modules/video_filter/sepia.c

   1 /*****************************************************************************
   2  * sepia.c : Sepia video plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2010 VLC authors and VideoLAN
   5  * $Id$
   6  *
   7  * Authors: Branko Kokanovic <branko.kokanovic@gmail.com>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
  17  * GNU Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 /*****************************************************************************
  25  * Preamble
  26  *****************************************************************************/
  27
  28 #ifdef HAVE_CONFIG_H
  29 # include "config.h"
  30 #endif
  31
  32 #include <vlc_common.h>
  33 #include <vlc_plugin.h>
  34 #include <vlc_filter.h>
  35 #include <vlc_cpu.h>
  36 #include <vlc_atomic.h>
  37
  38 #include <assert.h>
  39 #include "filter_picture.h"
  40
  41 /*****************************************************************************
  42  * Local prototypes
  43  *****************************************************************************/
  44 static int  Create      ( vlc_object_t * );
  45 static void Destroy     ( vlc_object_t * );
  46
  47 static void RVSepia( picture_t *, picture_t *, int );
  48 static void PlanarI420Sepia( picture_t *, picture_t *, int);
  49 static void PackedYUVSepia( picture_t *, picture_t *, int);
  50 static picture_t *Filter( filter_t *, picture_t * );
  51 static const char *const ppsz_filter_options[] = {
  52     "intensity", NULL
  53 };
  54
  55 /*****************************************************************************
  56  * Module descriptor
  57  *****************************************************************************/
  58 #define SEPIA_INTENSITY_TEXT N_("Sepia intensity")
  59 #define SEPIA_INTENSITY_LONGTEXT N_("Intensity of sepia effect" )
  60
  61 #define CFG_PREFIX "sepia-"
  62
  63 vlc_module_begin ()
  64     set_description( N_("Sepia video filter") )
  65     set_shortname( N_("Sepia" ) )
  66     set_help( N_("Gives video a warmer tone by applying sepia effect") )
  67     set_category( CAT_VIDEO )
  68     set_subcategory( SUBCAT_VIDEO_VFILTER )
  69     set_capability( "video filter", 0 )
  70     add_integer_with_range( CFG_PREFIX "intensity", 120, 0, 255,
  71                            SEPIA_INTENSITY_TEXT, SEPIA_INTENSITY_LONGTEXT,
  72                            false )
  73     set_callbacks( Create, Destroy )
  74 vlc_module_end ()
  75
  76 /*****************************************************************************
  77  * callback prototypes
  78  *****************************************************************************/
  79 static int FilterCallback( vlc_object_t *, char const *,
  80                            vlc_value_t, vlc_value_t, void * );
  81
  82 typedef void (*SepiaFunction)( picture_t *, picture_t *, int );
  83
  84 static const struct
  85 {
  86     vlc_fourcc_t i_chroma;
  87     SepiaFunction pf_sepia;
  88 } p_sepia_cfg[] = {
  89     { VLC_CODEC_I420, PlanarI420Sepia },
  90     { VLC_CODEC_RGB24, RVSepia },
  91     { VLC_CODEC_RGB32, RVSepia },
  92     { VLC_CODEC_UYVY, PackedYUVSepia },
  93     { VLC_CODEC_VYUY, PackedYUVSepia },
  94     { VLC_CODEC_YUYV, PackedYUVSepia },
  95     { VLC_CODEC_YVYU, PackedYUVSepia },
  96     { 0, NULL }
  97 };
  98
  99 /*****************************************************************************
 100  * filter_sys_t: adjust filter method descriptor
 101  *****************************************************************************/
 102 struct filter_sys_t
 103 {
 104     SepiaFunction pf_sepia;
 105     atomic_int i_intensity;
 106 };
 107
 108 /*****************************************************************************
 109  * Create: allocates Sepia video thread output method
 110  *****************************************************************************
 111  * This function allocates and initializes a Sepia vout method.
