modules/video_filter/scale.c

   1 /*****************************************************************************
   2  * resize.c: video scaling module for YUVP/A, I420 and RGBA pictures
   3  *  Uses the low quality "nearest neighbour" algorithm.
   4  *****************************************************************************
   5  * Copyright (C) 2003-2007 the VideoLAN team
   6  * $Id$
   7  *
   8  * Authors: Gildas Bazin <gbazin@videolan.org>
   9  *          Antoine Cellerier <dionoea @t videolan dot org>
  10  *
  11  * This program is free software; you can redistribute it and/or modify
  12  * it under the terms of the GNU General Public License as published by
  13  * the Free Software Foundation; either version 2 of the License, or
  14  * (at your option) any later version.
  15  *
  16  * This program is distributed in the hope that it will be useful,
  17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19  * GNU General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU General Public License
  22  * along with this program; if not, write to the Free Software
  23  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  24  *****************************************************************************/
  25
  26 /*****************************************************************************
  27  * Preamble
  28  *****************************************************************************/
  29 #ifdef HAVE_CONFIG_H
  30 # include "config.h"
  31 #endif
  32
  33 #include <vlc_common.h>
  34 #include <vlc_plugin.h>
  35 #include <vlc_filter.h>
  36
  37 /****************************************************************************
  38  * Local prototypes
  39  ****************************************************************************/
  40 static int  OpenFilter ( vlc_object_t * );
  41 static picture_t *Filter( filter_t *, picture_t * );
  42
  43 /*****************************************************************************
  44  * Module descriptor
  45  *****************************************************************************/
  46 vlc_module_begin ()
  47     set_description( N_("Video scaling filter") )
  48     set_capability( "video filter2", 10 )
  49     set_callbacks( OpenFilter, NULL )
  50 vlc_module_end ()
  51
  52 /*****************************************************************************
  53  * OpenFilter: probe the filter and return score
  54  *****************************************************************************/
  55 static int OpenFilter( vlc_object_t *p_this )
  56 {
  57     filter_t *p_filter = (filter_t*)p_this;
  58
  59     if( ( p_filter->fmt_in.video.i_chroma != VLC_CODEC_YUVP &&
  60           p_filter->fmt_in.video.i_chroma != VLC_CODEC_YUVA &&
  61           p_filter->fmt_in.video.i_chroma != VLC_CODEC_I420 &&
  62           p_filter->fmt_in.video.i_chroma != VLC_CODEC_YV12 &&
  63           p_filter->fmt_in.video.i_chroma != VLC_CODEC_RGB32 &&
  64           p_filter->fmt_in.video.i_chroma != VLC_CODEC_RGBA ) ||
  65         p_filter->fmt_in.video.i_chroma != p_filter->fmt_out.video.i_chroma )
  66     {
  67         return VLC_EGENERIC;
  68     }
  69
  70     p_filter->pf_video_filter = Filter;
  71
  72     msg_Dbg( p_filter, "%ix%i -> %ix%i", p_filter->fmt_in.video.i_width,
  73              p_filter->fmt_in.video.i_height, p_filter->fmt_out.video.i_width,
  74              p_filter->fmt_out.video.i_height );
  75
  76     return VLC_SUCCESS;
  77 }
  78
  79 /****************************************************************************
  80  * Filter: the whole thing
  81  ****************************************************************************/
  82 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
  83 {
  84     picture_t *p_pic_dst;
  85     int i_plane;
  86
  87     if( !p_pic ) return NULL;
  88
  89     if( (p_filter->fmt_in.video.i_height == 0) ||
  90         (p_filter->fmt_in.video.i_width == 0) )
  91         return NULL;
  92
  93     if( (p_filter->fmt_out.video.i_height == 0) ||
  94         (p_filter->fmt_out.video.i_width == 0) )
  95         return NULL;
  96
  97     /* Request output picture */
  98     p_pic_dst = filter_NewPicture( p_filter );
  99     if( !p_pic_dst )
 100     {
 101         picture_Release( p_pic );
 102         return NULL;
 103     }
 104
 105     if( p_filter->fmt_in.video.i_chroma != VLC_CODEC_RGBA &&
 106         p_filter->fmt_in.video.i_chroma != VLC_CODEC_RGB32 )
 107     {
 108         for( i_plane = 0; i_plane < p_pic_dst->i_planes; i_plane++ )
 109         {
 110             const int i_src_pitch    = p_pic->p[i_plane].i_pitch;
