jpeg"
 	}
 	switch s {
 	case "raw", "rgba", "jpeg", "h264", "hevc":
-		overrideCodec.Store(s)
+		desktopOverrideCodec.Store(s)
 		h264WarnOnce = sync.Once{}
 		hevcWarnOnce = sync.Once{}
 		if s != "h264" {
 			resetH264Encoder()
-			resetH264Encoderbackstage()
 		}
 		if s != "hevc" {
 			resetHEVCEncoder()
 		}
 	case "":
-
 	default:
-		overrideCodec.Store("jpeg")
+		desktopOverrideCodec.Store("jpeg")
 		resetH264Encoder()
-		resetH264Encoderbackstage()
 		resetHEVCEncoder()
 	}
 }
 
+func SetBackstageQualityAndCodec(quality int, codec string) {
+	if quality > 0 {
+		if quality > 100 {
+			quality = 100
+		}
+		backstageOverrideQuality.Store(int64(quality))
+	}
+	s := strings.ToLower(strings.TrimSpace(codec))
+	if s == "h264" && !h264Available() {
+		detail := h264AvailabilityDetail()
+		log.Printf("capture: requested backstage codec=h264 but unavailable (%s); forcing codec=jpeg", detail)
+		s = "jpeg"
+	}
+	switch s {
+	case "raw", "rgba", "jpeg", "h264":
+		backstageOverrideCodec.Store(s)
+		backstageH264WarnOnce = sync.Once{}
+		if s != "h264" {
+			resetH264Encoderbackstage()
+		}
+	case "":
+	default:
+		backstageOverrideCodec.Store("jpeg")
+		resetH264Encoderbackstage()
+	}
+}
+
 func Nowbackstage(ctx context.Context, env *rt.Env) error {
 	if env.Cfg.DisableCapture {
 		return sendBlackFramebackstage(ctx, env)
@@ -1725,7 +1788,7 @@ func captureAndSendVirtual(ctx context.Context, env *rt.Env) error {
 	}
 	captureDur := time.Since(t0)
 
-	willSendViaWebRTC := blockCodec() == "h264" && webrtcpub.IsActive(webrtcpub.Kindbackstage)
+	willSendViaWebRTC := backstageCodec() == "h264" && webrtcpub.IsActive(webrtcpub.Kindbackstage)
 	var slotAcquired bool
 	if !willSendViaWebRTC && !AcquireFrameSlot() {
 		PutRGBA(img)
@@ -1733,7 +1796,7 @@ func captureAndSendVirtual(ctx context.Context, env *rt.Env) error {
 	}
 	slotAcquired = !willSendViaWebRTC
 
-	quality := jpegQuality()
+	quality := backstageJPEGQuality()
 	frame, encodeDur, err := buildFramebackstage(img, 0, quality)
 	PutRGBA(img)
 	img = nil
@@ -1873,7 +1936,7 @@ func captureAndSendbackstage(ctx context.Context, env *rt.Env) error {
 	}
 	captureDur := time.Since(t0)
 
-	willSendViaWebRTC := blockCodec() == "h264" && webrtcpub.IsActive(webrtcpub.Kindbackstage)
+	willSendViaWebRTC := backstageCodec() == "h264" && webrtcpub.IsActive(webrtcpub.Kindbackstage)
 	var slotAcquired bool
 	if !willSendViaWebRTC && !AcquireFrameSlot() {
 		PutRGBA(img)
@@ -1881,7 +1944,7 @@ func captureAndSendbackstage(ctx context.Context, env *rt.Env) error {
 	}
 	slotAcquired = !willSendViaWebRTC
 
-	quality := jpegQuality()
+	quality := backstageJPEGQuality()
 	frame, encodeDur, err := buildFramebackstage(img, display, quality)
 	PutRGBA(img)
 	img = nil

Overlord-Client/cmd/agent/capture/capture_smoke.go

@@ -39,7 +39,7 @@ func RunCaptureSmoke(opts CaptureSmokeOptions) []CaptureSmokeResult {
 		opts.Display = 0
 	}
 	if opts.FPS > 0 {
-		SetH264TargetFPS(opts.FPS)
+		SetDesktopH264TargetFPS(opts.FPS)
 	}
 	if opts.MaxHeight != 0 {
 		SetMaxResolution(opts.MaxHeight)

Overlord-Client/cmd/agent/capture/capture_test.go

@@ -144,7 +144,7 @@ func TestActualScreenCapture(t *testing.T) {
 		t.Log("WARNING: Captured image appears to be solid color (may indicate capture issue)")
 	}
 
-	quality := jpegQuality()
+	quality := desktopJPEGQuality()
 	frame, encodeDur, err := buildFrame(img, 0, quality)
 	if err != nil {
 		t.Errorf("Failed to build frame from captured image: %v", err)
@@ -270,7 +270,7 @@ func TestFrameFPS(t *testing.T) {
 }
 
 func TestJPEGQuality(t *testing.T) {
-	quality := jpegQuality()
+	quality := desktopJPEGQuality()
 	if quality < 1 || quality > 100 {
 		t.Errorf("JPEG quality out of range: %d (expected 1-100)", quality)
 	}
@@ -479,11 +479,11 @@ func TestSetFrameFlowTargetFPSEnvOverride(t *testing.T) {
 }
 
 func TestRequestDesktopFullFrameRequestsWebRTCKeyframe(t *testing.T) {
-	_ = webrtcpub.ConsumeKeyframeRequest()
+	_ = webrtcpub.ConsumeKeyframeRequest(webrtcpub.KindDesktop)
 
 	RequestDesktopFullFrame()
 
-	if !webrtcpub.ConsumeKeyframeRequest() {
+	if !webrtcpub.ConsumeKeyframeRequest(webrtcpub.KindDesktop) {
 		t.Fatal("expected desktop full-frame request to force the next WebRTC video frame to be a keyframe")
 	}
 }

Overlord-Client/cmd/agent/capture/h264_bitrate_reset_windows.go

@@ -3,5 +3,5 @@
 package capture
 
 func resetH264TextureEncoderForBitrate() {
-	resetH264D3D11TextureEncoder()
+	resetAllH264D3D11TextureEncoders()
 }

Overlord-Client/cmd/agent/capture/h264_codec_test.go

@@ -1,6 +1,8 @@
 package capture
 
 import (
+	"errors"
+	"fmt"
 	"image"
 	"image/color"
 	"os"
@@ -12,14 +14,17 @@ import (
 func resetCodecSelectionForTest() {
 	blockCodecOnce = sync.Once{}
 	cachedBlockCodec = ""
-	overrideCodec.Store("")
+	desktopOverrideCodec.Store("")
+	backstageOverrideCodec.Store("")
+	desktopOverrideQuality.Store(0)
+	backstageOverrideQuality.Store(0)
 }
 
 func TestSetQualityAndCodec_H264FallbackDependsOnAvailability(t *testing.T) {
 	t.Cleanup(resetCodecSelectionForTest)
 
-	SetQualityAndCodec(80, "h264")
+	SetDesktopQualityAndCodec(80, "h264")
-	got := blockCodec()
+	got := desktopCodec()
 
 	if h264Available() {
 		if got != "h264" {
@@ -36,13 +41,56 @@ func TestSetQualityAndCodec_H264FallbackDependsOnAvailability(t *testing.T) {
 func TestSetQualityAndCodec_InvalidCodecForcesJpeg(t *testing.T) {
 	t.Cleanup(resetCodecSelectionForTest)
 
-	SetQualityAndCodec(75, "invalid-codec")
+	SetDesktopQualityAndCodec(75, "invalid-codec")
-	got := blockCodec()
+	got := desktopCodec()
 	if got != "jpeg" {
 		t.Fatalf("expected invalid codec to force jpeg, got %q", got)
 	}
 }
 
