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

   1 /*****************************************************************************
   2  * mirror.c : Mirror video plugin for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2009 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
  35 #include <assert.h>
  36 #include <vlc_filter.h>
  37 #include "filter_picture.h"
  38
  39 /*****************************************************************************
  40  * Local prototypes
  41  *****************************************************************************/
  42 static int  Create      ( vlc_object_t * );
  43 static void Destroy     ( vlc_object_t * );
  44
  45 static picture_t *Filter( filter_t *, picture_t * );
  46 static void VerticalMirror( picture_t *, picture_t *, int plane, bool );
  47 static void HorizontalMirror( picture_t *, picture_t *, int, bool );
  48 static void PlanarVerticalMirror( picture_t *, picture_t *, int plane, bool );
  49 static void YUV422VerticalMirror( picture_t *, picture_t *, int plane, bool, bool );
  50 static void RV24VerticalMirror( picture_t *, picture_t *, int plane, bool );
  51 static void RV32VerticalMirror( picture_t *, picture_t *, int plane, bool );
  52
  53 static void YUV422Mirror2Pixels( uint8_t *, uint8_t *, bool );
  54
  55 static const char *const ppsz_filter_options[] = {
  56     "split", "direction", NULL
  57 };
  58
  59 /*****************************************************************************
  60  * Module descriptor
  61  *****************************************************************************/
  62 #define ORIENTATION_TEXT N_("Mirror orientation")
  63 #define ORIENTATION_LONGTEXT N_("Defines orientation of the mirror splitting. \
  64     Can be vertical or horizontal" )
  65 static const int pi_orientation_values[] = { 0, 1 };
  66 static const char *const ppsz_orientation_descriptions[] = {
  67   N_("Vertical"), N_("Horizontal") };
  68
  69 #define DIRECTION_TEXT N_("Direction")
  70 #define DIRECTION_LONGTEXT N_("Direction of the mirroring" )
  71 static const int pi_direction_values[] = { 0, 1 };
  72 static const char *const ppsz_direction_descriptions[] = {
  73   N_("Left to right/Top to bottom"), N_("Right to left/Bottom to top") };
  74
  75 #define CFG_PREFIX "mirror-"
  76
  77 vlc_module_begin ()
  78     set_description( N_("Mirror video filter") )
  79     set_shortname( N_("Mirror video" ))
  80     set_help( N_("Splits video in two same parts, like in a mirror") )
  81     set_category( CAT_VIDEO )
  82     set_subcategory( SUBCAT_VIDEO_VFILTER )
  83     set_capability( "video filter2", 0 )
  84     add_integer( CFG_PREFIX "split", 0, NULL, ORIENTATION_TEXT,
  85                 ORIENTATION_LONGTEXT, false )
  86         change_integer_list( pi_orientation_values,
  87                             ppsz_orientation_descriptions, NULL )
  88     add_integer( CFG_PREFIX "direction", 0, NULL, DIRECTION_TEXT,
  89                 DIRECTION_LONGTEXT, false )
  90         change_integer_list( pi_direction_values, ppsz_direction_descriptions,
  91                             NULL )
  92     set_callbacks( Create, Destroy )
  93 vlc_module_end ()
  94
  95 /*****************************************************************************
  96  * callback prototypes
  97  *****************************************************************************/
  98 static int FilterCallback( vlc_object_t *, char const *,
  99                            vlc_value_t, vlc_value_t, void * );
 100
 101 /*****************************************************************************
 102  * filter_sys_t: adjust filter method descriptor
 103  *****************************************************************************/
 104 struct filter_sys_t
 105 {
 106     int i_split;
 107     int i_direction;
 108     vlc_mutex_t lock;
 109 };
 110
 111 /*****************************************************************************
 112  * Create: allocates Mirror video thread output method
 113  *****************************************************************************
 114  * This function allocates and initializes a Mirror vout method.
