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