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         change_safe();
  71 vlc_module_end();
  72
  73 static const char *ppsz_filter_options[] = {
  74     "mask", NULL
  75 };
  76
  77 struct filter_sys_t
  78 {
  79     picture_t *p_mask;
  80     vlc_mutex_t mask_lock;
  81 };
  82
  83 static int Create( vlc_object_t *p_this )
  84 {
  85     filter_t *p_filter = (filter_t *)p_this;
  86     filter_sys_t *p_sys;
  87     char *psz_string;
  88
  89     if( p_filter->fmt_in.video.i_chroma != VLC_FOURCC('Y','U','V','A') )
  90     {
  91         msg_Err( p_filter,
  92                  "Unsupported input chroma \"%4s\". "
  93                  "Alphamask can only use \"YUVA\".",
  94                  (char*)&p_filter->fmt_in.video.i_chroma );
  95         return VLC_EGENERIC;
  96     }
  97
  98     /* Allocate structure */
  99     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 100     if( p_filter->p_sys == NULL )
 101     {
 102         msg_Err( p_filter, "out of memory" );
 103         return VLC_ENOMEM;
 104     }
 105     p_sys = p_filter->p_sys;
 106
 107     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 108                        p_filter->p_cfg );
 109
 110     vlc_mutex_init( p_filter, &p_sys->mask_lock );
 111     psz_string =
 112         var_CreateGetStringCommand( p_filter, CFG_PREFIX "mask" );
 113     var_AddCallback( p_filter, CFG_PREFIX "mask", MaskCallback,
 114                      p_filter );
 115     p_sys->p_mask = NULL;
 116     if( psz_string && *psz_string )
 117     {
 118         LoadMask( p_filter, psz_string );
 119         if( !p_sys->p_mask )
 120             msg_Err( p_filter, "Error while loading mask (%s).",
 121                      psz_string );
 122     }
 123     free( psz_string );
 124
 125     p_filter->pf_video_filter = Filter;
 126
 127     return VLC_SUCCESS;
 128 }
 129
 130 static void Destroy( vlc_object_t *p_this )
 131 {
 132     filter_t *p_filter = (filter_t *)p_this;
 133     filter_sys_t *p_sys = p_filter->p_sys;
 134
 135     vlc_mutex_destroy( &p_sys->mask_lock );
 136     if( p_filter->p_sys->p_mask )
 137         p_filter->p_sys->p_mask->pf_release( p_filter->p_sys->p_mask );
 138
 139     free( p_filter->p_sys );
 140 }
 141
 142 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 143 {
 144     filter_sys_t *p_sys = p_filter->p_sys;
 145
 146     vlc_mutex_lock( &p_sys->mask_lock );
 147     plane_t *p_mask = p_sys->p_mask->p+A_PLANE;
 148     plane_t *p_apic = p_pic->p+A_PLANE;
 149     if(    p_mask->i_visible_pitch
 150         != p_apic->i_visible_pitch
 151         || p_mask->i_visible_lines
 152         != p_apic->i_visible_lines )
 153     {
 154         msg_Warn( p_filter,
 155                   "Mask size (%d x %d) and image size (%d x %d) "
 156                   "don't match. The mask will not be applied.",
 157                   p_mask->i_visible_pitch,
 158                   p_mask->i_visible_lines,
 159                   p_apic->i_visible_pitch,
 160                   p_apic->i_visible_lines );
 161     }
 162     else
 163     {
 164         if( p_mask->i_pitch != p_apic->i_pitch
 165         ||  p_mask->i_lines != p_apic->i_lines )
 166         {
 167             /* visible plane sizes match ... but not the underlying
 168              * buffer. I'm not sure that this can happen,
 169              * but better safe than sorry. */
 170             int i_line;
 171             int i_lines = p_mask->i_visible_lines;
 172             uint8_t *p_src = p_mask->p_pixels;
 173             uint8_t *p_dst = p_apic->p_pixels;
 174             int i_src_pitch = p_mask->i_pitch;
 175             int i_dst_pitch = p_apic->i_pitch;
 176             int i_visible_pitch = p_mask->i_visible_pitch;
 177             for( i_line = 0; i_line < i_lines; i_line++,
 178                  p_src += i_src_pitch, p_dst += i_dst_pitch )
 179             {
 180                 p_filter->p_libvlc->pf_memcpy(
 181                     p_dst, p_src, i_visible_pitch );
 182             }
 183         }
 184         else
 185         {
 186             /* plane sizes match */
 187             p_filter->p_libvlc->pf_memcpy(
 188                 p_apic->p_pixels, p_mask->p_pixels,
 189                 p_mask->i_pitch * p_mask->i_lines );
 190         }
 191     }
 192     vlc_mutex_unlock( &p_sys->mask_lock );
 193     return p_pic;
 194 }
 195
 196 /* copied from video_filters/erase.c . Gruik ? */
 197 static void LoadMask( filter_t *p_filter, const char *psz_filename )
 198 {
 199     image_handler_t *p_image;
 200     video_format_t fmt_in, fmt_out;
 201     memset( &fmt_in, 0, sizeof( video_format_t ) );
 202     memset( &fmt_out, 0, sizeof( video_format_t ) );
 203     fmt_out.i_chroma = VLC_FOURCC('Y','U','V','A');
 204     if( p_filter->p_sys->p_mask )
 205         p_filter->p_sys->p_mask->pf_release( p_filter->p_sys->p_mask );
 206     p_image = image_HandlerCreate( p_filter );
 207     p_filter->p_sys->p_mask =
 208         image_ReadUrl( p_image, psz_filename, &fmt_in, &fmt_out );
 209     image_HandlerDelete( p_image );
 210 }
 211
 212 /*****************************************************************************
 213 * Callback to update params on the fly
 214 *****************************************************************************/
 215 static int MaskCallback( vlc_object_t *p_this, char const *psz_var,
 216                          vlc_value_t oldval, vlc_value_t newval,
 217                          void *p_data )
 218 {
 219     filter_t *p_filter = (filter_t *)p_data;
 220     filter_sys_t *p_sys = p_filter->p_sys;
 221     int i_ret = VLC_SUCCESS;
 222
 223 #define VAR_IS( a ) !strcmp( psz_var, CFG_PREFIX a )
 224     if( VAR_IS( "mask" ) )
 225     {
 226         vlc_mutex_lock( &p_sys->mask_lock );
 227         if( newval.psz_string && *newval.psz_string )
 228         {
 229             LoadMask( p_filter, newval.psz_string );
 230             if( !p_sys->p_mask )
 231             {
 232                 msg_Err( p_filter, "Error while loading mask (%s).",
 233                          newval.psz_string );
 234                 i_ret = VLC_EGENERIC;
 235             }
 236         }
 237         else if( p_sys->p_mask )
 238         {
 239             p_sys->p_mask->pf_release( p_sys->p_mask );
 240             p_sys->p_mask = NULL;
 241         }
 242         vlc_mutex_unlock( &p_sys->mask_lock );
 243     }
 244 #undef VAR_IS
 245
 246     return i_ret;
 247 }