Improve playback startup resiliance

- Fixes #426

resources/lib/playback.py

@@ -54,7 +54,7 @@ def playback_triage(plex_id=None, plex_type=None, path=None, resolve=True):
         LOG.error('Not yet authenticated for PMS, abort starting playback')
         # "Unauthorized for PMS"
         dialog('notification', lang(29999), lang(30017))
-        _ensure_resolve()
+        _ensure_resolve(abort=True)
         return
     playqueue = PQ.get_playqueue_from_type(
         v.KODI_PLAYLIST_TYPE_FROM_PLEX_TYPE[plex_type])
@@ -64,8 +64,12 @@ def playback_triage(plex_id=None, plex_type=None, path=None, resolve=True):
     LOG.debug('playQueue position: %s for %s', pos, playqueue)
     # Have we already initiated playback?
     try:
-        playqueue.items[pos]
+        item = playqueue.items[pos]
     except IndexError:
+        initiate = True
+    else:
+        initiate = True if item.plex_id != plex_id else False
+    if initiate:
         _playback_init(plex_id, plex_type, playqueue, pos)
     else:
         # kick off playback on second pass
@@ -84,7 +88,7 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
         LOG.error('Could not get a PMS xml for plex id %s', plex_id)
         # "Play error"
         dialog('notification', lang(29999), lang(30128), icon='{error}')
-        _ensure_resolve()
+        _ensure_resolve(abort=True)
         return
     if playqueue.kodi_pl.size() > 1:
         # Special case - we already got a filled Kodi playqueue
@@ -92,7 +96,7 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
             _init_existing_kodi_playlist(playqueue)
         except PL.PlaylistError:
             LOG.error('Aborting playback_init for longer Kodi playlist')
-            _ensure_resolve()
+            _ensure_resolve(abort=True)
             return
         # Now we need to use setResolvedUrl for the item at position pos
         _conclude_playback(playqueue, pos)
@@ -101,9 +105,8 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
     # playqueues
     # Fail the item we're trying to play now so we can restart the player
     _ensure_resolve()
-    api = API(xml[0])
     trailers = False
-    if (plex_type == v.PLEX_TYPE_MOVIE and not api.resume_point() and
+    if (plex_type == v.PLEX_TYPE_MOVIE and not state.RESUME_PLAYBACK and
             settings('enableCinema') == "true"):
         if settings('askCinema') == "true":
             # "Play trailers?"
@@ -124,7 +127,7 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
                       plex_id, xml.attrib.get('librarySectionUUID'))
             # "Play error"
             dialog('notification', lang(29999), lang(30128), icon='{error}')
-            _ensure_resolve()
+            _ensure_resolve(abort=True)
             return
         # Should already be empty, but just in case
         PL.get_playlist_details_from_xml(playqueue, xml)
@@ -135,11 +138,13 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
     # Reset some playback variables
     state.CONTEXT_MENU_PLAY = False
     state.FORCE_TRANSCODE = False
+    # Do NOT set offset, because Kodi player will return here to resolveURL
     # New thread to release this one sooner (e.g. harddisk spinning up)
-    thread = Thread(target=Player().play,
+    thread = Thread(target=threaded_playback,
-                    args=(playqueue.kodi_pl, ))
+                    args=(playqueue.kodi_pl, pos, None))
     thread.setDaemon(True)
-    LOG.info('Done initializing PKC playback, starting Kodi player')
+    LOG.info('Done initializing playback, starting Kodi player at pos %s',
+             pos)
     # By design, PKC will start Kodi playback using Player().play(). Kodi
     # caches paths like our plugin://pkc. If we use Player().play() between
     # 2 consecutive startups of exactly the same Kodi library item, Kodi's
@@ -149,7 +154,7 @@ def _playback_init(plex_id, plex_type, playqueue, pos):
     thread.start()
 
 
-def _ensure_resolve():
+def _ensure_resolve(abort=False):
     """
     Will check whether RESOLVE=True and if so, fail Kodi playback startup
     with the path 'PKC_Dummy_Path_Which_Fails' using setResolvedUrl (and some
@@ -158,11 +163,17 @@ def _ensure_resolve():
     This way we're making sure that other Python instances (calling default.py)
     will be destroyed.
     """
-    if RESOLVE is True:
+    if RESOLVE:
         state.PKC_CAUSED_STOP = True
         result = Playback_Successful()
         result.listitem = PKC_ListItem(path='PKC_Dummy_Path_Which_Fails')
         pickle_me(result)
+    if abort:
+        # Reset some playback variables
+        state.CONTEXT_MENU_PLAY = False
+        state.FORCE_TRANSCODE = False
+        state.RESUMABLE = False
+        state.RESUME_PLAYBACK = False
 
 
 def _init_existing_kodi_playlist(playqueue):
@@ -291,6 +302,7 @@ def _conclude_playback(playqueue, pos):
         listitem.setSubtitles(api.cache_external_subs())
     elif item.playmethod == 'Transcode':
         playutils.audio_subtitle_prefs(listitem)
+
     if state.RESUME_PLAYBACK is True:
         state.RESUME_PLAYBACK = False
         if (item.offset is None and
@@ -335,7 +347,7 @@ def process_indirect(key, offset, resolve=True):
         xml[0].attrib
     except (TypeError, IndexError, AttributeError):
         LOG.error('Could not download PMS metadata')
-        _ensure_resolve()
+        _ensure_resolve(abort=True)
         return
     if offset != '0':
         offset = int(v.PLEX_TO_KODI_TIMEFACTOR * float(offset))
@@ -358,7 +370,7 @@ def process_indirect(key, offset, resolve=True):
         xml[0].attrib
     except (TypeError, IndexError, AttributeError):
         LOG.error('Could not download last xml for playurl')
-        _ensure_resolve()
+        _ensure_resolve(abort=True)
         return
     playurl = xml[0].attrib['key']
     item.file = playurl