modules/video_filter/sharpen.c

   1 /*****************************************************************************
   2  * sharpen.c: Sharpen video filter
   3  *****************************************************************************
   4  * Copyright (C) 2003-2007 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Author: Jérémy DEMEULE <dj_mulder at djduron dot no-ip dot org>
   8  *         Jean-Baptiste Kempf <jb at videolan dot org>
   9  *
  10  * This program is free software; you can redistribute it and/or modify it
  11  * under the terms of the GNU Lesser General Public License as published by
  12  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public License
  21  * along with this program; if not, write to the Free Software Foundation,
  22  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  23  *****************************************************************************/
  24
  25 /* The sharpen filter. */
  26 /*
  27  * static int filter[] = { -1, -1, -1,
  28  *                         -1,  8, -1,
  29  *                         -1, -1, -1 };
  30  */
  31
  32 /*****************************************************************************
  33  * Preamble
  34  *****************************************************************************/
  35
  36 #ifdef HAVE_CONFIG_H
  37 # include "config.h"
  38 #endif
  39
  40 #include <vlc_common.h>
  41 #include <vlc_plugin.h>
  42
  43 #include <vlc_filter.h>
  44 #include "filter_picture.h"
  45
  46 #define SIG_TEXT N_("Sharpen strength (0-2)")
  47 #define SIG_LONGTEXT N_("Set the Sharpen strength, between 0 and 2. Defaults to 0.05.")
  48
  49 /*****************************************************************************
  50  * Local prototypes
  51  *****************************************************************************/
  52 static int  Create    ( vlc_object_t * );
  53 static void Destroy   ( vlc_object_t * );
  54
  55 static picture_t *Filter( filter_t *, picture_t * );
  56 static int SharpenCallback( vlc_object_t *, char const *,
  57                             vlc_value_t, vlc_value_t, void * );
  58
  59 #define SHARPEN_HELP N_("Augment contrast between contours.")
  60 #define FILTER_PREFIX "sharpen-"
  61
  62 /*****************************************************************************
  63  * Module descriptor
  64  *****************************************************************************/
  65 vlc_module_begin ()
  66     set_description( N_("Sharpen video filter") )
  67     set_shortname( N_("Sharpen") )
  68     set_help(SHARPEN_HELP)
  69     set_category( CAT_VIDEO )
  70     set_subcategory( SUBCAT_VIDEO_VFILTER )
  71     set_capability( "video filter2", 0 )
  72     add_float_with_range( "sharpen-sigma", 0.05, 0.0, 2.0,
  73         SIG_TEXT, SIG_LONGTEXT, false )
  74     add_shortcut( "sharpen" )
  75     set_callbacks( Create, Destroy )
  76 vlc_module_end ()
  77
  78 static const char *const ppsz_filter_options[] = {
  79     "sigma", NULL
  80 };
  81
  82 /*****************************************************************************
  83  * filter_sys_t: Sharpen video filter descriptor
  84  *****************************************************************************
  85  * This structure is part of the video output thread descriptor.
  86  * It describes the Sharpen specific properties of an output thread.
  87  *****************************************************************************/
  88
  89 struct filter_sys_t
  90 {
  91     vlc_mutex_t lock;
  92     int tab_precalc[512];
  93 };
  94
  95 /*****************************************************************************
  96  * clip: avoid negative value and value > 255
  97  *****************************************************************************/
  98 inline static int32_t clip( int32_t a )
  99 {
 100     return (a > 255) ? 255 : (a < 0) ? 0 : a;
 101 }
 102
 103 static void init_precalc_table(filter_sys_t *p_filter, float sigma)
 104 {
 105     for(int i = 0; i < 512; ++i)
 106     {
 107         p_filter->tab_precalc[i] = (i - 256) * sigma;
 108     }
 109 }
 110
 111 /*****************************************************************************
 112  * Create: allocates Sharpen video thread output method
 113  *****************************************************************************
 114  * This function allocates and initializes a Sharpen vout method.
 115  *****************************************************************************/
 116 static int Create( vlc_object_t *p_this )
 117 {
 118     filter_t *p_filter = (filter_t *)p_this;
 119
 120     const vlc_fourcc_t fourcc = p_filter->fmt_in.video.i_chroma;
 121     const vlc_chroma_description_t *p_chroma = vlc_fourcc_GetChromaDescription( fourcc );
 122     if( !p_chroma || p_chroma->plane_count != 3 || p_chroma->pixel_size != 1 ) {
 123         msg_Err( p_filter, "Unsupported chroma (%4.4s)", (char*)&fourcc );
 124         return VLC_EGENERIC;
 125     }
 126
 127     /* Allocate structure */
 128     p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 129     if( p_filter->p_sys == NULL )
 130         return VLC_ENOMEM;
 131
 132     p_filter->pf_video_filter = Filter;
 133
 134     config_ChainParse( p_filter, FILTER_PREFIX, ppsz_filter_options,
 135                    p_filter->p_cfg );
 136
 137     float sigma = var_CreateGetFloatCommand( p_filter, FILTER_PREFIX "sigma" );
 138     init_precalc_table(p_filter->p_sys, sigma);
 139
 140     vlc_mutex_init( &p_filter->p_sys->lock );
 141     var_AddCallback( p_filter, FILTER_PREFIX "sigma",
 142                      SharpenCallback, p_filter->p_sys );
 143
 144     return VLC_SUCCESS;
 145 }
 146
 147
 148 /*****************************************************************************
 149  * Destroy: destroy Sharpen video thread output method
 150  *****************************************************************************
 151  * Terminate an output method created by SharpenCreateOutputMethod
 152  *****************************************************************************/
 153 static void Destroy( vlc_object_t *p_this )
 154 {
 155     filter_t *p_filter = (filter_t *)p_this;
 156     filter_sys_t *p_sys = p_filter->p_sys;
 157
 158     var_DelCallback( p_filter, FILTER_PREFIX "sigma", SharpenCallback, p_sys );
 159     vlc_mutex_destroy( &p_sys->lock );
 160     free( p_sys );
 161 }
 162
 163 /*****************************************************************************
 164  * Render: displays previously rendered output
 165  *****************************************************************************
 166  * This function send the currently rendered image to Invert image, waits
 167  * until it is displayed and switch the two rendering buffers, preparing next
 168  * frame.
