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libvlc_event_manager: remove exceptions
[vlc] / src / control / media_list_player.c
1 /*****************************************************************************
2  * media_list_player.c: libvlc new API media_list player functions
3  *****************************************************************************
4  * Copyright (C) 2007 the VideoLAN team
5  * $Id$
6  *
7  * Authors: Pierre d'Herbemont <pdherbemont # videolan.org>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License as published by
11  * the Free Software Foundation; either version 2 of the License, or
12  * (at your option) any later version.
13  *
14  * This program is distributed in the hope that it will be useful,
15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17  * GNU General Public License for more details.
18  *
19  * You should have received a copy of the GNU General Public License
20  * along with this program; if not, write to the Free Software
21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
22  *****************************************************************************/
23
24 #ifdef HAVE_CONFIG_H
25 # include "config.h"
26 #endif
27
28 #include <vlc/libvlc.h>
29 #include <vlc/libvlc_media.h>
30 #include <vlc/libvlc_media_list.h>
31 #include <vlc/libvlc_media_player.h>
32 #include <vlc/libvlc_media_list_player.h>
33 #include <vlc/libvlc_events.h>
34 #include <assert.h>
35
36 #include "libvlc_internal.h"
37
38 #include "media_internal.h" // Abuse, could and should be removed
39 #include "media_list_path.h"
40
41 //#define DEBUG_MEDIA_LIST_PLAYER
42
43 /* This is a very dummy implementation of playlist on top of
44  * media_list and media_player.
45  *
46  * All this code is doing is simply computing the next item
47  * of a tree of media_list (see get_next_index()), and play
48  * the next item when the current is over. This is happening
49  * via the event callback media_player_reached_end().
50  *
51  * This is thread safe, and we use a two keys (locks) scheme
52  * to discriminate between callbacks and regular uses.
53  */
54
55 struct libvlc_media_list_player_t
56 {
57     libvlc_event_manager_t *    p_event_manager;
58     libvlc_instance_t *         p_libvlc_instance;
59     int                         i_refcount;
60     /* Protect access to this structure. */
61     vlc_mutex_t                 object_lock;
62     /* Protect access to this structure and from callback execution. */
63     vlc_mutex_t                 mp_callback_lock;
64     /* Indicate to media player callbacks that they are cancelled. */
65     bool                        are_mp_callback_cancelled;
66     libvlc_media_list_path_t    current_playing_item_path;
67     libvlc_media_t *            p_current_playing_item;
68     libvlc_media_list_t *       p_mlist;
69     libvlc_media_player_t *     p_mi;
70     libvlc_playback_mode_t      e_playback_mode;
71 };
72
73 /* This is not yet exported by libvlccore */
74 static inline void vlc_assert_locked(vlc_mutex_t *mutex)
75 {
76     VLC_UNUSED(mutex);
77 }
78
79 /*
80  * Forward declaration
81  */
82
83 static void set_relative_playlist_position_and_play(
84                                             libvlc_media_list_player_t * p_mlp,
85                                             int i_relative_position,
86                                             libvlc_exception_t * p_e);
87 static void stop(libvlc_media_list_player_t * p_mlp);
88
89 /*
90  * Private functions
91  */
92
93 /**************************************************************************
94  * Shortcuts
95  **************************************************************************/
96 static inline void lock(libvlc_media_list_player_t * p_mlp)
97 {
98     // Obtain an access to this structure
99     vlc_mutex_lock(&p_mlp->object_lock);
100
101     // Make sure no callback will occurs at the same time
102     vlc_mutex_lock(&p_mlp->mp_callback_lock);
103 }
104
105 static inline void unlock(libvlc_media_list_player_t * p_mlp)
106 {
107     vlc_mutex_unlock(&p_mlp->mp_callback_lock);
108     vlc_mutex_unlock(&p_mlp->object_lock);
109 }
110
111 static inline void assert_locked(libvlc_media_list_player_t * p_mlp)
112 {
113     vlc_assert_locked(&p_mlp->mp_callback_lock);
114 }
115
116 static inline libvlc_event_manager_t * mlist_em(libvlc_media_list_player_t * p_mlp)
117 {
118     assert_locked(p_mlp);
119     return libvlc_media_list_event_manager(p_mlp->p_mlist);
120 }
121
122 static inline libvlc_event_manager_t * mplayer_em(libvlc_media_list_player_t * p_mlp)
123 {
124     assert_locked(p_mlp);
125     return libvlc_media_player_event_manager(p_mlp->p_mi);
126 }
127
128 /**************************************************************************
129  *       get_next_path (private)
130  *
131  *  Returns the path to the next item in the list.
