modules/video_filter/opencv_example.cpp

   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) 2006-2012 VLC authors and VideoLAN
   7  * Copyright (C) 2012 Edward Wang
   8  *
   9  * Authors: Dugal Harris <dugalh@protoclea.co.za>
  10  *          Edward Wang <edward.c.wang@compdigitec.com>
  11  *
  12  * This program is free software; you can redistribute it and/or modify it
  13  * under the terms of the GNU Lesser General Public License as published by
  14  * the Free Software Foundation; either version 2.1 of the License, or
  15  * (at your option) any later version.
  16  *
  17  * This program is distributed in the hope that it will be useful,
  18  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  19  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  20  * GNU Lesser General Public License for more details.
  21  *
  22  * You should have received a copy of the GNU Lesser General Public License
  23  * along with this program; if not, write to the Free Software Foundation,
  24  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  25  *****************************************************************************/
  26
  27 /*****************************************************************************
  28  * Preamble
  29  *****************************************************************************/
  30
  31 #ifdef HAVE_CONFIG_H
  32 # include "config.h"
  33 #endif
  34
  35 #include <vlc_common.h>
  36 #include <vlc_plugin.h>
  37 #include <vlc_filter.h>
  38 #include <vlc_picture.h>
  39 #include <vlc_vout.h>
  40 #include <vlc_image.h>
  41 #include "filter_event_info.h"
  42
  43 #include <opencv2/core/core_c.h>
  44 #include <opencv2/core/core.hpp>
  45 #include <opencv2/imgproc/imgproc_c.h>
  46 #include <opencv2/imgproc/imgproc.hpp>
  47 #include <opencv2/objdetect/objdetect.hpp>
  48
  49 /*****************************************************************************
  50  * filter_sys_t : filter descriptor
  51  *****************************************************************************/
  52 struct filter_sys_t
  53 {
  54     CvMemStorage* p_storage;
  55     CvHaarClassifierCascade* p_cascade;
  56     video_filter_event_info_t event_info;
  57     int i_id;
  58 };
  59
  60 /****************************************************************************
  61  * Local prototypes
  62  ****************************************************************************/
  63 static int  OpenFilter ( vlc_object_t * );
  64 static void CloseFilter( vlc_object_t * );
  65
  66 static picture_t *Filter( filter_t *, picture_t * );
  67
  68 /*****************************************************************************
  69  * Module descriptor
  70  *****************************************************************************/
  71 vlc_module_begin ()
  72     set_description( N_("OpenCV face detection example filter") )
  73     set_shortname( N_( "OpenCV example" ))
  74     set_capability( "opencv internal filter", 1 )
  75     add_shortcut( "opencv_example" )
  76
  77     set_category( CAT_VIDEO )
  78     set_subcategory( SUBCAT_VIDEO_VFILTER )
  79     set_callbacks( OpenFilter, CloseFilter )
  80
  81     add_string( "opencv-haarcascade-file", "c:\\haarcascade_frontalface_alt.xml",
  82                           N_("Haar cascade filename"),
  83                           N_("Name of XML file containing Haar cascade description"), false);
  84 vlc_module_end ()
  85
  86 /*****************************************************************************
  87  * OpenFilter: probe the filter and return score
  88  *****************************************************************************/
  89 static int OpenFilter( vlc_object_t *p_this )
  90 {
  91     filter_t *p_filter = (filter_t*)p_this;
  92     filter_sys_t *p_sys;
  93
  94     /* Allocate the memory needed to store the decoder's structure */
  95     if( ( p_filter->p_sys = p_sys =
  96           (filter_sys_t *)malloc(sizeof(filter_sys_t)) ) == NULL )
  97     {
  98         return VLC_ENOMEM;
  99     }
 100
 101     //init the video_filter_event_info_t struct
 102     p_sys->event_info.i_region_size = 0;
 103     p_sys->event_info.p_region = NULL;
 104     p_sys->i_id = 0;
 105
 106     p_filter->pf_video_filter = Filter;
 107
 108     //create the VIDEO_FILTER_EVENT_VARIABLE
 109     vlc_value_t val;
