diff --git a/cmd/mxl-pattern/main.go b/cmd/mxl-pattern/main.go
index e2785d1..65f6a14 100644
--- a/cmd/mxl-pattern/main.go
+++ b/cmd/mxl-pattern/main.go
@@ -355,7 +355,7 @@ func buildVideoConfig(args appArgs) (*video.Config, error) {
 			)
 		}
 
-		definition, err = flowdef.ParseV210Video(data)
+		definition, err = flowdef.ParseVideo(data)
 		if err != nil {
 			return nil, fmt.Errorf(
 				"parse video flow definition %q: %w",
diff --git a/internal/flowdef/flowdef.go b/internal/flowdef/flowdef.go
index 0e0b108..a5cbdd3 100644
--- a/internal/flowdef/flowdef.go
+++ b/internal/flowdef/flowdef.go
@@ -12,6 +12,7 @@ const (
 	FormatVideo      = "urn:x-nmos:format:video"
 	FormatAudio      = "urn:x-nmos:format:audio"
 	MediaTypeV210    = "video/v210"
+	MediaTypeV210A   = "video/v210a"
 	MediaTypeFloat32 = "audio/float32"
 
 	InterlaceProgressive = "progressive"
@@ -75,7 +76,12 @@ type VideoComponent struct {
 	BitDepth uint   `json:"bit_depth"`
 }
 
-func NewV210Video(id string, width, height uint, rate Rational) (Video, error) {
+func newVideo(
+	id string,
+	width, height uint,
+	rate Rational,
+	mediaType string,
+) (Video, error) {
 	definition := Video{
 		Common: Common{
 			Description: "go-mxl-pattern-gen generated video",
@@ -86,7 +92,7 @@ func NewV210Video(id string, width, height uint, rate Rational) (Video, error) {
 			Format:    FormatVideo,
 			Label:     "go-mxl-pattern-gen generated video",
 			Parents:   []string{},
-			MediaType: MediaTypeV210,
+			MediaType: mediaType,
 		},
 		GrainRate:     rate,
 		FrameWidth:    width,
@@ -105,7 +111,15 @@ func NewV210Video(id string, width, height uint, rate Rational) (Video, error) {
 	return definition, nil
 }
 
-func ParseV210Video(data []byte) (Video, error) {
+func NewV210Video(id string, width, height uint, rate Rational) (Video, error) {
+	return newVideo(id, width, height, rate, MediaTypeV210)
+}
+
+func NewV210AVideo(id string, width, height uint, rate Rational) (Video, error) {
+	return newVideo(id, width, height, rate, MediaTypeV210A)
+}
+
+func ParseVideo(data []byte) (Video, error) {
 	var definition Video
 	if err := json.Unmarshal(data, &definition); err != nil {
 		return Video{}, fmt.Errorf("decode video flow definition: %w", err)
@@ -123,8 +137,10 @@ func (v Video) Validate() error {
 	if v.Format != FormatVideo {
 		return fmt.Errorf("format must be %q, got %q", FormatVideo, v.Format)
 	}
-	if v.MediaType != MediaTypeV210 {
-		return fmt.Errorf("media_type must be %q, got %q", MediaTypeV210, v.MediaType)
+	switch v.MediaType {
+	case MediaTypeV210, MediaTypeV210A:
+	default:
+		return fmt.Errorf("media_type must be %q or %q, got %q", MediaTypeV210, MediaTypeV210A, v.MediaType)
 	}
 	if v.InterlaceMode != InterlaceProgressive {
 		return fmt.Errorf("interlace_mode must be %q, got %q", InterlaceProgressive, v.InterlaceMode)
diff --git a/internal/flowdef/flowdef_test.go b/internal/flowdef/flowdef_test.go
index dbf8fe7..74f0ee4 100644
--- a/internal/flowdef/flowdef_test.go
+++ b/internal/flowdef/flowdef_test.go
@@ -28,6 +28,29 @@ func TestNewV210Video(t *testing.T) {
 	}
 }
 
