Change InbandEventStream to array and add unit test (#91)

* NLP-4379 : Minor changes to inband event stream

* NLP-4379 : Add unit test

* NLP-4379 : Review comments

Author: jjeyaprakash

mpd/fixtures/inband_event_stream.mpd

@@ -0,0 +1,11 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<MPD xmlns="urn:mpeg:dash:schema:mpd:2011" profiles="urn:mpeg:dash:profile:isoff-live:2011" type="static" mediaPresentationDuration="PT6M16S" minBufferTime="PT1.97S">
+  <Period>
+    <AdaptationSet mimeType="video/mp4" startWithSAP="1" scanType="progressive" id="7357" segmentAlignment="true">
+      <InbandEventStream schemeIdUri="https://aomedia.org/emsg/ID3" value="0"></InbandEventStream>
+      <Representation bandwidth="1518664" codecs="avc1.4d401f" frameRate="30000/1001" height="540" id="800" width="960">
+        <InbandEventStream schemeIdUri="https://aomedia.org/emsg/ID3" value="1"></InbandEventStream>
+      </Representation>
+    </AdaptationSet>
+  </Period>
+</MPD>

mpd/mpd.go

@@ -53,19 +53,20 @@ const (
 
 // Known error variables
 var (
-	ErrNoDASHProfileSet               error = errors.New("No DASH profile set")
-	ErrAdaptationSetNil                     = errors.New("Adaptation Set nil")
-	ErrSegmentTemplateLiveProfileOnly       = errors.New("Segment template can only be used with Live Profile")
-	ErrSegmentTemplateNil                   = errors.New("Segment Template nil ")
-	ErrRepresentationNil                    = errors.New("Representation nil")
-	ErrAccessibilityNil                     = errors.New("Accessibility nil")
-	ErrBaseURLEmpty                         = errors.New("Base URL empty")
-	ErrSegmentBaseOnDemandProfileOnly       = errors.New("Segment Base can only be used with On-Demand Profile")
-	ErrSegmentBaseNil                       = errors.New("Segment Base nil")
-	ErrAudioChannelConfigurationNil         = errors.New("Audio Channel Configuration nil")
-	ErrInvalidDefaultKID                    = errors.New("Invalid Default KID string, should be 32 characters")
-	ErrPROEmpty                             = errors.New("PlayReady PRO empty")
-	ErrContentProtectionNil                 = errors.New("Content Protection nil")
+	ErrNoDASHProfileSet                error = errors.New("No DASH profile set")
+	ErrAdaptationSetNil                      = errors.New("Adaptation Set nil")
+	ErrSegmentTemplateLiveProfileOnly        = errors.New("Segment template can only be used with Live Profile")
+	ErrSegmentTemplateNil                    = errors.New("Segment Template nil ")
+	ErrRepresentationNil                     = errors.New("Representation nil")
+	ErrAccessibilityNil                      = errors.New("Accessibility nil")
+	ErrBaseURLEmpty                          = errors.New("Base URL empty")
+	ErrSegmentBaseOnDemandProfileOnly        = errors.New("Segment Base can only be used with On-Demand Profile")
+	ErrSegmentBaseNil                        = errors.New("Segment Base nil")
+	ErrAudioChannelConfigurationNil          = errors.New("Audio Channel Configuration nil")
+	ErrInvalidDefaultKID                     = errors.New("Invalid Default KID string, should be 32 characters")
+	ErrPROEmpty                              = errors.New("PlayReady PRO empty")
+	ErrContentProtectionNil                  = errors.New("Content Protection nil")
+	ErrInbandEventStreamSchemeUriEmpty       = errors.New("Inband Event Stream schemeIdUri Empty")
 )
 
 type MPD struct {
@@ -124,7 +125,7 @@ type CommonAttributesAndElements struct {
 	ContentProtection         []ContentProtectioner `xml:"ContentProtection,omitempty"`
 	EssentialProperty         []DescriptorType      `xml:"EssentialProperty,omitempty"`
 	SupplementalProperty      []DescriptorType      `xml:"SupplementalProperty,omitempty"`
-	InbandEventStream         *DescriptorType       `xml:"inbandEventStream,attr"`
+	InbandEventStream         []DescriptorType      `xml:"InbandEventStream,omitempty"`
 }
 
 type contentProtections []ContentProtectioner
@@ -1101,6 +1102,21 @@ func (as *AdaptationSet) AddNewAccessibilityElement(scheme AccessibilityElementS
 	return accessibility, nil
 }
 