 115  *****************************************************************************/
 116 static int Create( vlc_object_t *p_this )
 117 {
 118     filter_t *p_filter = (filter_t *)p_this;
 119     filter_sys_t *p_sys;
 120
 121     switch( p_filter->fmt_in.video.i_chroma )
 122     {
 123         CASE_PLANAR_YUV_SQUARE
 124             break;
 125         CASE_PACKED_YUV_422
 126             break;
 127         case VLC_CODEC_RGB24:
 128         case VLC_CODEC_RGB32:
 129             break;
 130
 131         default:
 132             msg_Err( p_filter, "Unsupported input chroma (%4.4s)",
 133                      (char*)&(p_filter->fmt_in.video.i_chroma) );
 134             return VLC_EGENERIC;
 135     }
 136
 137     if( p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
 138     {
 139         msg_Err( p_filter, "Input and output chromas don't match" );
 140         return VLC_EGENERIC;
 141     }
 142
 143     /* Allocate structure */
 144     p_sys = p_filter->p_sys = malloc( sizeof( filter_sys_t ) );
 145     if( p_filter->p_sys == NULL )
 146         return VLC_ENOMEM;
 147
 148     config_ChainParse( p_filter, CFG_PREFIX, ppsz_filter_options,
 149                        p_filter->p_cfg );
 150     p_sys->i_split = var_CreateGetIntegerCommand( p_filter, CFG_PREFIX "split" );
 151     p_sys->i_direction = var_CreateGetIntegerCommand( p_filter,
 152                                                     CFG_PREFIX "direction" );
 153
 154     vlc_mutex_init( &p_sys->lock );
 155
 156     var_AddCallback( p_filter, CFG_PREFIX "split", FilterCallback, NULL );
 157     var_AddCallback( p_filter, CFG_PREFIX "direction", FilterCallback, NULL );
 158
 159     p_filter->pf_video_filter = Filter;
 160
 161     return VLC_SUCCESS;
 162 }
 163
 164 /*****************************************************************************
 165  * Destroy: destroy Mirror video thread output method
 166  *****************************************************************************
 167  * Terminate an output method created by MirrorCreateOutputMethod
 168  *****************************************************************************/
 169 static void Destroy( vlc_object_t *p_this )
 170 {
 171     filter_t *p_filter = (filter_t *)p_this;
 172
 173     var_DelCallback( p_filter, CFG_PREFIX "split", FilterCallback, NULL );
 174     var_DelCallback( p_filter, CFG_PREFIX "direction", FilterCallback, NULL );
 175
 176     vlc_mutex_destroy( &p_filter->p_sys->lock );
 177     free( p_filter->p_sys );
 178 }
 179
 180 /*****************************************************************************
 181  * Render: displays previously rendered output
 182  *****************************************************************************
 183  * This function send the currently rendered image to Mirror image, waits
 184  * until it is displayed and switch the two rendering buffers, preparing next
 185  * frame.
 186  *****************************************************************************/
 187 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
 188 {
 189     picture_t *p_outpic;
 190     bool b_vertical_split, b_left_to_right;
 191     int i_index;
 192
 193     if( !p_pic ) return NULL;
 194
 195     filter_sys_t *p_sys = p_filter->p_sys;
 196     vlc_mutex_lock( &p_sys->lock );
 197     b_vertical_split = p_sys->i_split == 0 ? true : false;
 198     b_left_to_right = p_sys->i_direction == 0 ? true : false;
 199     vlc_mutex_unlock( &p_sys->lock );
 200
 201     p_outpic = filter_NewPicture( p_filter );
 202     if( !p_outpic )
 203     {
 204         msg_Warn( p_filter, "can't get output picture" );
 205         picture_Release( p_pic );
 206         return NULL;
 207     }
 208
 209     for( i_index = 0 ; i_index < p_pic->i_planes ; i_index++ )
 210     {
 211         if ( b_vertical_split )
 212             VerticalMirror( p_pic, p_outpic, i_index, b_left_to_right );
 213         else
 214             HorizontalMirror( p_pic, p_outpic, i_index, b_left_to_right );
 215     }
 216
 217     return CopyInfoAndRelease( p_outpic, p_pic );
 218 }
 219
 220 /*****************************************************************************
 221  * VerticalMirror: Mirrors vertically image
 222  *****************************************************************************
 223  * This function is a simple delegate to concrete function for vertical
 224  * mirroring depending on the input format.
