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 fire this immediately after showing a frame
54 * or when a frame should be shown (if audio-only consumer).
55 * \event \em consumer-frame-render The base class fires this immediately before rendering a frame.
56 * \event \em consumer-thread-started The base class fires when beginning execution of a rendering thread.
57 * \event \em consumer-thread-stopped The base class fires when a rendering thread has ended.
58 * \event \em consumer-stopping This is fired when stop was requested, but before render threads are joined.
59 * \event \em consumer-stopped This is fired when the subclass implementation calls mlt_consumer_stopped().
60 * \properties \em fps video frames per second as floating point (read only)
61 * \properties \em frame_rate_num the numerator of the video frame rate, overrides \p mlt_profile_s
62 * \properties \em frame_rate_den the denominator of the video frame rate, overrides \p mlt_profile_s
63 * \properties \em width the horizontal video resolution, overrides \p mlt_profile_s
64 * \properties \em height the vertical video resolution, overrides \p mlt_profile_s
65 * \properties \em progressive a flag that indicates if the video is interlaced
66 * or progressive, overrides \p mlt_profile_s
67 * \properties \em aspect_ratio the video sample (pixel) aspect ratio as floating point (read only)
68 * \properties \em sample_aspect_num the numerator of the sample aspect ratio, overrides \p mlt_profile_s
69 * \properties \em sample_aspect_den the denominator of the sample aspect ratio, overrides \p mlt_profile_s
70 * \properties \em display_ratio the video frame aspect ratio as floating point (read only)
71 * \properties \em display_aspect_num the numerator of the video frame aspect ratio, overrides \p mlt_profile_s
72 * \properties \em display_aspect_den the denominator of the video frame aspect ratio, overrides \p mlt_profile_s
73 * \properties \em priority the OS scheduling priority for the render threads when real_time is not 0.
74 * \properties \em top_field_first when not progressive, whether interlace field order is top-field-first, defaults to 0.
75 * Set this to -1 if the consumer does not care about the field order.
76 * \properties \em mlt_image_format the image format to request in rendering threads, defaults to yuv422
77 * \properties \em mlt_audio_format the audio format to request in rendering threads, defaults to S16
82 /** A consumer is a service. */
83 struct mlt_service_s parent;
85 /** Start the consumer to pull frames (virtual function).
87 * \param mlt_consumer a consumer
88 * \return true if there was an error
90 int ( *start )( mlt_consumer );
92 /** Stop the consumer (virtual function).
94 * \param mlt_consumer a consumer
95 * \return true if there was an error
97 int ( *stop )( mlt_consumer );
99 /** Get whether the consumer is running or stopped (virtual function).
101 * \param mlt_consumer a consumer
102 * \return true if the consumer is stopped
104 int ( *is_stopped )( mlt_consumer );
106 /** Purge the consumer of buffered data (virtual function).
108 * \param mlt_consumer a consumer
110 void ( *purge )( mlt_consumer );
112 /** The destructor virtual function
114 * \param mlt_consumer a consumer
116 void ( *close )( mlt_consumer );
118 void *local; /**< \private instance object */
119 void *child; /**< \private the object of a subclass */
122 #define MLT_CONSUMER_SERVICE( consumer ) ( &( consumer )->parent )
123 #define MLT_CONSUMER_PROPERTIES( consumer ) MLT_SERVICE_PROPERTIES( MLT_CONSUMER_SERVICE( consumer ) )
125 extern int mlt_consumer_init( mlt_consumer self, void *child, mlt_profile profile );
126 extern mlt_consumer mlt_consumer_new( mlt_profile profile );
127 extern mlt_service mlt_consumer_service( mlt_consumer self );
128 extern mlt_properties mlt_consumer_properties( mlt_consumer self );
129 extern int mlt_consumer_connect( mlt_consumer self, mlt_service producer );
130 extern int mlt_consumer_start( mlt_consumer self );
131 extern void mlt_consumer_purge( mlt_consumer self );
132 extern int mlt_consumer_put_frame( mlt_consumer self, mlt_frame frame );
133 extern mlt_frame mlt_consumer_get_frame( mlt_consumer self );
134 extern mlt_frame mlt_consumer_rt_frame( mlt_consumer self );
135 extern int mlt_consumer_stop( mlt_consumer self );
136 extern int mlt_consumer_is_stopped( mlt_consumer self );
137 extern void mlt_consumer_stopped( mlt_consumer self );
138 extern void mlt_consumer_close( mlt_consumer );
139 extern mlt_position mlt_consumer_position( mlt_consumer );