src/lib/subtitle_decoder.cc

   1 /*
   2     Copyright (C) 2013-2016 Carl Hetherington <cth@carlh.net>
   3
   4     This file is part of DCP-o-matic.
   5
   6     DCP-o-matic 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     DCP-o-matic 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 DCP-o-matic.  If not, see <http://www.gnu.org/licenses/>.
  18
  19 */
  20
  21 #include "subtitle_decoder.h"
  22 #include "subtitle_content.h"
  23 #include "util.h"
  24 #include <sub/subtitle.h>
  25 #include <boost/shared_ptr.hpp>
  26 #include <boost/foreach.hpp>
  27 #include <boost/algorithm/string.hpp>
  28 #include <iostream>
  29
  30 using std::list;
  31 using std::cout;
  32 using std::string;
  33 using std::min;
  34 using boost::shared_ptr;
  35 using boost::optional;
  36 using boost::function;
  37
  38 SubtitleDecoder::SubtitleDecoder (
  39         Decoder* parent,
  40         shared_ptr<const SubtitleContent> c,
  41         function<list<ContentTimePeriod> (ContentTimePeriod, bool)> image_during,
  42         function<list<ContentTimePeriod> (ContentTimePeriod, bool)> text_during
  43         )
  44         : DecoderPart (parent)
  45         , _content (c)
  46         , _image_during (image_during)
  47         , _text_during (text_during)
  48 {
  49
  50 }
  51
  52 /** Called by subclasses when an image subtitle is ready.
  53  *  @param period Period of the subtitle.
  54  *  @param image Subtitle image.
  55  *  @param rect Area expressed as a fraction of the video frame that this subtitle
  56  *  is for (e.g. a width of 0.5 means the width of the subtitle is half the width
  57  *  of the video frame)
  58  */
  59 void
  60 SubtitleDecoder::give_image (ContentTimePeriod period, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
  61 {
  62         _decoded_image.push_back (ContentImageSubtitle (period, image, rect));
  63 }
  64
  65 void
  66 SubtitleDecoder::give_text (ContentTimePeriod period, list<dcp::SubtitleString> s)
  67 {
  68         /* We must escape < and > in strings, otherwise they might confuse our subtitle
  69            renderer (which uses some HTML-esque markup to do bold/italic etc.)
  70         */
  71         BOOST_FOREACH (dcp::SubtitleString& i, s) {
  72                 string t = i.text ();
  73                 boost::algorithm::replace_all (t, "<", "&lt;");
  74                 boost::algorithm::replace_all (t, ">", "&gt;");
  75                 i.set_text (t);
  76         }
  77
  78         _decoded_text.push_back (ContentTextSubtitle (period, s));
  79 }
  80
  81 /** Get the subtitles that correspond to a given list of periods.
  82  *  @param subs Subtitles.
  83  *  @param sp Periods for which to extract subtitles from subs.
  84  */
  85 template <class T>
  86 list<T>
  87 SubtitleDecoder::get (list<T> const & subs, list<ContentTimePeriod> const & sp, ContentTimePeriod period, bool accurate)
  88 {
  89         if (sp.empty ()) {
  90                 return list<T> ();
  91         }
  92
  93         /* Find the time of the first subtitle we don't have in subs */
  94         optional<ContentTime> missing;
  95         BOOST_FOREACH (ContentTimePeriod i, sp) {
  96                 typename list<T>::const_iterator j = subs.begin();
  97                 while (j != subs.end() && j->period() != i) {
  98                         ++j;
  99                 }
 100                 if (j == subs.end ()) {
 101                         missing = i.from;
 102                 }
 103         }
 104
 105         /* Suggest to our parent decoder that it might want to seek if we haven't got what we're being asked for */
 106         if (missing) {
 107                 maybe_seek (*missing, true);
 108         }
 109
 110         /* Now enough pass() calls will either:
 111          *  (a) give us what we want, or
 112          *  (b) hit the end of the decoder.
