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

   1 /*****************************************************************************
   2  * opencv_example.cpp : Example OpenCV internal video filter
   3  * (performs face identification).  Mostly taken from the facedetect.c
   4  * OpenCV sample.
   5  *****************************************************************************
   6  * Copyright (C) 2006 the VideoLAN team
   7  *
   8  * Authors: Dugal Harris <dugalh@protoclea.co.za>
   9  *
  10  * This program is free software; you can redistribute it and/or modify
  11  * it under the terms of the GNU General Public License as published by
  12  * the Free Software Foundation; either version 2 of the License, or
  13  * (at your option) any later version.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18  * GNU General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU General Public License
  21  * along with this program; if not, write to the Free Software
  22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /*****************************************************************************
  26  * Preamble
  27  *****************************************************************************/
  28
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_filter.h>
  36 #include <vlc_vout.h>
  37 #include <vlc_image.h>
  38 #include "filter_event_info.h"
  39
  40 #include <cxcore.h>
  41 #include <cv.h>
  42
  43 /*****************************************************************************
  44  * filter_sys_t : filter descriptor
  45  *****************************************************************************/
  46 struct filter_sys_t
  47 {
  48     CvMemStorage* p_storage;
  49     CvHaarClassifierCascade* p_cascade;
  50     video_filter_event_info_t event_info;
  51     int i_id;
  52 };
  53
  54 /****************************************************************************
  55  * Local prototypes
  56  ****************************************************************************/
  57 static int  OpenFilter ( vlc_object_t * );
  58 static void CloseFilter( vlc_object_t * );
  59
  60 static picture_t *Filter( filter_t *, picture_t * );
  61
  62 /*****************************************************************************
  63  * Module descriptor
  64  *****************************************************************************/
  65 vlc_module_begin ()
  66     set_description( N_("OpenCV face detection example filter") )
  67     set_shortname( N_( "OpenCV example" ))
  68     set_capability( "opencv example", 1 )
  69     add_shortcut( "opencv_example" )
  70
  71     set_category( CAT_VIDEO )
  72     set_subcategory( SUBCAT_VIDEO_VFILTER2 )
  73     set_callbacks( OpenFilter, CloseFilter )
  74
  75     add_string( "opencv-haarcascade-file", "c:\\haarcascade_frontalface_alt.xml", NULL,
  76                           N_("Haar cascade filename"),
  77                           N_("Name of XML file containing Haar cascade description"), false);
  78 vlc_module_end ()
  79
  80 /*****************************************************************************
  81  * OpenFilter: probe the filter and return score
  82  *****************************************************************************/
  83 static int OpenFilter( vlc_object_t *p_this )
  84 {
  85     filter_t *p_filter = (filter_t*)p_this;
  86     filter_sys_t *p_sys;
  87
  88     /* Allocate the memory needed to store the decoder's structure */
  89     if( ( p_filter->p_sys = p_sys =
  90           (filter_sys_t *)malloc(sizeof(filter_sys_t)) ) == NULL )
  91     {
  92         return VLC_ENOMEM;
  93     }
  94
  95     //init the video_filter_event_info_t struct
  96     p_sys->event_info.i_region_size = 0;
  97     p_sys->event_info.p_region = NULL;
  98     p_sys->i_id = 0;
  99
 100     p_filter->pf_video_filter = Filter;
 101
 102     //create the VIDEO_FILTER_EVENT_VARIABLE
 103     vlc_value_t val;
 104     if (var_Create( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE, VLC_VAR_ADDRESS | VLC_VAR_DOINHERIT ) != VLC_SUCCESS)
 105         msg_Err( p_filter, "Could not create %s", VIDEO_FILTER_EVENT_VARIABLE);
 106
 107     val.p_address = &(p_sys->event_info);
 108     if (var_Set( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE, val )!=VLC_SUCCESS)
 109         msg_Err( p_filter, "Could not set %s", VIDEO_FILTER_EVENT_VARIABLE);
 110
 111     //OpenCV init specific to this example
 112     char* filename = var_InheritString( p_filter, "opencv-haarcascade-file" );
 113     p_sys->p_cascade = (CvHaarClassifierCascade*)cvLoad( filename, 0, 0, 0 );
 114     p_sys->p_storage = cvCreateMemStorage(0);
 115     free( filename );
 116
 117     return VLC_SUCCESS;
 118 }
 119
 120 /*****************************************************************************
 121  * CloseFilter: clean up the filter
 122  *****************************************************************************/
 123 static void CloseFilter( vlc_object_t *p_this )
 124 {
 125     filter_t *p_filter = (filter_t*)p_this;
 126     filter_sys_t *p_sys = p_filter->p_sys;
 127
 128     if( p_sys->p_cascade )
 129         cvReleaseHaarClassifierCascade( &p_sys->p_cascade );
 130
 131     if( p_sys->p_storage )
 132         cvReleaseMemStorage( &p_sys->p_storage );
 133
 134     free( p_sys->event_info.p_region );
 135     free( p_sys );
 136
 137     var_Destroy( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE);
 138 }
 139
 140 /****************************************************************************
 141  * Filter: Check for faces and raises an event when one is found.
