feat(room): add --track-name flag to lk room join

Tracks published via --publish previously had no way to set a name:
file tracks were named after the file and socket tracks were unnamed,
making them hard for subscribers to identify.

Add a --track-name flag that overrides the published track name for
file, socket, and simulcast publishes. Defaults are unchanged.

Resolves #669

Author: Scorpion197

cmd/lk/join.go

@@ -188,7 +188,7 @@ func _deprecatedJoinRoom(ctx context.Context, cmd *cli.Command) error {
 					_ = room.LocalParticipant.UnpublishTrack(pub.SID())
 				}
 			}
-			if err = handlePublish(room, pub, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete); err != nil {
+			if err = handlePublish(room, pub, "", fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete); err != nil {
 				return err
 			}
 		}
@@ -200,6 +200,7 @@ func _deprecatedJoinRoom(ctx context.Context, cmd *cli.Command) error {
 
 func handlePublish(room *lksdk.Room,
 	name string,
+	trackName string,
 	fps float64,
 	h26xStreamingFormat string,
 	attachFrameMetadata bool,
@@ -210,9 +211,23 @@ func handlePublish(room *lksdk.Room,
 		if err != nil {
 			return err
 		}
-		return publishSocket(room, mimeType, socketType, address, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete)
+		return publishSocket(room, mimeType, socketType, address, trackName, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete)
+	}
+	return publishFile(room, name, trackName, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete)
+}
+
+// trackPublicationOptions builds publish options, preferring the user-provided
+// track name over the per-source default.
+func trackPublicationOptions(trackName, defaultName string, attachFrameMetadata bool) *lksdk.TrackPublicationOptions {
+	name := defaultName
+	if trackName != "" {
+		name = trackName
+	}
+	return &lksdk.TrackPublicationOptions{
+		Name:                name,
+		AttachUserTimestamp: attachFrameMetadata,
+		AttachFrameId:       attachFrameMetadata,
 	}
-	return publishFile(room, name, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete)
 }
 
 func publishDemo(room *lksdk.Room) error {
@@ -243,6 +258,7 @@ func publishDemo(room *lksdk.Room) error {
 
 func publishFile(room *lksdk.Room,
 	filename string,
+	trackName string,
 	fps float64,
 	h26xStreamingFormat string,
 	attachFrameMetadata bool,
@@ -290,11 +306,7 @@ func publishFile(room *lksdk.Room,
 	if err != nil {
 		return err
 	}
-	pub, err = room.LocalParticipant.PublishTrack(track, &lksdk.TrackPublicationOptions{
-		Name:                filename,
-		AttachUserTimestamp: attachFrameMetadata,
-		AttachFrameId:       attachFrameMetadata,
-	})
+	pub, err = room.LocalParticipant.PublishTrack(track, trackPublicationOptions(trackName, filename, attachFrameMetadata))
 	return err
 }
 
@@ -336,6 +348,7 @@ func publishSocket(room *lksdk.Room,
 	mimeType string,
 	socketType string,
 	address string,
+	trackName string,
 	fps float64,
 	h26xStreamingFormat string,
 	attachFrameMetadata bool,
@@ -362,13 +375,14 @@ func publishSocket(room *lksdk.Room,
 	}
 
 	// Publish to room
-	err = publishReader(room, sock, mime, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete)
+	err = publishReader(room, sock, mime, trackName, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete)
 	return err
 }
 
 func publishReader(room *lksdk.Room,
 	in io.ReadCloser,
 	mime string,
+	trackName string,
 	fps float64,
 	h26xStreamingFormat string,
 	attachFrameMetadata bool,
@@ -409,10 +423,7 @@ func publishReader(room *lksdk.Room,
 	if err != nil {
 		return err
 	}
-	pub, err = room.LocalParticipant.PublishTrack(track, &lksdk.TrackPublicationOptions{
-		AttachUserTimestamp: attachFrameMetadata,
-		AttachFrameId:       attachFrameMetadata,
-	})
+	pub, err = room.LocalParticipant.PublishTrack(track, trackPublicationOptions(trackName, "", attachFrameMetadata))
 	if err != nil {
 		return err
 	}
@@ -519,7 +530,7 @@ type simulcastLayer struct {
 }
 