 110     if (var_Create( p_filter->obj.libvlc, VIDEO_FILTER_EVENT_VARIABLE, VLC_VAR_ADDRESS | VLC_VAR_DOINHERIT ) != VLC_SUCCESS)
 111         msg_Err( p_filter, "Could not create %s", VIDEO_FILTER_EVENT_VARIABLE);
 112
 113     val.p_address = &(p_sys->event_info);
 114     if (var_Set( p_filter->obj.libvlc, VIDEO_FILTER_EVENT_VARIABLE, val )!=VLC_SUCCESS)
 115         msg_Err( p_filter, "Could not set %s", VIDEO_FILTER_EVENT_VARIABLE);
 116
 117     //OpenCV init specific to this example
 118     char* filename = var_InheritString( p_filter, "opencv-haarcascade-file" );
 119     p_sys->p_cascade = (CvHaarClassifierCascade*)cvLoad( filename, 0, 0, 0 );
 120     p_sys->p_storage = cvCreateMemStorage(0);
 121     free( filename );
 122
 123     return VLC_SUCCESS;
 124 }
 125
 126 /*****************************************************************************
 127  * CloseFilter: clean up the filter
 128  *****************************************************************************/
 129 static void CloseFilter( 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     if( p_sys->p_cascade )
 135         cvReleaseHaarClassifierCascade( &p_sys->p_cascade );
 136
 137     if( p_sys->p_storage )
 138         cvReleaseMemStorage( &p_sys->p_storage );
 139
 140     free( p_sys->event_info.p_region );
 141     free( p_sys );
 142
 143     var_Destroy( p_filter->obj.libvlc, VIDEO_FILTER_EVENT_VARIABLE);
 144 }
 145
 146 /****************************************************************************
 147  * Filter: Check for faces and raises an event when one is found.
 148  ****************************************************************************/
 149 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 150 {
 151     IplImage** p_img = NULL;
 152     CvPoint pt1, pt2;
 153     int scale = 1;
 154     filter_sys_t *p_sys = p_filter->p_sys;
 155
 156     if ((!p_pic) )
 157     {
 158         msg_Err( p_filter, "no image array" );
 159         return NULL;
 160     }
 161     //(hack) cast the picture_t to array of IplImage*
 162     p_img = (IplImage**) p_pic;
 163
 164     //check the image array for validity
 165     if ((!p_img[0]))    //1st plane is 'I' i.e. greyscale
 166     {
 167         msg_Err( p_filter, "no image" );
 168         return NULL;
 169     }
 170
 171     //perform face detection
 172     cvClearMemStorage(p_sys->p_storage);
 173     if( p_sys->p_cascade )
 174     {
 175         //we should make some of these params config variables
 176         CvSeq *faces = cvHaarDetectObjects( p_img[0], p_sys->p_cascade,
 177                                             p_sys->p_storage, 1.15, 5,
 178                                             CV_HAAR_DO_CANNY_PRUNING,
 179                                             cvSize(20, 20) );
 180         //create the video_filter_region_info_t struct
 181         if (faces && (faces->total > 0))
 182         {
 183             //msg_Dbg( p_filter, "Found %d face(s)", faces->total );
 184             free( p_sys->event_info.p_region );
 185             p_sys->event_info.p_region = (video_filter_region_info_t*)
 186                     calloc( faces->total, sizeof(video_filter_region_info_t));
 187             if( !p_sys->event_info.p_region )
 188                 return NULL;
 189             p_sys->event_info.i_region_size = faces->total;
 190         }
 191
 192         //populate the video_filter_region_info_t struct
 193         for( int i = 0; i < (faces ? faces->total : 0); i++ )
 194         {
 195             CvRect *r = (CvRect*)cvGetSeqElem( faces, i );
 196             pt1.x = r->x*scale;
 197             pt2.x = (r->x+r->width)*scale;
 198             pt1.y = r->y*scale;
 199             pt2.y = (r->y+r->height)*scale;
 200             cvRectangle( p_img[0], pt1, pt2, CV_RGB(0,0,0), 3, 8, 0 );
 201
 202             *(CvRect*)(&(p_sys->event_info.p_region[i])) = *r;
 203             p_sys->event_info.p_region[i].i_id = p_sys->i_id++;
 204             p_sys->event_info.p_region[i].p_description = "Face Detected";
 205         }
 206
 207         if (faces && (faces->total > 0))    //raise the video filter event
 208             var_TriggerCallback( p_filter->obj.libvlc, VIDEO_FILTER_EVENT_VARIABLE );
 209     }
 210     else
 211         msg_Err( p_filter, "No cascade - is opencv-haarcascade-file valid?" );
 212
 213     return p_pic;
 214 }
 215