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 #include <stdlib.h>                                      /* malloc(), free() */
  28 #include <string.h>
  29
  30 #include <vlc/vlc.h>
  31 #include <vlc_vout.h>
  32
  33 #include <vlc_image.h>
  34 #include <vlc_filter.h>
  35
  36 #define ALPHAMASK_HELP N_( \
  37     "Use an image's alpha channel as a transparency mask." )
  38
  39 #define MASK_TEXT N_("Transparency mask")
  40 #define MASK_LONGTEXT N_( \
  41     "Alpha blending transparency mask. Use's a png alpha channel.")
  42
  43 #define CFG_PREFIX "alphamask-"
  44
  45 /*****************************************************************************
  46  * Local prototypes
  47  *****************************************************************************/
  48 static int  Create      ( vlc_object_t * );
  49 static void Destroy     ( vlc_object_t * );
  50
  51 static picture_t *Filter( filter_t *, picture_t * );
  52 static void LoadMask( filter_t *, const char * );
  53 static int MaskCallback( vlc_object_t *, char const *,
  54                          vlc_value_t, vlc_value_t, void * );
  55
  56 /*****************************************************************************
  57  * Module descriptor
  58  *****************************************************************************/
  59 vlc_module_begin();
  60     set_description( _("Alpha mask video filter") );
  61     set_shortname( _("Alpha mask" ));
  62     set_help( ALPHAMASK_HELP );
  63     set_category( CAT_VIDEO );
  64     set_subcategory( SUBCAT_VIDEO_VFILTER );
  65     set_capability( "video filter2", 0 );
  66     add_shortcut( "alphamask" );
  67     add_shortcut( "mask" );
  68     set_callbacks( Create, Destroy );
  69
  70     add_string( CFG_PREFIX "mask", NULL, NULL, MASK_TEXT,
  71                 MASK_LONGTEXT, VLC_FALSE );
  72 vlc_module_end();
  73
  74 static const char *ppsz_filter_options[] = {
  75     "mask", NULL
  76 };
  77
  78 struct filter_sys_t
  79 {
  80     picture_t *p_mask;
  81     vlc_mutex_t mask_lock;
  82 };
  83
  84 static int Create( vlc_object_t *p_this )
  85 {
  86     filter_t *p_filter = (filter_t *)p_this;
  87     filter_sys_t *p_sys;
  88     char *psz_string;
  89
  90     if( p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','A') )
  91     {
  92         msg_Err( p_filter,
  93                  "Unsupported input chroma \"%4s\". "
  94                  "Alphamask can only use \"YUVA\".",
  95                  (char*)&p_filter->fmt_in.video.i_chroma );
  96         return VLC_EGENERIC;
  97     }
  98
  99     /* Allocate structure */
 100     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 101     if( p_filter->p_sys == NULL )
 102     {
 103         msg_Err( p_filter, "out of memory" );
 104         return VLC_ENOMEM;
 105     }
 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_filter, &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         p_filter->p_sys->p_mask->pf_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_Warn( 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         if( p_mask->i_pitch != p_apic->i_pitch
 166         ||  p_mask->i_lines != p_apic->i_lines )
 167         {
 168             /* visible plane sizes match ... but not the underlying
 169              * buffer. I'm not sure that this can happen,
 170              * but better safe than sorry. */
 171             int i_line;
 172             int i_lines = p_mask->i_visible_lines;
 173             uint8_t *p_src = p_mask->p_pixels;
 174             uint8_t *p_dst = p_apic->p_pixels;
 175             int i_src_pitch = p_mask->i_pitch;
 176             int i_dst_pitch = p_apic->i_pitch;
 177             int i_visible_pitch = p_mask->i_visible_pitch;
 178             for( i_line = 0; i_line < i_lines; i_line++,
 179                  p_src += i_src_pitch, p_dst += i_dst_pitch )
 180             {
 181                 p_filter->p_libvlc->pf_memcpy(
 182                     p_dst, p_src, i_visible_pitch );
 183             }
 184         }
 185         else
 186         {
 187             /* plane sizes match */
 188             p_filter->p_libvlc->pf_memcpy(
 189                 p_apic->p_pixels, p_mask->p_pixels,
 190                 p_mask->i_pitch * p_mask->i_lines );
 191         }
 192     }
 193     vlc_mutex_unlock( &p_sys->mask_lock );
 194     return p_pic;
 195 }
 196
 197 /* copied from video_filters/erase.c . Gruik ? */
 198 static void LoadMask( filter_t *p_filter, const char *psz_filename )
 199 {
 200     image_handler_t *p_image;
 201     video_format_t fmt_in, fmt_out;
 202     memset( &fmt_in, 0, sizeof( video_format_t ) );
 203     memset( &fmt_out, 0, sizeof( video_format_t ) );
 204     fmt_out.i_chroma = VLC_FOURCC('Y','U','V','A');
 205     if( p_filter->p_sys->p_mask )
 206         p_filter->p_sys->p_mask->pf_release( p_filter->p_sys->p_mask );
 207     p_image = image_HandlerCreate( p_filter );
 208     p_filter->p_sys->p_mask =
 209         image_ReadUrl( p_image, psz_filename, &fmt_in, &fmt_out );
 210     image_HandlerDelete( p_image );
 211 }
 212
 213 /*****************************************************************************
 214 * Callback to update params on the fly
 215 *****************************************************************************/
 216 static int MaskCallback( vlc_object_t *p_this, char const *psz_var,
 217                          vlc_value_t oldval, vlc_value_t newval,
 218                          void *p_data )
 219 {
 220     filter_t *p_filter = (filter_t *)p_data;
 221     filter_sys_t *p_sys = p_filter->p_sys;
 222     int i_ret = VLC_SUCCESS;
 223
 224 #define VAR_IS( a ) !strcmp( psz_var, CFG_PREFIX a )
 225     if( VAR_IS( "mask" ) )
 226     {
 227         vlc_mutex_lock( &p_sys->mask_lock );
 228         if( newval.psz_string && *newval.psz_string )
 229         {
 230             LoadMask( p_filter, newval.psz_string );
 231             if( !p_sys->p_mask )
 232             {
 233                 msg_Err( p_filter, "Error while loading mask (%s).",
 234                          newval.psz_string );
 235                 i_ret = VLC_EGENERIC;
 236             }
 237         }
 238         else if( p_sys->p_mask )
 239         {
 240             p_sys->p_mask->pf_release( p_sys->p_mask );
 241             p_sys->p_mask = NULL;
 242         }
 243         vlc_mutex_unlock( &p_sys->mask_lock );
 244     }
 245 #undef VAR_IS
 246
 247     return i_ret;
 248 }