git.sesse.net Git - vlc/blob - modules/video_filter/sepia.c

   1 /*****************************************************************************
   2  * sepia.c : Sepia video plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2010 the VideoLAN team
   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
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 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 General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, 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
  37 #include <assert.h>
  38 #include "filter_picture.h"
  39
  40 /*****************************************************************************
  41  * Local prototypes
  42  *****************************************************************************/
  43 static int  Create      ( vlc_object_t * );
  44 static void Destroy     ( vlc_object_t * );
  45
  46 static void RVSepia( picture_t *, picture_t *, int );
  47 static void PlanarI420Sepia( picture_t *, picture_t *, int);
  48 static void PackedYUVSepia( picture_t *, picture_t *, int);
  49 static picture_t *Filter( filter_t *, picture_t * );
  50 static const char *const ppsz_filter_options[] = {
  51     "intensity", NULL
  52 };
  53
  54 /*****************************************************************************
  55  * Module descriptor
  56  *****************************************************************************/
  57 #define SEPIA_INTENSITY_TEXT N_("Sepia intensity")
  58 #define SEPIA_INTENSITY_LONGTEXT N_("Intensity of sepia effect" )
  59
  60 #define CFG_PREFIX "sepia-"
  61
  62 vlc_module_begin ()
  63     set_description( N_("Sepia video filter") )
  64     set_shortname( N_("Sepia" ) )
  65     set_help( N_("Gives video a warmer tone by applying sepia effect") )
  66     set_category( CAT_VIDEO )
  67     set_subcategory( SUBCAT_VIDEO_VFILTER )
  68     set_capability( "video filter2", 0 )
  69     add_integer_with_range( CFG_PREFIX "intensity", 120, 0, 255,
  70                            SEPIA_INTENSITY_TEXT, SEPIA_INTENSITY_LONGTEXT,
  71                            false )
  72     set_callbacks( Create, Destroy )
  73 vlc_module_end ()
  74
  75 /*****************************************************************************
  76  * callback prototypes
  77  *****************************************************************************/
  78 static int FilterCallback( vlc_object_t *, char const *,
  79                            vlc_value_t, vlc_value_t, void * );
  80
  81 typedef void (*SepiaFunction)( picture_t *, picture_t *, int );
  82
  83 static const struct
  84 {
  85     vlc_fourcc_t i_chroma;
  86     SepiaFunction pf_sepia;
  87 } p_sepia_cfg[] = {
  88     { VLC_CODEC_I420, PlanarI420Sepia },
  89     { VLC_CODEC_RGB24, RVSepia },
  90     { VLC_CODEC_RGB32, RVSepia },
  91     { VLC_CODEC_UYVY, PackedYUVSepia },
  92     { VLC_CODEC_VYUY, PackedYUVSepia },
  93     { VLC_CODEC_YUYV, PackedYUVSepia },
  94     { VLC_CODEC_YVYU, PackedYUVSepia },
  95     { 0, NULL }
  96 };
  97
  98 /*****************************************************************************
  99  * filter_sys_t: adjust filter method descriptor
 100  *****************************************************************************/
 101 struct filter_sys_t
 102 {
 103     SepiaFunction pf_sepia;
 104     int i_intensity;
 105     vlc_spinlock_t lock;
 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     p_sys->i_intensity= var_CreateGetIntegerCommand( p_filter,
 143                        CFG_PREFIX "intensity" );
 144
 145     vlc_spin_init( &p_sys->lock );
 146
 147     var_AddCallback( p_filter, CFG_PREFIX "intensity", FilterCallback, NULL );
 148
 149     p_filter->pf_video_filter = Filter;
 150
 151     return VLC_SUCCESS;
 152 }
 153
 154 /*****************************************************************************
 155  * Destroy: destroy sepia video thread output method
 156  *****************************************************************************
 157  * Terminate an output method
 158  *****************************************************************************/
 159 static void Destroy( vlc_object_t *p_this )
 160 {
 161     filter_t *p_filter = (filter_t *)p_this;
 162
 163     var_DelCallback( p_filter, CFG_PREFIX "intensity", FilterCallback, NULL );
 164
 165     vlc_spin_destroy( &p_filter->p_sys->lock );
 166     free( p_filter->p_sys );
 167 }
 168
 169 /*****************************************************************************
 170  * Render: displays previously rendered output
 171  *****************************************************************************
 172  * This function send the currently rendered image to sepia image, waits
 173  * until it is displayed and switch the two rendering buffers, preparing next
 174  * frame.
