Fix EXT-X-MEDIA parsing.

I really don't remember when it was broken or
it feature just made unfinished :\ Anyway it
passed tests now and seems worked ok.

reader.go

@@ -212,8 +212,6 @@ func decodeParamsLine(line string) map[string]string {
 
 // Parse one line of master playlist.
 func decodeLineOfMasterPlaylist(p *MasterPlaylist, state *decodingState, line string, strict bool) error {
-	var alt *Alternative
-	var alternatives []*Alternative
 	var err error
 
 	line = strings.TrimSpace(line)
@@ -228,9 +226,8 @@ func decodeLineOfMasterPlaylist(p *MasterPlaylist, state *decodingState, line st
 			return err
 		}
 	case strings.HasPrefix(line, "#EXT-X-MEDIA:"):
+		var alt Alternative
 		state.listType = MASTER
-		alt = new(Alternative)
-		alternatives = append(alternatives, alt)
 		for k, v := range decodeParamsLine(line[13:]) {
 			switch k {
 			case "TYPE":
@@ -261,13 +258,14 @@ func decodeLineOfMasterPlaylist(p *MasterPlaylist, state *decodingState, line st
 				alt.URI = v
 			}
 		}
+		state.alternatives = append(state.alternatives, &alt)
 	case !state.tagStreamInf && strings.HasPrefix(line, "#EXT-X-STREAM-INF:"):
 		state.tagStreamInf = true
 		state.listType = MASTER
 		state.variant = new(Variant)
-		if len(alternatives) > 0 {
-			state.variant.Alternatives = alternatives
-			alternatives = nil
+		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:]) {
@@ -310,9 +308,9 @@ func decodeLineOfMasterPlaylist(p *MasterPlaylist, state *decodingState, line st
 		state.listType = MASTER
 		state.variant = new(Variant)
 		state.variant.Iframe = true
-		if len(alternatives) > 0 {
-			state.variant.Alternatives = alternatives
-			alternatives = nil
+		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:]) {

reader_test.go

@@ -89,11 +89,25 @@ func TestDecodeMasterPlaylistWithAlternatives(t *testing.T) {
 	if p.ver != 3 {
 		t.Errorf("Version of parsed playlist = %d (must = 3)", p.ver)
 	}
-	// if len(p.Variants) != 5 {
-	// 	t.Fatal("Not all variants in master playlist parsed.")
-	// }
+	if len(p.Variants) != 4 {
+		t.Fatal("not all variants in master playlist parsed")
+	}
 	// TODO check other values
-	//fmt.Println(p.Encode().String())
+	for i, v := range p.Variants {
+		if i == 0 && len(v.Alternatives) != 3 {
+			t.Fatalf("not all alternatives from #EXT-X-MEDIA parsed (has %d but should be 3", len(v.Alternatives))
+		}
+		if i == 1 && len(v.Alternatives) != 3 {
+			t.Fatalf("not all alternatives from #EXT-X-MEDIA parsed (has %d but should be 3", len(v.Alternatives))
+		}
+		if i == 2 && len(v.Alternatives) != 3 {
+			t.Fatalf("not all alternatives from #EXT-X-MEDIA parsed (has %d but should be 3", len(v.Alternatives))
+		}
+		if i == 3 && len(v.Alternatives) > 0 {
+			t.Fatal("should not be alternatives for this variant")
+		}
+	}
+	// fmt.Println(p.Encode().String())
 }
 
 // Decode a master playlist with Name tag in EXT-X-STREAM-INF

structure.go

@@ -154,11 +154,11 @@ type VariantParams struct {
 	Resolution   string
 	Audio        string // EXT-X-STREAM-INF only
 	Video        string
-	Subtitles    string // EXT-X-STREAM-INF only
-	Captions     string // EXT-X-STREAM-INF only
-	Name         string // EXT-X-STREAM-INF only (non standard Wowza/JWPlayer extension to name the variant/quality in UA)
-	Iframe       bool   // EXT-X-I-FRAME-STREAM-INF
-	Alternatives []*Alternative
+	Subtitles    string         // EXT-X-STREAM-INF only
+	Captions     string         // EXT-X-STREAM-INF only
+	Name         string         // EXT-X-STREAM-INF only (non standard Wowza/JWPlayer extension to name the variant/quality in UA)
+	Iframe       bool           // EXT-X-I-FRAME-STREAM-INF
+	Alternatives []*Alternative // EXT-X-MEDIA
 }
 
 // This structure represents EXT-X-MEDIA tag in variants.
@@ -270,6 +270,7 @@ type decodingState struct {
 	offset             int64
 	duration           float64
 	variant            *Variant
+	alternatives       []*Alternative
 	xkey               *Key
 	xmap               *Map
 	scte               *SCTE