Constness changes
[melted] / src / framework / mlt_multitrack.c
1 /**
2 * \file mlt_multitrack.c
3 * \brief multitrack service class
4 * \see mlt_multitrack_s
5 *
6 * Copyright (C) 2003-2009 Ushodaya Enterprises Limited
7 * \author Charles Yates <charles.yates@pandora.be>
8 *
9 * This library is free software; you can redistribute it and/or
10 * modify it under the terms of the GNU Lesser General Public
11 * License as published by the Free Software Foundation; either
12 * version 2.1 of the License, or (at your option) any later version.
13 *
14 * This library 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 GNU
17 * Lesser General Public License for more details.
18 *
19 * You should have received a copy of the GNU Lesser General Public
20 * License along with this library; if not, write to the Free Software
21 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 */
23
24 #include "mlt_multitrack.h"
25 #include "mlt_playlist.h"
26 #include "mlt_frame.h"
27
28 #include <stdio.h>
29 #include <stdlib.h>
30
31 /* Forward reference. */
32
33 static int producer_get_frame( mlt_producer producer, mlt_frame_ptr frame, int index );
34
35 /** Construct and initialize a new multitrack.
36 *
37 * Sets the resource property to "<multitrack>".
38 *
39 * \public \memberof mlt_multitrack_s
40 * \return a new multitrack
41 */
42
43 mlt_multitrack mlt_multitrack_init( )
44 {
45 // Allocate the multitrack object
46 mlt_multitrack this = calloc( sizeof( struct mlt_multitrack_s ), 1 );
47
48 if ( this != NULL )
49 {
50 mlt_producer producer = &this->parent;
51 if ( mlt_producer_init( producer, this ) == 0 )
52 {
53 mlt_properties properties = MLT_MULTITRACK_PROPERTIES( this );
54 producer->get_frame = producer_get_frame;
55 mlt_properties_set_data( properties, "multitrack", this, 0, NULL, NULL );
56 mlt_properties_set( properties, "log_id", "multitrack" );
57 mlt_properties_set( properties, "resource", "<multitrack>" );
58 mlt_properties_set_int( properties, "in", 0 );
59 mlt_properties_set_int( properties, "out", -1 );
60 mlt_properties_set_int( properties, "length", 0 );
61 producer->close = ( mlt_destructor )mlt_multitrack_close;
62 }
63 else
64 {
65 free( this );
66 this = NULL;
67 }
68 }
69
70 return this;
71 }
72
73 /** Get the producer associated to this multitrack.
74 *
75 * \public \memberof mlt_multitrack_s
76 * \param this a multitrack
77 * \return the producer object
78 * \see MLT_MULTITRACK_PRODUCER
79 */
80
81 mlt_producer mlt_multitrack_producer( mlt_multitrack this )
82 {
83 return this != NULL ? &this->parent : NULL;
84 }
85
86 /** Get the service associated this multitrack.
87 *
88 * \public \memberof mlt_multitrack_s
89 * \param this a multitrack
90 * \return the service object
91 * \see MLT_MULTITRACK_SERVICE
92 */
93
94 mlt_service mlt_multitrack_service( mlt_multitrack this )
95 {
96 return MLT_MULTITRACK_SERVICE( this );
97 }
98
99 /** Get the properties associated this multitrack.
100 *
101 * \public \memberof mlt_multitrack_s
102 * \param this a multitrack
103 * \return the multitrack's property list
104 * \see MLT_MULTITRACK_PROPERTIES
105 */
106
107 mlt_properties mlt_multitrack_properties( mlt_multitrack this )
108 {
109 return MLT_MULTITRACK_PROPERTIES( this );
110 }
111
112 /** Initialize position related information.