 169  *****************************************************************************/
 170 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 171 {
 172     picture_t *p_outpic;
 173     int i, j;
 174     uint8_t *p_src = NULL;
 175     uint8_t *p_out = NULL;
 176     int i_src_pitch;
 177     int i_out_pitch;
 178     int pix;
 179     const int v1 = -1;
 180     const int v2 = 3; /* 2^3 = 8 */
 181
 182     if( !p_pic ) return NULL;
 183
 184     p_outpic = filter_NewPicture( p_filter );
 185     if( !p_outpic )
 186     {
 187         picture_Release( p_pic );
 188         return NULL;
 189     }
 190
 191     /* process the Y plane */
 192     p_src = p_pic->p[Y_PLANE].p_pixels;
 193     p_out = p_outpic->p[Y_PLANE].p_pixels;
 194     i_src_pitch = p_pic->p[Y_PLANE].i_pitch;
 195     i_out_pitch = p_outpic->p[Y_PLANE].i_pitch;
 196
 197     /* perform convolution only on Y plane. Avoid border line. */
 198     vlc_mutex_lock( &p_filter->p_sys->lock );
 199     for( i = 0; i < p_pic->p[Y_PLANE].i_visible_lines; i++ )
 200     {
 201         if( (i == 0) || (i == p_pic->p[Y_PLANE].i_visible_lines - 1) )
 202         {
 203             for( j = 0; j < p_pic->p[Y_PLANE].i_visible_pitch; j++ )
 204                 p_out[i * i_out_pitch + j] = clip( p_src[i * i_src_pitch + j] );
 205             continue ;
 206         }
 207         for( j = 0; j < p_pic->p[Y_PLANE].i_visible_pitch; j++ )
 208         {
 209             if( (j == 0) || (j == p_pic->p[Y_PLANE].i_visible_pitch - 1) )
 210             {
 211                 p_out[i * i_out_pitch + j] = p_src[i * i_src_pitch + j];
 212                 continue ;
 213             }
 214
 215             pix = (p_src[(i - 1) * i_src_pitch + j - 1] * v1) +
 216                   (p_src[(i - 1) * i_src_pitch + j    ] * v1) +
 217                   (p_src[(i - 1) * i_src_pitch + j + 1] * v1) +
 218                   (p_src[(i    ) * i_src_pitch + j - 1] * v1) +
 219                   (p_src[(i    ) * i_src_pitch + j    ] << v2) +
 220                   (p_src[(i    ) * i_src_pitch + j + 1] * v1) +
 221                   (p_src[(i + 1) * i_src_pitch + j - 1] * v1) +
 222                   (p_src[(i + 1) * i_src_pitch + j    ] * v1) +
 223                   (p_src[(i + 1) * i_src_pitch + j + 1] * v1);
 224
 225            pix = pix >= 0 ? clip(pix) : -clip(pix * -1);
 226            p_out[i * i_out_pitch + j] = clip( p_src[i * i_src_pitch + j] +
 227                p_filter->p_sys->tab_precalc[pix + 256] );
 228         }
 229     }
 230     vlc_mutex_unlock( &p_filter->p_sys->lock );
 231
 232     plane_CopyPixels( &p_outpic->p[U_PLANE], &p_pic->p[U_PLANE] );
 233     plane_CopyPixels( &p_outpic->p[V_PLANE], &p_pic->p[V_PLANE] );
 234
 235     return CopyInfoAndRelease( p_outpic, p_pic );
 236 }
 237
 238 static int SharpenCallback( vlc_object_t *p_this, char const *psz_var,
 239                             vlc_value_t oldval, vlc_value_t newval,
 240                             void *p_data )
 241 {
 242     VLC_UNUSED(p_this); VLC_UNUSED(oldval); VLC_UNUSED(psz_var);
 243     filter_sys_t *p_sys = (filter_sys_t *)p_data;
 244
 245     vlc_mutex_lock( &p_sys->lock );
 246     init_precalc_table( p_sys,  VLC_CLIP( newval.f_float, 0.f, 2.f ) );
 247     vlc_mutex_unlock( &p_sys->lock );
 248     return VLC_SUCCESS;
 249 }