 175  *****************************************************************************/
 176 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 177 {
 178     picture_t *p_outpic;
 179     int intensity;
 180
 181     if( !p_pic ) return NULL;
 182
 183     filter_sys_t *p_sys = p_filter->p_sys;
 184     vlc_spin_lock( &p_sys->lock );
 185     intensity = p_sys->i_intensity;
 186     vlc_spin_unlock( &p_sys->lock );
 187
 188     p_outpic = filter_NewPicture( p_filter );
 189     if( !p_outpic )
 190     {
 191         msg_Warn( p_filter, "can't get output picture" );
 192         picture_Release( p_pic );
 193         return NULL;
 194     }
 195
 196     p_sys->pf_sepia( p_pic, p_outpic, intensity );
 197
 198     return CopyInfoAndRelease( p_outpic, p_pic );
 199 }
 200
 201 #if defined(CAN_COMPILE_SSE2)
 202 /*****************************************************************************
 203  * Sepia8ySSE2
 204  *****************************************************************************
 205  * This function applies sepia effect to eight bytes of yellow using SSE4.1
 206  * instructions. It copies those 8 bytes to 128b register and fills the gaps
 207  * with zeroes and following operations are made with word-operating instructs.
 208  *****************************************************************************/
 209 static inline void Sepia8ySSE2(uint8_t * dst, const uint8_t * src,
 210                          int i_intensity_spread)
 211 {
 212     __asm__ volatile (
 213         // y = y - y / 4 + i_intensity / 4
 214         "movq            (%1), %%xmm1\n"
 215         "punpcklbw     %%xmm7, %%xmm1\n"
 216         "movq            (%1), %%xmm2\n" // store bytes as words with 0s in between
 217         "punpcklbw     %%xmm7, %%xmm2\n"
 218         "movd              %2, %%xmm3\n"
 219         "pshufd    $0, %%xmm3, %%xmm3\n"
 220         "psrlw             $2, %%xmm2\n"    // rotate right 2
 221         "psubusb       %%xmm1, %%xmm2\n"    // subtract
 222         "psrlw             $2, %%xmm3\n"
 223         "paddsb        %%xmm1, %%xmm3\n"    // add
 224         "packuswb      %%xmm2, %%xmm1\n"    // pack back to bytes
 225         "movq          %%xmm1, (%0)  \n"    // load to dest
 226         :
 227         :"r" (dst), "r"(src), "r"(i_intensity_spread)
 228         :"memory");
 229 }
 230 #endif
 231
 232 /*****************************************************************************
 233  * PlanarI420Sepia: Applies sepia to one frame of the planar I420 video
 234  *****************************************************************************
 235  * This function applies sepia effect to one frame of the video by iterating
 236  * through video lines. We iterate for every two lines and for every two pixels
 237  * in line to calculate new sepia values for four y components as well for u
 238  * and v components.