 // handleSimulcastPublish handles publishing multiple H.264 streams as a simulcast track
-func handleSimulcastPublish(room *lksdk.Room, urls []string, fps float64, h26xStreamingFormat string, attachFrameMetadata bool, onPublishComplete func(*lksdk.LocalTrackPublication)) error {
+func handleSimulcastPublish(room *lksdk.Room, urls []string, trackName string, fps float64, h26xStreamingFormat string, attachFrameMetadata bool, onPublishComplete func(*lksdk.LocalTrackPublication)) error {
 	// Parse all URLs
 	var layers []simulcastLayer
 	for _, url := range urls {
@@ -605,11 +616,7 @@ func handleSimulcastPublish(room *lksdk.Room, urls []string, fps float64, h26xSt
 
 	// Publish simulcast track
 	var err error
-	pub, err = room.LocalParticipant.PublishSimulcastTrack(tracks, &lksdk.TrackPublicationOptions{
-		Name:                "simulcast",
-		AttachUserTimestamp: attachFrameMetadata,
-		AttachFrameId:       attachFrameMetadata,
-	})
+	pub, err = room.LocalParticipant.PublishSimulcastTrack(tracks, trackPublicationOptions(trackName, "simulcast", attachFrameMetadata))
 	if err != nil {
 		// Clean up tracks on publish failure
 		for _, track := range tracks {

cmd/lk/join_test.go

@@ -84,6 +84,27 @@ func TestParseSocketString(t *testing.T) {
 	assert.Equal(t, err, nil, "Expected no error for valid vp8 TCP socket")
 }
 
+func TestTrackPublicationOptions(t *testing.T) {
+	// Default name is used when no override is given
+	opts := trackPublicationOptions("", "video.h264", false)
+	assert.Equal(t, "video.h264", opts.Name)
+	assert.False(t, opts.AttachUserTimestamp)
+	assert.False(t, opts.AttachFrameId)
+
+	// Override takes precedence over the default name
+	opts = trackPublicationOptions("camera-main", "video.h264", false)
+	assert.Equal(t, "camera-main", opts.Name)
+
+	// Socket publishes have no default name unless overridden
+	opts = trackPublicationOptions("", "", false)
+	assert.Equal(t, "", opts.Name)
+
+	opts = trackPublicationOptions("screen-share", "", true)
+	assert.Equal(t, "screen-share", opts.Name)
+	assert.True(t, opts.AttachUserTimestamp)
+	assert.True(t, opts.AttachFrameId)
+}
+
 func TestParseSimulcastURL(t *testing.T) {
 	// Test TCP format
 	parts, err := parseSimulcastURL("h264://localhost:8080/640x480")

cmd/lk/room.go

@@ -160,6 +160,11 @@ var (
 								"Can publish from Unix or TCP socket using the format '<codec>:///<socket_path>' or '<codec>://<host:port>' respectively. Valid codecs are \"h264\", \"h265\", \"vp8\", \"opus\". " +
 								"For simulcast: use 2-3 h264:// or h265:// URLs with format '<codec>://<host:port>/<width>x<height>' or '<codec>:///path/to/<socket_path>/<width>x<height>' (all layers must use the same codec; quality determined by width order)",
 						},
+						&cli.StringFlag{
+							Name: "track-name",
+							Usage: "`NAME` of the published track. Applies to all tracks published via --publish. " +
+								"If unset, file tracks are named after the file and socket tracks are unnamed",
+						},
 						&cli.StringFlag{
 							Name:  "publish-data",
 							Usage: "Publish user data to the room.",
@@ -996,6 +1001,7 @@ func joinRoom(ctx context.Context, cmd *cli.Command) error {
 
 	// Handle publishing
 	if len(publishUrls) > 0 {
+		trackName := cmd.String("track-name")
 		if simulcastMode {
 			// Handle simulcast publishing
 			fps := cmd.Float("fps")
@@ -1011,7 +1017,7 @@ func joinRoom(ctx context.Context, cmd *cli.Command) error {
 				}
 			}
 
-			if err = handleSimulcastPublish(room, publishUrls, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete); err != nil {
+			if err = handleSimulcastPublish(room, publishUrls, trackName, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete); err != nil {
 				return err
 			}
 		} else {
@@ -1029,7 +1035,7 @@ func joinRoom(ctx context.Context, cmd *cli.Command) error {
 						_ = room.LocalParticipant.UnpublishTrack(pub.SID())
 					}
 				}
-				if err = handlePublish(room, pub, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete); err != nil {
+				if err = handlePublish(room, pub, trackName, fps, h26xStreamingFormat, attachFrameMetadata, onPublishComplete); err != nil {
 					return err
 				}
 			}