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 "log.h"
  25 #include "compose.hpp"
  26 #include <sub/subtitle.h>
  27 #include <boost/shared_ptr.hpp>
  28 #include <boost/foreach.hpp>
  29 #include <boost/algorithm/string.hpp>
  30 #include <iostream>
  31
  32 using std::list;
  33 using std::cout;
  34 using std::string;
  35 using std::min;
  36 using boost::shared_ptr;
  37 using boost::optional;
  38 using boost::function;
  39
  40 SubtitleDecoder::SubtitleDecoder (
  41         Decoder* parent,
  42         shared_ptr<const SubtitleContent> c,
  43         shared_ptr<Log> log,
  44         function<list<ContentTimePeriod> (ContentTimePeriod, bool)> image_during,
  45         function<list<ContentTimePeriod> (ContentTimePeriod, bool)> text_during
  46         )
  47         : DecoderPart (parent, log)
  48         , _content (c)
  49         , _image_during (image_during)
  50         , _text_during (text_during)
  51 {
  52
  53 }
  54
  55 /** Called by subclasses when an image subtitle is ready.
  56  *  @param period Period of the subtitle.
  57  *  @param image Subtitle image.
  58  *  @param rect Area expressed as a fraction of the video frame that this subtitle
  59  *  is for (e.g. a width of 0.5 means the width of the subtitle is half the width
  60  *  of the video frame)
  61  */
  62 void
  63 SubtitleDecoder::give_image (ContentTimePeriod period, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
  64 {
  65         _decoded_image.push_back (ContentImageSubtitle (period, image, rect));
  66         _position = period.from;
  67 }
  68
  69 void
  70 SubtitleDecoder::give_text (ContentTimePeriod period, list<dcp::SubtitleString> s)
  71 {
  72         /* We must escape < and > in strings, otherwise they might confuse our subtitle
  73            renderer (which uses some HTML-esque markup to do bold/italic etc.)
  74         */
  75         BOOST_FOREACH (dcp::SubtitleString& i, s) {
  76                 string t = i.text ();
  77                 boost::algorithm::replace_all (t, "<", "&lt;");
  78                 boost::algorithm::replace_all (t, ">", "&gt;");
  79                 i.set_text (t);
  80         }
  81
  82         _decoded_text.push_back (ContentTextSubtitle (period, s));
  83         _position = period.from;
  84 }
  85
  86 /** Get the subtitles that correspond to a given list of periods.
  87  *  @param subs Subtitles.
  88  *  @param sp Periods for which to extract subtitles from subs.
  89  */
  90 template <class T>
  91 list<T>
  92 SubtitleDecoder::get (list<T> const & subs, list<ContentTimePeriod> const & sp, ContentTimePeriod period, bool accurate)
  93 {
  94         if (sp.empty ()) {
  95                 return list<T> ();
  96         }
  97
  98         /* Find the time of the first subtitle we don't have in subs */
  99         optional<ContentTime> missing;
 100         BOOST_FOREACH (ContentTimePeriod i, sp) {
 101                 typename list<T>::const_iterator j = subs.begin();
 102                 while (j != subs.end() && j->period() != i) {
 103                         ++j;
 104                 }
 105                 if (j == subs.end ()) {
 106                         missing = i.from;
 107                 }
 108         }
 109
 110         /* Suggest to our parent decoder that it might want to seek if we haven't got what we're being asked for */
 111         if (missing) {
 112                 _log->log (String::compose ("SD suggests seek to %1", to_string (*missing)), LogEntry::TYPE_DEBUG_DECODE);
 113                 maybe_seek (*missing, true);
 114         }
 115
 116         /* Now enough pass() calls will either:
 117          *  (a) give us what we want, or
 118          *  (b) hit the end of the decoder.
