audio flowdef

internal/flowdef/flowdef.go

@@ -9,9 +9,10 @@ import (
 )
 
 const (
-	FormatVideo   = "urn:x-nmos:format:video"
-	FormatAudio   = "urn:x-nmos:format:audio"
-	MediaTypeV210 = "video/v210"
+	FormatVideo      = "urn:x-nmos:format:video"
+	FormatAudio      = "urn:x-nmos:format:audio"
+	MediaTypeV210    = "video/v210"
+	MediaTypeFloat32 = "audio/float32"
 
 	InterlaceProgressive = "progressive"
 	ColorSpaceBT709      = "BT709"
@@ -32,6 +33,22 @@ type Rational struct {
 	Denominator uint `json:"denominator"`
 }
 
+func (r *Rational) UnmarshalJSON(data []byte) error {
+	var value struct {
+		Numerator   uint  `json:"numerator"`
+		Denominator *uint `json:"denominator"`
+	}
+	if err := json.Unmarshal(data, &value); err != nil {
+		return err
+	}
+	r.Numerator = value.Numerator
+	r.Denominator = 1
+	if value.Denominator != nil {
+		r.Denominator = *value.Denominator
+	}
+	return nil
+}
+
 type Video struct {
 	Common
 
@@ -141,3 +158,66 @@ func (v Video) Validate() error {
 	}
 	return nil
 }
+
+func NewFloat32Audio(
+	id string,
+	channels uint,
+	rate Rational,
+) (Audio, error) {
+	definition := Audio{
+		Common: Common{
+			Description: "go-mxl-pattern-gen generated audio",
+			ID:          id,
+			Tags: map[string][]string{
+				"urn:x-nmos:tag:grouphint/v1.0": {
+					"go-mxl-pattern-gen:Audio",
+				},
+			},
+			Format:    FormatAudio,
+			Label:     "go-mxl-pattern-gen generated audio",
+			Parents:   []string{},
+			MediaType: MediaTypeFloat32,
+		},
+		SampleRate:   rate,
+		ChannelCount: channels,
+		BitDepth:     32,
+	}
+	if err := definition.Validate(); err != nil {
+		return Audio{}, err
+	}
+	return definition, nil
+}
+
+func (a Audio) Validate() error {
+	if err := uuid.Validate(a.ID); err != nil {
+		return fmt.Errorf("invalid id %q: %w", a.ID, err)
+	}
+	if a.Format != FormatAudio {
+		return fmt.Errorf("format must be %q, got %q", FormatAudio, a.Format)
+	}
+	if a.MediaType != MediaTypeFloat32 {
+		return fmt.Errorf("media_type must be %q, got %q", MediaTypeFloat32, a.MediaType)
+	}
+	if a.ChannelCount == 0 {
+		return fmt.Errorf("channel_count must be greater than zero")
+	}
+	if a.SampleRate.Numerator == 0 || a.SampleRate.Denominator == 0 {
+		return fmt.Errorf("sample_rate numerator and denominator must be greater than zero, got %d/%d",
+			a.SampleRate.Numerator, a.SampleRate.Denominator)
+	}
+	if a.BitDepth != 32 {
+		return fmt.Errorf("bit_depth must be 32, got %d", a.BitDepth)
+	}
+	return nil
+}
+
+func ParseFloat32Audio(data []byte) (Audio, error) {
+	var definition Audio
+	if err := json.Unmarshal(data, &definition); err != nil {
+		return Audio{}, fmt.Errorf("decode audio flow definition: %w", err)
+	}
+	if err := definition.Validate(); err != nil {
+		return Audio{}, fmt.Errorf("invalid audio flow definition: %w", err)
+	}
+	return definition, nil
+}