modules/codec/substext.h

   1 /*****************************************************************************
   2  * subsdec.c : text subtitle decoder
   3  *****************************************************************************
   4  * Copyright © 2011-2015 VLC authors and VideoLAN
   5  *
   6  * Authors: Laurent Aimer <fenrir@videolan.org>
   7  *          Jean-Baptiste Kempf <jb@videolan.org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify it
  10  * under the terms of the GNU Lesser General Public License as published by
  11  * the Free Software Foundation; either version 2.1 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 Lesser General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU Lesser General Public License
  20  * along with this program; if not, write to the Free Software Foundation,
  21  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #include <vlc_strings.h>
  25 #include <vlc_text_style.h>
  26
  27 typedef struct subpicture_updater_sys_region_t subpicture_updater_sys_region_t;
  28
  29 enum subpicture_updater_sys_region_flags_e
  30 {
  31     UPDT_REGION_ORIGIN_X_IS_PERCENTILE = 1 << 0,
  32     UPDT_REGION_ORIGIN_Y_IS_PERCENTILE = 1 << 1,
  33     UPDT_REGION_EXTENT_X_IS_PERCENTILE = 1 << 2,
  34     UPDT_REGION_EXTENT_Y_IS_PERCENTILE = 1 << 3,
  35     UPDT_REGION_IGNORE_BACKGROUND      = 1 << 4,
  36     UPDT_REGION_USES_GRID_COORDINATES  = 1 << 5,
  37     UPDT_REGION_FIX_DONE               = 1 << 31,
  38 };
  39
  40 #define EIA608_MARGIN  0.10
  41 #define EIA608_VISIBLE 0.80
  42 #define EIA608_ROWS 15
  43
  44 #define FONT_TO_LINE_HEIGHT_RATIO 1.06
  45
  46 struct subpicture_updater_sys_region_t
  47 {
  48     struct
  49     {
  50         int x;
  51         int y;
  52     } origin, extent;
  53     /* store above percentile meanings as modifier flags */
  54     int flags; /* subpicture_updater_sys_region_flags_e */
  55     int align; /* alignment of the region itself */
  56     int inner_align; /* alignment of content inside the region */
  57     text_style_t *p_region_style;
  58     text_segment_t *p_segments;
  59     subpicture_updater_sys_region_t *p_next;
  60 };
  61
  62 struct subpicture_updater_sys_t {
  63
  64     /* a min of one region */
  65     subpicture_updater_sys_region_t region;
  66
  67     /* styling */
  68     text_style_t *p_default_style; /* decoder (full or partial) defaults */
  69     float margin_ratio;
  70 };
  71
  72 static inline void SubpictureUpdaterSysRegionClean(subpicture_updater_sys_region_t *p_updtregion)
  73 {
  74     text_segment_ChainDelete( p_updtregion->p_segments );
  75     text_style_Delete( p_updtregion->p_region_style );
  76 }
  77
  78 static inline void SubpictureUpdaterSysRegionInit(subpicture_updater_sys_region_t *p_updtregion)
  79 {
  80     memset(p_updtregion, 0, sizeof(*p_updtregion));
  81 }
  82
  83 static inline subpicture_updater_sys_region_t *SubpictureUpdaterSysRegionNew( )
  84 {
  85     subpicture_updater_sys_region_t *p_region = malloc(sizeof(*p_region));
  86     if(p_region)
  87         SubpictureUpdaterSysRegionInit(p_region);
  88     return p_region;
  89 }
  90
  91 static inline void SubpictureUpdaterSysRegionAdd(subpicture_updater_sys_region_t *p_prev,
  92                                                  subpicture_updater_sys_region_t *p_new)
  93 {
  94     subpicture_updater_sys_region_t **pp_next = &p_prev->p_next;
  95     for(; *pp_next; pp_next = &(*pp_next)->p_next);
  96     *pp_next = p_new;
  97 }
  98
  99 static int SubpictureTextValidate(subpicture_t *subpic,
 100                                   bool has_src_changed, const video_format_t *fmt_src,
 101                                   bool has_dst_changed, const video_format_t *fmt_dst,