 239  *****************************************************************************/
 240 static void PlanarI420Sepia( picture_t *p_pic, picture_t *p_outpic,
 241                                int i_intensity )
 242 {
 243     // prepared values to copy for U and V channels
 244     const uint8_t filling_const_8u = 128 - i_intensity / 6;
 245     const uint8_t filling_const_8v = 128 + i_intensity / 14;
 246
 247 #if defined(CAN_COMPILE_SSE2)
 248     if (vlc_CPU_SSE2())
 249     {
 250         /* prepared value for faster broadcasting in xmm register */
 251         int i_intensity_spread = 0x10001 * (uint8_t) i_intensity;
 252
 253         __asm__ volatile(
 254             "pxor      %%xmm7, %%xmm7\n"
 255         ::);
 256
 257         /* iterate for every two visible line in the frame */
 258         for (int y = 0; y < p_pic->p[Y_PLANE].i_visible_lines - 1; y += 2)
 259         {
 260             const int i_dy_line1_start = y * p_outpic->p[Y_PLANE].i_pitch;
 261             const int i_dy_line2_start =
 262             (y + 1) * p_outpic->p[Y_PLANE].i_pitch;
 263             const int i_du_line_start =
 264             (y / 2) * p_outpic->p[U_PLANE].i_pitch;
 265             const int i_dv_line_start =
 266             (y / 2) * p_outpic->p[V_PLANE].i_pitch;
 267             int x = 0;
 268             /* iterate for every visible line in the frame (eight values at once) */
 269             for ( ; x < p_pic->p[Y_PLANE].i_visible_pitch - 15; x += 16 )
 270             {
 271                 /* Compute yellow channel values with asm function */
 272                 Sepia8ySSE2(
 273                     &p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x],
 274                     &p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x],
 275                     i_intensity_spread );
 276                 Sepia8ySSE2(
 277                     &p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x],
 278                     &p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x],
 279                     i_intensity_spread );
 280                 Sepia8ySSE2(
 281                     &p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 8],
 282                     &p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 8],
 283                     i_intensity_spread );
 284                 Sepia8ySSE2(
 285                     &p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 8],
 286                     &p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 8],
 287                     i_intensity_spread );
 288                 /* Copy precomputed values to destination memory location */
 289                 memset(
 290                     &p_outpic->p[U_PLANE].p_pixels[i_du_line_start + (x / 2)],
 291                     filling_const_8u, 8 );
 292                 memset(
 293                     &p_outpic->p[V_PLANE].p_pixels[i_dv_line_start + (x / 2)],
 294                     filling_const_8v, 8 );
 295             }
 296             /* Completing the job, the cycle above takes really big chunks, so
 297               this makes sure the job will be done completely */
 298             for ( ; x < p_pic->p[Y_PLANE].i_visible_pitch - 1; x += 2 )
 299             {
 300                 // y = y - y/4 {to prevent overflow} + intensity / 4
 301                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] =
 302                     p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] -
 303                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] >> 2) +
 304                     (i_intensity >> 2);
 305                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] =
 306                     p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] -
 307                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] >> 2) +
 308                     (i_intensity >> 2);
 309                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] =
 310                     p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] -
 311                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] >> 2) +
 312                     (i_intensity >> 2);
 313                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] =
 314                     p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] -
 315                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] >> 2) +
 316                     (i_intensity >> 2);
 317                 // u = 128 {half => B&W} - intensity / 6
 318                 p_outpic->p[U_PLANE].p_pixels[i_du_line_start + (x / 2)] =
 319                     filling_const_8u;
 320                 // v = 128 {half => B&W} + intensity / 14
 321                 p_outpic->p[V_PLANE].p_pixels[i_dv_line_start + (x / 2)] =
 322                     filling_const_8v;
 323             }
 324         }
 325     }
 326     else
 327 #endif
 328     {
 329         /* iterate for every two visible line in the frame */
 330         for( int y = 0; y < p_pic->p[Y_PLANE].i_visible_lines - 1; y += 2)
 331         {
 332             const int i_dy_line1_start = y * p_outpic->p[Y_PLANE].i_pitch;
