research.m1stereo.tv/gitweb/ - melted/blob - src/framework/mlt_consumer.h

   1 /**
   2  * \file mlt_consumer.h
   3  * \brief abstraction for all consumer services
   4  * \see mlt_consumer_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 #ifndef _MLT_CONSUMER_H_
  25 #define _MLT_CONSUMER_H_
  26
  27 #include "mlt_service.h"
  28 #include "mlt_events.h"
  29 #include <pthread.h>
  30
  31 /** \brief Consumer abstract service class
  32  *
  33  * A consumer is a service that pulls audio and video from the connected
  34  * producers, filters, and transitions. Typically a consumer is used to
  35  * output audio and/or video to a device, file, or socket.
  36  *
  37  * \extends mlt_service_s
  38  * \properties \em rescale the scaling algorithm to pass on to all scaling
  39  * filters, defaults to "bilinear"
  40  * \properties \em buffer the number of frames to use in the asynchronous
  41  * render thread, defaults to 25
  42  * \properties \em frequency the audio sample rate to use in Hertz, defaults to 48000
  43  * \properties \em channels the number of audio channels to use, defaults to 2
  44  * \properties \em real_time the asynchronous behavior: 1 (default) for asynchronous
  45  * with frame dropping, -1 for asynchronous without frame dropping, 0 to disable (synchronous)
  46  * \properties \em test_card the name of a resource to use as the test card, defaults to
  47  * environment variable MLT_TEST_CARD. If undefined, the hard-coded default test card is
  48  * white silence. A test card is what appears when nothing is produced.
  49  * \event \em consumer-frame-show Subclass implementations should fire this.
  50  * \event \em consumer-frame-render The abstract class fires this.
  51  * \event \em consumer-stopped
  52  * \properties \em fps video frames per second as floating point (read only)
  53  * \properties \em frame_rate_num the numerator of the video frame rate, overrides \p mlt_profile_s
  54  * \properties \em frame_rate_den the denominator of the video frame rate, overrides \p mlt_profile_s
  55  * \properties \em width the horizontal video resolution, overrides \p mlt_profile_s
  56  * \properties \em height the vertical video resolution, overrides \p mlt_profile_s
  57  * \properties \em progressive a flag that indicates if the video is interlaced
  58  * or progressive, overrides \p mlt_profile_s
  59  * \properties \em aspect_ratio the video sample (pixel) aspect ratio as floating point (read only)
  60  * \properties \em sample_aspect_num the numerator of the sample aspect ratio, overrides \p mlt_profile_s
  61  * \properties \em sample_aspect_den the denominator of the sample aspect ratio, overrides \p mlt_profile_s
  62  * \properties \em display_ratio the video frame aspect ratio as floating point (read only)
  63  * \properties \em display_aspect_num the numerator of the video frame aspect ratio, overrides \p mlt_profile_s
  64  * \properties \em display_aspect_den the denominator of the video frame aspect ratio, overrides \p mlt_profile_s
  65  *
  66  */
  67
  68 struct mlt_consumer_s
  69 {
  70         /** A consumer is a service. */
  71         struct mlt_service_s parent;
  72
  73         /** Start the consumer to pull frames (virtual function).
  74          *
  75          * \param mlt_consumer a consumer
  76          * \return true if there was an error
  77          */
  78         int ( *start )( mlt_consumer );
  79
  80         /** Stop the consumer (virtual function).
  81          *
  82          * \param mlt_consumer a consumer
  83          * \return true if there was an error
  84          */
  85         int ( *stop )( mlt_consumer );
  86
  87         /** Get whether the consumer is running or stopped (virtual function).
  88          *
  89          * \param mlt_consumer a consumer
  90          * \return true if the consumer is stopped
  91          */
  92         int ( *is_stopped )( mlt_consumer );
  93
  94         /** The destructor virtual function
  95          *
  96          * \param mlt_consumer a consumer
  97          */
  98         void ( *close )( mlt_consumer );
  99
 100         void *local; /**< \private instance object */
 101         void *child; /**< \private the object of a subclass */
 102
 103         int real_time;
 104         int ahead;
 105         mlt_image_format format;
 106         mlt_deque queue;
 107         pthread_t ahead_thread;
 108         pthread_mutex_t mutex;
 109         pthread_cond_t cond;
 110         pthread_mutex_t put_mutex;
 111         pthread_cond_t put_cond;
 112         mlt_frame put;
 113         int put_active;
 114         mlt_event event_listener;
 115 };
 116
 117 #define MLT_CONSUMER_SERVICE( consumer )        ( &( consumer )->parent )
 118 #define MLT_CONSUMER_PROPERTIES( consumer )     MLT_SERVICE_PROPERTIES( MLT_CONSUMER_SERVICE( consumer ) )
 119
 120 extern int mlt_consumer_init( mlt_consumer self, void *child, mlt_profile profile );
 121 extern mlt_consumer mlt_consumer_new( mlt_profile profile );
 122 extern mlt_service mlt_consumer_service( mlt_consumer self );
 123 extern mlt_properties mlt_consumer_properties( mlt_consumer self );
 124 extern int mlt_consumer_connect( mlt_consumer self, mlt_service producer );
 125 extern int mlt_consumer_start( mlt_consumer self );
 126 extern void mlt_consumer_purge( mlt_consumer self );
 127 extern int mlt_consumer_put_frame( mlt_consumer self, mlt_frame frame );
 128 extern mlt_frame mlt_consumer_get_frame( mlt_consumer self );
 129 extern mlt_frame mlt_consumer_rt_frame( mlt_consumer self );
 130 extern int mlt_consumer_stop( mlt_consumer self );
 131 extern int mlt_consumer_is_stopped( mlt_consumer self );
 132 extern void mlt_consumer_stopped( mlt_consumer self );
 133 extern void mlt_consumer_close( mlt_consumer );
 134
 135 #endif