+func TestDesktopAndBackstageCodecSelectionsAreIndependent(t *testing.T) {
+	t.Cleanup(resetCodecSelectionForTest)
+
+	SetDesktopQualityAndCodec(80, "h264")
+	SetBackstageQualityAndCodec(65, "jpeg")
+
+	wantDesktop := "jpeg"
+	if h264Available() {
+		wantDesktop = "h264"
+	}
+	if got := desktopCodec(); got != wantDesktop {
+		t.Fatalf("desktop codec = %q, want %q after backstage update", got, wantDesktop)
+	}
+	if got := backstageCodec(); got != "jpeg" {
+		t.Fatalf("backstage codec = %q, want jpeg", got)
+	}
+	if got := desktopJPEGQuality(); got != 80 {
+		t.Fatalf("desktop quality = %d, want 80", got)
+	}
+	if got := backstageJPEGQuality(); got != 65 {
+		t.Fatalf("backstage quality = %d, want 65", got)
+	}
+}
+
+func TestDesktopHardwareFailureDoesNotChangeBackstageCodec(t *testing.T) {
+	t.Cleanup(func() {
+		desktopHardwareFallbackUntil.Store(0)
+		resetCodecSelectionForTest()
+	})
+	SetDesktopQualityAndCodec(80, "h264")
+	SetBackstageQualityAndCodec(65, "h264")
+	before := backstageCodec()
+
+	suppressDesktopHardwareH264(errors.New("NVENC session failure"))
+
+	if !useDesktopSoftwareH264() {
+		t.Fatal("desktop did not enter temporary software H.264 fallback")
+	}
+	if got := backstageCodec(); got != before {
+		t.Fatalf("backstage codec changed from %q to %q after desktop encoder failure", before, got)
+	}
+}
+
 func TestH264AvailabilityDetail_NotEmpty(t *testing.T) {
 	detail := strings.TrimSpace(h264AvailabilityDetail())
 	if detail == "" {
@@ -93,6 +141,59 @@ func TestEncodeH264Frame_WhenAvailableProducesBytes(t *testing.T) {
 	}
 }
 
+func TestDesktopAndBackstageH264EncodeConcurrently(t *testing.T) {
+	if !h264Available() {
+		t.Skip("h264 is unavailable in this build")
+	}
+	SetDesktopH264TargetFPS(60)
+	SetBackstageH264TargetFPS(30)
+	t.Cleanup(func() {
+		resetH264Encoder()
+		resetH264Encoderbackstage()
+	})
+
+	const width, height = 640, 360
+	start := make(chan struct{})
+	results := make(chan error, 2)
+	run := func(name string, encode func(*image.RGBA) ([]byte, error), seed uint8) {
+		<-start
+		img := image.NewRGBA(image.Rect(0, 0, width, height))
+		produced := false
+		for frame := range 12 {
+			for y := range height {
+				for x := range width {
+					img.SetRGBA(x, y, color.RGBA{
+						R: uint8(x*3+frame*7) + seed,
+						G: uint8(y*3+frame*5) + seed,
+						B: uint8(frame*11) + seed,
+						A: 255,
+					})
+				}
+			}
+			out, err := encode(img)
+			if err != nil {
+				results <- fmt.Errorf("%s encode frame %d: %w", name, frame, err)
+				return
+			}
+			produced = produced || len(out) > 0
+		}
+		if !produced {
+			results <- fmt.Errorf("%s produced no H.264 output", name)
+			return
+		}
+		results <- nil
+	}
+
+	go run("desktop", encodeH264Frame, 17)
+	go run("backstage", encodeH264Framebackstage, 83)
+	close(start)
+	for range 2 {
+		if err := <-results; err != nil {
+			t.Fatal(err)
+		}
+	}
+}
+
 func TestBlockCodec_UsesEnvWhenNoOverride(t *testing.T) {
 	prev := os.Getenv(blockCodecEnv)
 	if err := os.Setenv(blockCodecEnv, "raw"); err != nil {
@@ -104,7 +205,7 @@ func TestBlockCodec_UsesEnvWhenNoOverride(t *testing.T) {
 	})
 
 	resetCodecSelectionForTest()
-	got := blockCodec()
+	got := desktopCodec()
 	if got != "raw" {
 		t.Fatalf("expected env codec raw, got %q", got)
 	}

Overlord-Client/cmd/agent/capture/h264_direct_windows.go

@@ -17,13 +17,13 @@ func directVideoKeyframeDue(requested bool, nowNs, lastKeyframeNs int64) bool {
 }
 
 func tryBuildDirectH264Frame(display int) (wire.Frame, time.Duration, time.Duration, bool, error) {
-	codec := blockCodec()
+	codec := desktopCodec()
 	if (codec != "h264" && codec != "hevc") || (codec == "h264" && useDesktopSoftwareH264()) || !useDesktopDuplication() {
 		return wire.Frame{}, 0, 0, false, nil
 	}
 	now := time.Now()
 	forceKeyframe := directVideoKeyframeDue(
-		webrtcpub.ConsumeKeyframeRequest(),
+		webrtcpub.ConsumeKeyframeRequest(webrtcpub.KindDesktop),
 		now.UnixNano(),
 		lastKeyframe.Load(),
 	)

Overlord-Client/cmd/agent/capture/h264_encoder_stub.go

@@ -24,6 +24,7 @@ func resetH264Encoder() {}
 func RequestDesktopH264Keyframe() {}
 
 func resetH264Encoderbackstage()    {}
+func RequestBackstageH264Keyframe() {}
 
 func encodeH264Framebackstage(_ *image.RGBA) ([]byte, error) {
 	return nil, errors.New("h264 support not available (cgo disabled)")
@@ -33,4 +34,6 @@ func encodeH264FrameWebcam(_ *image.RGBA) ([]byte, error) {
 	return nil, errors.New("h264 support not available (cgo disabled)")
 }
 
-func SetH264TargetFPS(_ int) {}
+func SetDesktopH264TargetFPS(_ int)   {}
+func SetBackstageH264TargetFPS(_ int) {}
+func SetWebcamH264TargetFPS(_ int)    {}

Overlord-Client/cmd/agent/capture/h264_encoder_windows.go

@@ -519,7 +519,9 @@ type mfH264Candidate struct {
 }
 
 var (
-	h264TargetFPS atomic.Int64
+	desktopH264TargetFPS   atomic.Int64
+	backstageH264TargetFPS atomic.Int64
+	webcamH264TargetFPS    atomic.Int64
 
 	h264Mu      sync.Mutex
 	h264Enc     h264FrameEncoder
@@ -565,7 +567,7 @@ func encodeH264FrameWithEncoder(slot *h264FrameEncoder, stream string, img *imag
 		return nil, fmt.Errorf("h264 frame size must be even, got %dx%d", width, height)
 	}
 
-	fps := activeH264FPS()
+	fps := activeH264FPSForStream(stream)
 	if *slot == nil || !(*slot).Matches(width, height, fps) {
 		if *slot != nil {
 			(*slot).Close()
@@ -577,7 +579,39 @@ func encodeH264FrameWithEncoder(slot *h264FrameEncoder, stream string, img *imag
 		}
 		*slot = enc
 	}
-	return (*slot).Encode(img)
+	return encodeH264FrameWithRuntimeFallback(slot, stream, img, fps, newSoftwareH264Fallback)
+}
+
+type h264SoftwareFallbackFactory func(width, height, fps int) (h264FrameEncoder, error)
+
+func newSoftwareH264Fallback(width, height, fps int) (h264FrameEncoder, error) {
+	return newMFSoftwareH264Encoder(width, height, fps)
+}
+
+func encodeH264FrameWithRuntimeFallback(
+	slot *h264FrameEncoder,
+	stream string,
+	img *image.RGBA,
+	fps int,
+	createSoftware h264SoftwareFallbackFactory,
+) ([]byte, error) {
+	out, err := (*slot).Encode(img)
+	if err == nil {
+		return out, nil
+	}
+	hardwareErr := err
+	closeH264Encoder(slot)
+	fallback, fallbackErr := createSoftware(img.Bounds().Dx(), img.Bounds().Dy(), fps)
+	if fallbackErr != nil {
+		return nil, fmt.Errorf("%s h264 encoder failed (%v) and software fallback could not start: %w", stream, hardwareErr, fallbackErr)
+	}
+	*slot = fallback
+	log.Printf("capture: %s h264 encoder failed at runtime: %v; switched this stream to Media Foundation software H.264", stream, hardwareErr)
+	out, err = fallback.Encode(img)
+	if err != nil {
+		return nil, fmt.Errorf("%s software h264 fallback encode failed after hardware error %v: %w", stream, hardwareErr, err)
+	}
+	return out, nil
 }
 
 func h264Available() bool {
@@ -601,18 +635,45 @@ func h264AvailabilityDetail() string {
 	return "Windows Media Foundation H.264 MFT (Microsoft H.264 encoder fallback; hardware unavailable: " + detail + ")"
 }
 
