5996e14e6813e81aca5389e93e50701234eff4f4
[melted] / src / framework / mlt_transition.c
1 /*
2 * mlt_transition.c -- abstraction for all transition services
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
10 *
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
15 *
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
19 */
20
21 #include "config.h"
22
23 #include "mlt_transition.h"
24 #include "mlt_frame.h"
25
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29
30 /** Forward references.
31 */
32
33 static int transition_get_frame( mlt_service this, mlt_frame_ptr frame, int index );
34
35 /** Constructor.
36 */
37
38 int mlt_transition_init( mlt_transition this, void *child )
39 {
40 mlt_service service = &this->parent;
41 memset( this, 0, sizeof( struct mlt_transition_s ) );
42 this->child = child;
43 if ( mlt_service_init( service, this ) == 0 )
44 {
45 mlt_properties properties = mlt_transition_properties( this );
46
47 service->get_frame = transition_get_frame;
48 service->close = ( mlt_destructor )mlt_transition_close;
49 service->close_object = this;
50
51 mlt_properties_set_position( properties, "in", 0 );
52 mlt_properties_set_position( properties, "out", 0 );
53 mlt_properties_set_int( properties, "a_track", 0 );
54 mlt_properties_set_int( properties, "b_track", 1 );
55
56 return 0;
57 }
58 return 1;
59 }
60
61 /** Create a new transition.
62 */
63
64 mlt_transition mlt_transition_new( )
65 {
66 mlt_transition this = calloc( 1, sizeof( struct mlt_transition_s ) );
67 if ( this != NULL )
68 mlt_transition_init( this, NULL );
69 return this;
70 }
71
72 /** Get the service associated to the transition.
73 */
74
75 mlt_service mlt_transition_service( mlt_transition this )
76 {
77 return this != NULL ? &this->parent : NULL;
78 }
79
80 /** Get the properties interface.
81 */
82
83 mlt_properties mlt_transition_properties( mlt_transition this )
84 {
85 return mlt_service_properties( mlt_transition_service( this ) );
86 }
87
88 /** Connect this transition with a producers a and b tracks.
89 */
90
91 int mlt_transition_connect( mlt_transition this, mlt_service producer, int a_track, int b_track )
92 {
93 int ret = mlt_service_connect_producer( &this->parent, producer, a_track );
94 if ( ret == 0 )
95 {
96 mlt_properties properties = mlt_transition_properties( this );
97 this->producer = producer;
98 mlt_properties_set_int( properties, "a_track", a_track );
99 mlt_properties_set_int( properties, "b_track", b_track );
100 }
101 return ret;
102 }
103
104 /** Set the in and out points.
105 */
106
107 void mlt_transition_set_in_and_out( mlt_transition this, mlt_position in, mlt_position out )
108 {
109 mlt_properties properties = mlt_transition_properties( this );
110 mlt_properties_set_position( properties, "in", in );
111 mlt_properties_set_position( properties, "out", out );
112 }
113
114 /** Get the index of the a track.
115 */
116
117 int mlt_transition_get_a_track( mlt_transition this )
118 {
119 return mlt_properties_get_int( mlt_transition_properties( this ), "a_track" );
120 }
121
122 /** Get the index of the b track.
123 */
124
125 int mlt_transition_get_b_track( mlt_transition this )
126 {
127 return mlt_properties_get_int( mlt_transition_properties( this ), "b_track" );
128 }
129
130 /** Get the in point.
131 */
132
133 mlt_position mlt_transition_get_in( mlt_transition this )
134 {
135 return mlt_properties_get_position( mlt_transition_properties( this ), "in" );
136 }
137
138 /** Get the out point.
139 */
140
141 mlt_position mlt_transition_get_out( mlt_transition this )
142 {
143 return mlt_properties_get_position( mlt_transition_properties( this ), "out" );
144 }
145
146 /** Process the frame.
