src/lib/subtitle_decoder.cc

   1 /*
   2     Copyright (C) 2013-2017 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         ContentTime first
  45         )
  46         : DecoderPart (parent, log)
  47         , _content (c)
  48         , _position (first)
  49 {
  50
  51 }
  52
  53 /** Called by subclasses when an image subtitle is starting.
  54  *  @param from From time of the subtitle.
  55  *  @param image Subtitle image.
  56  *  @param rect Area expressed as a fraction of the video frame that this subtitle
  57  *  is for (e.g. a width of 0.5 means the width of the subtitle is half the width
  58  *  of the video frame)
  59  */
  60 void
  61 SubtitleDecoder::emit_image_start (ContentTime from, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
  62 {
  63         ImageStart (ContentImageSubtitle (from, image, rect));
  64 }
  65
  66 void
  67 SubtitleDecoder::emit_text_start (ContentTime from, list<dcp::SubtitleString> s)
  68 {
  69         /* We must escape < and > in strings, otherwise they might confuse our subtitle
  70            renderer (which uses some HTML-esque markup to do bold/italic etc.)
  71         */
  72         BOOST_FOREACH (dcp::SubtitleString& i, s) {
  73                 string t = i.text ();
  74                 boost::algorithm::replace_all (t, "<", "&lt;");
  75                 boost::algorithm::replace_all (t, ">", "&gt;");
  76                 i.set_text (t);
  77         }
  78
  79         TextStart (ContentTextSubtitle (from, s));
  80         _position = from;
  81 }
  82
  83 void
  84 SubtitleDecoder::emit_text_start (ContentTime from, sub::Subtitle const & subtitle)
  85 {
  86         /* See if our next subtitle needs to be vertically placed on screen by us */
  87         bool needs_placement = false;
  88         optional<int> bottom_line;
  89         BOOST_FOREACH (sub::Line i, subtitle.lines) {
  90                 if (!i.vertical_position.reference || i.vertical_position.reference.get() == sub::TOP_OF_SUBTITLE) {
  91                         needs_placement = true;
  92                         DCPOMATIC_ASSERT (i.vertical_position.line);
  93                         if (!bottom_line || bottom_line.get() < i.vertical_position.line.get()) {
  94                                 bottom_line = i.vertical_position.line.get();
  95                         }
  96                 }
  97         }
  98
  99         /* Find the lowest proportional position */
 100         optional<float> lowest_proportional;
 101         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 102                 if (i.vertical_position.proportional) {
 103                         if (!lowest_proportional) {
 104                                 lowest_proportional = i.vertical_position.proportional;
 105                         } else {
 106                                 lowest_proportional = min (lowest_proportional.get(), i.vertical_position.proportional.get());
 107                         }
 108                 }
 109         }
 110
 111         list<dcp::SubtitleString> out;
 112         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 113                 BOOST_FOREACH (sub::Block j, i.blocks) {
 114
 115                         if (!j.font_size.specified()) {
 116                                 /* Fallback default font size if no other has been specified */
 117                                 j.font_size.set_points (48);
 118                         }
 119
 120                         float v_position;
 121                         dcp::VAlign v_align;
 122                         if (needs_placement) {
 123                                 DCPOMATIC_ASSERT (i.vertical_position.line);
 124                                 /* This 1.015 is an arbitrary value to lift the bottom sub off the bottom
 125                                    of the screen a bit to a pleasing degree.
 126                                 */
 127                                 v_position = 1.015 -
 128                                         (1 + bottom_line.get() - i.vertical_position.line.get())
 129                                         * 1.2 * content()->line_spacing() * content()->y_scale() * j.font_size.proportional (72 * 11);
 130
 131                                 v_align = dcp::VALIGN_TOP;
 132                         } else {
 133                                 DCPOMATIC_ASSERT (i.vertical_position.proportional);
 134                                 DCPOMATIC_ASSERT (i.vertical_position.reference);
 135                                 v_position = i.vertical_position.proportional.get();
 136
 137                                 if (lowest_proportional) {
 138                                         /* Adjust line spacing */
 139                                         v_position = ((v_position - lowest_proportional.get()) * content()->line_spacing()) + lowest_proportional.get();
 140                                 }
 141
 142                                 switch (i.vertical_position.reference.get()) {
 143                                 case sub::TOP_OF_SCREEN:
 144                                         v_align = dcp::VALIGN_TOP;
 145                                         break;
 146                                 case sub::VERTICAL_CENTRE_OF_SCREEN:
 147                                         v_align = dcp::VALIGN_CENTER;
 148                                         break;
 149                                 case sub::BOTTOM_OF_SCREEN:
 150                                         v_align = dcp::VALIGN_BOTTOM;
 151                                         break;
 152                                 default:
 153                                         v_align = dcp::VALIGN_TOP;
 154                                         break;
 155                                 }
 156                         }
 157
 158                         dcp::Effect effect = dcp::NONE;
 159                         if (content()->outline()) {
 160                                 effect = dcp::BORDER;
 161                         } else if (content()->shadow()) {
 162                                 effect = dcp::SHADOW;
 163                         }
 164
 165                         dcp::HAlign h_align;
 166                         switch (i.horizontal_position.reference) {
 167                         case sub::LEFT_OF_SCREEN:
 168                                 h_align = dcp::HALIGN_LEFT;
 169                                 break;
 170                         case sub::HORIZONTAL_CENTRE_OF_SCREEN:
 171                                 h_align = dcp::HALIGN_CENTER;
 172                                 break;
 173                         case sub::RIGHT_OF_SCREEN:
 174                                 h_align = dcp::HALIGN_RIGHT;
 175                                 break;
 176                         default:
 177                                 h_align = dcp::HALIGN_CENTER;
 178                                 break;
 179                         }
 180
 181                         out.push_back (
 182                                 dcp::SubtitleString (
 183                                         string(TEXT_FONT_ID),
 184                                         j.italic,
 185                                         j.bold,
 186                                         j.underline,
 187                                         /* force the colour to whatever is configured */
 188                                         content()->colour(),
 189                                         j.font_size.points (72 * 11),
 190                                         1.0,
 191                                         dcp::Time (from.seconds(), 1000),
 192                                         /* XXX: hmm; this is a bit ugly (we don't know the to time yet) */
 193                                         dcp::Time (),
 194                                         i.horizontal_position.proportional,
 195                                         h_align,
 196                                         v_position,
 197                                         v_align,
 198                                         dcp::DIRECTION_LTR,
 199                                         j.text,
 200                                         effect,
 201                                         content()->effect_colour(),
 202                                         dcp::Time (content()->fade_in().seconds(), 1000),
 203                                         dcp::Time (content()->fade_out().seconds(), 1000)
 204                                         )
 205                                 );
 206                 }
 207         }
 208
 209         emit_text_start (from, out);
 210 }
 211
 212 void
 213 SubtitleDecoder::emit_stop (ContentTime to)
 214 {
 215         Stop (to);
 216 }
 217
 218 void
 219 SubtitleDecoder::emit_text (ContentTimePeriod period, list<dcp::SubtitleString> s)
 220 {
 221         emit_text_start (period.from, s);
 222         emit_stop (period.to);
 223 }
 224
 225 void
 226 SubtitleDecoder::emit_text (ContentTimePeriod period, sub::Subtitle const & s)
 227 {
 228         emit_text_start (period.from, s);
 229         emit_stop (period.to);
 230 }
 231
 232 void
 233 SubtitleDecoder::seek ()
 234 {
 235         _position = ContentTime ();
 236 }