 333             const int i_dy_line2_start = ( y + 1 ) * p_outpic->p[Y_PLANE].i_pitch;
 334             const int i_du_line_start = (y/2) * p_outpic->p[U_PLANE].i_pitch;
 335             const int i_dv_line_start = (y/2) * p_outpic->p[V_PLANE].i_pitch;
 336             // to prevent sigsegv if one pic is smaller (theoretically)
 337             int i_picture_size_limit = p_pic->p[Y_PLANE].i_visible_pitch
 338                       < p_outpic->p[Y_PLANE].i_visible_pitch
 339                       ? (p_pic->p[Y_PLANE].i_visible_pitch - 1) :
 340                       (p_outpic->p[Y_PLANE].i_visible_pitch - 1);
 341             /* iterate for every two visible line in the frame */
 342             for( int x = 0; x < i_picture_size_limit; x += 2)
 343             {
 344                 // y = y - y/4 {to prevent overflow} + intensity / 4
 345                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] =
 346                     p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] -
 347                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x] >> 2) +
 348                     (i_intensity >> 2);
 349                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] =
 350                     p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] -
 351                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line1_start + x + 1] >> 2) +
 352                     (i_intensity >> 2);
 353                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] =
 354                     p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] -
 355                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x] >> 2) +
 356                     (i_intensity >> 2);
 357                 p_outpic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] =
 358                     p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] -
 359                     (p_pic->p[Y_PLANE].p_pixels[i_dy_line2_start + x + 1] >> 2) +
 360                     (i_intensity >> 2);
 361                 // u = 128 {half => B&W} - intensity / 6
 362                 p_outpic->p[U_PLANE].p_pixels[i_du_line_start + (x / 2)] =
 363                     filling_const_8u;
 364                 // v = 128 {half => B&W} + intensity / 14
 365                 p_outpic->p[V_PLANE].p_pixels[i_dv_line_start + (x / 2)] =
 366                     filling_const_8v;
 367             }
 368         }
 369     }
 370 }
 371
 372 /*****************************************************************************
 373  * PackedYUVSepia: Applies sepia to one frame of the packed YUV video
 374  *****************************************************************************
 375  * This function applies sepia effext to one frame of the video by iterating
 376  * through video lines. In every pass, we calculate new values for pixels
 377  * (UYVY, VYUY, YUYV and YVYU formats are supported)
 378  *****************************************************************************/
 379 static void PackedYUVSepia( picture_t *p_pic, picture_t *p_outpic,
 380                            int i_intensity )
 381 {
 382     uint8_t *p_in, *p_in_end, *p_line_end, *p_out;
 383     int i_yindex = 1, i_uindex = 2, i_vindex = 0;
 384
 385     GetPackedYuvOffsets( p_outpic->format.i_chroma,
 386                         &i_yindex, &i_uindex, &i_vindex );
 387
 388     // prepared values to copy for U and V channels
 389     const uint8_t filling_const_8u = 128 - i_intensity / 6;
 390     const uint8_t filling_const_8v = 128 + i_intensity / 14;
 391
 392     p_in = p_pic->p[0].p_pixels;
 393     p_in_end = p_in + p_pic->p[0].i_visible_lines
 394         * p_pic->p[0].i_pitch;
 395     p_out = p_outpic->p[0].p_pixels;
 396
 397     {
 398         while( p_in < p_in_end )
 399         {
 400             p_line_end = p_in + p_pic->p[0].i_visible_pitch;
 401             while( p_in < p_line_end )
 402             {
 403                 /* calculate new, sepia values */
 404                 p_out[i_yindex] =
 405                     p_in[i_yindex] - (p_in[i_yindex] >> 2) + (i_intensity >> 2);
 406                 p_out[i_yindex + 2] =
 407                     p_in[i_yindex + 2] - (p_in[i_yindex + 2] >> 2)
 408                     + (i_intensity >> 2);
 409                 p_out[i_uindex] = filling_const_8u;
 410                 p_out[i_vindex] = filling_const_8v;
 411                 p_in += 4;
 412                 p_out += 4;
 413             }
 414             p_in += p_pic->p[0].i_pitch - p_pic->p[0].i_visible_pitch;
 415             p_out += p_outpic->p[0].i_pitch
 416                 - p_outpic->p[0].i_visible_pitch;
 417         }
 418     }
 419 }
 420
 421 /*****************************************************************************
 422  * RVSepia: Applies sepia to one frame of the RV24/RV32 video
 423  *****************************************************************************
 424  * This function applies sepia effect to one frame of the video by iterating
 425  * through video lines and calculating new values for every byte in chunks of
 426  * 3 (RV24) or 4 (RV32) bytes.