 112  *****************************************************************************/
 113 static int Create( vlc_object_t *p_this )
 114 {
 115     filter_t *p_filter = (filter_t *)p_this;
 116     filter_sys_t *p_sys;
 117
 118     /* Allocate structure */
 119     p_sys = p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 120     if( p_filter->p_sys == NULL )
 121         return VLC_ENOMEM;
 122
 123     p_sys->pf_sepia = NULL;
 124
 125     for( int i = 0; p_sepia_cfg[i].i_chroma != 0; i++ )
 126     {
 127         if( p_sepia_cfg[i].i_chroma != p_filter->fmt_in.video.i_chroma )
 128             continue;
 129         p_sys->pf_sepia = p_sepia_cfg[i].pf_sepia;
 130     }
 131
 132     if( p_sys->pf_sepia == NULL )
 133     {
 134         msg_Err( p_filter, "Unsupported input chroma (%4.4s)",
 135                 (char*)&(p_filter->fmt_in.video.i_chroma) );
 136         free( p_sys );
 137         return VLC_EGENERIC;
 138     }
 139
 140     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 141                        p_filter->p_cfg );
 142     atomic_init( &p_sys->i_intensity,
 143              var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "intensity" ) );
 144     var_AddCallback( p_filter, CFG_PREFIX "intensity", FilterCallback, NULL );
 145
 146     p_filter->pf_video_filter = Filter;
 147
 148     return VLC_SUCCESS;
 149 }
 150
 151 /*****************************************************************************
 152  * Destroy: destroy sepia video thread output method
 153  *****************************************************************************
 154  * Terminate an output method
 155  *****************************************************************************/
 156 static void Destroy( vlc_object_t *p_this )
 157 {
 158     filter_t *p_filter = (filter_t *)p_this;
 159
 160     var_DelCallback( p_filter, CFG_PREFIX "intensity", FilterCallback, NULL );
 161
 162     free( p_filter->p_sys );
 163 }
 164
 165 /*****************************************************************************
 166  * Render: displays previously rendered output
 167  *****************************************************************************
 168  * This function send the currently rendered image to sepia image, waits
 169  * until it is displayed and switch the two rendering buffers, preparing next
 170  * frame.
 171  *****************************************************************************/
 172 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 173 {
 174     picture_t *p_outpic;
 175
 176     if( !p_pic ) return NULL;
 177
 178     filter_sys_t *p_sys = p_filter->p_sys;
 179     int intensity = atomic_load( &p_sys->i_intensity );
 180
 181     p_outpic = filter_NewPicture( p_filter );
 182     if( !p_outpic )
 183     {
 184         msg_Warn( p_filter, "can't get output picture" );
 185         picture_Release( p_pic );
 186         return NULL;
 187     }
 188
 189     p_sys->pf_sepia( p_pic, p_outpic, intensity );
 190
 191     return CopyInfoAndRelease( p_outpic, p_pic );
 192 }
 193
 194 #if defined(CAN_COMPILE_SSE2)
 195 /*****************************************************************************
 196  * Sepia8ySSE2
 197  *****************************************************************************
 198  * This function applies sepia effect to eight bytes of yellow using SSE4.1
 199  * instructions. It copies those 8 bytes to 128b register and fills the gaps
 200  * with zeroes and following operations are made with word-operating instructs.
 201  *****************************************************************************/
 202 VLC_SSE
 203 static inline void Sepia8ySSE2(uint8_t * dst, const uint8_t * src,
 204                          int i_intensity_spread)
 205 {
 206     __asm__ volatile (
 207         // y = y - y / 4 + i_intensity / 4
 208         "movq            (%1), %%xmm1\n"
 209         "punpcklbw     %%xmm7, %%xmm1\n"
 210         "movq            (%1), %%xmm2\n" // store bytes as words with 0s in between
 211         "punpcklbw     %%xmm7, %%xmm2\n"
 212         "movd              %2, %%xmm3\n"
 213         "pshufd    $0, %%xmm3, %%xmm3\n"
 214         "psrlw             $2, %%xmm2\n"    // rotate right 2
 215         "psubusb       %%xmm1, %%xmm2\n"    // subtract
 216         "psrlw             $2, %%xmm3\n"
 217         "paddsb        %%xmm1, %%xmm3\n"    // add
 218         "packuswb      %%xmm2, %%xmm1\n"    // pack back to bytes
 219         "movq          %%xmm1, (%0)  \n"    // load to dest
 220         :
 221         :"r" (dst), "r"(src), "r"(i_intensity_spread)
 222         :"memory", "xmm1", "xmm2", "xmm3");
 223 }
 224
 225 VLC_SSE
 226 static void PlanarI420SepiaSSE( picture_t *p_pic, picture_t *p_outpic,
 227                                 int i_intensity )
