Add support for CHANNELS attribute in EXT-X-MEDIA tag. (#54)

* Added support for CHANNELS attribute in EXT-X-MEDIA tag.

It can be a list seperated by /, but it is only defined for TYPE: AUDIO,
and then only the first parameter is used.

Also updated the test so it contains the CHANNELS attribute.

From the specification:
CHANNELS

      The value is a quoted-string that specifies an ordered,
      "/"-separated list of parameters.  If the TYPE attribute is AUDIO
      then the first parameter is a count of audio channels expressed as
      a decimal-integer, indicating the maximum number of independent,
      simultaneous audio channels present in any Media Segment in the
      Rendition.  For example, an AC-3 5.1 rendition would have a
      CHANNELS="6" attribute.  No other CHANNELS parameters are
      currently defined.

      All audio EXT-X-MEDIA tags SHOULD have a CHANNELS attribute.  If a
      Master Playlist contains two renditions encoded with the same
      codec but a different number of channels, then the CHANNELS
      attribute is REQUIRED; otherwise it is OPTIONAL.

Signed-off-by: Even Thomassen <even.thomassen@noriginmedia.com>

* MediaData.channels is now primitive int, instead of Integer.

Also included channels in hashcode.

Signed-off-by: Even Thomassen <even.thomassen@noriginmedia.com>

src/main/java/com/iheartradio/m3u8/Constants.java

@@ -39,6 +39,7 @@ final class Constants {
     public static  final String FORCED = "FORCED";
     public static  final String IN_STREAM_ID = "INSTREAM-ID";
     public static  final String CHARACTERISTICS = "CHARACTERISTICS";
+    public static  final String CHANNELS = "CHANNELS";
 
     public static final String EXT_X_STREAM_INF_TAG = "EXT-X-STREAM-INF";
     public static final String EXT_X_I_FRAME_STREAM_INF_TAG = "EXT-X-I-FRAME-STREAM-INF";

src/main/java/com/iheartradio/m3u8/MasterPlaylistLineParser.java

@@ -1,15 +1,11 @@
 package com.iheartradio.m3u8;
 
+import com.iheartradio.m3u8.data.*;
+
 import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
-import com.iheartradio.m3u8.data.IFrameStreamInfo;
-import com.iheartradio.m3u8.data.MediaData;
-import com.iheartradio.m3u8.data.MediaType;
-import com.iheartradio.m3u8.data.StreamInfo;
-import com.iheartradio.m3u8.data.StreamInfoBuilder;
-
 class MasterPlaylistLineParser implements LineParser {
     private final IExtTagParser mTagParser;
     private final LineParser mLineParser;
@@ -164,6 +160,20 @@ public void parse(Attribute attribute, MediaData.Builder builder, ParseState sta
                     }
                 }
             });
+
+            HANDLERS.put(Constants.CHANNELS, new AttributeParser<MediaData.Builder>() {
+                @Override
+                public void parse(Attribute attribute, MediaData.Builder builder, ParseState state) throws ParseException {
+                    final String[] channelsStrings = ParseUtil.parseQuotedString(attribute.value, getTag()).split(Constants.LIST_SEPARATOR);
+
+                    if (channelsStrings.length == 0 || channelsStrings[0].isEmpty()) {
+                        throw ParseException.create(ParseExceptionType.EMPTY_MEDIA_CHANNELS, getTag(), attribute.toString());
+                    } else {
+                        final int channelsCount = ParseUtil.parseInt(channelsStrings[0], getTag());
+                        builder.withChannels(channelsCount);
+                    }
+                }
+            });
         }
 
         @Override

src/main/java/com/iheartradio/m3u8/ParseExceptionType.java

@@ -3,6 +3,7 @@
 public enum ParseExceptionType {
     AUTO_SELECT_DISABLED_FOR_DEFAULT("default media data must be auto selected"),
     BAD_EXT_TAG_FORMAT("bad format found for an EXT tag"),
+    EMPTY_MEDIA_CHANNELS("CHANNELS is empty"),
     EMPTY_MEDIA_CHARACTERISTICS("CHARACTERISTICS is empty"),
     EMPTY_MEDIA_GROUP_ID("GROUP-ID is empty"),
     EMPTY_MEDIA_NAME("NAME is empty"),

src/main/java/com/iheartradio/m3u8/data/MediaData.java

@@ -4,6 +4,8 @@
 import java.util.Objects;
 
 public class MediaData {
+    public static final int NO_CHANNELS = -1;
+
     private final MediaType mType;
     private final String mUri;
     private final String mGroupId;
@@ -15,6 +17,7 @@ public class MediaData {
     private final boolean mForced;
     private final String mInStreamId;
     private final List<String> mCharacteristics;
+    private final int mChannels;
 
     private MediaData(
             MediaType type,
@@ -27,7 +30,8 @@ private MediaData(
             boolean isAutoSelect,
             boolean isForced,
             String inStreamId,
-            List<String> characteristics) {
+            List<String> characteristics,
+            int channels) {
         mType = type;
         mUri = uri;
         mGroupId = groupId;
@@ -39,6 +43,7 @@ private MediaData(
         mForced = isForced;
         mInStreamId = inStreamId;
         mCharacteristics = DataUtil.emptyOrUnmodifiable(characteristics);
+        mChannels = channels;
     }
 
     public MediaType getType() {
@@ -105,6 +110,14 @@ public List<String> getCharacteristics() {
         return mCharacteristics;
     }
 
