Add go modules, add possibility to query device caps

device_cap.go

@@ -1,13 +1,15 @@
 package v4l2
 
+import "errors"
+
 // HasCapability return whether the device has a capability a particular capability.
 //
 // Example:
 //
 //	device, err := v4l2.Open(v4l2.Video17)
-//	
+//
 //	// ...
-//	
+//
 //	hasVideoCaptureCapability, err := device.HasCapability(CapabilityVideoCapture)
 func (receiver Device) HasCapability(cap uint32) (bool, error) {
 	if err := receiver.unfit(); nil != err {
@@ -33,3 +35,42 @@ func (receiver Device) MustHasCapability(cap uint32) bool {
 
 	return datum
 }
+
+
+// HasDeviceCapability return whether the device has a particular device capability.
+//
+// Example:
+//
+//	device, err := v4l2.Open(v4l2.Video17)
+//
+//	// ...
+//
+//	hasVideoCaptureCapability, err := device.HasDeviceCapability(CapabilityVideoCapture)
+func (receiver Device) HasDeviceCapability(cap uint32) (bool, error) {
+	if hasDeviceCaps, err := receiver.HasCapability(CapabilityDeviceCaps); err != nil {
+		return false, err
+	} else if !hasDeviceCaps {
+		return false, errors.New("No device caps available")
+	}
+
+	has := 0 != (receiver.cap.deviceCaps & cap)
+	return has, nil
+}
+
+// MustHasDeviceCapability return whether the device has a particular device capability.
+//
+// Example:
+//
+//	device, err := v4l2.Open(v4l2.Video17)
+//
+//	// ...
+//
+//	hasVideoCaptureCapability, err := device.MustHasDeviceCapability(CapabilityVideoCapture)
+func (receiver Device) MustHasDeviceCapability(cap uint32) bool {
+	if hasDeviceCaps := receiver.MustHasCapability(CapabilityDeviceCaps); !hasDeviceCaps {
+		panic(errors.New("No device caps available"))
+	}
+
+	has := 0 != (receiver.cap.deviceCaps & cap)
+	return has
+}

go.mod

@@ -0,0 +1,5 @@
+module github.com/reiver/go-v4l2
+
+go 1.16
+
+require golang.org/x/sys v0.0.0-20210331175145-43e1dd70ce54

go.sum

@@ -0,0 +1,2 @@
+golang.org/x/sys v0.0.0-20210331175145-43e1dd70ce54 h1:rF3Ohx8DRyl8h2zw9qojyLHLhrJpEMgyPOImREEryf0=
+golang.org/x/sys v0.0.0-20210331175145-43e1dd70ce54/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=