Remove Kind in favor of type assertion

mediadevices.go

@@ -60,8 +60,7 @@ func (m *mediaDevices) GetUserMedia(constraints MediaStreamConstraints) (MediaSt
 // videoSelect implements SelectSettings algorithm for video type.
 // Reference: https://w3c.github.io/mediacapture-main/#dfn-selectsettings
 func (m *mediaDevices) videoSelect(constraints VideoTrackConstraints) (Tracker, error) {
-	videoFilterFn := driver.FilterKind(driver.Video)
-	drivers := driver.GetManager().Query(videoFilterFn)
+	drivers := driver.GetManager().VideoDrivers()
 
 	var bestDriver driver.VideoDriver
 	var bestSetting driver.VideoSetting
@@ -111,8 +110,7 @@ func (m *mediaDevices) videoSelect(constraints VideoTrackConstraints) (Tracker,
 // audioSelect implements SelectSettings algorithm for audio type.
 // Reference: https://w3c.github.io/mediacapture-main/#dfn-selectsettings
 func (m *mediaDevices) audioSelect(constraints AudioTrackConstraints) (Tracker, error) {
-	audioFilterFn := driver.FilterKind(driver.Audio)
-	drivers := driver.GetManager().Query(audioFilterFn)
+	drivers := driver.GetManager().AudioDrivers()
 
 	var bestDriver driver.AudioDriver
 	var bestSetting driver.AudioSetting

pkg/driver/camera_linux.go

@@ -15,11 +15,11 @@ import (
 // Camera implementation using v4l2
 // Reference: https://linuxtv.org/downloads/v4l-dvb-apis/uapi/v4l/videodev.html#videodev
 type camera struct {
-	path    string
-	cam     *webcam.Webcam
-	formats map[webcam.PixelFormat]frame.Format
+	path            string
+	cam             *webcam.Webcam
+	formats         map[webcam.PixelFormat]frame.Format
 	reversedFormats map[frame.Format]webcam.PixelFormat
-	settings 	[]VideoSetting
+	settings        []VideoSetting
 }
 
 var _ VideoAdapter = &camera{}
@@ -34,8 +34,8 @@ func init() {
 
 func newCamera(path string) *camera {
 	formats := map[webcam.PixelFormat]frame.Format{
-		webcam.PixelFormat(C.V4L2_PIX_FMT_YUYV): frame.FormatYUYV,
-		webcam.PixelFormat(C.V4L2_PIX_FMT_NV12): frame.FormatNV21,
+		webcam.PixelFormat(C.V4L2_PIX_FMT_YUYV):  frame.FormatYUYV,
+		webcam.PixelFormat(C.V4L2_PIX_FMT_NV12):  frame.FormatNV21,
 		webcam.PixelFormat(C.V4L2_PIX_FMT_MJPEG): frame.FormatMJPEG,
 	}
 
@@ -45,8 +45,8 @@ func newCamera(path string) *camera {
 	}
 
 	return &camera{
-		path: path,
-		formats: formats,
+		path:            path,
+		formats:         formats,
 		reversedFormats: reversedFormats,
 	}
 }
@@ -61,8 +61,8 @@ func (c *camera) Open() error {
 	for format := range cam.GetSupportedFormats() {
 		for _, frameSize := range cam.GetSupportedFrameSizes(format) {
 			settings = append(settings, VideoSetting{
-				Width:  int(frameSize.MaxWidth),
-				Height: int(frameSize.MaxHeight),
+				Width:       int(frameSize.MaxWidth),
+				Height:      int(frameSize.MaxHeight),
 				FrameFormat: c.formats[format],
 			})
 		}
@@ -135,7 +135,6 @@ func (c *camera) Stop() error {
 
 func (c *camera) Info() Info {
 	return Info{
-		Kind: 		Video,
 		DeviceType: Camera,
 	}
 }

pkg/driver/const.go

@@ -1,12 +1,5 @@
 package driver
 
-type Kind string
-
-const (
-	Video Kind = "video"
-	Audio      = "audio"
-)
-
 type DeviceType string
 
 const (

pkg/driver/driver.go

@@ -1,10 +1,11 @@
 package driver
 
 import (
+	"time"
+
 	"github.com/pion/mediadevices/pkg/frame"
 	"github.com/pion/mediadevices/pkg/io/audio"
 	"github.com/pion/mediadevices/pkg/io/video"
-	"time"
 )
 
 type OpenCloser interface {
@@ -17,7 +18,6 @@ type Infoer interface {
 }
 
 type Info struct {
-	Kind       Kind
 	DeviceType DeviceType
 }
 

pkg/driver/manager.go

@@ -2,14 +2,10 @@ package driver
 
 import "fmt"
 
+// FilterFn is being used to decide if a driver should be included in the
+// query result.
 type FilterFn func(Driver) bool
 
-func FilterKind(k Kind) FilterFn {
-	return func(d Driver) bool {
-		return d.Info().Kind == k
-	}
-}
-
 // Manager is a singleton to manage multiple drivers and their states
 type Manager struct {
 	drivers map[string]Driver
@@ -46,3 +42,19 @@ func (m *Manager) Query(f FilterFn) []Driver {
 
 	return results
 }
+
+// VideoDrivers gets a list of registered VideoDriver
+func (m *Manager) VideoDrivers() []Driver {
+	return m.Query(func(d Driver) bool {
+		_, ok := d.(VideoDriver)
+		return ok
+	})
+}
+
+// AudioDrivers gets a list of registered AudioDriver
+func (m *Manager) AudioDrivers() []Driver {
+	return m.Query(func(d Driver) bool {
+		_, ok := d.(AudioDriver)
+		return ok
+	})
+}

pkg/driver/microphone_linux.go

@@ -100,7 +100,6 @@ func (m *microphone) Stop() error {
 
 func (m *microphone) Info() Info {
 	return Info{
-		Kind:       Audio,
 		DeviceType: Microphone,
 	}
 }

track.go

@@ -27,10 +27,10 @@ type track struct {
 
 func newTrack(pc *webrtc.PeerConnection, d driver.Driver, codecName string) (*track, error) {
 	var kind webrtc.RTPCodecType
-	switch d.Info().Kind {
-	case driver.Video:
+	switch d.(type) {
+	case driver.VideoDriver:
 		kind = webrtc.RTPCodecTypeVideo
-	case driver.Audio:
+	case driver.AudioDriver:
 		kind = webrtc.RTPCodecTypeAudio
 	}