+func TestNewV210AVideo(t *testing.T) {
+	definition, err := NewV210AVideo(testVideoID, 1280, 720, Rational{Numerator: 50, Denominator: 1})
+	if err != nil {
+		t.Fatalf("NewV210AVideo: %v", err)
+	}
+	if definition.MediaType != MediaTypeV210A {
+		t.Fatalf("media type = %q, want %q", definition.MediaType, MediaTypeV210A)
+	}
+	wantComponents := []VideoComponent{
+		{Name: "Y", Width: 1280, Height: 720, BitDepth: 10},
+		{Name: "Cb", Width: 640, Height: 720, BitDepth: 10},
+		{Name: "Cr", Width: 640, Height: 720, BitDepth: 10},
+	}
+	if len(definition.Components) != len(wantComponents) {
+		t.Fatalf("component count = %d, want %d", len(definition.Components), len(wantComponents))
+	}
+	for i, want := range wantComponents {
+		if definition.Components[i] != want {
+			t.Fatalf("component %d = %+v, want %+v", i, definition.Components[i], want)
+		}
+	}
+}
+
 func TestNewV210VideoRejectsOddWidth(t *testing.T) {
 	_, err := NewV210Video(testVideoID, 1919, 1080, Rational{Numerator: 25, Denominator: 1})
 	if err == nil || !strings.Contains(err.Error(), "even") {
@@ -35,7 +58,7 @@ func TestNewV210VideoRejectsOddWidth(t *testing.T) {
 	}
 }
 
-func TestParseV210Video(t *testing.T) {
+func TestParseVideo(t *testing.T) {
 	want, err := NewV210Video(testVideoID, 1920, 1080, Rational{Numerator: 25, Denominator: 1})
 	if err != nil {
 		t.Fatalf("NewV210Video: %v", err)
@@ -45,28 +68,58 @@ func TestParseV210Video(t *testing.T) {
 		t.Fatalf("json.Marshal: %v", err)
 	}
 
-	got, err := ParseV210Video(data)
+	got, err := ParseVideo(data)
 	if err != nil {
-		t.Fatalf("ParseV210Video: %v", err)
+		t.Fatalf("ParseVideo: %v", err)
 	}
 	if got.ID != want.ID || got.FrameWidth != want.FrameWidth || got.GrainRate != want.GrainRate {
 		t.Fatalf("parsed definition = %+v, want %+v", got, want)
 	}
 }
 
-func TestParseV210VideoRejectsAudio(t *testing.T) {
+func TestParseVideoAcceptsV210A(t *testing.T) {
+	want, err := NewV210AVideo(testVideoID, 1920, 1080, Rational{Numerator: 25, Denominator: 1})
+	if err != nil {
+		t.Fatalf("NewV210AVideo: %v", err)
+	}
+	data, err := json.Marshal(want)
+	if err != nil {
+		t.Fatalf("json.Marshal: %v", err)
+	}
+
+	got, err := ParseVideo(data)
+	if err != nil {
+		t.Fatalf("ParseVideo: %v", err)
+	}
+	if got.MediaType != MediaTypeV210A {
+		t.Fatalf("media type = %q, want %q", got.MediaType, MediaTypeV210A)
+	}
+}
+
+func TestParseVideoRejectsAudio(t *testing.T) {
 	data := []byte(`{
 		"id":"5fbec3b1-1b0f-417d-9059-8b94a47197ed",
 		"format":"urn:x-nmos:format:audio",
 		"media_type":"audio/float32"
 	}`)
 
-	_, err := ParseV210Video(data)
+	_, err := ParseVideo(data)
 	if err == nil || !strings.Contains(err.Error(), "format must be") {
 		t.Fatalf("error = %v, want video format error", err)
 	}
 }
 
+func TestVideoRejectsUnknownMediaType(t *testing.T) {
+	definition, err := NewV210Video(testVideoID, 1920, 1080, Rational{Numerator: 25, Denominator: 1})
+	if err != nil {
+		t.Fatalf("NewV210Video: %v", err)
+	}
+	definition.MediaType = "video/unknown"
+	if err := definition.Validate(); err == nil || !strings.Contains(err.Error(), "media_type") {
+		t.Fatalf("error = %v, want media_type error", err)
+	}
+}
+
 func TestNewFloat32Audio(t *testing.T) {
 	definition, err := NewFloat32Audio(testAudioID, 2, Rational{Numerator: 48000, Denominator: 1})
 	if err != nil {