use exoplayer as music backend

app/build.gradle

@@ -42,6 +42,7 @@ android {
 
 dependencies {
     implementation 'com.github.jellyfin.jellyfin-apiclient-java:android:0.6.1'
+    implementation 'com.google.android.exoplayer:exoplayer:2.11.4'
 
     implementation 'androidx.core:core:1.2.0'
     implementation 'androidx.media:media:1.1.0'

app/src/main/java/com/dkanada/gramophone/service/MultiPlayer.java

@@ -1,44 +1,163 @@
 package com.dkanada.gramophone.service;
 
 import android.content.Context;
-import android.media.MediaPlayer;
-import android.os.PowerManager;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
+import android.net.Uri;
+
+import android.util.Log;
 import android.widget.Toast;
 
 import com.dkanada.gramophone.R;
 import com.dkanada.gramophone.service.playback.Playback;
 
-public class MultiPlayer implements Playback, MediaPlayer.OnErrorListener, MediaPlayer.OnCompletionListener {
+import com.google.android.exoplayer2.ExoPlaybackException;
-    public static final String TAG = MultiPlayer.class.getSimpleName();
+import com.google.android.exoplayer2.ExoPlayer;
+import com.google.android.exoplayer2.SimpleExoPlayer;
+import com.google.android.exoplayer2.source.ConcatenatingMediaSource;
+import com.google.android.exoplayer2.source.MediaSource;
+import com.google.android.exoplayer2.source.ProgressiveMediaSource;
+import com.google.android.exoplayer2.source.TrackGroupArray;
+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.DefaultHttpDataSourceFactory;
+import com.google.android.exoplayer2.util.Util;
 
-    private MediaPlayer mCurrentMediaPlayer = new MediaPlayer();
+import java.io.IOException;
-    private MediaPlayer mNextMediaPlayer;
+
+import okhttp3.Call;
+import okhttp3.Callback;
+import okhttp3.OkHttpClient;
+import okhttp3.Request;
+import okhttp3.Response;
+
+public class MultiPlayer implements Playback {
+    public static final String TAG = MultiPlayer.class.getSimpleName();
 
     private Context context;
 
-    @Nullable
+    private OkHttpClient httpClient;
+    private SimpleExoPlayer exoPlayer;
+
+    private ConcatenatingMediaSource mediaSource;
     private Playback.PlaybackCallbacks callbacks;
 
-    private boolean mIsInitialized = false;
+    private boolean isReady = false;
+    private boolean isPlaying = false;
+    private boolean isNew = false;
+    private boolean isFirst = true;
 
-    public MultiPlayer(final Context context) {
+    private ExoPlayer.EventListener eventListener = new ExoPlayer.EventListener() {
-        this.context = context;
+        @Override
-        mCurrentMediaPlayer.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK);
+        public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
+            Log.i(TAG,"onTracksChanged");
         }
 
         @Override
-    public boolean setDataSource(@NonNull final String path) {
+        public void onLoadingChanged(boolean isLoading) {
-        return true;
+            Log.i(TAG,"onLoadingChanged: isLoading = " + isLoading);
+        }
+
+        @Override
+        public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
+            Log.i(TAG,"onPlayerStateChanged: playWhenReady = " + playWhenReady);
+            Log.i(TAG,"onPlayerStateChanged: playbackState = " + playbackState);
+        }
+
+        @Override
+        public void onPositionDiscontinuity(int reason) {
+            Log.i(TAG,"onPositionDiscontinuity: reason = " + reason);
+            int windowIndex = exoPlayer.getCurrentWindowIndex();
+
+            if (windowIndex == 1) {
+                mediaSource.removeMediaSource(0);
+                if (mediaSource.getSize() != 0) {
+                    // there are still songs left in the queue
+                    callbacks.onTrackWentToNext();
+                } else {
+                    callbacks.onTrackEnded();
+                }
+            }
+        }
+
+        @Override
+        public void onPlayerError(ExoPlaybackException error) {
+            Log.i(TAG,"onPlaybackError: " + error.getMessage());
+            if (context != null) {
+                Toast.makeText(context, context.getResources().getString(R.string.unplayable_file), Toast.LENGTH_SHORT).show();
+            }
+
+            stop();
+        }
+    };
+
+    public MultiPlayer(final Context context) {
+        this.context = context;
+
+        httpClient = new OkHttpClient();
+        exoPlayer = new SimpleExoPlayer.Builder(context).build();
+        mediaSource = new ConcatenatingMediaSource();
+    }
+
+    @Override
+    public void setDataSource(@NonNull final String path) {
+        isReady = false;
+        if (context == null) {
+            return;
+        }
+
+        isNew = true;
+        mediaSource = new ConcatenatingMediaSource();
+
+        exoPlayer.addListener(eventListener);
+        exoPlayer.prepare(mediaSource);
+
+        appendDataSource(path, true);
+        isReady = true;
     }
 
