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  *
   5  * Copyright (C) 2003-2008 Ushodaya Enterprises Limited
   6  * \author Charles Yates <charles.yates@pandora.be>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #ifndef _MLT_CONSUMER_H_
  24 #define _MLT_CONSUMER_H_
  25
  26 #include "mlt_service.h"
  27 #include "mlt_events.h"
  28 #include <pthread.h>
  29
  30 /** \brief Consumer abstract service class
  31  *
  32  * A consumer is a service that pulls audio and video from the connected
  33  * producers, filters, and transitions. Typically a consumer is used to
  34  * output audio and/or video to a device, file, or socket.
  35  *
  36  * \extends mlt_service_s
  37  * \properties \em rescale the scaling algorithm to pass on to all scaling
  38  * filters, defaults to "bilinear"
  39  * \properties \em buffer the number of frames to use in the asynchronous
  40  * render thread, defaults to 25
  41  * \properties \em frequency the audio sample rate to use in Hertz, defaults to 48000
  42  * \properties \em channels the number of audio channels to use, defaults to 2
  43  * \properties \em real_time the asynchronous behavior: 1 (default) for asynchronous
  44  * with frame dropping, -1 for asynchronous without frame dropping, 0 to disable (synchronous)
  45  * \properties \em test_card the name of a resource to use as the test card, defaults to
  46  * environment variable MLT_TEST_CARD. If undefined, the hard-coded default test card is
  47  * white silence. A test card is what appears when nothing is produced.
  48  * \event \em consumer-frame-show Subclass implementations should fire this.
  49  * \event \em consumer-frame-render The abstract class fires this.
  50  * \event \em consumer-stopped
  51  * \properties \em fps video frames per second as floating point (read only)
  52  * \properties \em frame_rate_num the numerator of the video frame rate, overrides \p mlt_profile_s
  53  * \properties \em frame_rate_den the denominator of the video frame rate, overrides \p mlt_profile_s
  54  * \properties \em width the horizontal video resolution, overrides \p mlt_profile_s
  55  * \properties \em height the vertical video resolution, overrides \p mlt_profile_s
  56  * \properties \em progressive a flag that indicates if the video is interlaced
  57  * or progressive, overrides \p mlt_profile_s
  58  * \properties \em aspect_ratio the video sample (pixel) aspect ratio as floating point (read only)
  59  * \properties \em sample_aspect_num the numerator of the sample aspect ratio, overrides \p mlt_profile_s
  60  * \properties \em sample_aspect_den the denominator of the sample aspect ratio, overrides \p mlt_profile_s
  61  * \properties \em display_ratio the video frame aspect ratio as floating point (read only)
  62  * \properties \em display_aspect_num the numerator of the video frame aspect ratio, overrides \p mlt_profile_s
  63  * \properties \em display_aspect_den the denominator of the video frame aspect ratio, overrides \p mlt_profile_s
  64  *
  65  */
  66
  67 struct mlt_consumer_s
  68 {
  69         /** A consumer is a service. */
  70         struct mlt_service_s parent;
  71
  72         /** Start the consumer to pull frames (virtual function).
  73          *
  74          * \param mlt_consumer a consumer
  75          * \return true if there was an error
  76          */
  77         int ( *start )( mlt_consumer );
  78
  79         /** Stop the consumer (virtual function).
  80          *
  81          * \param mlt_consumer a consumer
  82          * \return true if there was an error
  83          */
  84         int ( *stop )( mlt_consumer );
  85
  86         /** Get whether the consumer is running or stopped (virtual function).
  87          *
  88          * \param mlt_consumer a consumer
  89          * \return true if the consumer is stopped
  90          */
  91         int ( *is_stopped )( mlt_consumer );
  92
  93         /** The destructor virtual function
  94          *
  95          * \param mlt_consumer a consumer
  96          */
  97         void ( *close )( mlt_consumer );
  98
  99         void *local; /**< \private instance object */
 100         void *child; /**< \private the object of a subclass */
 101
 102         int real_time;
 103         int ahead;
 104         mlt_image_format format;
 105         mlt_deque queue;
 106         pthread_t ahead_thread;
 107         pthread_mutex_t mutex;
 108         pthread_cond_t cond;
 109         pthread_mutex_t put_mutex;
 110         pthread_cond_t put_cond;
 111         mlt_frame put;
 112         int put_active;
 113         mlt_event event_listener;
 114 };
 115
 116 #define MLT_CONSUMER_SERVICE( consumer )        ( &( consumer )->parent )
 117 #define MLT_CONSUMER_PROPERTIES( consumer )     MLT_SERVICE_PROPERTIES( MLT_CONSUMER_SERVICE( consumer ) )
 118
 119 extern int mlt_consumer_init( mlt_consumer self, void *child, mlt_profile profile );
 120 extern mlt_consumer mlt_consumer_new( mlt_profile profile );
 121 extern mlt_service mlt_consumer_service( mlt_consumer self );
 122 extern mlt_properties mlt_consumer_properties( mlt_consumer self );
 123 extern int mlt_consumer_connect( mlt_consumer self, mlt_service producer );
 124 extern int mlt_consumer_start( mlt_consumer self );
 125 extern void mlt_consumer_purge( mlt_consumer self );
 126 extern int mlt_consumer_put_frame( mlt_consumer self, mlt_frame frame );
 127 extern mlt_frame mlt_consumer_get_frame( mlt_consumer self );
 128 extern mlt_frame mlt_consumer_rt_frame( mlt_consumer self );
 129 extern int mlt_consumer_stop( mlt_consumer self );
 130 extern int mlt_consumer_is_stopped( mlt_consumer self );
 131 extern void mlt_consumer_stopped( mlt_consumer self );
 132 extern void mlt_consumer_close( mlt_consumer );
 133
 134 #endif