 142  ****************************************************************************
 143  * p_pic: A picture_t with its p_data_orig member set to an array of
 144  * IplImages (one image for each picture_t plane).
 145  ****************************************************************************/
 146 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 147 {
 148     IplImage** p_img = NULL;
 149     int i_planes = 0;
 150     CvPoint pt1, pt2;
 151     int i, scale = 1;
 152     filter_sys_t *p_sys = p_filter->p_sys;
 153
 154     if ((!p_pic) )
 155     {
 156         msg_Err( p_filter, "no image array" );
 157         return NULL;
 158     }
 159     if (!(p_pic->p_data_orig))
 160     {
 161         msg_Err( p_filter, "no image array" );
 162         return NULL;
 163     }
 164     //(hack) cast the picture_t to array of IplImage*
 165     p_img = (IplImage**) p_pic->p_data_orig;
 166     i_planes = p_pic->i_planes;
 167
 168     //check the image array for validity
 169     if ((!p_img[0]))    //1st plane is 'I' i.e. greyscale
 170     {
 171         msg_Err( p_filter, "no image" );
 172         return NULL;
 173     }
 174     if ((p_pic->format.i_chroma != VLC_CODEC_I420))
 175     {
 176         msg_Err( p_filter, "wrong chroma - use I420" );
 177         return NULL;
 178     }
 179     if (i_planes<1)
 180     {
 181         msg_Err( p_filter, "no image planes" );
 182         return NULL;
 183     }
 184
 185     //perform face detection
 186     cvClearMemStorage(p_sys->p_storage);
 187     if( p_sys->p_cascade )
 188     {
 189         //we should make some of these params config variables
 190         CvSeq *faces = cvHaarDetectObjects( p_img[0], p_sys->p_cascade,
 191                                             p_sys->p_storage, 1.15, 5,
 192                                             CV_HAAR_DO_CANNY_PRUNING,
 193                                             cvSize(20, 20) );
 194         //create the video_filter_region_info_t struct
 195         if (faces && (faces->total > 0))
 196         {
 197             //msg_Dbg( p_filter, "Found %d face(s)", faces->total );
 198             free( p_sys->event_info.p_region );
 199             p_sys->event_info.p_region = (video_filter_region_info_t*)
 200                     calloc( faces->total, sizeof(video_filter_region_info_t));
 201             if( !p_sys->event_info.p_region )
 202                 return NULL;
 203             p_sys->event_info.i_region_size = faces->total;
 204         }
 205
 206         //populate the video_filter_region_info_t struct
 207         for( i = 0; i < (faces ? faces->total : 0); i++ )
 208         {
 209             CvRect *r = (CvRect*)cvGetSeqElem( faces, i );
 210             pt1.x = r->x*scale;
 211             pt2.x = (r->x+r->width)*scale;
 212             pt1.y = r->y*scale;
 213             pt2.y = (r->y+r->height)*scale;
 214             cvRectangle( p_img[0], pt1, pt2, CV_RGB(0,0,0), 3, 8, 0 );
 215
 216             *(CvRect*)(&(p_sys->event_info.p_region[i])) = *r;
 217             p_sys->event_info.p_region[i].i_id = p_sys->i_id++;
 218             p_sys->event_info.p_region[i].p_description = "Face Detected";
 219         }
 220
 221         if (faces && (faces->total > 0))    //raise the video filter event
 222             var_TriggerCallback( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE );
 223     }
 224     else
 225         msg_Err( p_filter, "No cascade - is opencv-haarcascade-file valid?" );
 226
 227     return p_pic;
 228 }
 229