Add Icy metadata support on Android (#78)

* Add Icy "info" metadata to Android playback events

* Add IcyMetadata stream to the Flutter module

* Update ExoPlayer to 2.11.4

* Use Player.EventListener.onTracksChanged to retrieve IcyHeaders

* Iterate over each track of trackGroups to look for IcyHeaders

android/build.gradle

@@ -40,8 +40,8 @@ android {
 }
 
 dependencies {
-    implementation 'com.google.android.exoplayer:exoplayer-core:2.11.1'
+    implementation 'com.google.android.exoplayer:exoplayer-core:2.11.4'
-    implementation 'com.google.android.exoplayer:exoplayer-dash:2.11.1'
+    implementation 'com.google.android.exoplayer:exoplayer-dash:2.11.4'
-    implementation 'com.google.android.exoplayer:exoplayer-hls:2.11.1'
+    implementation 'com.google.android.exoplayer:exoplayer-hls:2.11.4'
-    implementation 'com.google.android.exoplayer:exoplayer-smoothstreaming:2.11.1'
+    implementation 'com.google.android.exoplayer:exoplayer-smoothstreaming:2.11.4'
 }

android/src/main/java/com/ryanheise/just_audio/AudioPlayer.java

@@ -7,11 +7,18 @@ import com.google.android.exoplayer2.ExoPlaybackException;
 import com.google.android.exoplayer2.Player;
 import com.google.android.exoplayer2.PlaybackParameters;
 import com.google.android.exoplayer2.SimpleExoPlayer;
+import com.google.android.exoplayer2.metadata.Metadata;
+import com.google.android.exoplayer2.metadata.MetadataOutput;
+import com.google.android.exoplayer2.metadata.icy.IcyHeaders;
+import com.google.android.exoplayer2.metadata.icy.IcyInfo;
 import com.google.android.exoplayer2.source.ClippingMediaSource;
 import com.google.android.exoplayer2.source.MediaSource;
 import com.google.android.exoplayer2.source.ProgressiveMediaSource;
+import com.google.android.exoplayer2.source.TrackGroup;
+import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.source.dash.DashMediaSource;
 import com.google.android.exoplayer2.source.hls.HlsMediaSource;
+import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.upstream.DataSource;
 import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory;
 import com.google.android.exoplayer2.upstream.DefaultHttpDataSourceFactory;
@@ -28,17 +35,14 @@ import io.flutter.plugin.common.MethodChannel.Result;
 import io.flutter.plugin.common.PluginRegistry.Registrar;
 
 import java.io.IOException;
-import java.nio.ByteBuffer;
 import java.util.ArrayList;
-import java.util.Arrays;
+import java.util.Collections;
-import java.util.LinkedList;
-
 import android.content.Context;
 import android.net.Uri;
 
 import java.util.List;
 
-public class AudioPlayer implements MethodCallHandler, Player.EventListener {
+public class AudioPlayer implements MethodCallHandler, Player.EventListener, MetadataOutput {
 	static final String TAG = "AudioPlayer";
 
 	private final Registrar registrar;
@@ -64,6 +68,8 @@ public class AudioPlayer implements MethodCallHandler, Player.EventListener {
 	private boolean buffering;
 	private boolean justConnected;
 	private MediaSource mediaSource;
+	private IcyInfo icyInfo;
+	private IcyHeaders icyHeaders;
 
 	private final SimpleExoPlayer player;
 	private final Handler handler = new Handler();
@@ -109,6 +115,7 @@ public class AudioPlayer implements MethodCallHandler, Player.EventListener {
 		state = PlaybackState.none;
 
 		player = new SimpleExoPlayer.Builder(context).build();
+		player.addMetadataOutput(this);
 		player.addListener(this);
 	}
 
@@ -117,6 +124,38 @@ public class AudioPlayer implements MethodCallHandler, Player.EventListener {
 		handler.post(bufferWatcher);
 	}
 
+	@Override
+	public void onMetadata(Metadata metadata) {
+		for (int i = 0; i < metadata.length(); i++) {
+			final Metadata.Entry entry = metadata.get(i);
+			if (entry instanceof IcyInfo) {
+				icyInfo = (IcyInfo) entry;
+				broadcastPlaybackEvent();
+			}
+		}
+	}
+
+	@Override
+	public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
+		for (int i = 0; i < trackGroups.length; i++) {
+			TrackGroup trackGroup = trackGroups.get(i);
+
+			for (int j = 0; j < trackGroup.length; j++) {
+				Metadata metadata = trackGroup.getFormat(j).metadata;
+
+				if (metadata != null) {
+					for (int k = 0; k < metadata.length(); k++) {
+						final Metadata.Entry entry = metadata.get(k);
+						if (entry instanceof IcyHeaders) {
+							icyHeaders = (IcyHeaders) entry;
+							broadcastPlaybackEvent();
+						}
+					}
+				}
+			}
+		}
+	}
+
 	@Override
 	public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
 		switch (playbackState) {
@@ -261,6 +300,32 @@ public class AudioPlayer implements MethodCallHandler, Player.EventListener {
 		event.add(updatePosition = getCurrentPosition());
 		event.add(updateTime = System.currentTimeMillis());
 		event.add(Math.max(updatePosition, bufferedPosition));
+
+		final ArrayList<Object> icyData = new ArrayList<>();
+		final ArrayList<String> info;
+		final ArrayList<Object> headers;
+		if (icyInfo != null) {
+			info = new ArrayList<>();
+			info.add(icyInfo.title);
+			info.add(icyInfo.url);
+		} else {
+			info = new ArrayList<>(Collections.nCopies(2, null));
+		}
+		if (icyHeaders != null) {
+			headers = new ArrayList<>();
+			headers.add(icyHeaders.bitrate);
+			headers.add(icyHeaders.genre);
+			headers.add(icyHeaders.name);
+			headers.add(icyHeaders.metadataInterval);
+			headers.add(icyHeaders.url);
+			headers.add(icyHeaders.isPublic);
+		} else {
+			headers = new ArrayList<>(Collections.nCopies(6, null));
+		}
+		icyData.add(info);
+		icyData.add(headers);
+		event.add(icyData);
+
 		if (eventSink != null) {
 			eventSink.success(event);
 		}

