Store alternatives in all variants

reader.go

@@ -65,6 +65,7 @@ func (p *MasterPlaylist) decode(buf *bytes.Buffer, strict bool) error {
 	var eof bool
 
 	state := new(decodingState)
+	state.alternatives = make(map[string][]*Alternative)
 
 	for !eof {
 		line, err := buf.ReadString('\n')
@@ -81,9 +82,56 @@ func (p *MasterPlaylist) decode(buf *bytes.Buffer, strict bool) error {
 	if strict && !state.m3u {
 		return errors.New("#EXTM3U absent")
 	}
+
+	p.setAlternatives(state)
+
 	return nil
 }
 
+// Set alternatives for variants in master playlist. Internal function.
+func (p *MasterPlaylist) setAlternatives(state *decodingState) {
+	for _, variant := range p.Variants {
+		alts := []*Alternative{}
+
+		if variant.Audio != "" {
+			toSearch := state.alternatives["AUDIO"]
+			for _, alt := range toSearch {
+				if variant.Audio == alt.GroupId {
+					alts = append(alts, alt)
+				}
+			}
+		}
+		if variant.Video != "" {
+			toSearch := state.alternatives["VIDEO"]
+			for _, alt := range toSearch {
+				if variant.Video == alt.GroupId {
+					alts = append(alts, alt)
+				}
+			}
+		}
+		if variant.Subtitles != "" {
+			toSearch := state.alternatives["SUBTITLES"]
+			for _, alt := range toSearch {
+				if variant.Subtitles == alt.GroupId {
+					alts = append(alts, alt)
+				}
+			}
+		}
+		if variant.Captions != "" {
+			toSearch := state.alternatives["CLOSED-CAPTIONS"]
+			for _, alt := range toSearch {
+				if variant.Captions == alt.GroupId {
+					alts = append(alts, alt)
+				}
+			}
+		}
+
+		if len(alts) != 0 {
+			variant.Alternatives = alts
+		}
+	}
+}
+
 // Decode parses a media playlist passed from the buffer. If `strict`
 // parameter is true then return first syntax error.
 func (p *MediaPlaylist) Decode(data bytes.Buffer, strict bool) error {
@@ -190,6 +238,7 @@ func decode(buf *bytes.Buffer, strict bool, customDecoders []CustomDecoder) (Pla
 	var err error
 
 	state := new(decodingState)
+	state.alternatives = make(map[string][]*Alternative) // create the map for alternatives
 	wv := new(WV)
 
 	master = NewMasterPlaylist()
@@ -240,6 +289,7 @@ func decode(buf *bytes.Buffer, strict bool, customDecoders []CustomDecoder) (Pla
 
 	switch state.listType {
 	case MASTER:
+		master.setAlternatives(state)
 		return master, MASTER, nil
 	case MEDIA:
 		if media.Closed || media.MediaType == EVENT {
@@ -331,15 +381,11 @@ func decodeLineOfMasterPlaylist(p *MasterPlaylist, state *decodingState, line st
 				alt.URI = v
 			}
 		}
-		state.alternatives = append(state.alternatives, &alt)
+		state.alternatives[alt.Type] = append(state.alternatives[alt.Type], &alt)
 	case !state.tagStreamInf && strings.HasPrefix(line, "#EXT-X-STREAM-INF:"):
 		state.tagStreamInf = true
 		state.listType = MASTER
 		state.variant = new(Variant)
-		if len(state.alternatives) > 0 {
-			state.variant.Alternatives = state.alternatives
-			state.alternatives = nil
-		}
 		p.Variants = append(p.Variants, state.variant)
 		for k, v := range decodeParamsLine(line[18:]) {
 			switch k {
@@ -395,10 +441,6 @@ func decodeLineOfMasterPlaylist(p *MasterPlaylist, state *decodingState, line st
 		state.listType = MASTER
 		state.variant = new(Variant)
 		state.variant.Iframe = true
-		if len(state.alternatives) > 0 {
-			state.variant.Alternatives = state.alternatives
-			state.alternatives = nil
-		}
 		p.Variants = append(p.Variants, state.variant)
 		for k, v := range decodeParamsLine(line[26:]) {
 			switch k {

reader_test.go

@@ -102,6 +102,50 @@ func TestDecodeMasterPlaylistWithAlternatives(t *testing.T) {
 	// fmt.Println(p.Encode().String())
 }
 