113 *
114 * \public \memberof mlt_multitrack_s
115 * \param this a multitrack
116 */
117
118 void mlt_multitrack_refresh( mlt_multitrack this )
119 {
120 int i = 0;
121
122 // Obtain the properties of this multitrack
123 mlt_properties properties = MLT_MULTITRACK_PROPERTIES( this );
124
125 // We need to ensure that the multitrack reports the longest track as its length
126 mlt_position length = 0;
127
128 // Obtain stats on all connected services
129 for ( i = 0; i < this->count; i ++ )
130 {
131 // Get the producer from this index
132 mlt_track track = this->list[ i ];
133 mlt_producer producer = track->producer;
134
135 // If it's allocated then, update our stats
136 if ( producer != NULL )
137 {
138 // If we have more than 1 track, we must be in continue mode
139 if ( this->count > 1 )
140 mlt_properties_set( MLT_PRODUCER_PROPERTIES( producer ), "eof", "continue" );
141
142 // Determine the longest length
143 //if ( !mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( producer ), "hide" ) )
144 length = mlt_producer_get_playtime( producer ) > length ? mlt_producer_get_playtime( producer ) : length;
145 }
146 }
147
148 // Update multitrack properties now - we'll not destroy the in point here
149 mlt_events_block( properties, properties );
150 mlt_properties_set_position( properties, "length", length );
151 mlt_events_unblock( properties, properties );
152 mlt_properties_set_position( properties, "out", length - 1 );
153 }
154
155 /** Listener for producers on the playlist.
156 *
157 * \private \memberof mlt_multitrack_s
158 * \param producer a producer
159 * \param this a multitrack
160 */
161
162 static void mlt_multitrack_listener( mlt_producer producer, mlt_multitrack this )
163 {
164 mlt_multitrack_refresh( this );
165 }
166
167 /** Connect a producer to a given track.
168 *
169 * Note that any producer can be connected here, but see special case treatment
170 * of playlist in clip point determination below.
171 *
172 * \public \memberof mlt_multitrack_s
173 * \param this a multitrack
174 * \param producer the producer to connect to the multitrack producer
175 * \param track the 0-based index of the track on which to connect the multitrack
176 * \return true on error
177 */
178
179 int mlt_multitrack_connect( mlt_multitrack this, mlt_producer producer, int track )
180 {
181 // Connect to the producer to ourselves at the specified track
182 int result = mlt_service_connect_producer( MLT_MULTITRACK_SERVICE( this ), MLT_PRODUCER_SERVICE( producer ), track );
183
184 if ( result == 0 )
185 {
186 // Resize the producer list if need be
187 if ( track >= this->size )
188 {
189 int i;
190 this->list = realloc( this->list, ( track + 10 ) * sizeof( mlt_track ) );
191 for ( i = this->size; i < track + 10; i ++ )
192 this->list[ i ] = NULL;
193 this->size = track + 10;
194 }
195
196 if ( this->list[ track ] != NULL )
197 {
198 mlt_event_close( this->list[ track ]->event );
199 mlt_producer_close( this->list[ track ]->producer );
200 }
201 else
202 {
203 this->list[ track ] = malloc( sizeof( struct mlt_track_s ) );
204 }
205
206 // Assign the track in our list here
207 this->list[ track ]->producer = producer;
208 this->list[ track ]->event = mlt_events_listen( MLT_PRODUCER_PROPERTIES( producer ), this,
209 "producer-changed", ( mlt_listener )mlt_multitrack_listener );
210 mlt_properties_inc_ref( MLT_PRODUCER_PROPERTIES( producer ) );
211 mlt_event_inc_ref( this->list[ track ]->event );
212
213 // Increment the track count if need be
214 if ( track >= this->count )
215 this->count = track + 1;
216
217 // Refresh our stats
218 mlt_multitrack_refresh( this );
219 }
220
221 return result;
222 }
223
224 /** Get the number of tracks.
225 *
226 * \public \memberof mlt_multitrack_s
227 * \param this a multitrack
228 * \return the number of tracks
229 */
230
231 int mlt_multitrack_count( mlt_multitrack this )
232 {
233 return this->count;
234 }
235
236 /** Get an individual track as a producer.
237 *
238 * \public \memberof mlt_multitrack_s
239 * \param this a multitrack
240 * \param track the 0-based index of the producer to get
241 * \return the producer or NULL if not valid
242 */
243
244 mlt_producer mlt_multitrack_track( mlt_multitrack this, int track )
245 {
246 mlt_producer producer = NULL;
247
248 if ( this->list != NULL && track < this->count )
249 producer = this->list[ track ]->producer;
250
251 return producer;
252 }
253
254 /** Position comparison function for sorting.
