Wait QMediaPlayer buffering before entering playing state

QMediaPlayer needs to fill its internal buffer before it can play the
stream otherwise it can end up in a stalled state.

This commit also simplifies the logic for when the player needs to be
restarted and remove the need of an internal timer to poll the player
state.

Fixes choppy http playback.

mpd-interface/httpstream.cpp

@@ -172,7 +172,7 @@ void HttpStream::streamUrl(const QString &url)
         #else
         player=new QMediaPlayer(this);
         player->setMedia(qUrl);
-        player->setProperty(constUrlProperty, url);
+        connect(player, &QMediaPlayer::bufferStatusChanged, this, &HttpStream::bufferingProgress);
         #endif
         muted=false;
         setVolume(Configuration(metaObject()->className()).get("volume", currentVolume));
@@ -186,6 +186,18 @@ void HttpStream::streamUrl(const QString &url)
     emit update();
 }
 
+void HttpStream::bufferingProgress(int progress)
+{
+    MPDStatus * const status = MPDStatus::self();
+    if (status->state() == MPDState_Playing) {
+        if (progress == 100) {
+            player->play();
+        } else {
+            player->pause();
+        }
+    }
+}
+
 void HttpStream::updateStatus()
 {
     if (!player) {
@@ -198,11 +210,7 @@ void HttpStream::updateStatus()
     // evaluates to true when it is needed to start or restart media player
     bool playerNeedsToStart = status->state() == MPDState_Playing;
     #ifndef LIBVLC_FOUND
-    playerNeedsToStart = playerNeedsToStart &&
-           (QMediaPlayer::PlayingState!=player->state() ||
-            QMediaPlayer::InvalidMedia == player->mediaStatus() ||
-            QMediaPlayer::EndOfMedia == player->mediaStatus() ||
-            QMediaPlayer::NoMedia == player->mediaStatus());
+    playerNeedsToStart = playerNeedsToStart && player->state() == QMediaPlayer::StoppedState;
     #endif
 
     if (status->state()==state && !playerNeedsToStart) {
@@ -219,42 +227,44 @@ void HttpStream::updateStatus()
             startTimer();
         }
         #else
-        if (playerNeedsToStart)
-        {
-            QString url = player->property(constUrlProperty).toString();
+        if (playerNeedsToStart) {
+            QUrl url = player->media().canonicalUrl();
             if (!url.isEmpty())
             {
               DBUG << "Setting media" << url;
-              player->setMedia(QUrl(url));
+              player->setMedia(url);
             }
-            player->play();
-            startTimer();
         }
         #endif
         break;
     case MPDState_Paused:
+        #ifndef LIBVLC_FOUND
+        player->stop();
+        #endif
     case MPDState_Inactive:
     case MPDState_Stopped:
         #ifdef LIBVLC_FOUND
         libvlc_media_player_stop(player);
+        stopTimer();
         #else
         player->stop();
         #endif
-        stopTimer();
         break;
     default:
+        #ifdef LIBVLC_FOUND
         stopTimer();
+        #endif
         break;
     }
 }
 
 void HttpStream::checkPlayer()
 {
+    #ifdef LIBVLC_FOUND
     if (0==--playStateChecks) {
         stopTimer();
         DBUG << "Max checks reached";
     }
-    #ifdef LIBVLC_FOUND
     if (libvlc_Playing==libvlc_media_player_get_state(player)) {
         DBUG << "Playing";
         stopTimer();
@@ -262,14 +272,6 @@ void HttpStream::checkPlayer()
         DBUG << "Try again";
         libvlc_media_player_play(player);
     }
-    #else
-    if (QMediaPlayer::PlayingState==player->state()) {
-        DBUG << "Playing";
-        stopTimer();
-    } else {
-        DBUG << "Try again";
-        player->play();
-    }
     #endif
 }
 

mpd-interface/httpstream.h

@@ -62,6 +62,7 @@ private Q_SLOTS:
     void updateStatus();
     void streamUrl(const QString &url);
     void checkPlayer();
+    void bufferingProgress(int progress);
 
 private:
     void startTimer();