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 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 "filter_common.h"
  38 #include <vlc_image.h>
  39 #include "filter_event_info.h"
  40
  41 #include <cxcore.h>
  42 #include <cv.h>
  43
  44 /*****************************************************************************
  45  * filter_sys_t : filter descriptor
  46  *****************************************************************************/
  47 struct filter_sys_t
  48 {
  49     CvMemStorage* p_storage;
  50     CvHaarClassifierCascade* p_cascade;
  51     video_filter_event_info_t event_info;
  52     int i_id;
  53 };
  54
  55 /****************************************************************************
  56  * Local prototypes
  57  ****************************************************************************/
  58 static int  OpenFilter ( vlc_object_t * );
  59 static void CloseFilter( vlc_object_t * );
  60
  61 static picture_t *Filter( filter_t *, picture_t * );
  62
  63 /*****************************************************************************
  64  * Module descriptor
  65  *****************************************************************************/
  66 vlc_module_begin ()
  67     set_description( N_("OpenCV face detection example filter") )
  68     set_shortname( N_( "OpenCV example" ))
  69     set_capability( "opencv example", 1 )
  70     add_shortcut( "opencv_example" )
  71
  72     set_category( CAT_VIDEO )
  73     set_subcategory( SUBCAT_VIDEO_VFILTER2 )
  74     set_callbacks( OpenFilter, CloseFilter )
  75
  76     add_string( "opencv-haarcascade-file", "c:\\haarcascade_frontalface_alt.xml", NULL,
  77                           N_("Haar cascade filename"),
  78                           N_("Name of XML file containing Haar cascade description"), false);
  79 vlc_module_end ()
  80
  81 /*****************************************************************************
  82  * OpenFilter: probe the filter and return score
  83  *****************************************************************************/
  84 static int OpenFilter( vlc_object_t *p_this )
  85 {
  86     filter_t *p_filter = (filter_t*)p_this;
  87     filter_sys_t *p_sys;
  88
  89     /* Allocate the memory needed to store the decoder's structure */
  90     if( ( p_filter->p_sys = p_sys =
  91           (filter_sys_t *)malloc(sizeof(filter_sys_t)) ) == NULL )
  92     {
  93         return VLC_ENOMEM;
  94     }
  95
  96     //init the video_filter_event_info_t struct
  97     p_sys->event_info.i_region_size = 0;
  98     p_sys->event_info.p_region = NULL;
  99     p_sys->i_id = 0;
 100
 101     p_filter->pf_video_filter = Filter;
 102
 103     //create the VIDEO_FILTER_EVENT_VARIABLE
 104     vlc_value_t val;
 105     if (var_Create( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE, VLC_VAR_ADDRESS | VLC_VAR_DOINHERIT ) != VLC_SUCCESS)
 106         msg_Err( p_filter, "Could not create %s", VIDEO_FILTER_EVENT_VARIABLE);
 107
 108     val.p_address = &(p_sys->event_info);
 109     if (var_Set( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE, val )!=VLC_SUCCESS)
 110         msg_Err( p_filter, "Could not set %s", VIDEO_FILTER_EVENT_VARIABLE);
 111
 112     //OpenCV init specific to this example
 113     char* filename = var_InheritString( p_filter, "opencv-haarcascade-file" );
 114     p_filter->p_sys->p_cascade = (CvHaarClassifierCascade*)cvLoad( filename, 0, 0, 0 );
 115     p_filter->p_sys->p_storage = cvCreateMemStorage(0);
 116     free( filename );
 117
 118     return VLC_SUCCESS;
 119 }
 120
 121 /*****************************************************************************
 122  * CloseFilter: clean up the filter
 123  *****************************************************************************/
 124 static void CloseFilter( vlc_object_t *p_this )
 125 {
 126     filter_t *p_filter = (filter_t*)p_this;
 127     filter_sys_t *p_sys = p_filter->p_sys;
 128
 129     if( p_filter->p_sys->p_cascade )
 130         cvReleaseHaarClassifierCascade( &p_filter->p_sys->p_cascade );
 131
 132     if( p_filter->p_sys->p_storage )
 133         cvReleaseMemStorage( &p_filter->p_sys->p_storage );
 134
 135     free( p_filter->p_sys->event_info.p_region );
 136     free( p_sys );
 137
 138     var_Destroy( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE);
 139 }
 140
 141 /****************************************************************************
 142  * Filter: Check for faces and raises an event when one is found.
 143  ****************************************************************************
 144  * p_pic: A picture_t with its p_data_orig member set to an array of
 145  * IplImages (one image for each picture_t plane).
 146  ****************************************************************************/
 147 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 148 {
 149     IplImage** p_img = NULL;
 150     int i_planes = 0;
 151     CvPoint pt1, pt2;
 152     int i, scale = 1;
 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_filter->p_sys->p_storage);
 187     CvSeq* faces = NULL;
 188     if( p_filter->p_sys->p_cascade )
 189     {
 190         //we should make some of these params config variables
 191         faces = cvHaarDetectObjects( p_img[0], p_filter->p_sys->p_cascade,
 192             p_filter->p_sys->p_storage, 1.15, 5, CV_HAAR_DO_CANNY_PRUNING,
 193                                             cvSize(20, 20) );
 194         //create the video_filter_region_info_t struct
 195         CvRect* r;
 196         if (faces && (faces->total > 0))
 197         {
 198             //msg_Dbg( p_filter, "Found %d face(s)", faces->total );
 199             free( p_filter->p_sys->event_info.p_region );
 200             p_filter->p_sys->event_info.p_region = NULL;
 201             if( NULL == ( p_filter->p_sys->event_info.p_region =
 202                   (video_filter_region_info_t *)malloc(faces->total*sizeof(video_filter_region_info_t))))
 203             {
 204                 return NULL;
 205             }
 206             memset(p_filter->p_sys->event_info.p_region, 0, faces->total*sizeof(video_filter_region_info_t));
 207             p_filter->p_sys->event_info.i_region_size = faces->total;
 208         }
 209
 210         //populate the video_filter_region_info_t struct
 211         for( i = 0; i < (faces ? faces->total : 0); i++ )
 212         {
 213             r = (CvRect*)cvGetSeqElem( faces, i );
 214             pt1.x = r->x*scale;
 215             pt2.x = (r->x+r->width)*scale;
 216             pt1.y = r->y*scale;
 217             pt2.y = (r->y+r->height)*scale;
 218             cvRectangle( p_img[0], pt1, pt2, CV_RGB(0,0,0), 3, 8, 0 );
 219
 220             *(CvRect*)(&(p_filter->p_sys->event_info.p_region[i])) = *r;
 221             p_filter->p_sys->event_info.p_region[i].i_id = p_filter->p_sys->i_id++;
 222             p_filter->p_sys->event_info.p_region[i].p_description = "Face Detected";
 223         }
 224
 225         if (faces && (faces->total > 0))    //raise the video filter event
 226             var_TriggerCallback( p_filter->p_libvlc, VIDEO_FILTER_EVENT_VARIABLE );
 227     }
 228     else
 229         msg_Err( p_filter, "No cascade - is opencv-haarcascade-file valid?" );
 230
 231     return p_pic;
 232 }
 233