git.sesse.net Git - vlc/blob - modules/video_filter/alphamask.c

   1 /*****************************************************************************
   2  * alphamask.c : Alpha layer mask video filter for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2007 the VideoLAN team
   5  * $Id$
   6  *
   7  * Authors: Antoine Cellerier <dionoea at videolan tod 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 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_vout.h>
  35
  36 #include <vlc_image.h>
  37 #include <vlc_filter.h>
  38
  39 #define ALPHAMASK_HELP N_( \
  40     "Use an image's alpha channel as a transparency mask." )
  41
  42 #define MASK_TEXT N_("Transparency mask")
  43 #define MASK_LONGTEXT N_( \
  44     "Alpha blending transparency mask. Uses a png alpha channel.")
  45
  46 #define CFG_PREFIX "alphamask-"
  47
  48 /*****************************************************************************
  49  * Local prototypes
  50  *****************************************************************************/
  51 static int  Create      ( vlc_object_t * );
  52 static void Destroy     ( vlc_object_t * );
  53
  54 static picture_t *Filter( filter_t *, picture_t * );
  55 static void LoadMask( filter_t *, const char * );
  56 static int MaskCallback( vlc_object_t *, char const *,
  57                          vlc_value_t, vlc_value_t, void * );
  58
  59 /*****************************************************************************
  60  * Module descriptor
  61  *****************************************************************************/
  62 vlc_module_begin ()
  63     set_description( N_("Alpha mask video filter") )
  64     set_shortname( N_("Alpha mask" ))
  65     set_help( ALPHAMASK_HELP )
  66     set_category( CAT_VIDEO )
  67     set_subcategory( SUBCAT_VIDEO_VFILTER )
  68     set_capability( "video filter2", 0 )
  69     add_shortcut( "alphamask" )
  70     add_shortcut( "mask" )
  71     set_callbacks( Create, Destroy )
  72
  73     add_string( CFG_PREFIX "mask", NULL, NULL, MASK_TEXT,
  74                 MASK_LONGTEXT, false );
  75 vlc_module_end ()
  76
  77 static const char *const ppsz_filter_options[] = {
  78     "mask", NULL
  79 };
  80
  81 struct filter_sys_t
  82 {
  83     picture_t *p_mask;
  84     vlc_mutex_t mask_lock;
  85 };
  86
  87 static int Create( vlc_object_t *p_this )
  88 {
  89     filter_t *p_filter = (filter_t *)p_this;
  90     filter_sys_t *p_sys;
  91     char *psz_string;
  92
  93     if( p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','A') )
  94     {
  95         msg_Err( p_filter,
  96                  "Unsupported input chroma \"%4s\". "
  97                  "Alphamask can only use \"YUVA\".",
  98                  (char*)&p_filter->fmt_in.video.i_chroma );
  99         return VLC_EGENERIC;
 100     }
 101
 102     /* Allocate structure */
 103     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 104     if( p_filter->p_sys == NULL )
 105         return VLC_ENOMEM;
 106     p_sys = p_filter->p_sys;
 107
 108     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 109                        p_filter->p_cfg );
 110
 111     vlc_mutex_init( &p_sys->mask_lock );
 112     psz_string =
 113         var_CreateGetStringCommand( p_filter, CFG_PREFIX "mask" );
 114     var_AddCallback( p_filter, CFG_PREFIX "mask", MaskCallback,
 115                      p_filter );
 116     p_sys->p_mask = NULL;
 117     if( psz_string && *psz_string )
 118     {
 119         LoadMask( p_filter, psz_string );
 120         if( !p_sys->p_mask )
 121             msg_Err( p_filter, "Error while loading mask (%s).",