132  *  If looping is specified and the current item is the last list item in
133  *  the list it will return the first item in the list.
134  **************************************************************************/
135 static libvlc_media_list_path_t
136 get_next_path(libvlc_media_list_player_t * p_mlp, bool b_loop)
137 {
138     assert_locked(p_mlp);
139
140     /* We are entered with libvlc_media_list_lock(p_mlp->p_list) */
141     libvlc_media_list_path_t ret;
142     libvlc_media_list_t * p_parent_of_playing_item;
143     libvlc_media_list_t * p_sublist_of_playing_item;
144
145     if (!p_mlp->current_playing_item_path)
146     {
147         if (!libvlc_media_list_count(p_mlp->p_mlist))
148             return NULL;
149         return libvlc_media_list_path_with_root_index(0);
150     }
151
152     p_sublist_of_playing_item = libvlc_media_list_sublist_at_path(
153                             p_mlp->p_mlist,
154                             p_mlp->current_playing_item_path);
155
156     /* If item just gained a sublist just play it */
157     if (p_sublist_of_playing_item)
158     {
159         libvlc_media_list_release(p_sublist_of_playing_item);
160         return libvlc_media_list_path_copy_by_appending(p_mlp->current_playing_item_path, 0);
161     }
162
163     /* Try to catch parent element */
164     p_parent_of_playing_item = libvlc_media_list_parentlist_at_path(p_mlp->p_mlist,
165                             p_mlp->current_playing_item_path);
166
167     int depth = libvlc_media_list_path_depth(p_mlp->current_playing_item_path);
168     if (depth < 1 || !p_parent_of_playing_item)
169         return NULL;
170
171     ret = libvlc_media_list_path_copy(p_mlp->current_playing_item_path);
172     ret[depth - 1]++; /* set to next element */
173
174     /* If this goes beyond the end of the list */
175     while(ret[depth-1] >= libvlc_media_list_count(p_parent_of_playing_item))
176     {
177         depth--;
178         if (depth <= 0)
179         {
180             if(b_loop)
181             {
182                 ret[0] = 0;
183                 ret[1] = -1;
184                 break;
185             }
186             else
187             {
188                 free(ret);
189                 libvlc_media_list_release(p_parent_of_playing_item);
190                 return NULL;
191             }
192         }
193         ret[depth] = -1;
194         ret[depth-1]++;
195         p_parent_of_playing_item  = libvlc_media_list_parentlist_at_path(
196                                         p_mlp->p_mlist,
197                                         ret);
198     }
199
200     libvlc_media_list_release(p_parent_of_playing_item);
201     return ret;
202 }
203
204 /**************************************************************************
205  *       find_last_item (private)
206  *
207  *  Returns the path of the last descendant of a given item path.
208  *  Note: Due to the recursive nature of the function and the need to free
209  *        media list paths, paths passed in may be freed if they are replaced.
210           Recommended usage is to set return value to the same path that was
211           passed to the function (i.e. item = find_last_item(list, item); )
212  **************************************************************************/
213 static libvlc_media_list_path_t
214 find_last_item( libvlc_media_list_t * p_mlist, libvlc_media_list_path_t current_item )
215 {
216     libvlc_media_list_t * p_sublist = libvlc_media_list_sublist_at_path(p_mlist, current_item);
217     libvlc_media_list_path_t last_item_path = current_item;
218
219     if(p_sublist)
220     {
221         int i_count = libvlc_media_list_count(p_sublist);
222         if(i_count > 0)
223         {
224             /* Add the last sublist item to the path. */
225             last_item_path = libvlc_media_list_path_copy_by_appending(current_item, i_count - 1);
226             free(current_item);
227             /* Check that sublist item for more descendants. */
228             last_item_path = find_last_item(p_mlist, last_item_path);
229         }
230
231         libvlc_media_list_release(p_sublist);
232     }
233
234     return last_item_path;
235 }
236
237 /**************************************************************************
238  *       get_previous_path (private)
239  *
240  *  Returns the path to the preceding item in the list.
