Support for channels

reader.go

@@ -329,6 +329,12 @@ func decodeLineOfMasterPlaylist(p *MasterPlaylist, state *decodingState, line st
 				alt.Subtitles = v
 			case "URI":
 				alt.URI = v
+			case "CHANNELS":
+				channels, err := strconv.Atoi(v)
+				if err != nil {
+					return fmt.Errorf("non-integer value %q for CHANNELS attribute", v)
+				}
+				alt.Channels = uint(channels)
 			}
 		}
 		state.alternatives = append(state.alternatives, &alt)

reader_test.go

@@ -972,6 +972,40 @@ func TestDecodeMediaPlaylistStartTime(t *testing.T) {
 	}
 }
 
+func TestDecodeMasterChannels(t *testing.T) {
+	f, err := os.Open("sample-playlists/master-with-channels.m3u8")
+	if err != nil {
+		t.Fatal(err)
+	}
+	p, listType, err := DecodeFrom(bufio.NewReader(f), true)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if listType != MASTER {
+		t.Error("Input not recognized as master playlist.")
+	}
+	pp := p.(*MasterPlaylist)
+
+	alt0 := pp.Variants[0].Alternatives[0]
+	if alt0.Type != "AUDIO" {
+		t.Error("Expected AUDIO track in test input Alternatives[0]")
+	}
+
+	if alt0.Channels != 2 {
+		t.Error("Expected 2 channels track in test input Alternatives[0]")
+	}
+
+	alt1 := pp.Variants[0].Alternatives[1]
+	if alt1.Type != "AUDIO" {
+		t.Error("Expected AUDIO track in test input Alternatives[1]")
+	}
+
+	if alt1.Channels != 6 {
+		t.Error("Expected 6 channels track in test input Alternatives[1]")
+	}
+}
+
 /****************
  *  Benchmarks  *
  ****************/

sample-playlists/master-with-channels.m3u8

@@ -0,0 +1,13 @@
+#EXTM3U
+#EXT-X-VERSION:6
+#EXT-X-INDEPENDENT-SEGMENTS
+
+
+#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="a1",NAME="English",LANGUAGE="en-US",AUTOSELECT=YES,DEFAULT=YES,CHANNELS="2",URI="a1/prog_index.m3u8"
+#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="a2",NAME="English",LANGUAGE="en-US",AUTOSELECT=YES,DEFAULT=YES,CHANNELS="6",URI="a2/prog_index.m3u8"
+
+#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=2190673,BANDWIDTH=2523597,CODECS="avc1.640020,mp4a.40.2",RESOLUTION=960x540,FRAME-RATE=60.000,AUDIO="a1"
+v5/prog_index.m3u8
+#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=8052613,BANDWIDTH=9873268,CODECS="avc1.64002a,mp4a.40.2",RESOLUTION=1920x1080,FRAME-RATE=60.000,AUDIO="a1"
+v9/prog_index.m3u8
+

structure.go

@@ -197,6 +197,7 @@ type Alternative struct {
 	Forced          string
 	Characteristics string
 	Subtitles       string
+	Channels        uint
 }
 
 // MediaSegment structure represents a media segment included in a

writer.go

@@ -155,6 +155,11 @@ func (p *MasterPlaylist) Encode() *bytes.Buffer {
 					p.buf.WriteString(alt.URI)
 					p.buf.WriteRune('"')
 				}
+				if alt.Channels != 0 {
+					p.buf.WriteString(",CHANNELS=\"")
+					p.buf.WriteString(strconv.FormatUint(uint64(alt.Channels), 10))
+					p.buf.WriteRune('"')
+				}
 				p.buf.WriteRune('\n')
 			}
 		}