3 * \brief abstraction for all consumer services
6 * Copyright (C) 2003-2010 Ushodaya Enterprises Limited
7 * \author Charles Yates <charles.yates@pandora.be>
8 * \author Dan Dennedy <dan@dennedy.org>
10 * This library is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
15 * This library is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with this library; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25 #ifndef _MLT_CONSUMER_H_
26 #define _MLT_CONSUMER_H_
28 #include "mlt_service.h"
29 #include "mlt_events.h"
32 /** \brief Consumer abstract service class
34 * A consumer is a service that pulls audio and video from the connected
35 * producers, filters, and transitions. Typically a consumer is used to
36 * output audio and/or video to a device, file, or socket.
38 * \extends mlt_service_s
39 * \properties \em rescale the scaling algorithm to pass on to all scaling
40 * filters, defaults to "bilinear"
41 * \properties \em buffer the number of frames to use in the asynchronous
42 * render thread, defaults to 25
43 * \properties \em prefill the number of frames to render before commencing
44 * output when real_time <> 0, defaults to the size of buffer
45 * \properties \em drop_max the maximum number of consecutively dropped frames, defaults to 5
46 * \properties \em frequency the audio sample rate to use in Hertz, defaults to 48000
47 * \properties \em channels the number of audio channels to use, defaults to 2
48 * \properties \em real_time the asynchronous behavior: 1 (default) for asynchronous
49 * with frame dropping, -1 for asynchronous without frame dropping, 0 to disable (synchronous)
50 * \properties \em test_card the name of a resource to use as the test card, defaults to
51 * environment variable MLT_TEST_CARD. If undefined, the hard-coded default test card is
52 * white silence. A test card is what appears when nothing is produced.
53 * \event \em consumer-frame-show Subclass implementations should fire this.
54 * \event \em consumer-frame-render The abstract class fires this.
55 * \event \em consumer-stopped
56 * \properties \em fps video frames per second as floating point (read only)
57 * \properties \em frame_rate_num the numerator of the video frame rate, overrides \p mlt_profile_s
58 * \properties \em frame_rate_den the denominator of the video frame rate, overrides \p mlt_profile_s
59 * \properties \em width the horizontal video resolution, overrides \p mlt_profile_s
60 * \properties \em height the vertical video resolution, overrides \p mlt_profile_s
61 * \properties \em progressive a flag that indicates if the video is interlaced
62 * or progressive, overrides \p mlt_profile_s
63 * \properties \em aspect_ratio the video sample (pixel) aspect ratio as floating point (read only)
64 * \properties \em sample_aspect_num the numerator of the sample aspect ratio, overrides \p mlt_profile_s
65 * \properties \em sample_aspect_den the denominator of the sample aspect ratio, overrides \p mlt_profile_s
66 * \properties \em display_ratio the video frame aspect ratio as floating point (read only)
67 * \properties \em display_aspect_num the numerator of the video frame aspect ratio, overrides \p mlt_profile_s
68 * \properties \em display_aspect_den the denominator of the video frame aspect ratio, overrides \p mlt_profile_s
69 * \properties \em priority the OS scheduling priority for the render threads when real_time is not 0.
70 * \properties \em top_field_first when not progressive, whether interlace field order is top-field-first, defaults to 0
71 * \properties \em mlt_image_format the image format to request in rendering threads, defaults to yuv422
72 * \properties \em mlt_audio_format the audio format to request in rendering threads, defaults to S16
77 /** A consumer is a service. */
78 struct mlt_service_s parent;
80 /** Start the consumer to pull frames (virtual function).
82 * \param mlt_consumer a consumer
83 * \return true if there was an error
85 int ( *start )( mlt_consumer );
87 /** Stop the consumer (virtual function).
89 * \param mlt_consumer a consumer
90 * \return true if there was an error
92 int ( *stop )( mlt_consumer );
94 /** Get whether the consumer is running or stopped (virtual function).
96 * \param mlt_consumer a consumer
97 * \return true if the consumer is stopped
99 int ( *is_stopped )( mlt_consumer );
101 /** The destructor virtual function
103 * \param mlt_consumer a consumer
105 void ( *close )( mlt_consumer );
107 void *local; /**< \private instance object */
108 void *child; /**< \private the object of a subclass */
112 mlt_image_format format;
114 pthread_t ahead_thread;
115 pthread_mutex_t queue_mutex;
116 pthread_cond_t queue_cond;
117 pthread_mutex_t put_mutex;
118 pthread_cond_t put_cond;
121 mlt_event event_listener;
122 mlt_position position;
124 /* additional fields added for the parallel work queue */
125 mlt_deque worker_threads;
126 pthread_mutex_t done_mutex;
127 pthread_cond_t done_cond;
128 int consecutive_dropped;
129 int consecutive_rendered;
134 #define MLT_CONSUMER_SERVICE( consumer ) ( &( consumer )->parent )
135 #define MLT_CONSUMER_PROPERTIES( consumer ) MLT_SERVICE_PROPERTIES( MLT_CONSUMER_SERVICE( consumer ) )
137 extern int mlt_consumer_init( mlt_consumer self, void *child, mlt_profile profile );
138 extern mlt_consumer mlt_consumer_new( mlt_profile profile );
139 extern mlt_service mlt_consumer_service( mlt_consumer self );
140 extern mlt_properties mlt_consumer_properties( mlt_consumer self );
141 extern int mlt_consumer_connect( mlt_consumer self, mlt_service producer );
142 extern int mlt_consumer_start( mlt_consumer self );
143 extern void mlt_consumer_purge( mlt_consumer self );
144 extern int mlt_consumer_put_frame( mlt_consumer self, mlt_frame frame );
145 extern mlt_frame mlt_consumer_get_frame( mlt_consumer self );
146 extern mlt_frame mlt_consumer_rt_frame( mlt_consumer self );
147 extern int mlt_consumer_stop( mlt_consumer self );
148 extern int mlt_consumer_is_stopped( mlt_consumer self );
149 extern void mlt_consumer_stopped( mlt_consumer self );
150 extern void mlt_consumer_close( mlt_consumer );
151 extern mlt_position mlt_consumer_position( mlt_consumer );