241  *  If looping is specified and the current item is the first list item in
242  *  the list it will return the last descendant of the last item in the list.
243  **************************************************************************/
244 static libvlc_media_list_path_t
245 get_previous_path(libvlc_media_list_player_t * p_mlp, bool b_loop)
246 {
247     assert_locked(p_mlp);
248
249     /* We are entered with libvlc_media_list_lock(p_mlp->p_list) */
250     libvlc_media_list_path_t ret;
251     libvlc_media_list_t * p_parent_of_playing_item;
252
253     if (!p_mlp->current_playing_item_path)
254     {
255         if (!libvlc_media_list_count(p_mlp->p_mlist))
256             return NULL;
257         return libvlc_media_list_path_with_root_index(0);
258     }
259
260     /* Try to catch parent element */
261     p_parent_of_playing_item = libvlc_media_list_parentlist_at_path(
262                                             p_mlp->p_mlist,
263                                             p_mlp->current_playing_item_path);
264
265     int depth = libvlc_media_list_path_depth(p_mlp->current_playing_item_path);
266     if (depth < 1 || !p_parent_of_playing_item)
267         return NULL;
268
269     /* Set the return path to the current path */
270     ret = libvlc_media_list_path_copy(p_mlp->current_playing_item_path);
271
272     /* Change the return path to the previous list entry */
273     ret[depth - 1]--; /* set to previous element */
274     ret[depth] = -1;
275
276     /* Is the return path is beyond the start of the current list? */
277     if(ret[depth - 1] < 0)
278     {
279         /* Move to parent of current item */
280         depth--;
281
282         /* Are we at the root level of the tree? */
283         if (depth <= 0)
284         {
285             // Is looping enabled?
286             if(b_loop)
287             {
288                 int i_count = libvlc_media_list_count(p_parent_of_playing_item);
289
290                 /* Set current play item to the last element in the list */
291                 ret[0] = i_count - 1;
292                 ret[1] = -1;
293
294                 /* Set the return path to the last descendant item of the current item */
295                 ret = find_last_item(p_mlp->p_mlist, ret);
296             }
297             else
298             {
299                 /* No looping so return empty path. */
300                 free(ret);
301                 ret = NULL;
302             }
303         }
304         else
305         {
306             /* This is the case of moving backward from the beginning of the
307             *  subitem list to its parent item.
308             *  This ensures that current path is properly terminated to
309             *  use that parent.
310             */
311             ret[depth] = -1;
312         }
313     }
314     else
315     {
316         ret = find_last_item(p_mlp->p_mlist, ret);
317     }
318
319     libvlc_media_list_release(p_parent_of_playing_item);
320     return ret;
321 }
322
323 /**************************************************************************
324  *       media_player_reached_end (private) (Event Callback)
325  **************************************************************************/
326 static void
327 media_player_reached_end(const libvlc_event_t * p_event, void * p_user_data)
328 {
329     VLC_UNUSED(p_event);
330     libvlc_media_list_player_t * p_mlp = p_user_data;
331     libvlc_exception_t e;
332     libvlc_exception_init(&e);
333
334     vlc_mutex_lock(&p_mlp->mp_callback_lock);
335     if (!p_mlp->are_mp_callback_cancelled)
336         set_relative_playlist_position_and_play(p_mlp, 1, &e);
337     vlc_mutex_unlock(&p_mlp->mp_callback_lock);
338
339     // There is no point in reporting an error from this callback
340     libvlc_exception_clear(&e);
341 }
342
343 /**************************************************************************
344  *       playlist_item_deleted (private) (Event Callback)
345  **************************************************************************/
346 static void
347 mlist_item_deleted(const libvlc_event_t * p_event, void * p_user_data)
348 {
349     // Nothing to do. For now.