     @Override
     public void setNextDataSource(@Nullable final String path) {
+        if (context == null) {
+            return;
         }
 
-    private boolean appendDataSource(@NonNull final String path) {
+        if (mediaSource.getSize() >= 2) {
-        return true;
+            mediaSource.removeMediaSource(1);
+        }
+
+        appendDataSource(path, false);
+    }
+
+    private void appendDataSource(String path, boolean next) {
+        Uri uri = Uri.parse(path);
+
+        DataSource.Factory dataSource = new DefaultHttpDataSourceFactory(Util.getUserAgent(context, this.getClass().getName()));
+        httpClient.newCall(new Request.Builder().url(path).head().build()).enqueue(new Callback() {
+            @Override
+            public void onFailure(Call call, IOException e) {
+                Toast.makeText(context, context.getResources().getString(R.string.unplayable_file), Toast.LENGTH_SHORT).show();
+                e.printStackTrace();
+            }
+
+            @Override
+            public void onResponse(Call call, Response response) {
+                MediaSource source;
+                if (response.header("Content-Type").equals("application/x-mpegURL")) {
+                    source = new HlsMediaSource.Factory(dataSource).createMediaSource(uri);
+                } else {
+                    source = new ProgressiveMediaSource.Factory(dataSource).createMediaSource(uri);
+                }
+
+                mediaSource.addMediaSource(source);
+                if (!isFirst && next) {
+                    start();
+                }
+
+                isFirst = false;
+            }
+        });
     }
 
     @Override
@@ -48,135 +167,61 @@ public class MultiPlayer implements Playback, MediaPlayer.OnErrorListener, Media
 
     @Override
     public boolean isInitialized() {
-        return mIsInitialized;
+        return isReady;
     }
 
     @Override
     public boolean start() {
-        try {
+        isPlaying = true;
-            mCurrentMediaPlayer.start();
+        exoPlayer.setPlayWhenReady(true);
-            return true;
+
-        } catch (IllegalStateException e) {
+        if (isNew) {
-            return false;
+            callbacks.onTrackStarted();
+            isNew = false;
         }
+
+        return true;
     }
 
     @Override
     public void stop() {
-        mCurrentMediaPlayer.reset();
+        exoPlayer.release();
-        mIsInitialized = false;
+        isReady = false;
-    }
-
-    @Override
-    public void release() {
-        stop();
-
-        mCurrentMediaPlayer.release();
-        if (mNextMediaPlayer != null) {
-            mNextMediaPlayer.release();
-        }
     }
 
     @Override
     public boolean pause() {
-        try {
+        isPlaying = false;
-            mCurrentMediaPlayer.pause();
+        exoPlayer.setPlayWhenReady(false);
         return true;
-        } catch (IllegalStateException e) {
-            return false;
-        }
     }
 
     @Override
     public boolean isPlaying() {
-        return mIsInitialized && mCurrentMediaPlayer.isPlaying();
+        return isReady && isPlaying;
     }
 
     @Override
     public int duration() {
-        if (!mIsInitialized) {
+        if (!isReady) return -1;
-            return -1;
+        return (int) exoPlayer.getDuration();
-        }
-
-        try {
-            return mCurrentMediaPlayer.getDuration();
-        } catch (IllegalStateException e) {
-            return -1;
-        }
     }
 
     @Override
     public int position() {
-        if (!mIsInitialized) {
+        if (!isReady) return -1;
-            return -1;
+        return (int) exoPlayer.getCurrentPosition();
-        }
-
-        try {
-            return mCurrentMediaPlayer.getCurrentPosition();
-        } catch (IllegalStateException e) {
-            return -1;
-        }
     }
 