 228 {
 229     /* prepared values to copy for U and V channels */
 230     const uint8_t filling_const_8u = 128 - i_intensity / 6;
 231     const uint8_t filling_const_8v = 128 + i_intensity / 14;
 232     /* prepared value for faster broadcasting in xmm register */
 233     int i_intensity_spread = 0x10001 * (uint8_t) i_intensity;
 234
 235     __asm__ volatile(
 236         "pxor      %%xmm7, %%xmm7\n"
 237         ::: "xmm7");
 238
 239     /* iterate for every two visible line in the frame */
 240     for (int y = 0; y < p_pic->p[Y_PLANE].i_visible_lines - 1; y += 2)
 241     {
 242         const int i_dy_line1_start = y * p_outpic->p[Y_PLANE].i_pitch;
 243         const int i_dy_line2_start = (y + 1) * p_outpic->p[Y_PLANE].i_pitch;
 244         const int i_du_line_start =  (y / 2) * p_outpic->p[U_PLANE].i_pitch;
 245         const int i_dv_line_start =  (y / 2) * p_outpic->p[V_PLANE].i_pitch;
 246         int x = 0;
 247         /* iterate for every visible line in the frame (eight values at once) */
 248         for ( ; x < p_pic->p[Y_PLANE].i_visible_pitch - 15; x += 16 )
 249         {
 250             /* Compute yellow channel values with asm function */
 251             Sepia8ySSE2(&p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x],
 252                         &p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x],
 253                         i_intensity_spread );
 254             Sepia8ySSE2(&p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x],
 255                         &p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x],
 256                         i_intensity_spread );
 257             Sepia8ySSE2(&p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 8],
 258                         &p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 8],
 259                         i_intensity_spread );
 260             Sepia8ySSE2(&p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 8],
 261                         &p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 8],
 262                         i_intensity_spread );
 263             /* Copy precomputed values to destination memory location */
 264             memset(&p_outpic->p[U_PLANE].p_pixels[i_du_line_start + (x / 2)],
 265                    filling_const_8u, 8 );
 266             memset(&p_outpic->p[V_PLANE].p_pixels[i_dv_line_start + (x / 2)],
 267                    filling_const_8v, 8 );
 268         }
 269         /* Completing the job, the cycle above takes really big chunks, so
 270            this makes sure the job will be done completely */
 271         for ( ; x < p_pic->p[Y_PLANE].i_visible_pitch - 1; x += 2 )
 272         {
 273             // y = y - y/4 {to prevent overflow} + intensity / 4
 274             p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] =
 275                 p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] -
 276                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] >> 2) +
 277                 (i_intensity >> 2);
 278             p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] =
 279                 p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] -
 280                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] >> 2) +
 281                 (i_intensity >> 2);
 282             p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] =
 283                 p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] -
 284                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] >> 2) +
 285                 (i_intensity >> 2);
 286             p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] =
 287                 p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] -
 288                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] >> 2) +
 289                 (i_intensity >> 2);
 290             // u = 128 {half => B&W} - intensity / 6
 291             p_outpic->p[U_PLANE].p_pixels[i_du_line_start + (x / 2)] =
 292                 filling_const_8u;
 293             // v = 128 {half => B&W} + intensity / 14
 294             p_outpic->p[V_PLANE].p_pixels[i_dv_line_start + (x / 2)] =
 295                 filling_const_8v;
 296         }
 297     }
 298 }
 299 #endif
 300
 301 /*****************************************************************************
 302  * PlanarI420Sepia: Applies sepia to one frame of the planar I420 video
 303  *****************************************************************************
 304  * This function applies sepia effect to one frame of the video by iterating
 305  * through video lines. We iterate for every two lines and for every two pixels
 306  * in line to calculate new sepia values for four y components as well for u
 307  * and v components.