+    public boolean hasChannels() {
+        return mChannels != NO_CHANNELS;
+    }
+
+    public Integer getChannels() {
+        return mChannels;
+    }
+
     public Builder buildUpon() {
         return new Builder(
                 mType,
@@ -117,7 +130,8 @@ public Builder buildUpon() {
                 mAutoSelect,
                 mForced,
                 mInStreamId,
-                mCharacteristics);
+                mCharacteristics,
+                mChannels);
     }
 
     @Override
@@ -133,7 +147,8 @@ public int hashCode() {
                 mLanguage,
                 mName,
                 mType,
-                mUri);
+                mUri,
+                mChannels);
     }
 
     @Override
@@ -154,7 +169,8 @@ public boolean equals(Object o) {
                mAutoSelect == other.mAutoSelect &&
                mForced == other.mForced &&
                Objects.equals(mInStreamId, other.mInStreamId) &&
-               Objects.equals(mCharacteristics, other.mCharacteristics);
+               Objects.equals(mCharacteristics, other.mCharacteristics) &&
+               mChannels == other.mChannels;
     }
 
     public static class Builder {
@@ -169,6 +185,7 @@ public static class Builder {
         private boolean mForced;
         private String mInStreamId;
         private List<String> mCharacteristics;
+        private int mChannels = NO_CHANNELS;
 
         public Builder() {
         }
@@ -184,7 +201,8 @@ private Builder(
                 boolean autoSelect,
                 boolean forced,
                 String inStreamId,
-                List<String> characteristics) {
+                List<String> characteristics,
+                int channels) {
             mType = type;
             mUri = uri;
             mGroupId = groupId;
@@ -196,6 +214,7 @@ private Builder(
             mForced = forced;
             mInStreamId = inStreamId;
             mCharacteristics = characteristics;
+            mChannels = channels;
         }
 
         public Builder withType(MediaType type) {
@@ -253,6 +272,11 @@ public Builder withCharacteristics(List<String> characteristics) {
             return this;
         }
 
+        public Builder withChannels(int channels) {
+            mChannels = channels;
+            return this;
+        }
+
         public MediaData build() {
             return new MediaData(
                     mType,
@@ -265,7 +289,8 @@ public MediaData build() {
                     mAutoSelect,
                     mForced,
                     mInStreamId,
-                    mCharacteristics);
+                    mCharacteristics,
+                    mChannels);
         }
     }
 
@@ -276,6 +301,7 @@ public String toString() {
                 + ", mAssociatedLanguage=" + mAssociatedLanguage + ", mName="
                 + mName + ", mDefault=" + mDefault + ", mAutoSelect="
                 + mAutoSelect + ", mForced=" + mForced + ", mInStreamId="
-                + mInStreamId + ", mCharacteristics=" + mCharacteristics + "]";
+                + mInStreamId + ", mCharacteristics=" + mCharacteristics
+                + ", mChannels=" + mChannels + "]";
     }
 }

src/test/resources/masterPlaylistWithAlternativeAudio.m3u8

@@ -1,7 +1,7 @@
 #EXTM3U
-#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="English",DEFAULT=YES,AUTOSELECT=YES,LANGUAGE="en",URI="main/english-audio.m3u8"
-#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="Deutsch",DEFAULT=NO,AUTOSELECT=YES,LANGUAGE="de",URI="main/german-audio.m3u8"
-#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="Commentary",DEFAULT=NO,AUTOSELECT=NO,LANGUAGE="en",URI="commentary/audio-only.m3u8"
+#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="English",DEFAULT=YES,AUTOSELECT=YES,LANGUAGE="en",CHANNELS="2",URI="main/english-audio.m3u8"
+#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="Deutsch",DEFAULT=NO,AUTOSELECT=YES,LANGUAGE="de",CHANNELS="2",URI="main/german-audio.m3u8"
+#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="Commentary",DEFAULT=NO,AUTOSELECT=NO,LANGUAGE="en",CHANNELS="2",URI="commentary/audio-only.m3u8"
 #EXT-X-STREAM-INF:BANDWIDTH=1280000,CODECS="...",AUDIO="aac"
 low/video-only.m3u8
 #EXT-X-STREAM-INF:BANDWIDTH=2560000,CODECS="...",AUDIO="aac"