 225  *****************************************************************************/
 226 static void VerticalMirror( picture_t *p_pic, picture_t *p_outpic, int i_plane,
 227                            bool b_left_to_right )
 228 {
 229     switch( p_pic->format.i_chroma )
 230     {
 231         CASE_PLANAR_YUV_SQUARE
 232             PlanarVerticalMirror( p_pic, p_outpic, i_plane, b_left_to_right );
 233             break;
 234         case VLC_CODEC_YUYV:
 235         case VLC_CODEC_YVYU:
 236             YUV422VerticalMirror( p_pic, p_outpic, i_plane, b_left_to_right,
 237                                  true );
 238             break;
 239         case VLC_CODEC_UYVY:
 240         case VLC_CODEC_CYUV:
 241             YUV422VerticalMirror( p_pic, p_outpic, i_plane, b_left_to_right,
 242                                  false );
 243             break;
 244         case VLC_CODEC_RGB24:
 245             RV24VerticalMirror( p_pic, p_outpic, i_plane, b_left_to_right );
 246             break;
 247         case VLC_CODEC_RGB32:
 248             RV32VerticalMirror( p_pic, p_outpic, i_plane, b_left_to_right );
 249             break;
 250         default:
 251             assert( false );
 252     }
 253 }
 254
 255 /*****************************************************************************
 256  * PlanarVerticalMirror: Mirrors vertically image byte by byte
 257  *****************************************************************************
 258  * This function mirrors image vertically. It iterates for all lines in
 259  * image and for every line, it mirrors byte for byte if needed.
 260  * This function works for planar formats only.
 261  *****************************************************************************/
 262 static void PlanarVerticalMirror( picture_t *p_pic, picture_t *p_outpic,
 263                                  int i_plane, bool b_left_to_right )
 264 {
 265     uint8_t *p_in, *p_in_end, *p_line_start, *p_line_end, *p_out;
 266
 267     p_in = p_pic->p[i_plane].p_pixels;
 268     p_in_end = p_in + p_pic->p[i_plane].i_visible_lines
 269         * p_pic->p[i_plane].i_pitch;
 270     p_out = p_outpic->p[i_plane].p_pixels;
 271
 272     while( p_in < p_in_end ) {
 273         p_line_start = p_in;
 274         p_line_end = p_in + p_pic->p[i_plane].i_visible_pitch;
 275         while( p_in < p_line_end )
 276         {
 277             /* are we in the left part of the line */
 278             if ( p_in < p_line_start + ( p_line_end - p_line_start ) / 2 )
 279             {
 280                 if ( b_left_to_right )
 281                     *p_out = *p_in;
 282                 else
 283                     *p_out = *( p_line_end - ( p_in - p_line_start ) );
 284             }
 285             else
 286             {
 287                 if ( b_left_to_right )
 288                     *p_out = *( p_line_start + ( p_line_end - p_in ) );
 289                 else
 290                     *p_out = *p_in;
 291             }
 292             p_in++;
 293             p_out++;
 294         }
 295         p_in += p_pic->p[i_plane].i_pitch - p_pic->p[i_plane].i_visible_pitch;
 296         p_out += p_outpic->p[i_plane].i_pitch
 297             - p_outpic->p[i_plane].i_visible_pitch;
 298     }
 299 }
 300
 301 /*****************************************************************************
 302  * YUV422VerticalMirror: Mirrors vertically image byte by byte for YUV422 format
 303  *****************************************************************************
 304  * This function mirrors image vertically. It iterates for all lines in
 305  * image and for every line, it iterates for 4-byte chucks, properly mirroring
 306  * them vertically (swapping Y components and keeping Cb and Cr components).
 307  * This function works only for YUV422 packed formats.