 308  *****************************************************************************/
 309 static void PlanarI420Sepia( picture_t *p_pic, picture_t *p_outpic,
 310                                int i_intensity )
 311 {
 312 #if defined(CAN_COMPILE_SSE2)
 313     if (vlc_CPU_SSE2())
 314         return PlanarI420SepiaSSE( p_pic, p_outpic, i_intensity );
 315 #endif
 316
 317     // prepared values to copy for U and V channels
 318     const uint8_t filling_const_8u = 128 - i_intensity / 6;
 319     const uint8_t filling_const_8v = 128 + i_intensity / 14;
 320
 321     /* iterate for every two visible line in the frame */
 322     for( int y = 0; y < p_pic->p[Y_PLANE].i_visible_lines - 1; y += 2 )
 323     {
 324         const int i_dy_line1_start = y * p_outpic->p[Y_PLANE].i_pitch;
 325         const int i_dy_line2_start = ( y + 1 ) * p_outpic->p[Y_PLANE].i_pitch;
 326         const int i_du_line_start = (y/2) * p_outpic->p[U_PLANE].i_pitch;
 327         const int i_dv_line_start = (y/2) * p_outpic->p[V_PLANE].i_pitch;
 328         // to prevent sigsegv if one pic is smaller (theoretically)
 329         int i_picture_size_limit = p_pic->p[Y_PLANE].i_visible_pitch
 330                   < p_outpic->p[Y_PLANE].i_visible_pitch
 331                   ? (p_pic->p[Y_PLANE].i_visible_pitch - 1) :
 332                   (p_outpic->p[Y_PLANE].i_visible_pitch - 1);
 333         /* iterate for every two visible line in the frame */
 334         for( int x = 0; x < i_picture_size_limit; x += 2 )
 335         {
 336             // y = y - y/4 {to prevent overflow} + intensity / 4
 337             p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] =
 338                 p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] -
 339                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] >> 2) +
 340                 (i_intensity >> 2);
 341             p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] =
 342                 p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] -
 343                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] >> 2) +
 344                 (i_intensity >> 2);
 345             p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] =
 346                 p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] -
 347                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] >> 2) +
 348                 (i_intensity >> 2);
 349             p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] =
 350                 p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] -
 351                 (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] >> 2) +
 352                 (i_intensity >> 2);
 353             // u = 128 {half => B&W} - intensity / 6
 354             p_outpic->p[U_PLANE].p_pixels[i_du_line_start + (x / 2)] =
 355                 filling_const_8u;
 356             // v = 128 {half => B&W} + intensity / 14
 357             p_outpic->p[V_PLANE].p_pixels[i_dv_line_start + (x / 2)] =
 358                 filling_const_8v;
 359         }
 360     }
 361 }
 362
 363 /*****************************************************************************
 364  * PackedYUVSepia: Applies sepia to one frame of the packed YUV video
 365  *****************************************************************************
 366  * This function applies sepia effext to one frame of the video by iterating
 367  * through video lines. In every pass, we calculate new values for pixels
 368  * (UYVY, VYUY, YUYV and YVYU formats are supported)
 369  *****************************************************************************/
 370 static void PackedYUVSepia( picture_t *p_pic, picture_t *p_outpic,
 371                            int i_intensity )
 372 {
 373     uint8_t *p_in, *p_in_end, *p_line_end, *p_out;
 374     int i_yindex = 1, i_uindex = 2, i_vindex = 0;
 375
 376     GetPackedYuvOffsets( p_outpic->format.i_chroma,
 377                         &i_yindex, &i_uindex, &i_vindex );
 378
 379     // prepared values to copy for U and V channels
 380     const uint8_t filling_const_8u = 128 - i_intensity / 6;
 381     const uint8_t filling_const_8v = 128 + i_intensity / 14;
 382
 383     p_in = p_pic->p[0].p_pixels;
 384     p_in_end = p_in + p_pic->p[0].i_visible_lines
 385         * p_pic->p[0].i_pitch;
 386     p_out = p_outpic->p[0].p_pixels;
 387
 388     {
 389         while( p_in < p_in_end )
 390         {
 391             p_line_end = p_in + p_pic->p[0].i_visible_pitch;
 392             while( p_in < p_line_end )
 393             {
 394                 /* calculate new, sepia values */
 395                 p_out[i_yindex] =
 396                     p_in[i_yindex] - (p_in[i_yindex] >> 2) + (i_intensity >> 2);
 397                 p_out[i_yindex + 2] =
 398                     p_in[i_yindex + 2] - (p_in[i_yindex + 2] >> 2)
 399                     + (i_intensity >> 2);
 400                 p_out[i_uindex] = filling_const_8u;
 401                 p_out[i_vindex] = filling_const_8v;
 402                 p_in += 4;
 403                 p_out += 4;
 404             }
 405             p_in += p_pic->p[0].i_pitch - p_pic->p[0].i_visible_pitch;
 406             p_out += p_outpic->p[0].i_pitch
 407                 - p_outpic->p[0].i_visible_pitch;
 408         }
 409     }
 410 }
 411
 412 /*****************************************************************************
 413  * RVSepia: Applies sepia to one frame of the RV24/RV32 video
 414  *****************************************************************************
 415  * This function applies sepia effect to one frame of the video by iterating
 416  * through video lines and calculating new values for every byte in chunks of
 417  * 3 (RV24) or 4 (RV32) bytes.