-func SetH264TargetFPS(fps int) {
+func SetDesktopH264TargetFPS(fps int) {
+	setH264TargetFPS(&desktopH264TargetFPS, fps)
+}
+
+func SetBackstageH264TargetFPS(fps int) {
+	setH264TargetFPS(&backstageH264TargetFPS, fps)
+}
+
+func SetWebcamH264TargetFPS(fps int) {
+	setH264TargetFPS(&webcamH264TargetFPS, fps)
+}
+
+func setH264TargetFPS(target *atomic.Int64, fps int) {
 	if fps < 1 {
 		fps = 1
 	}
-	h264TargetFPS.Store(int64(fps))
+	target.Store(int64(fps))
 }
 
 func activeH264FPS() int {
-	if v := int(h264TargetFPS.Load()); v > 0 {
+	return activeH264FPSValue(&desktopH264TargetFPS, 60)
+}
+
+func activeH264FPSForStream(stream string) int {
+	switch stream {
+	case "backstage":
+		return activeH264FPSValue(&backstageH264TargetFPS, 60)
+	case "webcam":
+		return activeH264FPSValue(&webcamH264TargetFPS, 30)
+	default:
+		return activeH264FPS()
+	}
+}
+
+func activeH264FPSValue(target *atomic.Int64, fallback int) int {
+	if v := int(target.Load()); v > 0 {
 		return v
 	}
-	return 60
+	return fallback
 }
 
 func resetH264Encoder() {
@@ -622,7 +683,7 @@ func resetH264Encoder() {
 }
 
 func RequestDesktopH264Keyframe() {
-	requestH264D3D11TextureKeyframe()
+	requestH264D3D11TextureKeyframe("desktop")
 	resetH264Encoder()
 }
 
@@ -632,6 +693,11 @@ func resetH264Encoderbackstage() {
 	closeH264Encoder(&backstageH264Enc)
 }
 
+func RequestBackstageH264Keyframe() {
+	requestH264D3D11TextureKeyframe("backstage")
+	resetH264Encoderbackstage()
+}
+
 func closeH264Encoder(slot *h264FrameEncoder) {
 	if slot != nil && *slot != nil {
 		(*slot).Close()

Overlord-Client/cmd/agent/capture/h264_encoder_x264.go

@@ -21,7 +21,9 @@ var (
 	h264FPS                int
 	h264LastErr            error
 	h264Scratch            []byte
-	h264TargetFPS atomic.Int64 // set by the stream handler; default 60
+	desktopH264TargetFPS   atomic.Int64
+	backstageH264TargetFPS atomic.Int64
+	webcamH264TargetFPS    atomic.Int64
 )
 
 func encodeH264Frame(img *image.RGBA) ([]byte, error) {
@@ -70,22 +72,34 @@ func h264AvailabilityDetail() string {
 	return "cgo build with x264-go"
 }
 
-// SetH264TargetFPS sets the frame rate hint for the x264 encoder so its
+func SetDesktopH264TargetFPS(fps int) {
-// rate-control matches the actual capture cadence. Call this before (or
+	setH264TargetFPS(&desktopH264TargetFPS, fps)
-// when) streaming starts. The encoder is automatically re-created on the
+}
-// next frame if the value differs from the current one.
+
-func SetH264TargetFPS(fps int) {
+func SetBackstageH264TargetFPS(fps int) {
+	setH264TargetFPS(&backstageH264TargetFPS, fps)
+}
+
+func SetWebcamH264TargetFPS(fps int) {
+	setH264TargetFPS(&webcamH264TargetFPS, fps)
+}
+
+func setH264TargetFPS(target *atomic.Int64, fps int) {
 	if fps < 1 {
 		fps = 1
 	}
-	h264TargetFPS.Store(int64(fps))
+	target.Store(int64(fps))
 }
 
 func activeH264FPS() int {
-	if v := int(h264TargetFPS.Load()); v > 0 {
+	return activeH264FPSValue(&desktopH264TargetFPS, 60)
+}
+
+func activeH264FPSValue(target *atomic.Int64, fallback int) int {
+	if v := int(target.Load()); v > 0 {
 		return v
 	}
-	return 60 // sensible default for desktop streaming
+	return fallback
 }
 
 func ensureH264EncoderLocked(width, height int) error {
@@ -187,8 +201,12 @@ func resetH264Encoderbackstage() {
 	closebackstageH264EncoderLocked()
 }
 
+func RequestBackstageH264Keyframe() {
+	resetH264Encoderbackstage()
+}
+
 func ensurebackstageH264EncoderLocked(width, height int) error {
-	fps := activeH264FPS()
+	fps := activeH264FPSValue(&backstageH264TargetFPS, 60)
 	if backstageH264Enc != nil && backstageH264Width == width && backstageH264Height == height && backstageH264FPS == fps {
 		return nil
 	}
@@ -267,7 +285,7 @@ func encodeH264FrameWebcam(img *image.RGBA) ([]byte, error) {
 }
 
 func ensureWebcamH264EncoderLocked(width, height int) error {
-	fps := activeH264FPS()
+	fps := activeH264FPSValue(&webcamH264TargetFPS, 30)
 	if webcamH264Enc != nil && webcamH264Width == width && webcamH264Height == height && webcamH264FPS == fps {
 		return nil
 	}

Overlord-Client/cmd/agent/capture/h264_texture_encoder_windows.go

@@ -43,90 +43,107 @@ type h264D3D11TextureBackend interface {
 	Reset()
 }
 
-type nvencD3D11TextureBackend struct{}
+type nvencD3D11TextureBackend struct {
+	stream string
+}
 
-func (nvencD3D11TextureBackend) Name() string { return "NVIDIA NVENC" }
+func (*nvencD3D11TextureBackend) Name() string { return "NVIDIA NVENC" }
 
-func (nvencD3D11TextureBackend) Encode(req h264D3D11TextureRequest) ([]byte, error) {
+func (b *nvencD3D11TextureBackend) Encode(req h264D3D11TextureRequest) ([]byte, error) {
-	return encodeNativeH264D3D11Texture(req.Device, req.Texture, req.InputWidth, req.InputHeight,
+	return encodeNativeH264D3D11Texture(b.stream, req.Device, req.Texture, req.InputWidth, req.InputHeight,
 		req.EncodeWidth, req.EncodeHeight, req.FPS, req.DXGIFormat, req.ForceIDR)
 }
 
-func (nvencD3D11TextureBackend) RequestKeyframe() {
+func (b *nvencD3D11TextureBackend) RequestKeyframe() {
-	requestNativeH264D3D11TextureKeyframe()
+	requestNativeH264D3D11TextureKeyframe(b.stream)
 }
 
-func (nvencD3D11TextureBackend) Reset() {
+func (b *nvencD3D11TextureBackend) Reset() {
-	resetNativeH264D3D11TextureEncoder()
+	resetNativeH264D3D11TextureEncoder(b.stream)
 }
 