 308  *****************************************************************************/
 309 static void YUV422VerticalMirror( picture_t *p_pic, picture_t *p_outpic,
 310                                  int i_plane, bool b_left_to_right,
 311                                  bool b_y_is_odd )
 312 {
 313     uint8_t *p_in, *p_in_end, *p_line_start, *p_line_end, *p_out;
 314
 315     p_in = p_pic->p[i_plane].p_pixels;
 316     p_in_end = p_in + p_pic->p[i_plane].i_visible_lines
 317         * p_pic->p[i_plane].i_pitch;
 318     p_out = p_outpic->p[i_plane].p_pixels;
 319
 320     while( p_in < p_in_end )
 321     {
 322         p_line_start = p_in;
 323         p_line_end = p_in + p_pic->p[i_plane].i_visible_pitch;
 324         while( p_in < p_line_end )
 325         {
 326             /* are we in the left part of the line */
 327             if ( p_in < p_line_start + ( p_line_end - p_line_start ) / 2 )
 328             {
 329                 if ( b_left_to_right )
 330                 {
 331                     *p_out++ = *p_in++;
 332                     *p_out++ = *p_in++;
 333                     *p_out++ = *p_in++;
 334                     *p_out++ = *p_in++;
 335                 }
 336                 else
 337                 {
 338                     uint8_t *p_start = p_line_end - ( p_in - p_line_start );
 339                     YUV422Mirror2Pixels( p_out, p_start, b_y_is_odd );
 340                     p_in += 4;
 341                     p_out += 4;
 342                 }
 343             }
 344             else
 345             {
 346                 if ( b_left_to_right )
 347                 {
 348                     uint8_t *p_start = p_line_end - ( p_in - p_line_start );
 349                     YUV422Mirror2Pixels( p_out, p_start, b_y_is_odd );
 350                     p_in += 4;
 351                     p_out += 4;
 352                 }
 353                 else
 354                 {
 355                     *p_out++ = *p_in++;
 356                     *p_out++ = *p_in++;
 357                     *p_out++ = *p_in++;
 358                     *p_out++ = *p_in++;
 359                 }
 360             }
 361         }
 362         p_in += p_pic->p[i_plane].i_pitch - p_pic->p[i_plane].i_visible_pitch;
 363         p_out += p_outpic->p[i_plane].i_pitch
 364             - p_outpic->p[i_plane].i_visible_pitch;
 365     }
 366 }
 367
 368 /*****************************************************************************
 369  * YUV422Mirror2Pixels: Mirrors 2 consecutive pixels
 370  *****************************************************************************
 371  * This function mirrors two consecutive pixels of 4 byte size. Depending of
 372  * position of Y components (b_y_is_odd is true if Y components are first and
 373  * third (like in YUYV or YVYU), they are properly swapped, and Cb and Cr
 374  * component positions are preserved.
 375  *****************************************************************************/
 376 static void YUV422Mirror2Pixels( uint8_t* p_dst, uint8_t *p_src,
 377                                 bool b_y_is_odd )
 378 {
 379     if ( b_y_is_odd )
 380     {
 381         /* swap Y components */
 382         *p_dst = *( p_src + 2 );
 383         *( p_dst + 2 ) = *p_src;
 384         /* copy Cb and Cr components */
 385         *( p_dst + 1 ) = *( p_src + 1 );
 386         *( p_dst + 3 ) = *( p_src + 3 );
 387     }
 388     else{
 389         /* swap Y components */
 390         *( p_dst + 1 )= *( p_src + 3 );
 391         *( p_dst + 3 ) = *( p_src + 1);
 392         /* copy Cb and Cr components */
 393         *p_dst = *( p_src + 2 );
 394         *( p_dst + 2 ) = *p_src;
 395     }
 396 }
 397
 398 /*****************************************************************************
 399  * RV24VerticalMirror: Mirrors vertically image byte by byte for RV24 format
 400  *****************************************************************************
 401  * This function mirrors image vertically. It iterates for all lines in
 402  * image and for every line, it iterates for 3-byte chunks.
 403  * This function works only for RV24 formats.