255 *
256 * \private \memberof mlt_multitrack_s
257 * \param p1 a position
258 * \param p2 another position
259 * \return <0 if \p p1 is less than \p p2, 0 if equal, >0 if greater
260 */
261
262 static int position_compare( const void *p1, const void *p2 )
263 {
264 return *( mlt_position * )p1 - *( mlt_position * )p2;
265 }
266
267 /** Add a position to a set.
268 *
269 * \private \memberof mlt_multitrack_s
270 * \param array an array of positions (the set)
271 * \param size the current number of positions in the array (not the capacity of the array)
272 * \param position the position to add
273 * \return the new size of the array
274 */
275
276 static int add_unique( mlt_position *array, int size, mlt_position position )
277 {
278 int i = 0;
279 for ( i = 0; i < size; i ++ )
280 if ( array[ i ] == position )
281 break;
282 if ( i == size )
283 array[ size ++ ] = position;
284 return size;
285 }
286
287 /** Determine the clip point.
288 *
289 * <pre>
290 * Special case here: a 'producer' has no concept of multiple clips - only the
291 * playlist and multitrack producers have clip functionality. Further to that a
292 * multitrack determines clip information from any connected tracks that happen
293 * to be playlists.
294 *
295 * Additionally, it must locate clips in the correct order, for example, consider
296 * the following track arrangement:
297 *
298 * playlist1 |0.0 |b0.0 |0.1 |0.1 |0.2 |
299 * playlist2 |b1.0 |1.0 |b1.1 |1.1 |
300 *
301 * Note - b clips represent blanks. They are also reported as clip positions.
302 *
303 * When extracting clip positions from these playlists, we should get a sequence of:
304 *
305 * 0.0, 1.0, b0.0, 0.1, b1.1, 1.1, 0.1, 0.2, [out of playlist2], [out of playlist1]
306 * </pre>
307 *
308 * \public \memberof mlt_multitrack_s
309 * \param this a multitrack
310 * \param whence from where to extract
311 * \param index the 0-based index of which clip to extract
312 * \return the position of clip \p index relative to \p whence
313 */
314
315 mlt_position mlt_multitrack_clip( mlt_multitrack this, mlt_whence whence, int index )
316 {
317 mlt_position position = 0;
318 int i = 0;
319 int j = 0;
320 mlt_position *map = malloc( 1000 * sizeof( mlt_position ) );
321 int count = 0;
322
323 for ( i = 0; i < this->count; i ++ )
324 {
325 // Get the producer for this track
326 mlt_producer producer = this->list[ i ]->producer;
327
328 // If it's assigned and not a hidden track
329 if ( producer != NULL )
330 {
331 // Get the properties of this producer
332 mlt_properties properties = MLT_PRODUCER_PROPERTIES( producer );
333
334 // Determine if it's a playlist
335 mlt_playlist playlist = mlt_properties_get_data( properties, "playlist", NULL );
336
337 // Special case consideration of playlists
338 if ( playlist != NULL )
339 {
340 for ( j = 0; j < mlt_playlist_count( playlist ); j ++ )
341 count = add_unique( map, count, mlt_playlist_clip( playlist, mlt_whence_relative_start, j ) );
342 count = add_unique( map, count, mlt_producer_get_out( producer ) + 1 );
343 }
344 else
345 {
346 count = add_unique( map, count, 0 );
347 count = add_unique( map, count, mlt_producer_get_out( producer ) + 1 );
348 }
349 }
350 }
351
352 // Now sort the map
353 qsort( map, count, sizeof( mlt_position ), position_compare );
354
355 // Now locate the requested index
356 switch( whence )
357 {
358 case mlt_whence_relative_start:
359 if ( index < count )
360 position = map[ index ];
361 else
362 position = map[ count - 1 ];
363 break;
364
365 case mlt_whence_relative_current:
366 position = mlt_producer_position( MLT_MULTITRACK_PRODUCER( this ) );
367 for ( i = 0; i < count - 2; i ++ )
368 if ( position >= map[ i ] && position < map[ i + 1 ] )
369 break;
370 index += i;
371 if ( index >= 0 && index < count )
372 position = map[ index ];
373 else if ( index < 0 )
374 position = map[ 0 ];
375 else
376 position = map[ count - 1 ];
377 break;
378
379 case mlt_whence_relative_end:
380 if ( index < count )
381 position = map[ count - index - 1 ];
382 else
383 position = map[ 0 ];
384 break;
385 }
386
387 // Free the map
388 free( map );
389
390 return position;
391 }
392
393 /** Get frame method.