-var d3d11H264TextureRegistry = struct {
+type h264D3D11TextureRegistry struct {
 	sync.Mutex
 	backends []h264D3D11TextureBackend
 	active   h264D3D11TextureBackend
 	failures map[d3d11H264FailureKey]d3d11H264Failure
-}{
+}
-	backends: []h264D3D11TextureBackend{nvencD3D11TextureBackend{}},
+
+func newH264D3D11TextureRegistry(stream string) *h264D3D11TextureRegistry {
+	registry := &h264D3D11TextureRegistry{
+		backends: []h264D3D11TextureBackend{&nvencD3D11TextureBackend{stream: stream}},
 		failures: make(map[d3d11H264FailureKey]d3d11H264Failure),
 	}
-
-func init() {
 	if backend := newQSVD3D11TextureBackend(); backend != nil {
-		d3d11H264TextureRegistry.backends = append(d3d11H264TextureRegistry.backends, backend)
+		registry.backends = append(registry.backends, backend)
 	}
 	if backend := newAMFD3D11TextureBackend(); backend != nil {
-		d3d11H264TextureRegistry.backends = append(d3d11H264TextureRegistry.backends, backend)
+		registry.backends = append(registry.backends, backend)
 	}
+	return registry
 }
 
-func encodeH264D3D11Texture(req h264D3D11TextureRequest) ([]byte, string, error) {
+var (
+	d3d11H264TextureRegistry          = newH264D3D11TextureRegistry("desktop")
+	backstageD3D11H264TextureRegistry = newH264D3D11TextureRegistry("backstage")
+)
+
+func h264D3D11Registry(stream string) *h264D3D11TextureRegistry {
+	if stream == "backstage" {
+		return backstageD3D11H264TextureRegistry
+	}
+	return d3d11H264TextureRegistry
+}
+
+func encodeH264D3D11Texture(stream string, req h264D3D11TextureRequest) ([]byte, string, error) {
 	if req.Device == nil || req.Texture == nil {
 		return nil, "", fmt.Errorf("nil D3D11 device or texture")
 	}
-	d3d11H264TextureRegistry.Lock()
+	registry := h264D3D11Registry(stream)
-	defer d3d11H264TextureRegistry.Unlock()
+	registry.Lock()
+	defer registry.Unlock()
 
 	failedActiveName := ""
-	errorsByBackend := make([]string, 0, len(d3d11H264TextureRegistry.backends))
+	errorsByBackend := make([]string, 0, len(registry.backends))
-	if active := d3d11H264TextureRegistry.active; active != nil {
+	if active := registry.active; active != nil {
 		key := d3d11H264FailureKeyFor(active.Name(), req)
-		if failure, failed := activeD3D11H264Failure(key, time.Now()); !failed {
+		if failure, failed := registry.activeFailure(key, time.Now()); !failed {
 			out, err := active.Encode(req)
 			if err == nil {
-				delete(d3d11H264TextureRegistry.failures, key)
+				delete(registry.failures, key)
 				return out, active.Name(), nil
 			}
-			rememberD3D11H264Failure(key, err)
+			registry.rememberFailure(key, err)
 			active.Reset()
 			failedActiveName = active.Name()
 			errorsByBackend = append(errorsByBackend, active.Name()+": "+err.Error())
-			d3d11H264TextureRegistry.active = nil
+			registry.active = nil
 		} else {
 			errorsByBackend = append(errorsByBackend, active.Name()+": "+failure.err+" (cooldown)")
 			active.Reset()
 			failedActiveName = active.Name()
-			d3d11H264TextureRegistry.active = nil
+			registry.active = nil
 		}
 	}
 
 	now := time.Now()
-	for _, backend := range d3d11H264TextureRegistry.backends {
+	for _, backend := range registry.backends {
 		if backend == nil || (failedActiveName != "" && backend.Name() == failedActiveName) {
 			continue
 		}
 		key := d3d11H264FailureKeyFor(backend.Name(), req)
-		if failure, failed := activeD3D11H264Failure(key, now); failed {
+		if failure, failed := registry.activeFailure(key, now); failed {
 			errorsByBackend = append(errorsByBackend, backend.Name()+": "+failure.err+" (cooldown)")
 			continue
 		}
 		out, err := backend.Encode(req)
 		if err == nil {
-			delete(d3d11H264TextureRegistry.failures, key)
+			delete(registry.failures, key)
-			d3d11H264TextureRegistry.active = backend
+			registry.active = backend
 			return out, backend.Name(), nil
 		}
 		backend.Reset()
-		rememberD3D11H264Failure(key, err)
+		registry.rememberFailure(key, err)
 		errorsByBackend = append(errorsByBackend, backend.Name()+": "+err.Error())
 	}
 	if len(errorsByBackend) == 0 {
@@ -142,51 +159,58 @@ func d3d11H264FailureKeyFor(backend string, req h264D3D11TextureRequest) d3d11H2
 	}
 }
 
-func activeD3D11H264Failure(key d3d11H264FailureKey, now time.Time) (d3d11H264Failure, bool) {
+func (r *h264D3D11TextureRegistry) activeFailure(key d3d11H264FailureKey, now time.Time) (d3d11H264Failure, bool) {
-	failure, ok := d3d11H264TextureRegistry.failures[key]
+	failure, ok := r.failures[key]
 	if !ok {
 		return d3d11H264Failure{}, false
 	}
 	if !now.Before(failure.until) {
-		delete(d3d11H264TextureRegistry.failures, key)
+		delete(r.failures, key)
 		return d3d11H264Failure{}, false
 	}
 	return failure, true
 }
 
-func rememberD3D11H264Failure(key d3d11H264FailureKey, err error) {
+func (r *h264D3D11TextureRegistry) rememberFailure(key d3d11H264FailureKey, err error) {
-	if len(d3d11H264TextureRegistry.failures) > 128 {
+	if len(r.failures) > 128 {
 		now := time.Now()
-		for existingKey, failure := range d3d11H264TextureRegistry.failures {
+		for existingKey, failure := range r.failures {
 			if !now.Before(failure.until) {
-				delete(d3d11H264TextureRegistry.failures, existingKey)
+				delete(r.failures, existingKey)
 			}
 		}
 	}
-	d3d11H264TextureRegistry.failures[key] = d3d11H264Failure{until: time.Now().Add(d3d11H264FailureCooldown), err: err.Error()}
+	r.failures[key] = d3d11H264Failure{until: time.Now().Add(d3d11H264FailureCooldown), err: err.Error()}
 }
 
-func requestH264D3D11TextureKeyframe() {
+func requestH264D3D11TextureKeyframe(stream string) {
-	d3d11H264TextureRegistry.Lock()
+	registry := h264D3D11Registry(stream)
-	defer d3d11H264TextureRegistry.Unlock()
+	registry.Lock()
-	if d3d11H264TextureRegistry.active != nil {
+	defer registry.Unlock()
-		d3d11H264TextureRegistry.active.RequestKeyframe()
+	if registry.active != nil {
+		registry.active.RequestKeyframe()
 		return
 	}
-	for _, backend := range d3d11H264TextureRegistry.backends {
+	for _, backend := range registry.backends {
 		if backend != nil {
 			backend.RequestKeyframe()
 		}
 	}
 }
 
-func resetH264D3D11TextureEncoder() {
+func resetH264D3D11TextureEncoder(stream string) {
-	d3d11H264TextureRegistry.Lock()
+	registry := h264D3D11Registry(stream)
-	defer d3d11H264TextureRegistry.Unlock()
+	registry.Lock()
-	for _, backend := range d3d11H264TextureRegistry.backends {
+	defer registry.Unlock()
+	for _, backend := range registry.backends {
 		if backend != nil {
 			backend.Reset()
 		}
 	}
-	d3d11H264TextureRegistry.active = nil
+	registry.active = nil
+}
+
+func resetAllH264D3D11TextureEncoders() {
+	resetH264D3D11TextureEncoder("desktop")
+	resetH264D3D11TextureEncoder("backstage")
 }