 102                                   mtime_t ts)
 103 {
 104     subpicture_updater_sys_t *sys = subpic->updater.p_sys;
 105     VLC_UNUSED(fmt_src); VLC_UNUSED(fmt_dst); VLC_UNUSED(ts);
 106
 107     if (!has_src_changed && !has_dst_changed)
 108         return VLC_SUCCESS;
 109
 110     subpicture_updater_sys_region_t *p_updtregion = &sys->region;
 111
 112     if (!(p_updtregion->flags & UPDT_REGION_FIX_DONE) &&
 113         subpic->b_absolute && subpic->p_region &&
 114         subpic->i_original_picture_width > 0 &&
 115         subpic->i_original_picture_height > 0)
 116     {
 117         p_updtregion->flags |= UPDT_REGION_FIX_DONE;
 118         p_updtregion->origin.x = subpic->p_region->i_x;
 119         p_updtregion->origin.y = subpic->p_region->i_y;
 120         p_updtregion->extent.x = subpic->i_original_picture_width;
 121         p_updtregion->extent.y = subpic->i_original_picture_height;
 122         p_updtregion->flags &= ~(UPDT_REGION_ORIGIN_X_IS_PERCENTILE|UPDT_REGION_ORIGIN_Y_IS_PERCENTILE|
 123                                  UPDT_REGION_EXTENT_X_IS_PERCENTILE|UPDT_REGION_EXTENT_Y_IS_PERCENTILE);
 124     }
 125
 126     return VLC_EGENERIC;
 127 }
 128
 129 static void SubpictureTextUpdate(subpicture_t *subpic,
 130                                  const video_format_t *fmt_src,
 131                                  const video_format_t *fmt_dst,
 132                                  mtime_t ts)
 133 {
 134     subpicture_updater_sys_t *sys = subpic->updater.p_sys;
 135     VLC_UNUSED(fmt_src); VLC_UNUSED(ts);
 136
 137     if (fmt_dst->i_sar_num <= 0 || fmt_dst->i_sar_den <= 0)
 138         return;
 139
 140     video_format_t fmt;
 141     video_format_Init(&fmt, VLC_CODEC_TEXT);
 142
 143     if( sys->region.flags & UPDT_REGION_USES_GRID_COORDINATES )
 144     {
 145         fmt.i_sar_num = 4;
 146         fmt.i_sar_den = 3;
 147         subpic->i_original_picture_width  = fmt_dst->i_visible_height * fmt.i_sar_num / fmt.i_sar_den;
 148         subpic->i_original_picture_height = fmt_dst->i_visible_height;
 149     }
 150     else
 151     {
 152         subpic->i_original_picture_width  = fmt_dst->i_width * fmt_dst->i_sar_num / fmt_dst->i_sar_den;
 153         subpic->i_original_picture_height = fmt_dst->i_height;
 154         fmt.i_sar_num = 1;
 155         fmt.i_sar_den = 1;
 156     }
 157
 158     subpicture_region_t **pp_last_region = &subpic->p_region;
 159
 160     for( subpicture_updater_sys_region_t *p_updtregion = &sys->region;
 161                                           p_updtregion; p_updtregion = p_updtregion->p_next )
 162     {
 163         subpicture_region_t *r = *pp_last_region = subpicture_region_New(&fmt);
 164         if (!r)
 165             return;
 166         pp_last_region = &r->p_next;
 167
 168         r->p_text = text_segment_Copy( p_updtregion->p_segments );
 169         r->i_align  = p_updtregion->inner_align | p_updtregion->align; /* we do not support text align by itself */
 170         r->b_noregionbg = p_updtregion->flags & UPDT_REGION_IGNORE_BACKGROUND;
 171         r->b_gridmode = p_updtregion->flags & UPDT_REGION_USES_GRID_COORDINATES;
 172
 173         if( r->b_gridmode )
 174         {
 175             /* Ensure correct flags are set */
 176             r->i_align &= ~(SUBPICTURE_ALIGN_RIGHT | SUBPICTURE_ALIGN_BOTTOM);
 177             r->i_align |= (SUBPICTURE_ALIGN_LEFT | SUBPICTURE_ALIGN_TOP);
 178         }
 179
 180         if (!(p_updtregion->flags & UPDT_REGION_FIX_DONE))
 181         {
 182             const float margin_ratio = sys->margin_ratio;
 183             const int   margin_h     = margin_ratio * (( r->b_gridmode ) ? (unsigned) subpic->i_original_picture_width
 184                                                                          : fmt_dst->i_visible_width );