 111             const int i_dst_pitch    = p_pic_dst->p[i_plane].i_pitch;
 112             const int i_src_height   = p_filter->fmt_in.video.i_height;
 113             const int i_src_width    = p_filter->fmt_in.video.i_width;
 114             const int i_dst_height   = p_filter->fmt_out.video.i_height;
 115             const int i_dst_width    = p_filter->fmt_out.video.i_width;
 116             const int i_dst_visible_lines =
 117                                        p_pic_dst->p[i_plane].i_visible_lines;
 118             const int i_dst_visible_pitch =
 119                                        p_pic_dst->p[i_plane].i_visible_pitch;
 120             const int i_dst_hidden_pitch  = i_dst_pitch - i_dst_visible_pitch;
 121 #define SHIFT_SIZE 16
 122             const int i_height_coef  = ( i_src_height << SHIFT_SIZE )
 123                                        / i_dst_height;
 124             const int i_width_coef   = ( i_src_width << SHIFT_SIZE )
 125                                        / i_dst_width;
 126             const int i_src_height_1 = i_src_height - 1;
 127             const int i_src_width_1  = i_src_width - 1;
 128
 129             uint8_t *p_src = p_pic->p[i_plane].p_pixels;
 130             uint8_t *p_dst = p_pic_dst->p[i_plane].p_pixels;
 131             uint8_t *p_dstendline = p_dst + i_dst_visible_pitch;
 132             const uint8_t *p_dstend = p_dst + i_dst_visible_lines*i_dst_pitch;
 133
 134             const int i_shift_height = i_dst_height / i_src_height;
 135             const int i_shift_width = i_dst_width / i_src_width;
 136
 137             int l = 1<<(SHIFT_SIZE-i_shift_height);
 138             for( ; p_dst < p_dstend;
 139                  p_dst += i_dst_hidden_pitch,
 140                  p_dstendline += i_dst_pitch, l += i_height_coef )
 141             {
 142                 int k = 1<<(SHIFT_SIZE-i_shift_width);
 143                 uint8_t *p_srcl = p_src
 144                        + (__MIN( i_src_height_1, l >> SHIFT_SIZE )*i_src_pitch);
 145
 146                 for( ; p_dst < p_dstendline; p_dst++, k += i_width_coef )
 147                 {
 148                     *p_dst = p_srcl[__MIN( i_src_width_1, k >> SHIFT_SIZE )];
 149                 }
 150             }
 151         }
 152     }
 153     else /* RGBA */
 154     {
 155         const int i_src_pitch = p_pic->p->i_pitch;
 156         const int i_dst_pitch = p_pic_dst->p->i_pitch;
 157         const int i_src_height   = p_filter->fmt_in.video.i_height;
 158         const int i_src_width    = p_filter->fmt_in.video.i_width;
 159         const int i_dst_height   = p_filter->fmt_out.video.i_height;
 160         const int i_dst_width    = p_filter->fmt_out.video.i_width;
 161         const int i_dst_visible_lines =
 162                                    p_pic_dst->p->i_visible_lines;
 163         const int i_dst_visible_pitch =
 164                                    p_pic_dst->p->i_visible_pitch;
 165         const int i_dst_hidden_pitch  = i_dst_pitch - i_dst_visible_pitch;
 166         const int i_height_coef  = ( i_src_height << SHIFT_SIZE )
 167                                    / i_dst_height;
 168         const int i_width_coef   = ( i_src_width << SHIFT_SIZE )
 169                                    / i_dst_width;
 170         const int i_src_height_1 = i_src_height - 1;
 171         const int i_src_width_1  = i_src_width - 1;
 172
 173         uint32_t *p_src = (uint32_t*)p_pic->p->p_pixels;
 174         uint32_t *p_dst = (uint32_t*)p_pic_dst->p->p_pixels;
 175         uint32_t *p_dstendline = p_dst + (i_dst_visible_pitch>>2);
 176         const uint32_t *p_dstend = p_dst + i_dst_visible_lines*(i_dst_pitch>>2);
 177
 178         const int i_shift_height = i_dst_height / i_src_height;
 179         const int i_shift_width = i_dst_width / i_src_width;
 180
 181         int l = 1<<(SHIFT_SIZE-i_shift_height);
 182         for( ; p_dst < p_dstend;
 183              p_dst += (i_dst_hidden_pitch>>2),
 184              p_dstendline += (i_dst_pitch>>2),
 185              l += i_height_coef )
 186         {
 187             int k = 1<<(SHIFT_SIZE-i_shift_width);
 188             uint32_t *p_srcl = p_src
 189                     + (__MIN( i_src_height_1, l >> SHIFT_SIZE )*(i_src_pitch>>2));
 190             for( ; p_dst < p_dstendline; p_dst++, k += i_width_coef )
 191             {
 192                 *p_dst = p_srcl[__MIN( i_src_width_1, k >> SHIFT_SIZE )];
 193             }
 194         }
 195     }
 196
 197     picture_CopyProperties( p_pic_dst, p_pic );
 198     picture_Release( p_pic );
 199     return p_pic_dst;
 200 }