394 *
395 * <pre>
396 * Special case here: The multitrack must be used in a conjunction with a downstream
397 * tractor-type service, ie:
398 *
399 * Producer1 \
400 * Producer2 - multitrack - { filters/transitions } - tractor - consumer
401 * Producer3 /
402 *
403 * The get_frame of a tractor pulls frames from it's connected service on all tracks and
404 * will terminate as soon as it receives a test card with a last_track property. The
405 * important case here is that the mulitrack does not move to the next frame until all
406 * tracks have been pulled.
407 *
408 * Reasoning: In order to seek on a network such as above, the multitrack needs to ensure
409 * that all producers are positioned on the same frame. It uses the 'last track' logic
410 * to determine when to move to the next frame.
411 *
412 * Flaw: if a transition is configured to read from a b-track which happens to trigger
413 * the last frame logic (ie: it's configured incorrectly), then things are going to go
414 * out of sync.
415 *
416 * See playlist logic too.
417 * </pre>
418 *
419 * \private \memberof mlt_multitrack_s
420 * \param parent the producer interface to a mulitrack
421 * \param[out] frame a frame by reference
422 * \param index the 0-based track index
423 * \return true if there was an error
424 */
425
426 static int producer_get_frame( mlt_producer parent, mlt_frame_ptr frame, int index )
427 {
428 // Get the mutiltrack object
429 mlt_multitrack this = parent->child;
430
431 // Check if we have a track for this index
432 if ( index < this->count && this->list[ index ] != NULL )
433 {
434 // Get the producer for this track
435 mlt_producer producer = this->list[ index ]->producer;
436
437 // Get the track hide property
438 int hide = mlt_properties_get_int( MLT_PRODUCER_PROPERTIES( mlt_producer_cut_parent( producer ) ), "hide" );
439
440 // Obtain the current position
441 mlt_position position = mlt_producer_frame( parent );
442
443 // Get the parent properties
444 mlt_properties producer_properties = MLT_PRODUCER_PROPERTIES( parent );
445
446 // Get the speed
447 double speed = mlt_properties_get_double( producer_properties, "_speed" );
448
449 // Make sure we're at the same point
450 mlt_producer_seek( producer, position );
451
452 // Get the frame from the producer
453 mlt_service_get_frame( MLT_PRODUCER_SERVICE( producer ), frame, 0 );
454
455 // Indicate speed of this producer
456 mlt_properties properties = MLT_FRAME_PROPERTIES( *frame );
457 mlt_properties_set_double( properties, "_speed", speed );
458 mlt_properties_set_position( properties, "_position", position );
459 mlt_properties_set_int( properties, "hide", hide );
460 }
461 else
462 {
463 // Generate a test frame
464 *frame = mlt_frame_init( MLT_PRODUCER_SERVICE( parent ) );
465
466 // Update position on the frame we're creating
467 mlt_frame_set_position( *frame, mlt_producer_position( parent ) );
468
469 // Move on to the next frame
470 if ( index >= this->count )
471 {
472 // Let tractor know if we've reached the end
473 mlt_properties_set_int( MLT_FRAME_PROPERTIES( *frame ), "last_track", 1 );
474
475 // Move to the next frame
476 mlt_producer_prepare_next( parent );
477 }
478 }
479
480 return 0;
481 }
482
483 /** Close this instance and free its resources.
484 *
485 * \public \memberof mlt_multitrack_s
486 * \param this a multitrack
487 */
488
489 void mlt_multitrack_close( mlt_multitrack this )
490 {
491 if ( this != NULL && mlt_properties_dec_ref( MLT_MULTITRACK_PROPERTIES( this ) ) <= 0 )
492 {
493 int i = 0;
494 for ( i = 0; i < this->count; i ++ )
495 {
496 if ( this->list[ i ] != NULL )
497 {
498 mlt_event_close( this->list[ i ]->event );
499 mlt_producer_close( this->list[ i ]->producer );
500 free( this->list[ i ] );
501 }
502 }
503
504 // Close the producer
505 this->parent.close = NULL;
506 mlt_producer_close( &this->parent );
507
508 // Free the list
509 free( this->list );
510
511 // Free the object
512 free( this );
513 }
514 }