+// AddNewInbandEventStream - Adds a new InbandEventStream Descriptor to an adaptation set
+// uri - Scheme ID URI for the inband event stream
+// val - value for inband event stream
+func (as *AdaptationSet) AddNewInbandEventStream(uri string, val string) error {
+	if len(uri) <= 0 {
+		return ErrInbandEventStreamSchemeUriEmpty
+	}
+	evt := DescriptorType{
+		SchemeIDURI: Strptr(uri),
+		Value:       Strptr(val),
+	}
+	as.InbandEventStream = append(as.InbandEventStream, evt)
+	return nil
+}
+
 // Sets the BaseURL for a Representation.
 // baseURL - Base URL as a string (i.e. 800k/output-audio-und.mp4)
 func (r *Representation) SetNewBaseURL(baseURL string) error {
@@ -1166,3 +1182,18 @@ func (r *Representation) setAudioChannelConfiguration(acc *AudioChannelConfigura
 	r.AudioChannelConfiguration = acc
 	return nil
 }
+
+// AddNewInbandEventStream - Adds a new InbandEventStream Descriptor to a Representation
+// uri - Scheme ID URI for the inband event stream
+// val - value for inband event stream
+func (r *Representation) AddNewInbandEventStream(uri string, val string) error {
+	if len(uri) <= 0 {
+		return ErrInbandEventStreamSchemeUriEmpty
+	}
+	evt := DescriptorType{
+		SchemeIDURI: Strptr(uri),
+		Value:       Strptr(val),
+	}
+	r.InbandEventStream = append(r.InbandEventStream, evt)
+	return nil
+}

mpd/mpd_test.go

@@ -46,6 +46,7 @@ const (
 	VALID_SUBTITLE_URL                string = "http://example.com/content/sintel/subtitles/subtitles_en.vtt"
 	VALID_ROLE                        string = "main"
 	VALID_LOCATION                    string = "https://example.com/location.mpd"
+	VALID_SCHEME_ID_URI               string = "https://aomedia.org/emsg/ID3"
 )
 
 func TestNewMPDLive(t *testing.T) {
@@ -558,3 +559,34 @@ func TestReadWriteIdentical(t *testing.T) {
 		})
 	}
 }
+
+func TestSetInbandEventStream(t *testing.T) {
+	var (
+		err error
+		got string
+	)
+
+	m := NewMPD(DASH_PROFILE_LIVE, VALID_MEDIA_PRESENTATION_DURATION, VALID_MIN_BUFFER_TIME)
+	videoAS, _ := m.AddNewAdaptationSetVideoWithID("7357", DASH_MIME_TYPE_VIDEO_MP4, VALID_SCAN_TYPE, VALID_SEGMENT_ALIGNMENT, VALID_START_WITH_SAP)
+	err = videoAS.AddNewInbandEventStream(VALID_SCHEME_ID_URI, "0")
+
+	require.NoError(t, err)
+
+	r, _ := videoAS.AddNewRepresentationVideo(VALID_VIDEO_BITRATE, VALID_VIDEO_CODEC, VALID_VIDEO_ID, VALID_VIDEO_FRAMERATE, VALID_VIDEO_WIDTH, VALID_VIDEO_HEIGHT)
+	err = r.AddNewInbandEventStream(VALID_SCHEME_ID_URI, "1")
+
+	require.NoError(t, err)
+
+	got, err = m.WriteToString()
+	require.NoError(t, err)
+
+	testfixtures.CompareFixture(t, "fixtures/inband_event_stream.mpd", got)
+}
+
+func TestSetInbandEventStreamError(t *testing.T) {
+	m := NewMPD(DASH_PROFILE_LIVE, VALID_MEDIA_PRESENTATION_DURATION, VALID_MIN_BUFFER_TIME)
+	videoAS, _ := m.AddNewAdaptationSetVideoWithID("7357", DASH_MIME_TYPE_VIDEO_MP4, VALID_SCAN_TYPE, VALID_SEGMENT_ALIGNMENT, VALID_START_WITH_SAP)
+	err := videoAS.AddNewInbandEventStream("", "")
+
+	require.EqualErr(t, ErrInbandEventStreamSchemeUriEmpty, err)
+}