 185             const int   margin_v     = margin_ratio * fmt_dst->i_visible_height;
 186
 187             if (r->i_align & SUBPICTURE_ALIGN_LEFT)
 188                 r->i_x = margin_h + fmt_dst->i_x_offset;
 189             else if (r->i_align & SUBPICTURE_ALIGN_RIGHT)
 190                 r->i_x = margin_h + fmt_dst->i_width - (fmt_dst->i_visible_width + fmt_dst->i_x_offset);
 191
 192             if (r->i_align & SUBPICTURE_ALIGN_TOP )
 193                 r->i_y = margin_v + fmt_dst->i_y_offset;
 194             else if (r->i_align & SUBPICTURE_ALIGN_BOTTOM )
 195                 r->i_y = margin_v + fmt_dst->i_height - (fmt_dst->i_visible_height + fmt_dst->i_y_offset);
 196
 197             if( r->b_gridmode )
 198             {
 199                 r->i_y += p_updtregion->origin.y * /* row number */
 200                          (EIA608_VISIBLE / EIA608_ROWS) *
 201                          (fmt_dst->i_visible_height - r->i_y) * FONT_TO_LINE_HEIGHT_RATIO;
 202             }
 203
 204         } else {
 205             /* FIXME it doesn't adapt on crop settings changes */
 206             r->i_x = p_updtregion->origin.x * fmt_dst->i_width  / p_updtregion->extent.x;
 207             r->i_y = p_updtregion->origin.y * fmt_dst->i_height / p_updtregion->extent.y;
 208         }
 209
 210         /* Add missing default style, if any, to all segments */
 211         for ( text_segment_t* p_segment = r->p_text; p_segment; p_segment = p_segment->p_next )
 212         {
 213             /* Add decoder defaults */
 214             if( p_segment->style )
 215                 text_style_Merge( p_segment->style, sys->p_default_style, false );
 216             else
 217                 p_segment->style = text_style_Duplicate( sys->p_default_style );
 218             /* Update all segments font sizes in pixels, *** metric used by renderers *** */
 219             /* We only do this when a fixed font size isn't set */
 220             if( p_segment->style && p_segment->style->f_font_relsize && !p_segment->style->i_font_size )
 221             {
 222                 p_segment->style->i_font_size = p_segment->style->f_font_relsize *
 223                                                 subpic->i_original_picture_height / 100;
 224             }
 225         }
 226
 227     }
 228 }
 229 static void SubpictureTextDestroy(subpicture_t *subpic)
 230 {
 231     subpicture_updater_sys_t *sys = subpic->updater.p_sys;
 232
 233     SubpictureUpdaterSysRegionClean( &sys->region );
 234     subpicture_updater_sys_region_t *p_region = sys->region.p_next;
 235     while( p_region )
 236     {
 237         subpicture_updater_sys_region_t *p_next = p_region->p_next;
 238         SubpictureUpdaterSysRegionClean( p_region );
 239         p_region = p_next;
 240     }
 241     text_style_Delete( sys->p_default_style );
 242     free(sys);
 243 }
 244
 245 static inline subpicture_t *decoder_NewSubpictureText(decoder_t *decoder)
 246 {
 247     subpicture_updater_sys_t *sys = calloc(1, sizeof(*sys));
 248     subpicture_updater_t updater = {
 249         .pf_validate = SubpictureTextValidate,
 250         .pf_update   = SubpictureTextUpdate,
 251         .pf_destroy  = SubpictureTextDestroy,
 252         .p_sys       = sys,
 253     };
 254     SubpictureUpdaterSysRegionInit( &sys->region );
 255     sys->margin_ratio = 0.04;
 256     sys->p_default_style = text_style_Create( STYLE_NO_DEFAULTS );
 257     if(unlikely(!sys->p_default_style))
 258     {
 259         free(sys);
 260         return NULL;
 261     }
 262     subpicture_t *subpic = decoder_NewSubpicture(decoder, &updater);
 263     if (!subpic)
 264     {
 265         text_style_Delete(sys->p_default_style);
 266         free(sys);
 267     }
 268     return subpic;
 269 }