include/vlc_picture_pool.h

   1 /*****************************************************************************
   2  * vlc_picture_pool.h: picture pool definitions
   3  *****************************************************************************
   4  * Copyright (C) 2009 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program 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
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifndef VLC_PICTURE_POOL_H
  25 #define VLC_PICTURE_POOL_H 1
  26
  27 /**
  28  * \file
  29  * This file defines picture pool structures and functions in vlc
  30  */
  31
  32 #include <vlc_picture.h>
  33
  34 /**
  35  * Picture pool handle
  36  *
  37  * XXX it is not thread safe, all pool manipulations and picture_Release
  38  * must be properly locked if needed.
  39  */
  40 typedef struct picture_pool_t picture_pool_t;
  41
  42 /**
  43  * Picture pool configuration
  44  */
  45 typedef struct {
  46     int       picture_count;
  47     picture_t **picture;
  48
  49     int       (*lock)(picture_t *);
  50     void      (*unlock)(picture_t *);
  51 } picture_pool_configuration_t;
  52
  53 /**
  54  * It creates a picture_pool_t wrapping the given configuration.
  55  *
  56  * It avoids useless picture creations/destructions.
  57  * The given picture must not have a reference count greater than 1.
  58  * The pool takes ownership of the picture and MUST not be used directly.
  59  * When deleted, the pool will release the pictures using picture_Release.
  60  * If defined, picture_pool_configuration_t::lock will be called before
  61  * a picture is used, and picture_pool_configuration_t::unlock will be called
  62  * as soon as a picture is unused. They are allowed to modify picture_t::p and
  63  * access picture_t::p_sys.
  64  */
  65 VLC_EXPORT( picture_pool_t *, picture_pool_NewExtended, ( const picture_pool_configuration_t * ) LIBVLC_USED );
  66
  67 /**
  68  * It creates a picture_pool_t wrapping the given arrays of picture.
  69  *
  70  * It is provided as convenience.
  71  */
  72 VLC_EXPORT( picture_pool_t *, picture_pool_New, ( int picture_count, picture_t *picture[] ) LIBVLC_USED );
  73
  74 /**
  75  * It creates a picture_pool_t creating images using the given format.
  76  *
  77  * Provided for convenience.
  78  */
  79 VLC_EXPORT( picture_pool_t *, picture_pool_NewFromFormat, ( const video_format_t *, int picture_count ) LIBVLC_USED );
  80
  81 /**
  82  * It destroys a pool created by picture_pool_New.
  83  *
  84  * All pictures must already be released to the pool. The pool will then
  85  * released them.
  86  */
  87 VLC_EXPORT( void, picture_pool_Delete, ( picture_pool_t * ) );
  88
  89 /**
  90  * It retreives a picture_t from a pool.
  91  *
  92  * The picture must be release by using picture_Release.
  93  */
  94 VLC_EXPORT( picture_t *, picture_pool_Get, ( picture_pool_t * ) LIBVLC_USED );
  95
  96 /**
  97  * It forces the next picture_pool_Get to return a picture even if no
  98  * pictures are free.
  99  *
 100  * If b_reset is true, all pictures will be marked as free.
 101  *
 102  * It does it by releasing itself the oldest used picture if none is
 103  * available.
 104  * XXX it should be used with great care, the only reason you may need
 105  * it is to workaround a bug.
 106  */
 107 VLC_EXPORT( void, picture_pool_NonEmpty, ( picture_pool_t *, bool reset ) );
 108
 109 /**
 110  * It reserves picture_count pictures from the given pool and returns
 111  * a new pool with thoses pictures.
 112  *
 113  * The master pool must be full.
 114  * The returned pool must be deleted before the master pool.
 115  * When deleted, all pictures return to the master pool.
 116  */
 117 VLC_EXPORT( picture_pool_t *, picture_pool_Reserve, (picture_pool_t *, int picture_count) LIBVLC_USED );
 118
 119 /**
 120  * It returns the size of the given pool.
 121  */
 122 VLC_EXPORT( int, picture_pool_GetSize, (picture_pool_t *) );
 123
 124
 125 #endif /* VLC_PICTURE_POOL_H */
 126