     @Override
-    public int seek(final int whereto) {
+    public int seek(int position) {
-        try {
+        exoPlayer.seekTo(position);
-            mCurrentMediaPlayer.seekTo(whereto);
+        return position;
-            return whereto;
-        } catch (IllegalStateException e) {
-            return -1;
-        }
     }
 
     @Override
-    public boolean setVolume(final float vol) {
+    public boolean setVolume(float volume) {
-        try {
+        exoPlayer.setVolume(volume);
-            mCurrentMediaPlayer.setVolume(vol, vol);
         return true;
-        } catch (IllegalStateException e) {
-            return false;
-        }
-    }
-
-    @Override
-    public boolean setAudioSessionId(final int sessionId) {
-        try {
-            mCurrentMediaPlayer.setAudioSessionId(sessionId);
-            return true;
-        } catch (@NonNull IllegalArgumentException | IllegalStateException e) {
-            return false;
-        }
-    }
-
-    @Override
-    public int getAudioSessionId() {
-        return mCurrentMediaPlayer.getAudioSessionId();
-    }
-
-    @Override
-    public boolean onError(final MediaPlayer mp, final int what, final int extra) {
-        mIsInitialized = false;
-        mCurrentMediaPlayer.release();
-        mCurrentMediaPlayer = new MediaPlayer();
-        mCurrentMediaPlayer.setWakeMode(context, PowerManager.PARTIAL_WAKE_LOCK);
-        if (context != null) {
-            Toast.makeText(context, context.getResources().getString(R.string.unplayable_file), Toast.LENGTH_SHORT).show();
-        }
-
-        return false;
-    }
-
-    @Override
-    public void onCompletion(final MediaPlayer mp) {
-        if (mp == mCurrentMediaPlayer && mNextMediaPlayer != null) {
-            mIsInitialized = false;
-            mCurrentMediaPlayer.release();
-            mCurrentMediaPlayer = mNextMediaPlayer;
-            mIsInitialized = true;
-            mNextMediaPlayer = null;
-            if (callbacks != null) callbacks.onTrackWentToNext();
-        } else {
-            if (callbacks != null) callbacks.onTrackEnded();
-        }
     }
 }

app/src/main/java/com/dkanada/gramophone/service/MusicService.java

@@ -423,7 +423,6 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
 
                 position = restoredPosition;
                 openCurrent();
-                prepareNext();
 
                 if (restoredPositionInTrack > 0) seek(restoredPositionInTrack);
 
@@ -451,7 +450,7 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
         queueSaveHandler.removeCallbacksAndMessages(null);
         queueSaveHandlerThread.quitSafely();
 
-        playback.release();
+        playback.stop();
         playback = null;
         mediaSession.release();
     }
@@ -468,24 +467,20 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
         playSongAt(getNextPosition(force));
     }
 
-    private boolean openTrackAndPrepareNextAt(int position) {
+    private void openTrackAndPrepareNextAt(int position) {
         synchronized (this) {
             this.position = position;
-            boolean prepared = openCurrent();
+
-            if (prepared) prepareNextImpl();
+            openCurrent();
+
             notifyChange(META_CHANGED);
             notHandledMetaChangedForCurrentTrack = false;
-            return prepared;
         }
     }
 
-    private boolean openCurrent() {
+    private void openCurrent() {
         synchronized (this) {
-            try {
+            playback.setDataSource(getTrackUri(getCurrentSong()));
-                return playback.setDataSource(getTrackUri(getCurrentSong()));
-            } catch (Exception e) {
-                return false;
-            }
         }
     }
 
@@ -494,16 +489,10 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
         playerHandler.obtainMessage(PREPARE_NEXT).sendToTarget();
     }
 
-    private boolean prepareNextImpl() {
+    private void prepareNextImpl() {
         synchronized (this) {
-            try {
+            nextPosition = getNextPosition(false);
-                int nextPosition = getNextPosition(false);
             playback.setNextDataSource(getTrackUri(getSongAt(nextPosition)));
-                this.nextPosition = nextPosition;
-                return true;
-            } catch (Exception e) {
-                return false;
-            }
         }
     }
 