350     (void)p_event; (void)p_user_data;
351 }
352
353
354 /**************************************************************************
355  * install_playlist_observer (private)
356  **************************************************************************/
357 static void
358 install_playlist_observer(libvlc_media_list_player_t * p_mlp)
359 {
360     assert_locked(p_mlp);
361     libvlc_event_attach(mlist_em(p_mlp), libvlc_MediaListItemDeleted, mlist_item_deleted, p_mlp);
362 }
363
364 /**************************************************************************
365  * uninstall_playlist_observer (private)
366  **************************************************************************/
367 static void
368 uninstall_playlist_observer(libvlc_media_list_player_t * p_mlp)
369 {
370     assert_locked(p_mlp);
371     if (!p_mlp->p_mlist) return;
372     libvlc_event_detach(mlist_em(p_mlp), libvlc_MediaListItemDeleted, mlist_item_deleted, p_mlp);
373 }
374
375 /**************************************************************************
376  * install_media_player_observer (private)
377  **************************************************************************/
378 static void
379 install_media_player_observer(libvlc_media_list_player_t * p_mlp)
380 {
381     assert_locked(p_mlp);
382     libvlc_event_attach_async(mplayer_em(p_mlp), libvlc_MediaPlayerEndReached, media_player_reached_end, p_mlp);
383 }
384
385
386 /**************************************************************************
387  *       uninstall_media_player_observer (private)
388  **************************************************************************/
389 static void
390 uninstall_media_player_observer(libvlc_media_list_player_t * p_mlp)
391 {
392     assert_locked(p_mlp);
393     if (!p_mlp->p_mi) return;
394
395     // From now on, media_player callback won't be relevant.
396     p_mlp->are_mp_callback_cancelled = true;
397
398     // Allow callbacks to run, because detach() will wait until all callbacks are processed.
399     // This is safe because only callbacks are allowed, and there execution will be cancelled.
400     vlc_mutex_unlock(&p_mlp->mp_callback_lock);
401     libvlc_event_detach(mplayer_em(p_mlp), libvlc_MediaPlayerEndReached, media_player_reached_end, p_mlp);
402
403     // Now, lock back the callback lock. No more callback will be present from this point.
404     vlc_mutex_lock(&p_mlp->mp_callback_lock);
405     p_mlp->are_mp_callback_cancelled = false;
406
407     // What is here is safe, because we guarantee that we won't be able to anything concurrently,
408     // - except (cancelled) callbacks - thanks to the object_lock.
409 }
410
411 /**************************************************************************
412  *       set_current_playing_item (private)
413  *
414  * Playlist lock should be held
415  **************************************************************************/
416 static void
417 set_current_playing_item(libvlc_media_list_player_t * p_mlp, libvlc_media_list_path_t path)
418 {
419     assert_locked(p_mlp);
420
421     /* First, save the new path that we are going to play */
422     if (p_mlp->current_playing_item_path != path)
423     {
424         free(p_mlp->current_playing_item_path);
425         p_mlp->current_playing_item_path = path;
426     }
427
428     if (!path)
429         return;
430
431     libvlc_media_t * p_md;
432     p_md = libvlc_media_list_item_at_path(p_mlp->p_mlist, path);
433     if (!p_md)
434         return;
435
436     /* Make sure media_player_reached_end() won't get called */
437     uninstall_media_player_observer(p_mlp);
438
439     /* Create a new media_player if there is none */
440     if (!p_mlp->p_mi)
441         p_mlp->p_mi = libvlc_media_player_new_from_media(p_md, NULL);
442
443     libvlc_media_player_set_media(p_mlp->p_mi, p_md);
444
445     install_media_player_observer(p_mlp);
446     libvlc_media_release(p_md); /* for libvlc_media_list_item_at_index */
