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         )
  45         : DecoderPart (parent, log)
  46         , _content (c)
  47 {
  48
  49 }
  50
  51 /** Called by subclasses when an image subtitle is ready.
  52  *  @param period Period 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 (ContentTimePeriod period, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
  60 {
  61         ImageData (ContentImageSubtitle (period, image, rect));
  62 }
  63
  64 void
  65 SubtitleDecoder::emit_text (ContentTimePeriod period, 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         TextData (ContentTextSubtitle (period, s));
  78 }
  79
  80 void
  81 SubtitleDecoder::emit_text (ContentTimePeriod period, sub::Subtitle const & subtitle)
  82 {
  83         /* See if our next subtitle needs to be placed on screen by us */
  84         bool needs_placement = false;
  85         optional<int> bottom_line;
  86         BOOST_FOREACH (sub::Line i, subtitle.lines) {
  87                 if (!i.vertical_position.reference || i.vertical_position.reference.get() == sub::TOP_OF_SUBTITLE) {
  88                         needs_placement = true;
  89                         DCPOMATIC_ASSERT (i.vertical_position.line);
  90                         if (!bottom_line || bottom_line.get() < i.vertical_position.line.get()) {
  91                                 bottom_line = i.vertical_position.line.get();
  92                         }
  93                 }
  94         }
  95
  96         /* Find the lowest proportional position */
  97         optional<float> lowest_proportional;
  98         BOOST_FOREACH (sub::Line i, subtitle.lines) {
  99                 if (i.vertical_position.proportional) {
 100                         if (!lowest_proportional) {
 101                                 lowest_proportional = i.vertical_position.proportional;
 102                         } else {
 103                                 lowest_proportional = min (lowest_proportional.get(), i.vertical_position.proportional.get());
 104                         }
 105                 }
 106         }
 107
 108         list<dcp::SubtitleString> out;
 109         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 110                 BOOST_FOREACH (sub::Block j, i.blocks) {
 111
 112                         if (!j.font_size.specified()) {
 113                                 /* Fallback default font size if no other has been specified */
 114                                 j.font_size.set_points (48);
 115                         }
 116
 117                         float v_position;
 118                         dcp::VAlign v_align;
 119                         if (needs_placement) {
 120                                 DCPOMATIC_ASSERT (i.vertical_position.line);
 121                                 /* This 1.015 is an arbitrary value to lift the bottom sub off the bottom
 122                                    of the screen a bit to a pleasing degree.
 123                                 */
 124                                 v_position = 1.015 -
 125                                         (1 + bottom_line.get() - i.vertical_position.line.get())
 126                                         * 1.2 * content()->line_spacing() * content()->y_scale() * j.font_size.proportional (72 * 11);
 127
 128                                 v_align = dcp::VALIGN_TOP;
 129                         } else {
 130                                 DCPOMATIC_ASSERT (i.vertical_position.proportional);
 131                                 DCPOMATIC_ASSERT (i.vertical_position.reference);
 132                                 v_position = i.vertical_position.proportional.get();
 133
 134                                 if (lowest_proportional) {
 135                                         /* Adjust line spacing */
 136                                         v_position = ((v_position - lowest_proportional.get()) * content()->line_spacing()) + lowest_proportional.get();
 137                                 }
 138
 139                                 switch (i.vertical_position.reference.get()) {
 140                                 case sub::TOP_OF_SCREEN:
 141                                         v_align = dcp::VALIGN_TOP;
 142                                         break;
 143                                 case sub::CENTRE_OF_SCREEN:
 144                                         v_align = dcp::VALIGN_CENTER;
 145                                         break;
 146                                 case sub::BOTTOM_OF_SCREEN:
 147                                         v_align = dcp::VALIGN_BOTTOM;
 148                                         break;
 149                                 default:
 150                                         v_align = dcp::VALIGN_TOP;
 151                                         break;
 152                                 }
 153                         }
 154
 155                         dcp::Effect effect = dcp::NONE;
 156                         if (content()->outline()) {
 157                                 effect = dcp::BORDER;
 158                         } else if (content()->shadow()) {
 159                                 effect = dcp::SHADOW;
 160                         }
 161
 162                         out.push_back (
 163                                 dcp::SubtitleString (
 164                                         string(TEXT_FONT_ID),
 165                                         j.italic,
 166                                         j.bold,
 167                                         j.underline,
 168                                         /* force the colour to whatever is configured */
 169                                         content()->colour(),
 170                                         j.font_size.points (72 * 11),
 171                                         1.0,
 172                                         dcp::Time (period.from.seconds(), 1000),
 173                                         dcp::Time (period.to.seconds(), 1000),
 174                                         0,
 175                                         dcp::HALIGN_CENTER,
 176                                         v_position,
 177                                         v_align,
 178                                         dcp::DIRECTION_LTR,
 179                                         j.text,
 180                                         effect,
 181                                         content()->effect_colour(),
 182                                         dcp::Time (content()->fade_in().seconds(), 1000),
 183                                         dcp::Time (content()->fade_out().seconds(), 1000)
 184                                         )
 185                                 );
 186                 }
 187         }
 188
 189         emit_text (period, out);
 190 }