+func TestDecodeMasterPlaylistWithAlternativesDifferentOrder(t *testing.T) {
+	f, err := os.Open("sample-playlists/master-with-alternatives-diff-order.m3u8")
+	if err != nil {
+		t.Fatal(err)
+	}
+	p := NewMasterPlaylist()
+	err = p.DecodeFrom(bufio.NewReader(f), false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	// check parsed values
+	if p.ver != 3 {
+		t.Errorf("Version of parsed playlist = %d (must = 3)", p.ver)
+	}
+	if len(p.Variants) != 7 {
+		t.Fatal("not all variants in master playlist parsed")
+	}
+
+	for i, v := range p.Variants {
+		if i == 0 && len(v.Alternatives) != 3 {
+			t.Errorf("Expect 3 alternatives at %d but got %d\n", i, len(v.Alternatives))
+		}
+		if i == 1 && len(v.Alternatives) != 4 {
+			t.Errorf("Expect 4 alternatives at %d but got %d\n", i, len(v.Alternatives))
+		}
+		if i == 2 && len(v.Alternatives) != 4 {
+			t.Errorf("Expect 4 alternatives at %d but got %d\n", i, len(v.Alternatives))
+		}
+		if i == 3 && len(v.Alternatives) != 1 {
+			t.Errorf("Expect 1 alternative at %d but got %d\n", i, len(v.Alternatives))
+		}
+		if i == 4 && len(v.Alternatives) != 0 {
+			t.Errorf("Expect 0 alternatives at %d but got %d\n", i, len(v.Alternatives))
+		}
+		if i == 5 && len(v.Alternatives) != 1 {
+			t.Errorf("Expect 1 alternative at %d but got %d\n", i, len(v.Alternatives))
+		}
+		if i == 6 && len(v.Alternatives) != 1 {
+			t.Errorf("Expect 1 alternative at %d but got %d\n", i, len(v.Alternatives))
+		}
+	}
+
+}
+
 func TestDecodeMasterPlaylistWithClosedCaptionEqNone(t *testing.T) {
 	f, err := os.Open("sample-playlists/master-with-closed-captions-eq-none.m3u8")
 	if err != nil {

sample-playlists/master-with-alternatives-diff-order.m3u8

@@ -0,0 +1,54 @@
+#EXTM3U
+
+# Videos
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="low",NAME="Main",DEFAULT=YES,URI="low/main/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="low",NAME="Centerfield",DEFAULT=NO,URI="low/centerfield/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="low",NAME="Dugout",DEFAULT=NO,URI="low/dugout/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="mid",NAME="Main",DEFAULT=YES,URI="mid/main/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="mid",NAME="Centerfield",DEFAULT=NO,URI="mid/centerfield/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="mid",NAME="Dugout",DEFAULT=NO,URI="mid/dugout/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="hi",NAME="Main",DEFAULT=YES,URI="hi/main/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="hi",NAME="Centerfield",DEFAULT=NO,URI="hi/centerfield/audio-video.m3u8"
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="hi",NAME="Dugout",DEFAULT=NO,URI="hi/dugout/audio-video.m3u8"
+
+# Audios
+#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="a1",NAME="Audio1",DEFAULT=YES,URI="audio/a1.m3u8"
+
+# Captions
+#EXT-X-MEDIA:TYPE=CLOSED-CAPTIONS,GROUP-ID="cc",LANGUAGE="en",NAME="English",DEFAULT=YES,AUTOSELECT=YES
+
+# Subtitles
+#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="sub1",LANGUAGE="en",NAME="English",AUTOSELECT=YES,DEFAULT=YES,FORCED=NO,URI="s1/en/prog_index.m3u8"
+
+# External Media with no usage
+#EXT-X-MEDIA:TYPE=SUBTITLES,GROUP-ID="sub2",LANGUAGE="en",NAME="English",AUTOSELECT=YES,DEFAULT=YES,FORCED=NO,URI="s1/en/prog_index.m3u8"
+
+# Video
+#EXT-X-STREAM-INF:BANDWIDTH=1280000,VIDEO="low"
+low/main/audio-video.m3u8
+
+# Video and CC
+#EXT-X-STREAM-INF:BANDWIDTH=2560000,VIDEO="mid",CLOSED-CAPTIONS="cc"
+mid/main/audio-video.m3u8
+
+# Video and Subtitles
+#EXT-X-STREAM-INF:BANDWIDTH=7680000,VIDEO="hi",SUBTITLES="sub1"
+hi/main/audio-video.m3u8
+
+# Audio
+#EXT-X-STREAM-INF:BANDWIDTH=65000,CODECS="mp4a.40.5",AUDIO="a1"
+main/audio-only.m3u8
+
+# Non-existent group-id
+#EXT-X-STREAM-INF:BANDWIDTH=2560000,VIDEO="missing"
+missing-id/main/audio-video.m3u8
+
+# One group-id present and one non-existent group id
+#EXT-X-STREAM-INF:BANDWIDTH=2560000,VIDEO="missing",AUDIO="a1"
+missing-and-valid-id/main/audio-video.m3u8
+
+# Stream coming before external media 
+#EXT-X-STREAM-INF:BANDWIDTH=2560000,VIDEO="v1"
+pre-media/main/audio-video.m3u8
+
+#EXT-X-MEDIA:TYPE=VIDEO,GROUP-ID="v1",NAME="AfterStream",DEFAULT=NO,URI="after-stream/audio-video.m3u8"

structure.go

@@ -327,7 +327,7 @@ type decodingState struct {
 	duration           float64
 	title              string
 	variant            *Variant
-	alternatives       []*Alternative
+	alternatives       map[string][]*Alternative
 	xkey               *Key
 	xmap               *Map
 	scte               *SCTE