research.m1stereo.tv/gitweb/ - melted/blob - src/modules/plus/filter_invert.c

   1 /*
   2  * filter_invert.c -- invert filter
   3  * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
   4  * Author: Charles Yates <charles.yates@pandora.be>
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License as published by
   8  * the Free Software Foundation; either version 2 of the License, or
   9  * (at your option) any later version.
  10  *
  11  * This program is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * along with this program; if not, write to the Free Software Foundation,
  18  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  19  */
  20
  21 #include "filter_invert.h"
  22
  23 #include <framework/mlt_frame.h>
  24
  25 #include <stdio.h>
  26 #include <stdlib.h>
  27 #include <math.h>
  28
  29 static inline int clamp( int v, int l, int u )
  30 {
  31         return v < l ? l : ( v > u ? u : v );
  32 }
  33
  34 /** Do it :-).
  35 */
  36
  37 static int filter_get_image( mlt_frame this, uint8_t **image, mlt_image_format *format, int *width, int *height, int writable )
  38 {
  39         // Get the image
  40         int error = mlt_frame_get_image( this, image, format, width, height, 1 );
  41
  42         // Only process if we have no error and a valid colour space
  43         if ( error == 0 && *format == mlt_image_yuv422 )
  44         {
  45                 uint8_t *p = *image;
  46                 uint8_t *q = *image + *width * *height * 2;
  47                 uint8_t *r = *image;
  48
  49                 while ( p != q )
  50                 {
  51                         *p ++ = clamp( 251 - *r ++, 16, 235 );
  52                         *p ++ = clamp( 256 - *r ++, 16, 240 );
  53                 }
  54         }
  55
  56         return error;
  57 }
  58
  59 /** Filter processing.
  60 */
  61
  62 static mlt_frame filter_process( mlt_filter this, mlt_frame frame )
  63 {
  64         // Push the frame filter
  65         mlt_frame_push_get_image( frame, filter_get_image );
  66         return frame;
  67 }
  68
  69 /** Constructor for the filter.
  70 */
  71
  72 mlt_filter filter_invert_init( char *arg )
  73 {
  74         mlt_filter this = mlt_filter_new( );
  75         if ( this != NULL )
  76                 this->process = filter_process;
  77         return this;
  78 }
  79