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.to;
  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                         break;
 108                 }
 109         }
 110
 111         /* Suggest to our parent decoder that it might want to seek if we haven't got what we're being asked for */
 112         if (missing) {
 113                 _log->log (
 114                         String::compose (
 115                                 "SD suggests seek to %1 from %2",
 116                                 to_string (*missing),
 117                                 position() ? to_string(*position()) : "nowhere"),
 118                         LogEntry::TYPE_DEBUG_DECODE);
 119                 maybe_seek (*missing, true);
 120         }
 121
 122         /* Now enough pass() calls will either:
 123          *  (a) give us what we want, or
 124          *  (b) hit the end of the decoder.
 125          */
 126         while (!_parent->pass(Decoder::PASS_REASON_SUBTITLE, accurate) && (subs.empty() || (subs.back().period().to < sp.back().to))) {}
 127
 128         /* Now look for what we wanted in the data we have collected */
 129         /* XXX: inefficient */
 130
 131         list<T> out;
 132         BOOST_FOREACH (ContentTimePeriod i, sp) {
 133                 typename list<T>::const_iterator j = subs.begin();
 134                 while (j != subs.end() && j->period() != i) {
 135                         ++j;
 136                 }
 137                 if (j != subs.end()) {
 138                         out.push_back (*j);
 139                 }
 140         }
 141
 142         /* Discard anything in _decoded_image_subtitles that is outside 5 seconds either side of period */
 143
 144         list<ContentImageSubtitle>::iterator i = _decoded_image.begin();
 145         while (i != _decoded_image.end()) {
 146                 list<ContentImageSubtitle>::iterator tmp = i;
 147                 ++tmp;
 148
 149                 if (
 150                         i->period().to < (period.from - ContentTime::from_seconds (5)) ||
 151                         i->period().from > (period.to + ContentTime::from_seconds (5))
 152                         ) {
 153                         _decoded_image.erase (i);
 154                 }
 155
 156                 i = tmp;
 157         }
 158
 159         return out;
 160 }
 161
 162 list<ContentTextSubtitle>
 163 SubtitleDecoder::get_text (ContentTimePeriod period, bool starting, bool accurate)
 164 {
 165         return get<ContentTextSubtitle> (_decoded_text, _text_during (period, starting), period, accurate);
 166 }
 167
 168 list<ContentImageSubtitle>
 169 SubtitleDecoder::get_image (ContentTimePeriod period, bool starting, bool accurate)
 170 {
 171         return get<ContentImageSubtitle> (_decoded_image, _image_during (period, starting), period, accurate);
 172 }
 173
 174 void
 175 SubtitleDecoder::seek (ContentTime t, bool)
 176 {
 177         _log->log (String::compose ("SD seek to %1", to_string(t)), LogEntry::TYPE_DEBUG_DECODE);
 178         reset ();
 179         _position.reset ();
 180 }
 181
 182 void
 183 SubtitleDecoder::reset ()
 184 {
 185         _decoded_text.clear ();
 186         _decoded_image.clear ();
 187 }
 188
 189 void
 190 SubtitleDecoder::give_text (ContentTimePeriod period, sub::Subtitle const & subtitle)
 191 {
 192         /* See if our next subtitle needs to be placed on screen by us */
 193         bool needs_placement = false;
 194         optional<int> bottom_line;
 195         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 196                 if (!i.vertical_position.reference || i.vertical_position.reference.get() == sub::TOP_OF_SUBTITLE) {
 197                         needs_placement = true;
 198                         DCPOMATIC_ASSERT (i.vertical_position.line);
 199                         if (!bottom_line || bottom_line.get() < i.vertical_position.line.get()) {
 200                                 bottom_line = i.vertical_position.line.get();
 201                         }
 202                 }
 203         }
 204
 205         /* Find the lowest proportional position */
 206         optional<float> lowest_proportional;
 207         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 208                 if (i.vertical_position.proportional) {
 209                         if (!lowest_proportional) {
 210                                 lowest_proportional = i.vertical_position.proportional;
 211                         } else {
 212                                 lowest_proportional = min (lowest_proportional.get(), i.vertical_position.proportional.get());
 213                         }
 214                 }
 215         }
 216
 217         list<dcp::SubtitleString> out;
 218         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 219                 BOOST_FOREACH (sub::Block j, i.blocks) {
 220
 221                         if (!j.font_size.specified()) {
 222                                 /* Fallback default font size if no other has been specified */
 223                                 j.font_size.set_points (48);
 224                         }
 225
 226                         float v_position;
 227                         dcp::VAlign v_align;
 228                         if (needs_placement) {
 229                                 DCPOMATIC_ASSERT (i.vertical_position.line);
 230                                 /* This 1.015 is an arbitrary value to lift the bottom sub off the bottom
 231                                    of the screen a bit to a pleasing degree.
 232                                 */
 233                                 v_position = 1.015 -
 234                                         (1 + bottom_line.get() - i.vertical_position.line.get())
 235                                         * 1.2 * content()->line_spacing() * content()->y_scale() * j.font_size.proportional (72 * 11);
 236
 237                                 v_align = dcp::VALIGN_TOP;
 238                         } else {
 239                                 DCPOMATIC_ASSERT (i.vertical_position.proportional);
 240                                 DCPOMATIC_ASSERT (i.vertical_position.reference);
 241                                 v_position = i.vertical_position.proportional.get();
 242
 243                                 if (lowest_proportional) {
 244                                         /* Adjust line spacing */
 245                                         v_position = ((v_position - lowest_proportional.get()) * content()->line_spacing()) + lowest_proportional.get();
 246                                 }
 247
 248                                 switch (i.vertical_position.reference.get()) {
 249                                 case sub::TOP_OF_SCREEN:
 250                                         v_align = dcp::VALIGN_TOP;
 251                                         break;
 252                                 case sub::CENTRE_OF_SCREEN:
 253                                         v_align = dcp::VALIGN_CENTER;
 254                                         break;
 255                                 case sub::BOTTOM_OF_SCREEN:
 256                                         v_align = dcp::VALIGN_BOTTOM;
 257                                         break;
 258                                 default:
 259                                         v_align = dcp::VALIGN_TOP;
 260                                         break;
 261                                 }
 262                         }
 263
 264                         dcp::Effect effect = dcp::NONE;
 265                         if (content()->outline()) {
 266                                 effect = dcp::BORDER;
 267                         } else if (content()->shadow()) {
 268                                 effect = dcp::SHADOW;
 269                         }
 270
 271                         out.push_back (
 272                                 dcp::SubtitleString (
 273                                         string(TEXT_FONT_ID),
 274                                         j.italic,
 275                                         j.bold,
 276                                         j.underline,
 277                                         /* force the colour to whatever is configured */
 278                                         content()->colour(),
 279                                         j.font_size.points (72 * 11),
 280                                         1.0,
 281                                         dcp::Time (period.from.seconds(), 1000),
 282                                         dcp::Time (period.to.seconds(), 1000),
 283                                         0,
 284                                         dcp::HALIGN_CENTER,
 285                                         v_position,
 286                                         v_align,
 287                                         dcp::DIRECTION_LTR,
 288                                         j.text,
 289                                         effect,
 290                                         content()->effect_colour(),
 291                                         dcp::Time (content()->fade_in().seconds(), 1000),
 292                                         dcp::Time (content()->fade_out().seconds(), 1000)
 293                                         )
 294                                 );
 295                 }
 296         }
 297
 298         give_text (period, out);
 299 }