447 }
448
449 /*
450  * Public libvlc functions
451  */
452
453 /**************************************************************************
454  *         new (Public)
455  **************************************************************************/
456 libvlc_media_list_player_t *
457 libvlc_media_list_player_new(libvlc_instance_t * p_instance, libvlc_exception_t * p_e)
458 {
459     (void)p_e;
460     libvlc_media_list_player_t * p_mlp;
461     p_mlp = calloc( 1, sizeof(libvlc_media_list_player_t) );
462     if (unlikely(p_mlp == NULL))
463     {
464         libvlc_printerr("Not enough memory");
465         return NULL;
466     }
467
468     p_mlp->p_event_manager = libvlc_event_manager_new(p_mlp, p_instance);
469     if (unlikely(p_mlp->p_event_manager == NULL))
470     {
471         free (p_mlp);
472         return NULL;
473     }
474
475     libvlc_retain(p_instance);
476     p_mlp->p_libvlc_instance = p_instance;
477     p_mlp->i_refcount = 1;
478     vlc_mutex_init(&p_mlp->object_lock);
479     vlc_mutex_init(&p_mlp->mp_callback_lock);
480     libvlc_event_manager_register_event_type(p_mlp->p_event_manager, libvlc_MediaListPlayerNextItemSet);
481     p_mlp->e_playback_mode = libvlc_playback_mode_default;
482
483     return p_mlp;
484 }
485
486 /**************************************************************************
487  *         release (Public)
488  **************************************************************************/
489 void libvlc_media_list_player_release(libvlc_media_list_player_t * p_mlp)
490 {
491     if (!p_mlp)
492         return;
493
494     lock(p_mlp);
495     p_mlp->i_refcount--;
496     if (p_mlp->i_refcount > 0)
497     {
498         unlock(p_mlp);
499         return;
500     }
501
502     assert(p_mlp->i_refcount == 0);
503
504     /* Keep the lock(), because the uninstall functions
505      * check for it. That's convenient. */
506
507     if (p_mlp->p_mi)
508     {
509         uninstall_media_player_observer(p_mlp);
510         libvlc_media_player_release(p_mlp->p_mi);
511     }
512     if (p_mlp->p_mlist)
513     {
514         uninstall_playlist_observer(p_mlp);
515         libvlc_media_list_release(p_mlp->p_mlist);
516     }
517
518     unlock(p_mlp);
519     vlc_mutex_destroy(&p_mlp->object_lock);
520     vlc_mutex_destroy(&p_mlp->mp_callback_lock);
521
522     libvlc_event_manager_release(p_mlp->p_event_manager);
523
524     free(p_mlp->current_playing_item_path);
525     libvlc_release(p_mlp->p_libvlc_instance);
526     free(p_mlp);
527 }
528
529 /**************************************************************************
530  *        event_manager (Public)
531  **************************************************************************/
532 libvlc_event_manager_t *
533 libvlc_media_list_player_event_manager(libvlc_media_list_player_t * p_mlp)
534 {
535     return p_mlp->p_event_manager;
536 }
537
538 /**************************************************************************
539  *        set_media_player (Public)
540  **************************************************************************/
541 void libvlc_media_list_player_set_media_player(libvlc_media_list_player_t * p_mlp, libvlc_media_player_t * p_mi)
542 {
543     lock(p_mlp);
544
545     if (p_mlp->p_mi)
546     {
547         uninstall_media_player_observer(p_mlp);
548         libvlc_media_player_release(p_mlp->p_mi);
549     }
550     libvlc_media_player_retain(p_mi);
551     p_mlp->p_mi = p_mi;
552
553     install_media_player_observer(p_mlp);
554
555     unlock(p_mlp);
556 }
557
558 /**************************************************************************
559  *       set_media_list (Public)
560  **************************************************************************/
561 void libvlc_media_list_player_set_media_list(libvlc_media_list_player_t * p_mlp, libvlc_media_list_t * p_mlist)
562 {
563     assert (p_mlist);
564
565     lock(p_mlp);
