validating framerate

components/camera/videosource/webcam.go

@@ -157,6 +157,11 @@ func (c WebcamConfig) Validate(path string) ([]string, error) {
 			"got illegal negative dimensions for width_px and height_px (%d, %d) fields set for webcam camera",
 			c.Height, c.Width)
 	}
+	if c.FrameRate <= 0 {
+		return nil, fmt.Errorf(
+			"got illegal non-positive dimension for frame rate (%.2f) field set for webcam camera",
+			c.FrameRate)
+	}
 
 	return []string{}, nil
 }
@@ -640,7 +645,7 @@ func (c *monitoredWebcam) Properties(ctx context.Context) (camera.Properties, er
 		}
 		props.IntrinsicParams = &cameraIntrinsics
 
-		if c.conf.FrameRate != 0 {
+		if c.conf.FrameRate > 0 {
 			props.FrameRate = c.conf.FrameRate
 		}
 	}

components/camera/videosource/webcam_test.go

@@ -57,33 +57,50 @@ func TestDiscoveryWebcam(t *testing.T) {
 
 func TestWebcamValidation(t *testing.T) {
 	webCfg := &videosource.WebcamConfig{
-		Width:  1280,
-		Height: 640,
+		Width:     1280,
+		Height:    640,
+		FrameRate: 100,
 	}
 
-	// no error with positive width and height
+	// no error with positive width, height, and frame rate
 	deps, err := webCfg.Validate("path")
 	test.That(t, err, test.ShouldBeNil)
 	test.That(t, deps, test.ShouldResemble, []string{})
 
+	// no error with 0 width and 0 height
 	webCfg.Width = 0
 	webCfg.Height = 0
 	deps, err = webCfg.Validate("path")
 	test.That(t, err, test.ShouldBeNil)
 	test.That(t, deps, test.ShouldResemble, []string{})
 
-	// error with a negative width and positive height
+	// error with a negative width
 	webCfg.Width = -200
 	deps, err = webCfg.Validate("path")
 	test.That(t, err.Error(), test.ShouldEqual,
 		"got illegal negative dimensions for width_px and height_px (0, -200) fields set for webcam camera")
 	test.That(t, deps, test.ShouldBeNil)
 
-	// error with a positive width and negative height
+	// error with a negative height
 	webCfg.Width = 200
 	webCfg.Height = -200
 	deps, err = webCfg.Validate("path")
 	test.That(t, err.Error(), test.ShouldEqual,
 		"got illegal negative dimensions for width_px and height_px (-200, 200) fields set for webcam camera")
 	test.That(t, deps, test.ShouldBeNil)
+
+	// error with a negative frame rate
+	webCfg.Height = 200
+	webCfg.FrameRate = -100
+	deps, err = webCfg.Validate("path")
+	test.That(t, err.Error(), test.ShouldEqual,
+		"got illegal non-positive dimension for frame rate (-100.00) field set for webcam camera")
+	test.That(t, deps, test.ShouldBeNil)
+
+	// error with a 0 frame rate
+	webCfg.FrameRate = 0
+	deps, err = webCfg.Validate("path")
+	test.That(t, err.Error(), test.ShouldEqual,
+		"got illegal non-positive dimension for frame rate (0.00) field set for webcam camera")
+	test.That(t, deps, test.ShouldBeNil)
 }