 122                      psz_string );
 123     }
 124     free( psz_string );
 125
 126     p_filter->pf_video_filter = Filter;
 127
 128     return VLC_SUCCESS;
 129 }
 130
 131 static void Destroy( vlc_object_t *p_this )
 132 {
 133     filter_t *p_filter = (filter_t *)p_this;
 134     filter_sys_t *p_sys = p_filter->p_sys;
 135
 136     vlc_mutex_destroy( &p_sys->mask_lock );
 137     if( p_filter->p_sys->p_mask )
 138         picture_Release( p_filter->p_sys->p_mask );
 139
 140     free( p_filter->p_sys );
 141 }
 142
 143 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 144 {
 145     filter_sys_t *p_sys = p_filter->p_sys;
 146
 147     vlc_mutex_lock( &p_sys->mask_lock );
 148     plane_t *p_mask = p_sys->p_mask->p+A_PLANE;
 149     plane_t *p_apic = p_pic->p+A_PLANE;
 150     if(    p_mask->i_visible_pitch
 151         != p_apic->i_visible_pitch
 152         || p_mask->i_visible_lines
 153         != p_apic->i_visible_lines )
 154     {
 155         msg_Err( p_filter,
 156                   "Mask size (%d x %d) and image size (%d x %d) "
 157                   "don't match. The mask will not be applied.",
 158                   p_mask->i_visible_pitch,
 159                   p_mask->i_visible_lines,
 160                   p_apic->i_visible_pitch,
 161                   p_apic->i_visible_lines );
 162     }
 163     else
 164     {
 165         plane_CopyPixels( p_apic, p_mask );
 166     }
 167     vlc_mutex_unlock( &p_sys->mask_lock );
 168     return p_pic;
 169 }
 170
 171 /* copied from video_filters/erase.c . Gruik ? */
 172 static void LoadMask( filter_t *p_filter, const char *psz_filename )
 173 {
 174     image_handler_t *p_image;
 175     video_format_t fmt_in, fmt_out;
 176     memset( &fmt_in, 0, sizeof( video_format_t ) );
 177     memset( &fmt_out, 0, sizeof( video_format_t ) );
 178     fmt_out.i_chroma = VLC_FOURCC('Y','U','V','A');
 179     if( p_filter->p_sys->p_mask )
 180         picture_Release( p_filter->p_sys->p_mask );
 181     p_image = image_HandlerCreate( p_filter );
 182     p_filter->p_sys->p_mask =
 183         image_ReadUrl( p_image, psz_filename, &fmt_in, &fmt_out );
 184     image_HandlerDelete( p_image );
 185 }
 186
 187 /*****************************************************************************
 188 * Callback to update params on the fly
 189 *****************************************************************************/
 190 static int MaskCallback( vlc_object_t *p_this, char const *psz_var,
 191                          vlc_value_t oldval, vlc_value_t newval,
 192                          void *p_data )
 193 {
 194     VLC_UNUSED(p_this); VLC_UNUSED(oldval);
 195     filter_t *p_filter = (filter_t *)p_data;
 196     filter_sys_t *p_sys = p_filter->p_sys;
 197     int i_ret = VLC_SUCCESS;
 198
 199 #define VAR_IS( a ) !strcmp( psz_var, CFG_PREFIX a )
 200     if( VAR_IS( "mask" ) )
 201     {
 202         vlc_mutex_lock( &p_sys->mask_lock );
 203         if( newval.psz_string && *newval.psz_string )
 204         {
 205             LoadMask( p_filter, newval.psz_string );
 206             if( !p_sys->p_mask )
 207             {
 208                 msg_Err( p_filter, "Error while loading mask (%s).",
 209                          newval.psz_string );
 210                 i_ret = VLC_EGENERIC;
 211             }
 212         }
 213         else if( p_sys->p_mask )
 214         {
 215             picture_Release( p_sys->p_mask );
 216             p_sys->p_mask = NULL;
 217         }
 218         vlc_mutex_unlock( &p_sys->mask_lock );
 219     }
 220 #undef VAR_IS
 221
 222     return i_ret;
 223 }