modules/video_filter/scale.c

   1 /*****************************************************************************
   2  * scale.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 VLC authors and VideoLAN
   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 it
  12  * under the terms of the GNU Lesser General Public License as published by
  13  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  20  *
  21  * You should have received a copy of the GNU Lesser General Public License
  22  * along with this program; if not, write to the Free Software Foundation,
  23  * 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     video_format_ScaleCropAr( &p_filter->fmt_out.video, &p_filter->fmt_in.video );
  71     p_filter->pf_video_filter = Filter;
  72
  73     msg_Dbg( p_filter, "%ix%i -> %ix%i", p_filter->fmt_in.video.i_width,
  74              p_filter->fmt_in.video.i_height, p_filter->fmt_out.video.i_width,
  75              p_filter->fmt_out.video.i_height );
  76
  77     return VLC_SUCCESS;
  78 }
  79
  80 /****************************************************************************
  81  * Filter: the whole thing
  82  ****************************************************************************/
  83 static picture_t *Filter( filter_t *p_filter, picture_t *p_pic )
  84 {
  85     picture_t *p_pic_dst;
  86     int i_plane;
  87
  88     if( !p_pic ) return NULL;
  89
  90     if( (p_filter->fmt_in.video.i_height == 0) ||
  91         (p_filter->fmt_in.video.i_width == 0) )
  92         return NULL;
  93
  94     if( (p_filter->fmt_out.video.i_height == 0) ||
  95         (p_filter->fmt_out.video.i_width == 0) )
  96         return NULL;
  97
  98     video_format_ScaleCropAr( &p_filter->fmt_out.video, &p_filter->fmt_in.video );
  99
 100     /* Request output picture */
 101     p_pic_dst = filter_NewPicture( p_filter );
 102     if( !p_pic_dst )
 103     {
 104         picture_Release( p_pic );
 105         return NULL;
 106     }
 107
 108     if( p_filter->fmt_in.video.i_chroma != VLC_CODEC_RGBA &&
 109         p_filter->fmt_in.video.i_chroma != VLC_CODEC_RGB32 )
 110     {
 111         for( i_plane = 0; i_plane < p_pic_dst->i_planes; i_plane++ )
 112         {
 113             const int i_src_pitch    = p_pic->p[i_plane].i_pitch;
 114             const int i_dst_pitch    = p_pic_dst->p[i_plane].i_pitch;
 115             const int i_src_height   = p_filter->fmt_in.video.i_height;
 116             const int i_src_width    = p_filter->fmt_in.video.i_width;
 117             const int i_dst_height   = p_filter->fmt_out.video.i_height;
 118             const int i_dst_width    = p_filter->fmt_out.video.i_width;
 119             const int i_dst_visible_lines =
 120                                        p_pic_dst->p[i_plane].i_visible_lines;
 121             const int i_dst_visible_pitch =
 122                                        p_pic_dst->p[i_plane].i_visible_pitch;
 123             const int i_dst_hidden_pitch  = i_dst_pitch - i_dst_visible_pitch;
 124 #define SHIFT_SIZE 16
 125             const int i_height_coef  = ( i_src_height << SHIFT_SIZE )
 126                                        / i_dst_height;
 127             const int i_width_coef   = ( i_src_width << SHIFT_SIZE )
 128                                        / i_dst_width;
 129             const int i_src_height_1 = i_src_height - 1;
 130             const int i_src_width_1  = i_src_width - 1;
 131
 132             uint8_t *p_src = p_pic->p[i_plane].p_pixels;
 133             uint8_t *p_dst = p_pic_dst->p[i_plane].p_pixels;
 134             uint8_t *p_dstendline = p_dst + i_dst_visible_pitch;
 135             const uint8_t *p_dstend = p_dst + i_dst_visible_lines*i_dst_pitch;
 136
 137             const int i_shift_height = i_dst_height / i_src_height;
 138             const int i_shift_width = i_dst_width / i_src_width;
 139
 140             int l = 1<<(SHIFT_SIZE-i_shift_height);
 141             for( ; p_dst < p_dstend;
 142                  p_dst += i_dst_hidden_pitch,
 143                  p_dstendline += i_dst_pitch, l += i_height_coef )
 144             {
 145                 int k = 1<<(SHIFT_SIZE-i_shift_width);
 146                 uint8_t *p_srcl = p_src
 147                        + (__MIN( i_src_height_1, l >> SHIFT_SIZE )*i_src_pitch);
 148
 149                 for( ; p_dst < p_dstendline; p_dst++, k += i_width_coef )
 150                 {
 151                     *p_dst = p_srcl[__MIN( i_src_width_1, k >> SHIFT_SIZE )];
 152                 }
 153             }
 154         }
 155     }
 156     else /* RGBA */
 157     {
 158         const int i_src_pitch = p_pic->p->i_pitch;
 159         const int i_dst_pitch = p_pic_dst->p->i_pitch;
 160         const int i_src_height   = p_filter->fmt_in.video.i_height;
 161         const int i_src_width    = p_filter->fmt_in.video.i_width;
 162         const int i_dst_height   = p_filter->fmt_out.video.i_height;
 163         const int i_dst_width    = p_filter->fmt_out.video.i_width;
 164         const int i_dst_visible_lines =
 165                                    p_pic_dst->p->i_visible_lines;
 166         const int i_dst_visible_pitch =
 167                                    p_pic_dst->p->i_visible_pitch;
 168         const int i_dst_hidden_pitch  = i_dst_pitch - i_dst_visible_pitch;
 169         const int i_height_coef  = ( i_src_height << SHIFT_SIZE )
 170                                    / i_dst_height;
 171         const int i_width_coef   = ( i_src_width << SHIFT_SIZE )
 172                                    / i_dst_width;
 173         const int i_src_height_1 = i_src_height - 1;
 174         const int i_src_width_1  = i_src_width - 1;
 175
 176         uint32_t *p_src = (uint32_t*)p_pic->p->p_pixels;
 177         uint32_t *p_dst = (uint32_t*)p_pic_dst->p->p_pixels;
 178         uint32_t *p_dstendline = p_dst + (i_dst_visible_pitch>>2);
 179         const uint32_t *p_dstend = p_dst + i_dst_visible_lines*(i_dst_pitch>>2);
 180
 181         const int i_shift_height = i_dst_height / i_src_height;
 182         const int i_shift_width = i_dst_width / i_src_width;
 183
 184         int l = 1<<(SHIFT_SIZE-i_shift_height);
 185         for( ; p_dst < p_dstend;
 186              p_dst += (i_dst_hidden_pitch>>2),
 187              p_dstendline += (i_dst_pitch>>2),
 188              l += i_height_coef )
 189         {
 190             int k = 1<<(SHIFT_SIZE-i_shift_width);
 191             uint32_t *p_srcl = p_src
 192                     + (__MIN( i_src_height_1, l >> SHIFT_SIZE )*(i_src_pitch>>2));
 193             for( ; p_dst < p_dstendline; p_dst++, k += i_width_coef )
 194             {
 195                 *p_dst = p_srcl[__MIN( i_src_width_1, k >> SHIFT_SIZE )];
 196             }
 197         }
 198     }
 199
 200     picture_CopyProperties( p_pic_dst, p_pic );
 201     picture_Release( p_pic );
 202     return p_pic_dst;
 203 }