@@ -805,11 +794,7 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
     }
 
     private void playSongAtImpl(int position) {
-        if (openTrackAndPrepareNextAt(position)) {
+        openTrackAndPrepareNextAt(position);
-            play();
-        } else {
-            Toast.makeText(this, getResources().getString(R.string.unplayable_file), Toast.LENGTH_SHORT).show();
-        }
     }
 
     public void pause() {
@@ -1072,10 +1057,6 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
         }
     }
 
-    public int getAudioSessionId() {
-        return playback.getAudioSessionId();
-    }
-
     public MediaSessionCompat getMediaSession() {
         return mediaSession;
     }
@@ -1093,13 +1074,6 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
     @Override
     public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
         switch (key) {
-            case PreferenceUtil.GAPLESS_PLAYBACK:
-                if (sharedPreferences.getBoolean(key, false)) {
-                    prepareNext();
-                } else {
-                    playback.setNextDataSource(null);
-                }
-                break;
             case PreferenceUtil.SHOW_ALBUM_COVER:
             case PreferenceUtil.BLUR_ALBUM_COVER:
                 updateMediaSessionMetaData();
@@ -1114,6 +1088,12 @@ public class MusicService extends Service implements SharedPreferences.OnSharedP
         }
     }
 
+    @Override
+    public void onTrackStarted() {
+        handleAndSendChangeInternal(PLAY_STATE_CHANGED);
+        prepareNext();
+    }
+
     @Override
     public void onTrackWentToNext() {
         playerHandler.sendEmptyMessage(TRACK_WENT_TO_NEXT);

app/src/main/java/com/dkanada/gramophone/service/playback/Playback.java

@@ -3,7 +3,7 @@ package com.dkanada.gramophone.service.playback;
 import androidx.annotation.Nullable;
 
 public interface Playback {
-    boolean setDataSource(String path);
+    void setDataSource(String path);
 
     void setNextDataSource(@Nullable String path);
 
@@ -15,8 +15,6 @@ public interface Playback {
 
     void stop();
 
-    void release();
-
     boolean pause();
 
     boolean isPlaying();
@@ -29,11 +27,9 @@ public interface Playback {
 
     boolean setVolume(float vol);
 
-    boolean setAudioSessionId(int sessionId);
-
-    int getAudioSessionId();
-
     interface PlaybackCallbacks {
+        void onTrackStarted();
+
         void onTrackWentToNext();
 
         void onTrackEnded();

app/src/main/java/com/dkanada/gramophone/util/MusicUtil.java

@@ -7,6 +7,7 @@ import android.net.Uri;
 import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import android.text.TextUtils;
+import android.util.Log;
 import android.widget.Toast;
 
 import com.dkanada.gramophone.App;
@@ -16,6 +17,7 @@ import com.dkanada.gramophone.model.Artist;
 import com.dkanada.gramophone.model.Genre;
 import com.dkanada.gramophone.model.Song;
 
+import org.jellyfin.apiclient.interaction.ApiClient;
 import org.jellyfin.apiclient.interaction.Response;
 import org.jellyfin.apiclient.model.dto.UserItemDataDto;
 
@@ -24,7 +26,30 @@ import java.util.Locale;
 
 public class MusicUtil {
     public static Uri getSongFileUri(Song song) {
-        return Uri.parse(App.getApiClient().getApiUrl() + "/Audio/" + song.id + "/stream?static=true");
+        if (song.id == null) return null;
+
+        StringBuilder builder = new StringBuilder();
+        ApiClient apiClient = App.getApiClient();
+
+        builder.append(apiClient.getApiUrl());
+        builder.append("/Audio/");
+        builder.append(song.id);
+        builder.append("/universal");
+        builder.append("?UserId=" + apiClient.getCurrentUserId());
+        builder.append("&DeviceId=" + apiClient.getDeviceId());
+
+        // web max is 12444445 and 320kbps is 320000
+        builder.append("&MaxStreamingBitrate=10000000");
+        builder.append("&Container=flac");
+        builder.append("&TranscodingContainer=ts");
+        builder.append("&TranscodingProtocol=hls");
+
+        // preferred codec when transcoding
+        builder.append("&AudioCodec=aac");
+        builder.append("&api_key=" + apiClient.getAccessToken());
+
+        Log.i(MusicUtil.class.getName(), "playing audio: " + builder);
+        return Uri.parse(builder.toString());
     }
 
     @NonNull