Overlord-Client/cmd/agent/capture/h264_texture_encoder_windows_test.go

@@ -4,6 +4,7 @@ package capture
 
 import (
 	"errors"
+	"image"
 	"testing"
 	"unsafe"
 )
@@ -54,7 +55,7 @@ func TestD3D11TextureBackendSelectionAndFailover(t *testing.T) {
 
 	device, texture := 1, 2
 	req := h264D3D11TextureRequest{Device: unsafe.Pointer(&device), Texture: unsafe.Pointer(&texture)}
-	out, provider, err := encodeH264D3D11Texture(req)
+	out, provider, err := encodeH264D3D11Texture("desktop", req)
 	if err != nil {
 		t.Fatalf("first encode: %v", err)
 	}
@@ -65,7 +66,7 @@ func TestD3D11TextureBackendSelectionAndFailover(t *testing.T) {
 		t.Fatalf("unexpected calls first.reset=%d second.encode=%d", first.resetCalls, second.encodeCalls)
 	}
 
-	_, provider, err = encodeH264D3D11Texture(req)
+	_, provider, err = encodeH264D3D11Texture("desktop", req)
 	if err != nil || provider != "second" {
 		t.Fatalf("active backend reuse provider=%q err=%v", provider, err)
 	}
@@ -73,11 +74,11 @@ func TestD3D11TextureBackendSelectionAndFailover(t *testing.T) {
 		t.Fatalf("active backend was not reused: first=%d second=%d", first.encodeCalls, second.encodeCalls)
 	}
 
-	requestH264D3D11TextureKeyframe()
+	requestH264D3D11TextureKeyframe("desktop")
 	if second.keyframeCalls != 1 || first.keyframeCalls != 0 {
 		t.Fatalf("keyframe routed incorrectly: first=%d second=%d", first.keyframeCalls, second.keyframeCalls)
 	}
-	resetH264D3D11TextureEncoder()
+	resetH264D3D11TextureEncoder("desktop")
 	if first.resetCalls != 2 || second.resetCalls != 1 {
 		t.Fatalf("reset did not reach every backend: first=%d second=%d", first.resetCalls, second.resetCalls)
 	}
@@ -105,13 +106,129 @@ func TestD3D11TextureBackendFailuresUseCooldown(t *testing.T) {
 
 	device, texture := 1, 2
 	req := h264D3D11TextureRequest{Device: unsafe.Pointer(&device), Texture: unsafe.Pointer(&texture), EncodeWidth: 2560, EncodeHeight: 1440, FPS: 240}
-	if _, _, err := encodeH264D3D11Texture(req); err == nil {
+	if _, _, err := encodeH264D3D11Texture("desktop", req); err == nil {
 		t.Fatal("expected initial profile failure")
 	}
-	if _, _, err := encodeH264D3D11Texture(req); err == nil {
+	if _, _, err := encodeH264D3D11Texture("desktop", req); err == nil {
 		t.Fatal("expected cached profile failure")
 	}
 	if first.encodeCalls != 1 || second.encodeCalls != 1 {
 		t.Fatalf("failed profile was retried during cooldown: first=%d second=%d", first.encodeCalls, second.encodeCalls)
 	}
 }
+
+type fakeH264FrameEncoder struct {
+	output     []byte
+	err        error
+	encodeCall int
+	closed     bool
+}
+
+func (e *fakeH264FrameEncoder) Encode(*image.RGBA) ([]byte, error) {
+	e.encodeCall++
+	return e.output, e.err
+}
+
+func (e *fakeH264FrameEncoder) Close() {
+	e.closed = true
+}
+
+func (e *fakeH264FrameEncoder) Matches(_, _, _ int) bool {
+	return true
+}
+
+func TestH264RuntimeFailureFallsBackPerStream(t *testing.T) {
+	primary := &fakeH264FrameEncoder{err: errors.New("NVENC session failed")}
+	software := &fakeH264FrameEncoder{output: []byte{7, 8, 9}}
+	var slot h264FrameEncoder = primary
+	factoryCalls := 0
+	factory := func(width, height, fps int) (h264FrameEncoder, error) {
+		factoryCalls++
+		if width != 64 || height != 32 || fps != 47 {
+			t.Fatalf("fallback config = %dx%d@%d, want 64x32@47", width, height, fps)
+		}
+		return software, nil
+	}
+
+	out, err := encodeH264FrameWithRuntimeFallback(
+		&slot,
+		"backstage",
+		image.NewRGBA(image.Rect(0, 0, 64, 32)),
+		47,
+		factory,
+	)
+	if err != nil {
+		t.Fatalf("runtime fallback failed: %v", err)
+	}
+	if factoryCalls != 1 || primary.encodeCall != 1 || !primary.closed {
+		t.Fatalf("primary cleanup/fallback calls = factory:%d encode:%d closed:%v", factoryCalls, primary.encodeCall, primary.closed)
+	}
+	if slot != software || software.encodeCall != 1 {
+		t.Fatalf("software encoder was not retained after fallback")
+	}
+	if len(out) != 3 || out[0] != 7 {
+		t.Fatalf("fallback output = %v", out)
+	}
+}
+
+func TestH264TargetFPSIsIndependentPerStream(t *testing.T) {
+	SetDesktopH264TargetFPS(120)
+	SetBackstageH264TargetFPS(37)
+	SetWebcamH264TargetFPS(24)
+
+	if got := activeH264FPS(); got != 120 {
+		t.Fatalf("desktop fps = %d, want 120", got)
+	}
+	if got := activeH264FPSForStream("backstage"); got != 37 {
+		t.Fatalf("backstage fps = %d, want 37", got)
+	}
+	if got := activeH264FPSForStream("webcam"); got != 24 {
+		t.Fatalf("webcam fps = %d, want 24", got)
+	}
+}
+
+func TestD3D11TextureEncodersAreIsolatedByStream(t *testing.T) {
+	desktopBackend := &fakeD3D11TextureBackend{name: "desktop", outputs: [][]byte{{1}, {2}}}
+	backstageBackend := &fakeD3D11TextureBackend{name: "backstage", outputs: [][]byte{{3}}}
+	savedDesktop := d3d11H264TextureRegistry
+	savedBackstage := backstageD3D11H264TextureRegistry
+	d3d11H264TextureRegistry = &h264D3D11TextureRegistry{
+		backends: []h264D3D11TextureBackend{desktopBackend},
+		failures: make(map[d3d11H264FailureKey]d3d11H264Failure),
+	}
+	backstageD3D11H264TextureRegistry = &h264D3D11TextureRegistry{
+		backends: []h264D3D11TextureBackend{backstageBackend},
+		failures: make(map[d3d11H264FailureKey]d3d11H264Failure),
+	}
+	t.Cleanup(func() {
+		d3d11H264TextureRegistry = savedDesktop
+		backstageD3D11H264TextureRegistry = savedBackstage
+	})
+
+	desktopDevice, desktopTexture := 1, 2
+	backstageDevice, backstageTexture := 3, 4
+	desktopReq := h264D3D11TextureRequest{
+		Device: unsafe.Pointer(&desktopDevice), Texture: unsafe.Pointer(&desktopTexture),
+		EncodeWidth: 1920, EncodeHeight: 1080, FPS: 60,
+	}
+	backstageReq := h264D3D11TextureRequest{
+		Device: unsafe.Pointer(&backstageDevice), Texture: unsafe.Pointer(&backstageTexture),
+		EncodeWidth: 1280, EncodeHeight: 720, FPS: 30,
+	}
+
+	if _, _, err := encodeH264D3D11Texture("desktop", desktopReq); err != nil {
+		t.Fatalf("desktop encode: %v", err)
+	}
+	if _, _, err := encodeH264D3D11Texture("backstage", backstageReq); err != nil {
+		t.Fatalf("backstage encode: %v", err)
+	}
+	if _, _, err := encodeH264D3D11Texture("desktop", desktopReq); err != nil {
+		t.Fatalf("second desktop encode: %v", err)
+	}
+	if desktopBackend.encodeCalls != 2 || backstageBackend.encodeCalls != 1 {
+		t.Fatalf("stream calls crossed: desktop=%d backstage=%d", desktopBackend.encodeCalls, backstageBackend.encodeCalls)
+	}
+	if desktopBackend.resetCalls != 0 || backstageBackend.resetCalls != 0 {
+		t.Fatalf("one stream reset the other: desktop=%d backstage=%d", desktopBackend.resetCalls, backstageBackend.resetCalls)
+	}
+}