 418  *****************************************************************************/
 419 static void RVSepia( picture_t *p_pic, picture_t *p_outpic, int i_intensity )
 420 {
 421 #define SCALEBITS 10
 422 #define ONE_HALF  (1 << (SCALEBITS - 1))
 423 #define FIX(x)    ((int) ((x) * (1<<SCALEBITS) + 0.5))
 424     uint8_t *p_in, *p_in_end, *p_line_end, *p_out;
 425     bool b_isRV32 = p_pic->format.i_chroma == VLC_CODEC_RGB32;
 426     int i_rindex = 0, i_gindex = 1, i_bindex = 2;
 427
 428     GetPackedRgbIndexes( &p_outpic->format, &i_rindex, &i_gindex, &i_bindex );
 429
 430     p_in = p_pic->p[0].p_pixels;
 431     p_in_end = p_in + p_pic->p[0].i_visible_lines
 432         * p_pic->p[0].i_pitch;
 433     p_out = p_outpic->p[0].p_pixels;
 434
 435     /* Precompute values constant for this certain i_intensity, using the same
 436      * formula as YUV functions above */
 437     uint8_t r_intensity = (( FIX( 1.40200 * 255.0 / 224.0 ) * (i_intensity * 14)
 438                         + ONE_HALF )) >> SCALEBITS;
 439     uint8_t g_intensity = (( - FIX(0.34414*255.0/224.0) * ( - i_intensity / 6 )
 440                         - FIX( 0.71414 * 255.0 / 224.0) * ( i_intensity * 14 )
 441                         + ONE_HALF )) >> SCALEBITS;
 442     uint8_t b_intensity = (( FIX( 1.77200 * 255.0 / 224.0) * ( - i_intensity / 6 )
 443                         + ONE_HALF )) >> SCALEBITS;
 444
 445     while (p_in < p_in_end)
 446     {
 447         p_line_end = p_in + p_pic->p[0].i_visible_pitch;
 448         while (p_in < p_line_end)
 449         {
 450             /* do sepia: this calculation is based on the formula to calculate
 451              * YUV->RGB and RGB->YUV (in filter_picture.h) mode and that
 452              * y = y - y/4 + intensity/4 . As Y is the only channel that changes
 453              * through the whole image. After that, precomputed values are added
 454              * for each RGB channel and saved in the output image.
 455              * FIXME: needs cleanup */
 456             uint8_t i_y = ((( 66 * p_in[i_rindex] + 129 * p_in[i_gindex] +  25
 457                       * p_in[i_bindex] + 128 ) >> 8 ) * FIX(255.0/219.0))
 458                       - (((( 66 * p_in[i_rindex] + 129 * p_in[i_gindex] + 25
 459                       * p_in[i_bindex] + 128 ) >> 8 )
 460                       * FIX( 255.0 / 219.0 )) >> 2 ) + ( i_intensity >> 2 );
 461             p_out[i_rindex] = vlc_uint8(i_y + r_intensity);
 462             p_out[i_gindex] = vlc_uint8(i_y + g_intensity);
 463             p_out[i_bindex] = vlc_uint8(i_y + b_intensity);
 464             p_in += 3;
 465             p_out += 3;
 466             /* for rv32 we take 4 chunks at the time */
 467             if (b_isRV32) {
 468             /* alpha channel stays the same */
 469             *p_out++ = *p_in++;
 470             }
 471         }
 472
 473         p_in += p_pic->p[0].i_pitch - p_pic->p[0].i_visible_pitch;
 474         p_out += p_outpic->p[0].i_pitch
 475             - p_outpic->p[0].i_visible_pitch;
 476     }
 477 #undef SCALEBITS
 478 #undef ONE_HALF
 479 #undef FIX
 480 }
 481
 482 static int FilterCallback ( vlc_object_t *p_this, char const *psz_var,
 483                             vlc_value_t oldval, vlc_value_t newval,
 484                             void *p_data )
 485 {
 486     VLC_UNUSED(psz_var); VLC_UNUSED(oldval); VLC_UNUSED(p_data);
 487     filter_t *p_filter = (filter_t*)p_this;
 488     filter_sys_t *p_sys = p_filter->p_sys;
 489
 490     atomic_store( &p_sys->i_intensity, newval.i_int );
 491     return VLC_SUCCESS;
 492 }