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: invert.c 18062 2006-11-26 14:20:34Z zorglub $
   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 #include <vlc/vlc.h>
  29 #include <vlc_vout.h>
  30
  31 #include <vlc_image.h>
  32 #include <vlc_filter.h>
  33
  34 #define ALPHAMASK_HELP N_( \
  35     "Use an image's alpha channel as a transparency mask." )
  36
  37 #define MASK_TEXT N_("Transparency mask")
  38 #define MASK_LONGTEXT N_( \
  39     "Alpha blending transparency mask. Use's a png alpha channel.")
  40
  41 #define CFG_PREFIX "alphamask-"
  42
  43 /*****************************************************************************
  44  * Local prototypes
  45  *****************************************************************************/
  46 static int  Create      ( vlc_object_t * );
  47 static void Destroy     ( vlc_object_t * );
  48
  49 static picture_t *Filter( filter_t *, picture_t * );
  50 static void LoadMask( filter_t *, const char * );
  51 static int MaskCallback( vlc_object_t *, char const *,
  52                          vlc_value_t, vlc_value_t, void * );
  53
  54 /*****************************************************************************
  55  * Module descriptor
  56  *****************************************************************************/
  57 vlc_module_begin();
  58     set_description( _("Alpha mask video filter") );
  59     set_shortname( _("Alpha mask" ));
  60     set_help( ALPHAMASK_HELP );
  61     set_category( CAT_VIDEO );
  62     set_subcategory( SUBCAT_VIDEO_VFILTER );
  63     set_capability( "video filter2", 0 );
  64     add_shortcut( "alphamask" );
  65     add_shortcut( "mask" );
  66     set_callbacks( Create, Destroy );
  67
  68     add_string( CFG_PREFIX "mask", NULL, NULL, MASK_TEXT,
  69                 MASK_LONGTEXT, VLC_FALSE );
  70 vlc_module_end();
  71
  72 static const char *ppsz_filter_options[] = {
  73     "mask", NULL
  74 };
  75
  76 struct filter_sys_t
  77 {
  78     picture_t *p_mask;
  79     vlc_mutex_t mask_lock;
  80 };
  81
  82 static int Create( vlc_object_t *p_this )
  83 {
  84     filter_t *p_filter = (filter_t *)p_this;
  85     filter_sys_t *p_sys;
  86     char *psz_string;
  87
  88     if( p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','A') )
  89     {
  90         msg_Err( p_filter,
  91                  "Unsupported input chroma \"%4s\". "
  92                  "Alphamask can only use \"YUVA\".",
  93                  (char*)&p_filter->fmt_in.video.i_chroma );
  94         return VLC_EGENERIC;
  95     }
  96
  97     /* Allocate structure */
  98     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
  99     if( p_filter->p_sys == NULL )
 100     {
 101         msg_Err( p_filter, "out of memory" );
 102         return VLC_ENOMEM;
 103     }
 104     p_sys = p_filter->p_sys;
 105
 106     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 107                        p_filter->p_cfg );
 108
 109     vlc_mutex_init( p_filter, &p_sys->mask_lock );
 110     psz_string =
 111         var_CreateGetStringCommand( p_filter, CFG_PREFIX "mask" );
 112     var_AddCallback( p_filter, CFG_PREFIX "mask", MaskCallback,
 113                      p_filter );
 114     p_sys->p_mask = NULL;
 115     if( psz_string && *psz_string )
 116     {
 117         LoadMask( p_filter, psz_string );
 118         if( !p_sys->p_mask )
 119             msg_Err( p_filter, "Error while loading mask (%s).",
 120                      psz_string );
 121     }
 122     free( psz_string );
 123
 124     p_filter->pf_video_filter = Filter;
 125
 126     return VLC_SUCCESS;
 127 }
 128
 129 static void Destroy( vlc_object_t *p_this )
 130 {
 131     filter_t *p_filter = (filter_t *)p_this;
 132     filter_sys_t *p_sys = p_filter->p_sys;
 133
 134     vlc_mutex_destroy( &p_sys->mask_lock );
 135     if( p_filter->p_sys->p_mask )
 136         p_filter->p_sys->p_mask->pf_release( p_filter->p_sys->p_mask );
 137
 138     free( p_filter->p_sys );
 139 }
 140
 141 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 142 {
 143     filter_sys_t *p_sys = p_filter->p_sys;