Overlord-Client/cmd/agent/capture/native_h264_stub_windows.go

@@ -17,13 +17,13 @@ func nativeH264AvailabilityDetail() string {
 	return ""
 }
 
-func encodeNativeH264D3D11Texture(device, texture unsafe.Pointer, inputWidth, inputHeight, encodeWidth, encodeHeight, fps int, dxgiFormat uint32, forceIDR bool) ([]byte, error) {
+func encodeNativeH264D3D11Texture(_ string, device, texture unsafe.Pointer, inputWidth, inputHeight, encodeWidth, encodeHeight, fps int, dxgiFormat uint32, forceIDR bool) ([]byte, error) {
 	return nil, fmt.Errorf("native NVENC D3D11 texture encode requires cgo for input=%dx%d output=%dx%d@%dfps", inputWidth, inputHeight, encodeWidth, encodeHeight, fps)
 }
 
-func requestNativeH264D3D11TextureKeyframe() {}
+func requestNativeH264D3D11TextureKeyframe(_ string) {}
 
-func resetNativeH264D3D11TextureEncoder() {}
+func resetNativeH264D3D11TextureEncoder(_ string) {}
 
 func encodeNativeHEVCD3D11Texture(device, texture unsafe.Pointer, inputWidth, inputHeight, encodeWidth, encodeHeight, fps int, dxgiFormat uint32, forceIDR bool) ([]byte, error) {
 	return nil, fmt.Errorf("native NVENC HEVC D3D11 texture encode requires cgo for input=%dx%d output=%dx%d@%dfps", inputWidth, inputHeight, encodeWidth, encodeHeight, fps)

Overlord-Client/cmd/agent/capture/nvenc_d3d11_smoke_windows.go

@@ -1921,48 +1921,62 @@ func envBool(name string) bool {
 	}
 }
 
+type nativeTextureH264StreamState struct {
+	sync.Mutex
+	encoder  *nativeD3D11TextureH264Encoder
+	forceIDR atomic.Bool
+}
+
 var (
-	nativeTextureH264Mu       sync.Mutex
+	nativeTextureH264Streams  sync.Map
-	nativeTextureH264Enc      *nativeD3D11TextureH264Encoder
-	nativeTextureH264ForceIDR atomic.Bool
 	nativeTextureHEVCMu       sync.Mutex
 	nativeTextureHEVCEnc      *nativeD3D11TextureH264Encoder
 	nativeTextureHEVCForceIDR atomic.Bool
 )
 
-func encodeNativeH264D3D11Texture(device, texture unsafe.Pointer, inputWidth, inputHeight, encodeWidth, encodeHeight, fps int, dxgiFormat uint32, forceIDR bool) ([]byte, error) {
+func nativeTextureH264State(stream string) *nativeTextureH264StreamState {
+	if stream == "" {
+		stream = "desktop"
+	}
+	state, _ := nativeTextureH264Streams.LoadOrStore(stream, &nativeTextureH264StreamState{})
+	return state.(*nativeTextureH264StreamState)
+}
+
+func encodeNativeH264D3D11Texture(stream string, device, texture unsafe.Pointer, inputWidth, inputHeight, encodeWidth, encodeHeight, fps int, dxgiFormat uint32, forceIDR bool) ([]byte, error) {
 	if device == nil || texture == nil {
 		return nil, fmt.Errorf("nil D3D11 device or texture")
 	}
-	nativeTextureH264Mu.Lock()
+	state := nativeTextureH264State(stream)
-	defer nativeTextureH264Mu.Unlock()
+	state.Lock()
+	defer state.Unlock()
 
-	if nativeTextureH264Enc == nil || !nativeTextureH264Enc.Matches(device, inputWidth, inputHeight, encodeWidth, encodeHeight, fps, dxgiFormat) {
+	if state.encoder == nil || !state.encoder.Matches(device, inputWidth, inputHeight, encodeWidth, encodeHeight, fps, dxgiFormat) {
-		if nativeTextureH264Enc != nil {
+		if state.encoder != nil {
-			nativeTextureH264Enc.Close()
+			state.encoder.Close()
-			nativeTextureH264Enc = nil
+			state.encoder = nil
 		}
 		enc, err := newNativeD3D11TextureH264Encoder(device, inputWidth, inputHeight, encodeWidth, encodeHeight, fps, dxgiFormat)
 		if err != nil {
 			return nil, err
 		}
-		nativeTextureH264Enc = enc
+		state.encoder = enc
 	}
-	return nativeTextureH264Enc.EncodeTexture(texture, forceIDR || nativeTextureH264ForceIDR.Swap(false))
+	return state.encoder.EncodeTexture(texture, forceIDR || state.forceIDR.Swap(false))
 }
 
-func requestNativeH264D3D11TextureKeyframe() {
+func requestNativeH264D3D11TextureKeyframe(stream string) {
-	nativeTextureH264ForceIDR.Store(true)
+	nativeTextureH264State(stream).forceIDR.Store(true)
 }
 
-func resetNativeH264D3D11TextureEncoder() {
+func resetNativeH264D3D11TextureEncoder(stream string) {
-	nativeTextureH264Mu.Lock()
+	state := nativeTextureH264State(stream)
-	defer nativeTextureH264Mu.Unlock()
+	state.Lock()
-	if nativeTextureH264Enc != nil {
+	defer state.Unlock()
-		nativeTextureH264Enc.Close()
+	if state.encoder != nil {
-		nativeTextureH264Enc = nil
+		state.encoder.Close()
+		state.encoder = nil
 	}
-	nativeTextureH264ForceIDR.Store(false)
+	state.forceIDR.Store(false)
 }
 
 func encodeNativeHEVCD3D11Texture(device, texture unsafe.Pointer, inputWidth, inputHeight, encodeWidth, encodeHeight, fps int, dxgiFormat uint32, forceIDR bool) ([]byte, error) {

Overlord-Client/cmd/agent/capture/virtual_windows.go

@@ -213,7 +213,7 @@ var (
 )
 
 func VirtualTryDirectH264Frame() (wire.Frame, time.Duration, time.Duration, bool, error) {
-	if blockCodec() != "h264" {
+	if backstageCodec() != "h264" {
 		return wire.Frame{}, 0, 0, false, nil
 	}
 	return virtualDupState.captureDirectH264()
@@ -280,12 +280,12 @@ func (s *virtualDuplicationState) captureDirectH264() (wire.Frame, time.Duration
 }
 
 func (s *virtualDuplicationState) encodeCachedDirectH264(capStart time.Time, width, height int) (wire.Frame, time.Duration, time.Duration, bool, error) {
-	fps := activeH264FPS()
+	fps := activeH264FPSForStream("backstage")
 	encStart := time.Now()
-	out, _, err := encodeH264D3D11Texture(h264D3D11TextureRequest{
+	out, _, err := encodeH264D3D11Texture("backstage", h264D3D11TextureRequest{
 		Device: unsafe.Pointer(s.device), Texture: unsafe.Pointer(s.h264LastTex),
 		InputWidth: width, InputHeight: height, EncodeWidth: width, EncodeHeight: height,
-		FPS: fps, DXGIFormat: s.h264LastDesc.Format, ForceIDR: webrtcpub.ConsumeKeyframeRequest(),
+		FPS: fps, DXGIFormat: s.h264LastDesc.Format, ForceIDR: webrtcpub.ConsumeKeyframeRequest(webrtcpub.Kindbackstage),
 	})
 	encodeDur := time.Since(encStart)
 	if err != nil {