lib/just_audio.dart

@@ -69,6 +69,15 @@ class AudioPlayer {
     bufferedPosition: Duration.zero,
     speed: 1.0,
     duration: Duration.zero,
+    icyMetadata: IcyMetadata(
+        info: IcyInfo(title: null, url: null),
+        headers: IcyHeaders(
+            bitrate: null,
+            genre: null,
+            name: null,
+            metadataInterval: null,
+            url: null,
+            isPublic: null)),
   );
 
   Stream<AudioPlaybackEvent> _eventChannelStream;
@@ -83,6 +92,8 @@ class AudioPlayer {
 
   final _bufferedPositionSubject = BehaviorSubject<Duration>();
 
+  final _icyMetadataSubject = BehaviorSubject<IcyMetadata>();
+
   final _fullPlaybackStateSubject = BehaviorSubject<FullAudioPlaybackState>();
 
   double _volume = 1.0;
@@ -108,6 +119,15 @@ class AudioPlayer {
               bufferedPosition: Duration(milliseconds: data[4]),
               speed: _speed,
               duration: _duration,
+              icyMetadata: IcyMetadata(
+                  info: IcyInfo(title: data[5][0][0], url: data[5][0][1]),
+                  headers: IcyHeaders(
+                      bitrate: data[5][1][0],
+                      genre: data[5][1][1],
+                      name: data[5][1][2],
+                      metadataInterval: data[5][1][3],
+                      url: data[5][1][4],
+                      isPublic: data[5][1][5])),
             ));
     _eventChannelStreamSubscription =
         _eventChannelStream.listen(_playbackEventSubject.add);
@@ -117,11 +137,15 @@ class AudioPlayer {
         playbackEventStream.map((state) => state.buffering).distinct());
     _bufferedPositionSubject.addStream(
         playbackEventStream.map((state) => state.bufferedPosition).distinct());
-    _fullPlaybackStateSubject.addStream(
+    _icyMetadataSubject.addStream(
-        Rx.combineLatest2<AudioPlaybackState, bool, FullAudioPlaybackState>(
+        playbackEventStream.map((state) => state.icyMetadata).distinct());
+    _fullPlaybackStateSubject.addStream(Rx.combineLatest3<AudioPlaybackState,
+            bool, IcyMetadata, FullAudioPlaybackState>(
         playbackStateStream,
         bufferingStream,
-            (state, buffering) => FullAudioPlaybackState(state, buffering)));
+        icyMetadataStream,
+        (state, buffering, icyMetadata) =>
+            FullAudioPlaybackState(state, buffering, icyMetadata)));
   }
 
   /// The duration of any media set via [setUrl], [setFilePath] or [setAsset],
@@ -148,9 +172,13 @@ class AudioPlayer {
   /// Whether the player is buffering.
   bool get buffering => _audioPlaybackEvent.buffering;
 
+  IcyMetadata get icyMetadata => _audioPlaybackEvent.icyMetadata;
+
   /// A stream of buffering state changes.
   Stream<bool> get bufferingStream => _bufferingSubject.stream;
 
+  Stream<IcyMetadata> get icyMetadataStream => _icyMetadataSubject.stream;
+
   /// A stream of buffered positions.
   Stream<Duration> get bufferedPositionStream =>
       _bufferedPositionSubject.stream;
@@ -394,6 +422,8 @@ class AudioPlaybackEvent {
   /// The media duration.
   final Duration duration;
 
+  final IcyMetadata icyMetadata;
+
   AudioPlaybackEvent({
     @required this.state,
     @required this.buffering,
@@ -402,6 +432,7 @@ class AudioPlaybackEvent {
     @required this.bufferedPosition,
     @required this.speed,
     @required this.duration,
+    @required this.icyMetadata,
   });
 
   AudioPlaybackEvent copyWith({
@@ -462,6 +493,38 @@ enum AudioPlaybackState {
 class FullAudioPlaybackState {
   final AudioPlaybackState state;
   final bool buffering;
+  final IcyMetadata icyMetadata;
 
-  FullAudioPlaybackState(this.state, this.buffering);
+  FullAudioPlaybackState(this.state, this.buffering, this.icyMetadata);
+}
+
+class IcyInfo {
+  final String title;
+  final String url;
+
+  IcyInfo({@required this.title, @required this.url});
+}
+
+class IcyHeaders {
+  final int bitrate;
+  final String genre;
+  final String name;
+  final int metadataInterval;
+  final String url;
+  final bool isPublic;
+
+  IcyHeaders(
+      {@required this.bitrate,
+      @required this.genre,
+      @required this.name,
+      @required this.metadataInterval,
+      @required this.url,
+      @required this.isPublic});
+}
+
+class IcyMetadata {
+  final IcyInfo info;
+  final IcyHeaders headers;
+
+  IcyMetadata({@required this.info, @required this.headers});
 }