 144
 145     vlc_mutex_lock( &p_sys->mask_lock );
 146     plane_t *p_mask = p_sys->p_mask->p+A_PLANE;
 147     plane_t *p_apic = p_pic->p+A_PLANE;
 148     if(    p_mask->i_visible_pitch
 149         != p_apic->i_visible_pitch
 150         || p_mask->i_visible_lines
 151         != p_apic->i_visible_lines )
 152     {
 153         msg_Warn( p_filter,
 154                   "Mask size (%d x %d) and image size (%d x %d) "
 155                   "don't match. The mask will not be applied.",
 156                   p_mask->i_visible_pitch,
 157                   p_mask->i_visible_lines,
 158                   p_apic->i_visible_pitch,
 159                   p_apic->i_visible_lines );
 160     }
 161     else
 162     {
 163         if( p_mask->i_pitch != p_apic->i_pitch
 164         ||  p_mask->i_lines != p_apic->i_lines )
 165         {
 166             /* visible plane sizes match ... but not the underlying
 167              * buffer. I'm not sure that this can happen,
 168              * but better safe than sorry. */
 169             int i_line;
 170             int i_lines = p_mask->i_visible_lines;
 171             uint8_t *p_src = p_mask->p_pixels;
 172             uint8_t *p_dst = p_apic->p_pixels;
 173             int i_src_pitch = p_mask->i_pitch;
 174             int i_dst_pitch = p_apic->i_pitch;
 175             int i_visible_pitch = p_mask->i_visible_pitch;
 176             for( i_line = 0; i_line < i_lines; i_line++,
 177                  p_src += i_src_pitch, p_dst += i_dst_pitch )
 178             {
 179                 p_filter->p_libvlc->pf_memcpy(
 180                     p_dst, p_src, i_visible_pitch );
 181             }
 182         }
 183         else
 184         {
 185             /* plane sizes match */
 186             p_filter->p_libvlc->pf_memcpy(
 187                 p_apic->p_pixels, p_mask->p_pixels,
 188                 p_mask->i_pitch * p_mask->i_lines );
 189         }
 190     }
 191     vlc_mutex_unlock( &p_sys->mask_lock );
 192     return p_pic;
 193 }
 194
 195 /* copied from video_filters/erase.c . Gruik ? */
 196 static void LoadMask( filter_t *p_filter, const char *psz_filename )
 197 {
 198     image_handler_t *p_image;
 199     video_format_t fmt_in, fmt_out;
 200     memset( &fmt_in, 0, sizeof( video_format_t ) );
 201     memset( &fmt_out, 0, sizeof( video_format_t ) );
 202     fmt_out.i_chroma = VLC_FOURCC('Y','U','V','A');
 203     if( p_filter->p_sys->p_mask )
 204         p_filter->p_sys->p_mask->pf_release( p_filter->p_sys->p_mask );
 205     p_image = image_HandlerCreate( p_filter );
 206     p_filter->p_sys->p_mask =
 207         image_ReadUrl( p_image, psz_filename, &fmt_in, &fmt_out );
 208     image_HandlerDelete( p_image );
 209 }
 210
 211 /*****************************************************************************
 212 * Callback to update params on the fly
 213 *****************************************************************************/
 214 static int MaskCallback( vlc_object_t *p_this, char const *psz_var,
 215                          vlc_value_t oldval, vlc_value_t newval,
 216                          void *p_data )
 217 {
 218     filter_t *p_filter = (filter_t *)p_data;
 219     filter_sys_t *p_sys = p_filter->p_sys;
 220     int i_ret = VLC_SUCCESS;
 221
 222 #define VAR_IS( a ) !strcmp( psz_var, CFG_PREFIX a )
 223     if( VAR_IS( "mask" ) )
 224     {
 225         vlc_mutex_lock( &p_sys->mask_lock );
 226         if( newval.psz_string && *newval.psz_string )
 227         {
 228             LoadMask( p_filter, newval.psz_string );
 229             if( !p_sys->p_mask )
 230             {
 231                 msg_Err( p_filter, "Error while loading mask (%s).",
 232                          newval.psz_string );
 233                 i_ret = VLC_EGENERIC;
 234             }
 235         }
 236         else if( p_sys->p_mask )
 237         {
 238             p_sys->p_mask->pf_release( p_sys->p_mask );
 239             p_sys->p_mask = NULL;
 240         }
 241         vlc_mutex_unlock( &p_sys->mask_lock );
 242     }
 243 #undef VAR_IS
 244
 245     return i_ret;
 246 }