Overlord-Client/cmd/agent/capture/win_duplication.go

@@ -688,7 +688,7 @@ func (s *duplicationState) closeLocked() {
 		s.h264LastTex = nil
 		s.h264LastDesc = d3d11Texture2DDesc{}
 	}
-	resetH264D3D11TextureEncoder()
+	resetH264D3D11TextureEncoder("desktop")
 	resetNativeHEVCD3D11TextureEncoder()
 	if s.context != nil {
 		s.context.Release()
@@ -1027,7 +1027,7 @@ func encodeDesktopD3D11Texture(codec string, req h264D3D11TextureRequest) ([]byt
 			req.EncodeWidth, req.EncodeHeight, req.FPS, req.DXGIFormat, req.ForceIDR)
 		return out, "NVIDIA NVENC", err
 	}
-	return encodeH264D3D11Texture(req)
+	return encodeH264D3D11Texture("desktop", req)
 }
 
 func (s *duplicationState) cacheH264TextureLocked(src *d3d11Texture2D, srcDesc d3d11Texture2DDesc) error {

Overlord-Client/cmd/agent/handlers/backstage.go

@@ -32,7 +32,7 @@ func backstageStart(ctx context.Context, env *rt.Env, autoStartExplorer bool) er
 	//garble:controlflow block_splits=10 junk_jumps=10 flatten_passes=2
 	fps := activebackstageTargetFPS()
 	interval := time.Second / time.Duration(fps)
-	capture.SetH264TargetFPS(fps)
+	capture.SetBackstageH264TargetFPS(fps)
 	capture.SetFrameFlowTargetFPS(fps)
 	log.Printf("backstage: starting stream (target fps %d)", fps)
 
@@ -62,7 +62,7 @@ func backstageStart(ctx context.Context, env *rt.Env, autoStartExplorer bool) er
 			fps := activebackstageTargetFPS()
 			if fps != currentFPS {
 				currentFPS = fps
-				capture.SetH264TargetFPS(fps)
+				capture.SetBackstageH264TargetFPS(fps)
 				capture.SetFrameFlowTargetFPS(fps)
 				ticker.Reset(time.Second / time.Duration(fps))
 				log.Printf("backstage: target fps changed to %d", fps)
@@ -90,7 +90,7 @@ func activebackstageTargetFPS() int {
 func SetbackstageTargetFPS(fps int) int {
 	fps = clampDesktopTargetFPS(fps)
 	backstageTargetFPS.Store(int64(fps))
-	capture.SetH264TargetFPS(fps)
+	capture.SetBackstageH264TargetFPS(fps)
 	capture.SetFrameFlowTargetFPS(fps)
 	return fps
 }

Overlord-Client/cmd/agent/handlers/command.go

@@ -832,7 +832,7 @@ func HandleCommand(ctx context.Context, env *runtime.Env, envelope map[string]in
 			log.Printf("desktop: set quality=%d codec=%s software_h264=%v", quality, codec, softwareH264)
 		}
 		capture.SetDesktopSoftwareH264(softwareH264)
-		capture.SetQualityAndCodec(quality, codec)
+		capture.SetDesktopQualityAndCodec(quality, codec)
 		sendCommandResultSafe(env, cmdID, true, "")
 		return nil
 	case "desktop_request_keyframe":
@@ -1335,7 +1335,7 @@ func HandleCommand(ctx context.Context, env *runtime.Env, envelope map[string]in
 			}
 		}
 		log.Printf("backstage: set quality=%d codec=%s", quality, codec)
-		capture.SetQualityAndCodec(quality, codec)
+		capture.SetBackstageQualityAndCodec(quality, codec)
 		sendCommandResultSafe(env, cmdID, true, "")
 		return nil
 	case "backstage_request_keyframe":
@@ -2209,7 +2209,7 @@ func HandleCommand(ctx context.Context, env *runtime.Env, envelope map[string]in
 			}
 		}
 		log.Printf("hidden: set quality=%d codec=%s", quality, codec)
-		capture.SetQualityAndCodec(quality, codec)
+		capture.SetBackstageQualityAndCodec(quality, codec)
 		sendCommandResultSafe(env, cmdID, true, "")
 		return nil
 	case "virtual_request_keyframe":
@@ -2447,6 +2447,7 @@ func HandleCommand(ctx context.Context, env *runtime.Env, envelope map[string]in
 			fps = clampedFPS
 		}
 		env.WebcamFPS = fps
+		capture.SetWebcamH264TargetFPS(fps)
 		env.WebcamUseMaxFPS = useMax
 		sendCommandResultSafe(env, cmdID, true, "")
 		return nil

Overlord-Client/cmd/agent/handlers/desktop.go

@@ -32,7 +32,7 @@ func DesktopStart(ctx context.Context, env *rt.Env) error {
 	//garble:controlflow block_splits=10 junk_jumps=10 flatten_passes=2
 	fps := activeDesktopTargetFPS()
 	interval := time.Second / time.Duration(fps)
-	capture.SetH264TargetFPS(fps)
+	capture.SetDesktopH264TargetFPS(fps)
 	capture.SetFrameFlowTargetFPS(fps)
 	log.Printf("desktop: starting stream (target fps %d)", fps)
 	ticker := time.NewTicker(interval)
@@ -47,7 +47,7 @@ func DesktopStart(ctx context.Context, env *rt.Env) error {
 			fps := activeDesktopTargetFPS()
 			if fps != currentFPS {
 				currentFPS = fps
-				capture.SetH264TargetFPS(fps)
+				capture.SetDesktopH264TargetFPS(fps)
 				capture.SetFrameFlowTargetFPS(fps)
 				ticker.Reset(time.Second / time.Duration(fps))
 				log.Printf("desktop: target fps changed to %d", fps)
@@ -74,7 +74,7 @@ func activeDesktopTargetFPS() int {
 func SetDesktopTargetFPS(fps int) int {
 	fps = clampDesktopTargetFPS(fps)
 	desktopTargetFPS.Store(int64(fps))
-	capture.SetH264TargetFPS(fps)
+	capture.SetDesktopH264TargetFPS(fps)
 	capture.SetFrameFlowTargetFPS(fps)
 	return fps
 }

Overlord-Client/cmd/agent/handlers/virtual.go

@@ -16,7 +16,7 @@ var (
 func VirtualStart(ctx context.Context, env *rt.Env) error {
 	fps := activeVirtualTargetFPS()
 	interval := time.Second / time.Duration(fps)
-	capture.SetH264TargetFPS(fps)
+	capture.SetBackstageH264TargetFPS(fps)
 	capture.SetFrameFlowTargetFPS(fps)
 	log.Printf("virtual: starting stream (target fps %d)", fps)
 
@@ -38,7 +38,7 @@ func VirtualStart(ctx context.Context, env *rt.Env) error {
 			fps := activeVirtualTargetFPS()
 			if fps != currentFPS {
 				currentFPS = fps
-				capture.SetH264TargetFPS(fps)
+				capture.SetBackstageH264TargetFPS(fps)
 				capture.SetFrameFlowTargetFPS(fps)
 				ticker.Reset(time.Second / time.Duration(fps))
 				log.Printf("virtual: target fps changed to %d", fps)
@@ -65,7 +65,7 @@ func activeVirtualTargetFPS() int {
 func SetVirtualTargetFPS(fps int) int {
 	fps = clampDesktopTargetFPS(fps)
 	virtualTargetFPS.Store(int64(fps))
-	capture.SetH264TargetFPS(fps)
+	capture.SetBackstageH264TargetFPS(fps)
 	capture.SetFrameFlowTargetFPS(fps)
 	return fps
 }