 113          */
 114         while (!_parent->pass(Decoder::PASS_REASON_SUBTITLE, accurate) && (subs.empty() || (subs.back().period().to < sp.back().to))) {}
 115
 116         /* Now look for what we wanted in the data we have collected */
 117         /* XXX: inefficient */
 118
 119         list<T> out;
 120         BOOST_FOREACH (ContentTimePeriod i, sp) {
 121                 typename list<T>::const_iterator j = subs.begin();
 122                 while (j != subs.end() && j->period() != i) {
 123                         ++j;
 124                 }
 125                 if (j != subs.end()) {
 126                         out.push_back (*j);
 127                 }
 128         }
 129
 130         /* Discard anything in _decoded_image_subtitles that is outside 5 seconds either side of period */
 131
 132         list<ContentImageSubtitle>::iterator i = _decoded_image.begin();
 133         while (i != _decoded_image.end()) {
 134                 list<ContentImageSubtitle>::iterator tmp = i;
 135                 ++tmp;
 136
 137                 if (
 138                         i->period().to < (period.from - ContentTime::from_seconds (5)) ||
 139                         i->period().from > (period.to + ContentTime::from_seconds (5))
 140                         ) {
 141                         _decoded_image.erase (i);
 142                 }
 143
 144                 i = tmp;
 145         }
 146
 147         return out;
 148 }
 149
 150 list<ContentTextSubtitle>
 151 SubtitleDecoder::get_text (ContentTimePeriod period, bool starting, bool accurate)
 152 {
 153         return get<ContentTextSubtitle> (_decoded_text, _text_during (period, starting), period, accurate);
 154 }
 155
 156 list<ContentImageSubtitle>
 157 SubtitleDecoder::get_image (ContentTimePeriod period, bool starting, bool accurate)
 158 {
 159         return get<ContentImageSubtitle> (_decoded_image, _image_during (period, starting), period, accurate);
 160 }
 161
 162 void
 163 SubtitleDecoder::seek (ContentTime, bool)
 164 {
 165         reset ();
 166 }
 167
 168 void
 169 SubtitleDecoder::reset ()
 170 {
 171         _decoded_text.clear ();
 172         _decoded_image.clear ();
 173 }
 174
 175 void
 176 SubtitleDecoder::give_text (ContentTimePeriod period, sub::Subtitle const & subtitle)
 177 {
 178         /* See if our next subtitle needs to be placed on screen by us */
 179         bool needs_placement = false;
 180         optional<int> bottom_line;
 181         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 182                 if (!i.vertical_position.reference || i.vertical_position.reference.get() == sub::TOP_OF_SUBTITLE) {
 183                         needs_placement = true;
 184                         DCPOMATIC_ASSERT (i.vertical_position.line);
 185                         if (!bottom_line || bottom_line.get() < i.vertical_position.line.get()) {
 186                                 bottom_line = i.vertical_position.line.get();
 187                         }
 188                 }
 189         }
 190
 191         /* Find the lowest proportional position */
 192         optional<float> lowest_proportional;
 193         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 194                 if (i.vertical_position.proportional) {
 195                         if (!lowest_proportional) {
 196                                 lowest_proportional = i.vertical_position.proportional;
 197                         } else {
 198                                 lowest_proportional = min (lowest_proportional.get(), i.vertical_position.proportional.get());
 199                         }
 200                 }
 201         }
 202
 203         list<dcp::SubtitleString> out;
 204         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 205                 BOOST_FOREACH (sub::Block j, i.blocks) {
 206
 207                         if (!j.font_size.specified()) {
 208                                 /* Fallback default font size if no other has been specified */
 209                                 j.font_size.set_points (48);
 210                         }
 211
 212                         float v_position;
 213                         dcp::VAlign v_align;
 214                         if (needs_placement) {
 215                                 DCPOMATIC_ASSERT (i.vertical_position.line);
 216                                 /* This 1.015 is an arbitrary value to lift the bottom sub off the bottom
 217                                    of the screen a bit to a pleasing degree.
 218                                 */
 219                                 v_position = 1.015 -
 220                                         (1 + bottom_line.get() - i.vertical_position.line.get())
 221                                         * 1.2 * content()->line_spacing() * content()->y_scale() * j.font_size.proportional (72 * 11);
 222
 223                                 v_align = dcp::VALIGN_TOP;
 224                         } else {
 225                                 DCPOMATIC_ASSERT (i.vertical_position.proportional);
 226                                 DCPOMATIC_ASSERT (i.vertical_position.reference);
 227                                 v_position = i.vertical_position.proportional.get();
 228
 229                                 if (lowest_proportional) {
 230                                         /* Adjust line spacing */
 231                                         v_position = ((v_position - lowest_proportional.get()) * content()->line_spacing()) + lowest_proportional.get();
 232                                 }
 233
 234                                 switch (i.vertical_position.reference.get()) {
 235                                 case sub::TOP_OF_SCREEN:
 236                                         v_align = dcp::VALIGN_TOP;
 237                                         break;
 238                                 case sub::CENTRE_OF_SCREEN:
 239                                         v_align = dcp::VALIGN_CENTER;
 240                                         break;
 241                                 case sub::BOTTOM_OF_SCREEN:
 242                                         v_align = dcp::VALIGN_BOTTOM;
 243                                         break;
 244                                 default:
 245                                         v_align = dcp::VALIGN_TOP;
 246                                         break;
 247                                 }
 248                         }
 249
 250                         dcp::Effect effect = dcp::NONE;
 251                         if (content()->outline()) {
 252                                 effect = dcp::BORDER;
 253                         } else if (content()->shadow()) {
 254                                 effect = dcp::SHADOW;
 255                         }
 256
 257                         out.push_back (
 258                                 dcp::SubtitleString (
 259                                         string(TEXT_FONT_ID),
 260                                         j.italic,
 261                                         j.bold,
 262                                         j.underline,
 263                                         /* force the colour to whatever is configured */
 264                                         content()->colour(),
 265                                         j.font_size.points (72 * 11),
 266                                         1.0,
 267                                         dcp::Time (period.from.seconds(), 1000),
 268                                         dcp::Time (period.to.seconds(), 1000),
 269                                         0,
 270                                         dcp::HALIGN_CENTER,
 271                                         v_position,
 272                                         v_align,
 273                                         dcp::DIRECTION_LTR,
 274                                         j.text,
 275                                         effect,
 276                                         content()->effect_colour(),
 277                                         dcp::Time (content()->fade_in().seconds(), 1000),
 278                                         dcp::Time (content()->fade_out().seconds(), 1000)
 279                                         )
 280                                 );
 281                 }
 282         }
 283
 284         give_text (period, out);
 285 }