566     if (p_mlp->p_mlist)
567     {
568         uninstall_playlist_observer(p_mlp);
569         libvlc_media_list_release(p_mlp->p_mlist);
570     }
571     libvlc_media_list_retain(p_mlist);
572     p_mlp->p_mlist = p_mlist;
573
574     install_playlist_observer(p_mlp);
575
576     unlock(p_mlp);
577 }
578
579 /**************************************************************************
580  *        Play (Public)
581  **************************************************************************/
582 void libvlc_media_list_player_play(libvlc_media_list_player_t * p_mlp, libvlc_exception_t * p_e)
583 {
584     lock(p_mlp);
585     if (!p_mlp->current_playing_item_path)
586     {
587         set_relative_playlist_position_and_play(p_mlp, 1, p_e);
588         unlock(p_mlp);
589         return; /* Will set to play */
590     }
591     libvlc_media_player_play(p_mlp->p_mi, p_e);
592     unlock(p_mlp);
593 }
594
595
596 /**************************************************************************
597  *        Pause (Public)
598  **************************************************************************/
599 void libvlc_media_list_player_pause(libvlc_media_list_player_t * p_mlp, libvlc_exception_t * p_e)
600 {
601     lock(p_mlp);
602     if (!p_mlp->p_mi)
603     {
604         unlock(p_mlp);
605         return;
606     }
607     libvlc_media_player_pause(p_mlp->p_mi, p_e);
608     unlock(p_mlp);
609 }
610
611 /**************************************************************************
612  *        is_playing (Public)
613  **************************************************************************/
614 int
615 libvlc_media_list_player_is_playing(libvlc_media_list_player_t * p_mlp)
616 {
617     libvlc_state_t state = libvlc_media_player_get_state(p_mlp->p_mi);
618     return (state == libvlc_Opening) || (state == libvlc_Buffering) ||
619            (state == libvlc_Playing);
620 }
621
622 /**************************************************************************
623  *        State (Public)
624  **************************************************************************/
625 libvlc_state_t
626 libvlc_media_list_player_get_state(libvlc_media_list_player_t * p_mlp)
627 {
628     if (!p_mlp->p_mi)
629         return libvlc_Ended;
630     return libvlc_media_player_get_state(p_mlp->p_mi);
631 }
632
633 /**************************************************************************
634  *        Play item at index (Public)
635  **************************************************************************/
636 void libvlc_media_list_player_play_item_at_index(libvlc_media_list_player_t * p_mlp, int i_index, libvlc_exception_t *p_e)
637 {
638     lock(p_mlp);
639     set_current_playing_item(p_mlp, libvlc_media_list_path_with_root_index(i_index));
640     libvlc_media_player_play(p_mlp->p_mi, p_e);
641     unlock(p_mlp);
642
643     /* Send the next item event */
644     libvlc_event_t event;
645     event.type = libvlc_MediaListPlayerNextItemSet;
646     libvlc_event_send(p_mlp->p_event_manager, &event);
647 }
648
649 /**************************************************************************
650  *        Play item (Public)
651  **************************************************************************/
652 void libvlc_media_list_player_play_item(libvlc_media_list_player_t * p_mlp, libvlc_media_t * p_md, libvlc_exception_t * p_e)
653 {
654     lock(p_mlp);
655     libvlc_media_list_path_t path = libvlc_media_list_path_of_item(p_mlp->p_mlist, p_md);
656     if (!path)
657     {
658         libvlc_exception_raise(p_e);
659         libvlc_printerr("Item not found in media list");
660         unlock(p_mlp);
661         return;
662     }
663
664     set_current_playing_item(p_mlp, path);
665     libvlc_media_player_play(p_mlp->p_mi, p_e);
666     unlock(p_mlp);
667 }
668
669 /**************************************************************************
670  *       Stop (Private)
671  *
672  * Lock must be held.
