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
  53 namespace {
  54
  55 struct filter_sys_t
  56 {
  57     CvMemStorage* p_storage;
  58     CvHaarClassifierCascade* p_cascade;
  59     video_filter_event_info_t event_info;
  60     int i_id;
  61 };
  62
  63 } // namespace
  64
  65 /****************************************************************************
  66  * Local prototypes
  67  ****************************************************************************/
  68 static int  OpenFilter ( vlc_object_t * );
  69 static void CloseFilter( filter_t * );
  70
  71 static picture_t *Filter( filter_t *, picture_t * );
  72
  73 /*****************************************************************************
  74  * Module descriptor
  75  *****************************************************************************/
  76 vlc_module_begin ()
  77     set_description( N_("OpenCV face detection example filter") )
  78     set_shortname( N_( "OpenCV example" ))
  79     set_capability( "opencv internal filter", 1 )
  80     add_shortcut( "opencv_example" )
  81
  82     set_category( CAT_VIDEO )
  83     set_subcategory( SUBCAT_VIDEO_VFILTER )
  84     set_callback( OpenFilter )
  85
  86     add_string( "opencv-haarcascade-file", "c:\\haarcascade_frontalface_alt.xml",
  87                           N_("Haar cascade filename"),
  88                           N_("Name of XML file containing Haar cascade description"), false);
  89 vlc_module_end ()
  90
  91 /*****************************************************************************
  92  * OpenFilter: probe the filter and return score
  93  *****************************************************************************/
  94 static int OpenFilter( vlc_object_t *p_this )
  95 {
  96     filter_t *p_filter = (filter_t*)p_this;
  97     filter_sys_t *p_sys;
  98
  99     /* Allocate the memory needed to store the decoder's structure */
 100     if( ( p_filter->p_sys = p_sys =
 101           (filter_sys_t *)malloc(sizeof(filter_sys_t)) ) == NULL )
 102     {
 103         return VLC_ENOMEM;
 104     }
 105
 106     //init the video_filter_event_info_t struct
 107     p_sys->event_info.i_region_size = 0;
 108     p_sys->event_info.p_region = NULL;
 109     p_sys->i_id = 0;
 110
 111     static const struct FilterOperationInitializer {
 112         struct vlc_filter_operations ops {};
 113         FilterOperationInitializer()
 114         {
 115             ops.filter_video = Filter;
 116             ops.close        = CloseFilter;
 117         };
 118     } filter_ops;
 119     p_filter->ops = &filter_ops.ops;
 120
 121     //create the VIDEO_FILTER_EVENT_VARIABLE
 122     vlc_value_t val;
 123     if (var_Create( vlc_object_instance(p_filter), VIDEO_FILTER_EVENT_VARIABLE, VLC_VAR_ADDRESS | VLC_VAR_DOINHERIT ) != VLC_SUCCESS)
 124         msg_Err( p_filter, "Could not create %s", VIDEO_FILTER_EVENT_VARIABLE);
 125
 126     val.p_address = &(p_sys->event_info);
 127     if (var_Set( vlc_object_instance(p_filter), VIDEO_FILTER_EVENT_VARIABLE, val )!=VLC_SUCCESS)
 128         msg_Err( p_filter, "Could not set %s", VIDEO_FILTER_EVENT_VARIABLE);
 129
 130     //OpenCV init specific to this example
 131     char* filename = var_InheritString( p_filter, "opencv-haarcascade-file" );
 132     p_sys->p_cascade = (CvHaarClassifierCascade*)cvLoad( filename, 0, 0, 0 );
 133     p_sys->p_storage = cvCreateMemStorage(0);
 134     free( filename );
 135
 136     return VLC_SUCCESS;
 137 }
 138
 139 /*****************************************************************************
 140  * CloseFilter: clean up the filter
 141  *****************************************************************************/
 142 static void CloseFilter( filter_t *p_filter )
 143 {
 144     filter_sys_t *p_sys = static_cast<filter_sys_t *>(p_filter->p_sys);
 145
 146     if( p_sys->p_cascade )
 147         cvReleaseHaarClassifierCascade( &p_sys->p_cascade );
 148
 149     if( p_sys->p_storage )
 150         cvReleaseMemStorage( &p_sys->p_storage );
 151
 152     free( p_sys->event_info.p_region );
 153     free( p_sys );
 154
 155     var_Destroy( vlc_object_instance(p_filter), VIDEO_FILTER_EVENT_VARIABLE);
 156 }
 157
 158 /****************************************************************************
 159  * Filter: Check for faces and raises an event when one is found.
 160  ****************************************************************************/
 161 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 162 {
 163     IplImage** p_img = NULL;
 164     CvPoint pt1, pt2;
 165     int scale = 1;
 166     filter_sys_t *p_sys = static_cast<filter_sys_t *>(p_filter->p_sys);
 167
 168     if ((!p_pic) )
 169     {
 170         msg_Err( p_filter, "no image array" );
 171         return NULL;
 172     }
 173     //(hack) cast the picture_t to array of IplImage*
 174     p_img = (IplImage**) p_pic;
 175
 176     //check the image array for validity
 177     if ((!p_img[0]))    //1st plane is 'I' i.e. greyscale
 178     {
 179         msg_Err( p_filter, "no image" );
 180         return NULL;
 181     }
 182
 183     //perform face detection
 184     cvClearMemStorage(p_sys->p_storage);
 185     if( p_sys->p_cascade )
 186     {
 187         //we should make some of these params config variables
 188         CvSeq *faces = cvHaarDetectObjects( p_img[0], p_sys->p_cascade,
 189                                             p_sys->p_storage, 1.15, 5,
 190                                             CV_HAAR_DO_CANNY_PRUNING,
 191                                             cvSize(20, 20) );
 192         //create the video_filter_region_info_t struct
 193         if (faces && (faces->total > 0))
 194         {
 195             //msg_Dbg( p_filter, "Found %d face(s)", faces->total );
 196             free( p_sys->event_info.p_region );
 197             p_sys->event_info.p_region = (video_filter_region_info_t*)
 198                     calloc( faces->total, sizeof(video_filter_region_info_t));
 199             if( !p_sys->event_info.p_region )
 200                 return NULL;
 201             p_sys->event_info.i_region_size = faces->total;
 202         }
 203
 204         //populate the video_filter_region_info_t struct
 205         for( int i = 0; i < (faces ? faces->total : 0); i++ )
 206         {
 207             CvRect *r = (CvRect*)cvGetSeqElem( faces, i );
 208             pt1.x = r->x*scale;
 209             pt2.x = (r->x+r->width)*scale;
 210             pt1.y = r->y*scale;
 211             pt2.y = (r->y+r->height)*scale;
 212             cvRectangle( p_img[0], pt1, pt2, CV_RGB(0,0,0), 3, 8, 0 );
 213
 214             *(CvRect*)(&(p_sys->event_info.p_region[i])) = *r;
 215             p_sys->event_info.p_region[i].i_id = p_sys->i_id++;
 216             p_sys->event_info.p_region[i].p_description = "Face Detected";
 217         }
 218
 219         if (faces && (faces->total > 0))    //raise the video filter event
 220             var_TriggerCallback( vlc_object_instance(p_filter), VIDEO_FILTER_EVENT_VARIABLE );
 221     }
 222     else
 223         msg_Err( p_filter, "No cascade - is opencv-haarcascade-file valid?" );
 224
 225     return p_pic;
 226 }