 404  *****************************************************************************/
 405 static void RV24VerticalMirror( picture_t *p_pic, picture_t *p_outpic,
 406                                  int i_plane, bool b_left_to_right )
 407 {
 408     uint8_t *p_in, *p_in_end, *p_line_start, *p_line_end, *p_out;
 409
 410     p_in = p_pic->p[i_plane].p_pixels;
 411     p_in_end = p_in + p_pic->p[i_plane].i_visible_lines
 412         * p_pic->p[i_plane].i_pitch;
 413     p_out = p_outpic->p[i_plane].p_pixels;
 414
 415     while( p_in < p_in_end )
 416     {
 417         p_line_start = p_in;
 418         p_line_end = p_in + p_pic->p[i_plane].i_visible_pitch;
 419         while( p_in < p_line_end )
 420         {
 421             /* are we in the left part of the line */
 422             if ( p_in < p_line_start + ( p_line_end - p_line_start ) / 2 )
 423             {
 424                 if ( b_left_to_right )
 425                 {
 426                     *p_out++ = *p_in++;
 427                     *p_out++ = *p_in++;
 428                     *p_out++ = *p_in++;
 429                 }
 430                 else
 431                 {
 432                     uint8_t *p_pixel = p_line_end - ( p_in - p_line_start );
 433                     p_in += 3;
 434                     *p_out++ = *p_pixel++;
 435                     *p_out++ = *p_pixel++;
 436                     *p_out++ = *p_pixel++;
 437                 }
 438             }
 439             else
 440             {
 441                 if ( b_left_to_right )
 442                 {
 443                     uint8_t *p_pixel = p_line_end - ( p_in - p_line_start );
 444                     p_in += 3;
 445                     *p_out++ = *p_pixel++;
 446                     *p_out++ = *p_pixel++;
 447                     *p_out++ = *p_pixel++;
 448                 }
 449                 else
 450                 {
 451                     *p_out++ = *p_in++;
 452                     *p_out++ = *p_in++;
 453                     *p_out++ = *p_in++;
 454                 }
 455             }
 456         }
 457         p_in += p_pic->p[i_plane].i_pitch - p_pic->p[i_plane].i_visible_pitch;
 458         p_out += p_outpic->p[i_plane].i_pitch
 459             - p_outpic->p[i_plane].i_visible_pitch;
 460     }
 461 }
 462
 463 /*****************************************************************************
 464  * RV32VerticalMirror: Mirrors vertically image byte by byte for RV32 format
 465  *****************************************************************************
 466  * This function mirrors image vertically. It iterates for all lines in
 467  * image and for every line, it iterates for 4-byte chunks as 32-bit pointers.
 468  * This function works only for RV32 formats.
 469  *****************************************************************************/
 470 static void RV32VerticalMirror( picture_t *p_pic, picture_t *p_outpic,
 471                                  int i_plane, bool b_left_to_right )
 472 {
 473     uint8_t *p_in, *p_in_end, *p_out;
 474
 475     p_in = p_pic->p[i_plane].p_pixels;
 476     p_in_end = p_in + p_pic->p[i_plane].i_visible_lines
 477         * p_pic->p[i_plane].i_pitch;
 478     p_out = p_outpic->p[i_plane].p_pixels;
 479
 480     while( p_in < p_in_end )
 481     {
 482         uint32_t *p_in32, *p_out32, *p_line_start32, *p_line_end32;
 483         p_in32 = (uint32_t*) p_in;
 484         p_out32 = (uint32_t*) p_out;
 485         p_line_start32 = p_in32;
 486         p_line_end32 = (uint32_t*) ( p_in + p_pic->p[i_plane].i_visible_pitch) ;
 487
 488         while( p_in32 < p_line_end32 )
 489         {
 490             /* are we in the left part of the line */
 491             if ( p_in32 < p_line_start32 + ( p_line_end32 - p_line_start32 ) / 2 )
 492             {
 493                 if ( b_left_to_right )
 494                 {
 495                     *p_out32++ = *p_in32++;
 496                 }
 497                 else
 498                 {
 499                     uint32_t *p_pixel32 = p_line_end32 - ( p_in32 - p_line_start32 );
 500                     p_in32++;
 501                     *p_out++ = *p_pixel32;
 502                 }
 503             }
 504             else
 505             {
 506                 if ( b_left_to_right )
 507                 {
 508                     uint32_t *p_pixel32 = p_line_end32 - ( p_in32 - p_line_start32 );
 509                     p_in32++;
 510                     *p_out++ = *p_pixel32;
 511                 }
 512                 else
 513                 {
 514                     *p_out32++ = *p_in32++;
 515                 }
 516             }
 517         }
 518         p_in = (uint8_t*) p_in32;
 519         p_out = (uint8_t*) p_out32;
 520         p_in += p_pic->p[i_plane].i_pitch - p_pic->p[i_plane].i_visible_pitch;
 521         p_out += p_outpic->p[i_plane].i_pitch
 522             - p_outpic->p[i_plane].i_visible_pitch;
 523     }
 524 }
 525
 526 /*****************************************************************************
 527  * HorizontalMirror: Mirrors horizontally image byte by byte
 528  *****************************************************************************
 529  * This function mirrors image horizontally. It iterates for all lines in
 530  * image and for every line, determines if it should be copied, and if it does,
 531  * finds opposite line in picture and copies current byte from opposite line.