147
148 If we have no process method (unlikely), we simply return the a_frame unmolested.
149 */
150
151 mlt_frame mlt_transition_process( mlt_transition this, mlt_frame a_frame, mlt_frame b_frame )
152 {
153 if ( this->process == NULL || b_frame == NULL || ( mlt_frame_is_test_card( b_frame ) && mlt_frame_is_test_audio( b_frame ) ) )
154 return a_frame;
155 else if ( a_frame == NULL || ( mlt_frame_is_test_card( a_frame ) && mlt_frame_is_test_audio( a_frame ) ) )
156 return b_frame;
157 else
158 return this->process( this, a_frame, b_frame );
159 }
160
161 /** Get a frame from this filter.
162
163 The logic is complex here. A transition is applied to frames on the a and b tracks
164 specified in the connect method above. Since all frames are obtained via this
165 method for all tracks, we have to take special care that we only obtain the a and
166 b frames once - we do this on the first call to get a frame from either a or b.
167
168 After that, we have 2 cases to resolve:
169
170 1) if the track is the a_track and we're in the time zone, then we need to call the
171 process method to do the effect on the frame and remember we've passed it on
172 otherwise, we pass on the a_frame unmolested;
173 2) For all other tracks, we get the frames on demand.
174 */
175
176 static int transition_get_frame( mlt_service service, mlt_frame_ptr frame, int index )
177 {
178 mlt_transition this = service->child;
179
180 mlt_properties properties = mlt_transition_properties( this );
181
182 int a_track = mlt_properties_get_int( properties, "a_track" );
183 int b_track = mlt_properties_get_int( properties, "b_track" );
184 mlt_position in = mlt_properties_get_position( properties, "in" );
185 mlt_position out = mlt_properties_get_position( properties, "out" );
186
187 if ( ( index == a_track || index == b_track ) && !( this->a_held || this->b_held ) )
188 {
189 mlt_service_get_frame( this->producer, &this->a_frame, a_track );
190 mlt_service_get_frame( this->producer, &this->b_frame, b_track );
191 this->a_held = 1;
192 this->b_held = 1;
193 }
194
195 // Special case track processing
196 if ( index == a_track )
197 {
198 // Determine if we're in the right time zone
199 mlt_position position = mlt_frame_get_position( this->a_frame );
200 if ( position >= in && position <= out )
201 {
202 // Process the transition
203 *frame = mlt_transition_process( this, this->a_frame, this->b_frame );
204 if ( *frame == this->b_frame )
205 {
206 mlt_frame t = this->a_frame;
207 this->a_frame = this->b_frame;
208 this->b_frame = t;
209 }
210 if ( !mlt_properties_get_int( mlt_frame_properties( this->a_frame ), "test_image" ) )
211 mlt_properties_set_int( mlt_frame_properties( this->b_frame ), "test_image", 1 );
212 if ( !mlt_properties_get_int( mlt_frame_properties( this->a_frame ), "test_audio" ) )
213 mlt_properties_set_int( mlt_frame_properties( this->b_frame ), "test_audio", 1 );
214 this->a_held = 0;
215 }
216 else
217 {
218 // Pass on the 'a frame' and remember that we've done it
219 *frame = this->a_frame;
220 this->a_held = 0;
221 }
222 return 0;
223 }
224 if ( index == b_track )
225 {
226 // Pass on the 'b frame' and remember that we've done it
227 *frame = this->b_frame;
228 this->b_held = 0;
229 return 0;
230 }
231 else
232 {
233 // Pass through
234 return mlt_service_get_frame( this->producer, frame, index );
235 }
236 }
237
238 /** Close the transition.
239 */
240
241 void mlt_transition_close( mlt_transition this )
242 {
243 if ( this != NULL && mlt_properties_dec_ref( mlt_transition_properties( this ) ) <= 0 )
244 {
245 this->parent.close = NULL;
246 if ( this->close != NULL )
247 this->close( this );
248 else
249 mlt_service_close( &this->parent );
250 }
251 }