 427  *****************************************************************************/
 428 static void RVSepia( picture_t *p_pic, picture_t *p_outpic, int i_intensity )
 429 {
 430 #define SCALEBITS 10
 431 #define ONE_HALF  (1 << (SCALEBITS - 1))
 432 #define FIX(x)    ((int) ((x) * (1<<SCALEBITS) + 0.5))
 433     uint8_t *p_in, *p_in_end, *p_line_end, *p_out;
 434     bool b_isRV32 = p_pic->format.i_chroma == VLC_CODEC_RGB32;
 435     int i_rindex = 0, i_gindex = 1, i_bindex = 2;
 436
 437     GetPackedRgbIndexes( &p_outpic->format, &i_rindex, &i_gindex, &i_bindex );
 438
 439     p_in = p_pic->p[0].p_pixels;
 440     p_in_end = p_in + p_pic->p[0].i_visible_lines
 441         * p_pic->p[0].i_pitch;
 442     p_out = p_outpic->p[0].p_pixels;
 443
 444     /* Precompute values constant for this certain i_intensity, using the same
 445      * formula as YUV functions above */
 446     uint8_t r_intensity = (( FIX( 1.40200 * 255.0 / 224.0 ) * (i_intensity * 14)
 447                         + ONE_HALF )) >> SCALEBITS;
 448     uint8_t g_intensity = (( - FIX(0.34414*255.0/224.0) * ( - i_intensity / 6 )
 449                         - FIX( 0.71414 * 255.0 / 224.0) * ( i_intensity * 14 )
 450                         + ONE_HALF )) >> SCALEBITS;
 451     uint8_t b_intensity = (( FIX( 1.77200 * 255.0 / 224.0) * ( - i_intensity / 6 )
 452                         + ONE_HALF )) >> SCALEBITS;
 453
 454     while (p_in < p_in_end)
 455     {
 456         p_line_end = p_in + p_pic->p[0].i_visible_pitch;
 457         while (p_in < p_line_end)
 458         {
 459             /* do sepia: this calculation is based on the formula to calculate
 460              * YUV->RGB and RGB->YUV (in filter_picture.h) mode and that
 461              * y = y - y/4 + intensity/4 . As Y is the only channel that changes
 462              * through the whole image. After that, precomputed values are added
 463              * for each RGB channel and saved in the output image.
 464              * FIXME: needs cleanup */
 465             uint8_t i_y = ((( 66 * p_in[i_rindex] + 129 * p_in[i_gindex] +  25
 466                       * p_in[i_bindex] + 128 ) >> 8 ) * FIX(255.0/219.0))
 467                       - (((( 66 * p_in[i_rindex] + 129 * p_in[i_gindex] + 25
 468                       * p_in[i_bindex] + 128 ) >> 8 )
 469                       * FIX( 255.0 / 219.0 )) >> 2 ) + ( i_intensity >> 2 );
 470             p_out[i_rindex] = vlc_uint8(i_y + r_intensity);
 471             p_out[i_gindex] = vlc_uint8(i_y + g_intensity);
 472             p_out[i_bindex] = vlc_uint8(i_y + b_intensity);
 473             p_in += 3;
 474             p_out += 3;
 475             /* for rv32 we take 4 chunks at the time */
 476             if (b_isRV32) {
 477             /* alpha channel stays the same */
 478             *p_out++ = *p_in++;
 479             }
 480         }
 481
 482         p_in += p_pic->p[0].i_pitch - p_pic->p[0].i_visible_pitch;
 483         p_out += p_outpic->p[0].i_pitch
 484             - p_outpic->p[0].i_visible_pitch;
 485     }
 486 #undef SCALEBITS
 487 #undef ONE_HALF
 488 #undef FIX
 489 }
 490
 491 static int FilterCallback ( vlc_object_t *p_this, char const *psz_var,
 492                             vlc_value_t oldval, vlc_value_t newval,
 493                             void *p_data )
 494 {
 495     VLC_UNUSED(psz_var); VLC_UNUSED(oldval); VLC_UNUSED(p_data);
 496     filter_t *p_filter = (filter_t*)p_this;
 497     filter_sys_t *p_sys = p_filter->p_sys;
 498
 499     vlc_spin_lock( &p_sys->lock );
 500     p_sys->i_intensity = newval.i_int;
 501     vlc_spin_unlock( &p_sys->lock );
 502
 503     return VLC_SUCCESS;
 504 }