 119          */
 120         while (!_parent->pass(Decoder::PASS_REASON_SUBTITLE, accurate) && (subs.empty() || (subs.back().period().to < sp.back().to))) {}
 121
 122         /* Now look for what we wanted in the data we have collected */
 123         /* XXX: inefficient */
 124
 125         list<T> out;
 126         BOOST_FOREACH (ContentTimePeriod i, sp) {
 127                 typename list<T>::const_iterator j = subs.begin();
 128                 while (j != subs.end() && j->period() != i) {
 129                         ++j;
 130                 }
 131                 if (j != subs.end()) {
 132                         out.push_back (*j);
 133                 }
 134         }
 135
 136         /* Discard anything in _decoded_image_subtitles that is outside 5 seconds either side of period */
 137
 138         list<ContentImageSubtitle>::iterator i = _decoded_image.begin();
 139         while (i != _decoded_image.end()) {
 140                 list<ContentImageSubtitle>::iterator tmp = i;
 141                 ++tmp;
 142
 143                 if (
 144                         i->period().to < (period.from - ContentTime::from_seconds (5)) ||
 145                         i->period().from > (period.to + ContentTime::from_seconds (5))
 146                         ) {
 147                         _decoded_image.erase (i);
 148                 }
 149
 150                 i = tmp;
 151         }
 152
 153         return out;
 154 }
 155
 156 list<ContentTextSubtitle>
 157 SubtitleDecoder::get_text (ContentTimePeriod period, bool starting, bool accurate)
 158 {
 159         return get<ContentTextSubtitle> (_decoded_text, _text_during (period, starting), period, accurate);
 160 }
 161
 162 list<ContentImageSubtitle>
 163 SubtitleDecoder::get_image (ContentTimePeriod period, bool starting, bool accurate)
 164 {
 165         return get<ContentImageSubtitle> (_decoded_image, _image_during (period, starting), period, accurate);
 166 }
 167
 168 void
 169 SubtitleDecoder::seek (ContentTime t, bool)
 170 {
 171         _log->log (String::compose ("SD seek to %1", to_string(t)), LogEntry::TYPE_DEBUG_DECODE);
 172         reset ();
 173         _position.reset ();
 174 }
 175
 176 void
 177 SubtitleDecoder::reset ()
 178 {
 179         _decoded_text.clear ();
 180         _decoded_image.clear ();
 181 }
 182
 183 void
 184 SubtitleDecoder::give_text (ContentTimePeriod period, sub::Subtitle const & subtitle)
 185 {
 186         /* See if our next subtitle needs to be placed on screen by us */
 187         bool needs_placement = false;
 188         optional<int> bottom_line;
 189         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 190                 if (!i.vertical_position.reference || i.vertical_position.reference.get() == sub::TOP_OF_SUBTITLE) {
 191                         needs_placement = true;
 192                         DCPOMATIC_ASSERT (i.vertical_position.line);
 193                         if (!bottom_line || bottom_line.get() < i.vertical_position.line.get()) {
 194                                 bottom_line = i.vertical_position.line.get();
 195                         }
 196                 }
 197         }
 198
 199         /* Find the lowest proportional position */
 200         optional<float> lowest_proportional;
 201         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 202                 if (i.vertical_position.proportional) {
 203                         if (!lowest_proportional) {
 204                                 lowest_proportional = i.vertical_position.proportional;
 205                         } else {
 206                                 lowest_proportional = min (lowest_proportional.get(), i.vertical_position.proportional.get());
 207                         }
 208                 }
 209         }
 210
 211         list<dcp::SubtitleString> out;
 212         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 213                 BOOST_FOREACH (sub::Block j, i.blocks) {
 214
 215                         if (!j.font_size.specified()) {
 216                                 /* Fallback default font size if no other has been specified */
 217                                 j.font_size.set_points (48);
 218                         }
 219
 220                         float v_position;
 221                         dcp::VAlign v_align;
 222                         if (needs_placement) {
 223                                 DCPOMATIC_ASSERT (i.vertical_position.line);
 224                                 /* This 1.015 is an arbitrary value to lift the bottom sub off the bottom
 225                                    of the screen a bit to a pleasing degree.
 226                                 */
 227                                 v_position = 1.015 -
 228                                         (1 + bottom_line.get() - i.vertical_position.line.get())
 229                                         * 1.2 * content()->line_spacing() * content()->y_scale() * j.font_size.proportional (72 * 11);
 230
 231                                 v_align = dcp::VALIGN_TOP;
 232                         } else {
 233                                 DCPOMATIC_ASSERT (i.vertical_position.proportional);
 234                                 DCPOMATIC_ASSERT (i.vertical_position.reference);
 235                                 v_position = i.vertical_position.proportional.get();
 236
 237                                 if (lowest_proportional) {
 238                                         /* Adjust line spacing */
 239                                         v_position = ((v_position - lowest_proportional.get()) * content()->line_spacing()) + lowest_proportional.get();
 240                                 }
 241
 242                                 switch (i.vertical_position.reference.get()) {
 243                                 case sub::TOP_OF_SCREEN:
 244                                         v_align = dcp::VALIGN_TOP;
 245                                         break;
 246                                 case sub::CENTRE_OF_SCREEN:
 247                                         v_align = dcp::VALIGN_CENTER;
 248                                         break;
 249                                 case sub::BOTTOM_OF_SCREEN:
 250                                         v_align = dcp::VALIGN_BOTTOM;
 251                                         break;
 252                                 default:
 253                                         v_align = dcp::VALIGN_TOP;
 254                                         break;
 255                                 }
 256                         }
 257
 258                         dcp::Effect effect = dcp::NONE;
 259                         if (content()->outline()) {
 260                                 effect = dcp::BORDER;
 261                         } else if (content()->shadow()) {
 262                                 effect = dcp::SHADOW;
 263                         }
 264
 265                         out.push_back (
 266                                 dcp::SubtitleString (
 267                                         string(TEXT_FONT_ID),
 268                                         j.italic,
 269                                         j.bold,
 270                                         j.underline,
 271                                         /* force the colour to whatever is configured */
 272                                         content()->colour(),
 273                                         j.font_size.points (72 * 11),
 274                                         1.0,
 275                                         dcp::Time (period.from.seconds(), 1000),
 276                                         dcp::Time (period.to.seconds(), 1000),
 277                                         0,
 278                                         dcp::HALIGN_CENTER,
 279                                         v_position,
 280                                         v_align,
 281                                         dcp::DIRECTION_LTR,
 282                                         j.text,
 283                                         effect,
 284                                         content()->effect_colour(),
 285                                         dcp::Time (content()->fade_in().seconds(), 1000),
 286                                         dcp::Time (content()->fade_out().seconds(), 1000)
 287                                         )
 288                                 );
 289                 }
 290         }
 291
 292         give_text (period, out);
 293 }