673  **************************************************************************/
674 static void stop(libvlc_media_list_player_t * p_mlp)
675 {
676     assert_locked(p_mlp);
677
678     if (p_mlp->p_mi)
679     {
680         /* We are not interested in getting media stop event now */
681         uninstall_media_player_observer(p_mlp);
682         libvlc_media_player_stop(p_mlp->p_mi);
683         install_media_player_observer(p_mlp);
684     }
685
686     free(p_mlp->current_playing_item_path);
687     p_mlp->current_playing_item_path = NULL;
688 }
689
690 /**************************************************************************
691  *       Stop (Public)
692  **************************************************************************/
693 void libvlc_media_list_player_stop(libvlc_media_list_player_t * p_mlp)
694 {
695     lock(p_mlp);
696     stop(p_mlp);
697     unlock(p_mlp);
698 }
699
700 /**************************************************************************
701  *       Set relative playlist position and play (Private)
702  *
703  * Sets the currently played item to the given relative play item position
704  * (based on the currently playing item) and then begins the new item playback.
705  * Lock must be held.
706  **************************************************************************/
707 static void set_relative_playlist_position_and_play(
708                                       libvlc_media_list_player_t * p_mlp,
709                                       int i_relative_position,
710                                       libvlc_exception_t * p_e)
711 {
712     assert_locked(p_mlp);
713
714     if (!p_mlp->p_mlist)
715     {
716         libvlc_exception_raise(p_e);
717         libvlc_printerr("No media list");
718         return;
719     }
720
721     libvlc_media_list_lock(p_mlp->p_mlist);
722
723     libvlc_media_list_path_t path = p_mlp->current_playing_item_path;
724
725     if(p_mlp->e_playback_mode != libvlc_playback_mode_repeat)
726     {
727         bool b_loop = (p_mlp->e_playback_mode == libvlc_playback_mode_loop);
728
729         if(i_relative_position > 0)
730         {
731             do
732             {
733                 path = get_next_path(p_mlp, b_loop);
734                 set_current_playing_item(p_mlp, path);
735                 --i_relative_position;
736             }
737             while(i_relative_position > 0);
738         }
739         else if(i_relative_position < 0)
740         {
741             do
742             {
743                 path = get_previous_path(p_mlp, b_loop);
744                 set_current_playing_item(p_mlp, path);
745                 ++i_relative_position;
746             }
747             while (i_relative_position < 0);
748         }
749     }
750     else
751     {
752         set_current_playing_item(p_mlp, path);
753     }
754
755 #ifdef DEBUG_MEDIA_LIST_PLAYER
756     printf("Playing:");
757     libvlc_media_list_path_dump(path);
758 #endif
759
760     if (!path)
761     {
762         libvlc_media_list_unlock(p_mlp->p_mlist);
763         return;
764     }
765
766     libvlc_media_player_play(p_mlp->p_mi, p_e);
767
768     libvlc_media_list_unlock(p_mlp->p_mlist);
769
770     /* Send the next item event */
771     libvlc_event_t event;
772     event.type = libvlc_MediaListPlayerNextItemSet;
773     libvlc_media_t * p_md = libvlc_media_list_item_at_path(p_mlp->p_mlist, path);
774     event.u.media_list_player_next_item_set.item = p_md;
775     libvlc_event_send(p_mlp->p_event_manager, &event);
776     libvlc_media_release(p_md);
777 }
778
779 /**************************************************************************
780  *       Next (Public)
781  **************************************************************************/
782 void libvlc_media_list_player_next(libvlc_media_list_player_t * p_mlp,
783                                    libvlc_exception_t * p_e)
784 {
785     lock(p_mlp);
786     set_relative_playlist_position_and_play(p_mlp, 1, p_e);
787     unlock(p_mlp);
788 }
789
790 /**************************************************************************
791  *       Previous (Public)
792  **************************************************************************/
793 void libvlc_media_list_player_previous(libvlc_media_list_player_t * p_mlp,
794                                        libvlc_exception_t * p_e)
795 {
796     lock(p_mlp);
797     set_relative_playlist_position_and_play(p_mlp, -1, p_e);
798     unlock(p_mlp);
799 }
800
801 /**************************************************************************
802  *       Set Playback Mode (Public)
803  **************************************************************************/
804 void libvlc_media_list_player_set_playback_mode(
805                                             libvlc_media_list_player_t * p_mlp,
806                                             libvlc_playback_mode_t e_mode )
807 {
808     lock(p_mlp);
809     p_mlp->e_playback_mode = e_mode;
810     unlock(p_mlp);
811 }