Overlord-Client/cmd/agent/handlers/webcam.go

@@ -21,6 +21,7 @@ func WebcamStart(ctx context.Context, env *rt.Env) error {
 	if fps > 120 {
 		fps = 120
 	}
+	capture.SetWebcamH264TargetFPS(fps)
 	interval := time.Second / time.Duration(fps)
 	log.Printf("webcam: starting stream (max fps %d)", fps)
 	defer capture.CleanupWebcam()

Overlord-Client/cmd/agent/webrtcpub/p2p_pion.go

@@ -147,7 +147,7 @@ func StartP2POffer(ctx context.Context, kind Kind, sessionID string, offerSDP st
 			return "", fmt.Errorf("add video transceiver: %w", err)
 		}
 		if sender := tx.Sender(); sender != nil {
-			go drainRTCP(sender)
+			go drainRTCP(sender, kind)
 		}
 	}
 	if hasAudio {
@@ -172,7 +172,7 @@ func StartP2POffer(ctx context.Context, kind Kind, sessionID string, offerSDP st
 			return "", fmt.Errorf("add audio transceiver: %w", err)
 		}
 		if sender := tx.Sender(); sender != nil {
-			go drainRTCP(sender)
+			go drainRTCP(sender, "")
 		}
 	}
 

Overlord-Client/cmd/agent/webrtcpub/state.go

@@ -110,7 +110,7 @@ func registerVideoWriter(kind Kind, id string, w VideoWriter) {
 	entry.video = newLatestVideoWriter(w)
 	bucket[id] = entry
 	writersMu.Unlock()
-	RequestKeyframe()
+	RequestKeyframe(kind)
 }
 
 func registerAudioWriter(kind Kind, id string, w AudioWriter) {
@@ -155,14 +155,29 @@ func IsActive(kind Kind) bool {
 	return len(writers[string(kind)]) > 0
 }
 
-var keyframeWanted atomic.Bool
+var (
+	desktopKeyframeWanted   atomic.Bool
+	backstageKeyframeWanted atomic.Bool
+	webcamKeyframeWanted    atomic.Bool
+)
 
-func RequestKeyframe() {
+func keyframeRequestFlag(kind Kind) *atomic.Bool {
-	keyframeWanted.Store(true)
+	switch kind {
+	case Kindbackstage:
+		return &backstageKeyframeWanted
+	case KindWebcam:
+		return &webcamKeyframeWanted
+	default:
+		return &desktopKeyframeWanted
+	}
 }
 
-func ConsumeKeyframeRequest() bool {
+func RequestKeyframe(kind Kind) {
-	return keyframeWanted.Swap(false)
+	keyframeRequestFlag(kind).Store(true)
+}
+
+func ConsumeKeyframeRequest(kind Kind) bool {
+	return keyframeRequestFlag(kind).Swap(false)
 }
 
 func WriteH264(kind Kind, nalu []byte, dur time.Duration) error {

Overlord-Client/cmd/agent/webrtcpub/state_test.go

@@ -67,3 +67,21 @@ func TestWriteH264DoesNotBlockAndKeepsLatestPendingFrame(t *testing.T) {
 	}
 	t.Fatal("latest pending frame was not delivered")
 }
+
+func TestKeyframeRequestsAreIsolatedByStreamKind(t *testing.T) {
+	for _, kind := range []Kind{KindDesktop, Kindbackstage, KindWebcam} {
+		_ = ConsumeKeyframeRequest(kind)
+	}
+
+	RequestKeyframe(Kindbackstage)
+
+	if ConsumeKeyframeRequest(KindDesktop) {
+		t.Fatal("backstage keyframe request leaked into desktop stream")
+	}
+	if ConsumeKeyframeRequest(KindWebcam) {
+		t.Fatal("backstage keyframe request leaked into webcam stream")
+	}
+	if !ConsumeKeyframeRequest(Kindbackstage) {
+		t.Fatal("backstage keyframe request was not retained for backstage stream")
+	}
+}

Overlord-Client/cmd/agent/webrtcpub/whip_pion.go

@@ -25,7 +25,7 @@ import (
 	"github.com/pion/webrtc/v4/pkg/media"
 )
 
-func drainRTCP(sender *webrtc.RTPSender) {
+func drainRTCP(sender *webrtc.RTPSender, kind Kind) {
 	buf := make([]byte, 1500)
 	for {
 		n, _, err := sender.Read(buf)
@@ -39,7 +39,9 @@ func drainRTCP(sender *webrtc.RTPSender) {
 		for _, p := range packets {
 			switch p.(type) {
 			case *rtcp.PictureLossIndication, *rtcp.FullIntraRequest:
-				handleRTCPKeyframeFeedback()
+				if kind != "" {
+					handleRTCPKeyframeFeedback(kind)
+				}
 			}
 		}
 	}
@@ -48,11 +50,15 @@ func drainRTCP(sender *webrtc.RTPSender) {
 const h264SDPFmtpLine = "level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=640034"
 
 var rtcpKeyframeLogOnce sync.Once
-var lastRTCPKeyframeRequest atomic.Int64
+var (
+	lastDesktopRTCPKeyframeRequest   atomic.Int64
+	lastBackstageRTCPKeyframeRequest atomic.Int64
+	lastWebcamRTCPKeyframeRequest    atomic.Int64
+)
 
 const rtcpKeyframeMinInterval = 750 * time.Millisecond
 
-func handleRTCPKeyframeFeedback() {
+func handleRTCPKeyframeFeedback(kind Kind) {
 	if !honorRTCPKeyframes() {
 		rtcpKeyframeLogOnce.Do(func() {
 			log.Printf("webrtcpub: RTCP video keyframe recovery disabled by OVERLORD_WEBRTC_RTCP_KEYFRAMES")
@@ -61,15 +67,26 @@ func handleRTCPKeyframeFeedback() {
 	}
 	now := time.Now().UnixNano()
 	for {
-		last := lastRTCPKeyframeRequest.Load()
+		last := rtcpKeyframeTimestamp(kind).Load()
 		if last > 0 && time.Duration(now-last) < rtcpKeyframeMinInterval {
 			return
 		}
-		if lastRTCPKeyframeRequest.CompareAndSwap(last, now) {
+		if rtcpKeyframeTimestamp(kind).CompareAndSwap(last, now) {
 			break
 		}
 	}
-	RequestKeyframe()
+	RequestKeyframe(kind)
+}
+
+func rtcpKeyframeTimestamp(kind Kind) *atomic.Int64 {
+	switch kind {
+	case Kindbackstage:
+		return &lastBackstageRTCPKeyframeRequest
+	case KindWebcam:
+		return &lastWebcamRTCPKeyframeRequest
+	default:
+		return &lastDesktopRTCPKeyframeRequest
+	}
 }
 
 func honorRTCPKeyframes() bool {
@@ -188,7 +205,7 @@ func Start(ctx context.Context, kind Kind, opts Options) (*Publisher, error) {
 			return nil, fmt.Errorf("add video transceiver: %w", err)
 		}
 		if sender := tx.Sender(); sender != nil {
-			go drainRTCP(sender)
+			go drainRTCP(sender, kind)
 		}
 	}
 	if opts.HasAudio {
@@ -213,7 +230,7 @@ func Start(ctx context.Context, kind Kind, opts Options) (*Publisher, error) {
 			return nil, fmt.Errorf("add audio transceiver: %w", err)
 		}
 		if sender := tx.Sender(); sender != nil {
-			go drainRTCP(sender)
+			go drainRTCP(sender, "")
 		}
 	}