 532  * This function works both for planar, packed and RV24 formats.
 533  *****************************************************************************/
 534 static void HorizontalMirror( picture_t *p_pic, picture_t *p_outpic, int i_plane,
 535                              bool b_top_to_bottom )
 536 {
 537     uint8_t *p_in, *p_in_end, *p_line_start, *p_line_end, *p_out;
 538
 539     int i_curr_line = 0;
 540     int i_max_lines = p_pic->p[i_plane].i_visible_lines;
 541
 542     p_in = p_pic->p[i_plane].p_pixels;
 543     p_in_end = p_in + p_pic->p[i_plane].i_visible_lines
 544         * p_pic->p[i_plane].i_pitch;
 545     p_out = p_outpic->p[i_plane].p_pixels;
 546
 547     while( p_in < p_in_end )
 548     {
 549         p_line_start = p_in;
 550         p_line_end = p_in + p_pic->p[i_plane].i_visible_pitch;
 551         while( p_in < p_line_end )
 552         {
 553             uint8_t *p_inverse_line;
 554             /* are we in the upper part of the picture */
 555             if ( i_curr_line < i_max_lines/2 )
 556             {
 557                 if ( b_top_to_bottom )
 558                 {
 559                     *p_out = *p_in;
 560                 }
 561                 else
 562                 {
 563                     /* determines line inverse to current line */
 564                     p_inverse_line = p_pic->p[i_plane].p_pixels +
 565                         ( i_max_lines - i_curr_line - 1 ) * p_pic->p[i_plane].i_pitch;
 566                     *p_out = *( p_inverse_line + ( p_in - p_line_start ) );
 567                 }
 568             }
 569             else
 570             {
 571                 if ( b_top_to_bottom )
 572                 {
 573                     /* determines line inverse to current line */
 574                     p_inverse_line = p_pic->p[i_plane].p_pixels +
 575                         ( i_max_lines - i_curr_line - 1 ) * p_pic->p[i_plane].i_pitch;
 576                     *p_out = *( p_inverse_line + ( p_in - p_line_start ) );
 577                 }
 578                 else
 579                 {
 580                     *p_out = *p_in;
 581                 }
 582             }
 583             p_in++;
 584             p_out++;
 585         }
 586         i_curr_line++;
 587         p_in += p_pic->p[i_plane].i_pitch - p_pic->p[i_plane].i_visible_pitch;
 588         p_out += p_outpic->p[i_plane].i_pitch
 589             - p_outpic->p[i_plane].i_visible_pitch;
 590     }
 591 }
 592
 593 static int FilterCallback ( vlc_object_t *p_this, char const *psz_var,
 594                             vlc_value_t oldval, vlc_value_t newval, void *p_data )
 595 {
 596     (void)oldval;    (void)p_data;
 597     filter_t *p_filter = (filter_t*)p_this;
 598     filter_sys_t *p_sys = p_filter->p_sys;
 599
 600     if( !strcmp( psz_var, CFG_PREFIX "split" ) )
 601     {
 602         vlc_mutex_lock( &p_sys->lock );
 603         p_sys->i_split = newval.i_int;
 604         vlc_mutex_unlock( &p_sys->lock );
 605     }
 606     else /* CFG_PREFIX "direction" */
 607     {
 608         vlc_mutex_lock( &p_sys->lock );
 609         p_sys->i_direction = newval.i_int;
 610         vlc_mutex_unlock( &p_sys->lock );
 611     }
 612
 613     return VLC_SUCCESS;
 614 }