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