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 <sub/subtitle.h>
  25 #include <boost/shared_ptr.hpp>
  26 #include <boost/foreach.hpp>
  27 #include <boost/algorithm/string.hpp>
  28 #include <iostream>
  29
  30 using std::list;
  31 using std::cout;
  32 using std::string;
  33 using std::min;
  34 using boost::shared_ptr;
  35 using boost::optional;
  36 using boost::function;
  37
  38 SubtitleDecoder::SubtitleDecoder (
  39         Decoder* parent,
  40         shared_ptr<const SubtitleContent> c,
  41         function<list<ContentTimePeriod> (ContentTimePeriod, bool)> image_during,
  42         function<list<ContentTimePeriod> (ContentTimePeriod, bool)> text_during
  43         )
  44         : _parent (parent)
  45         , _content (c)
  46         , _image_during (image_during)
  47         , _text_during (text_during)
  48 {
  49
  50 }
  51
  52 /** Called by subclasses when an image subtitle is ready.
  53  *  @param period Period of the subtitle.
  54  *  @param image Subtitle image.
  55  *  @param rect Area expressed as a fraction of the video frame that this subtitle
  56  *  is for (e.g. a width of 0.5 means the width of the subtitle is half the width
  57  *  of the video frame)
  58  */
  59 void
  60 SubtitleDecoder::give_image (ContentTimePeriod period, shared_ptr<Image> image, dcpomatic::Rect<double> rect)
  61 {
  62         _decoded_image.push_back (ContentImageSubtitle (period, image, rect));
  63 }
  64
  65 void
  66 SubtitleDecoder::give_text (ContentTimePeriod period, list<dcp::SubtitleString> s)
  67 {
  68         /* We must escape < and > in strings, otherwise they might confuse our subtitle
  69            renderer (which uses some HTML-esque markup to do bold/italic etc.)
  70         */
  71         BOOST_FOREACH (dcp::SubtitleString& i, s) {
  72                 string t = i.text ();
  73                 boost::algorithm::replace_all (t, "<", "&lt;");
  74                 boost::algorithm::replace_all (t, ">", "&gt;");
  75                 i.set_text (t);
  76         }
  77
  78         _decoded_text.push_back (ContentTextSubtitle (period, s));
  79 }
  80
  81 /** @param sp Full periods of subtitles that are showing or starting during the specified period */
  82 template <class T>
  83 list<T>
  84 SubtitleDecoder::get (list<T> const & subs, list<ContentTimePeriod> const & sp, ContentTimePeriod period, bool starting, bool accurate)
  85 {
  86         if (sp.empty ()) {
  87                 /* Nothing in this period */
  88                 return list<T> ();
  89         }
  90
  91         /* Seek if what we want is before what we have, or a more than a little bit after */
  92         if (subs.empty() || sp.back().to < subs.front().period().from || sp.front().from > (subs.back().period().to + ContentTime::from_seconds (1))) {
  93                 _parent->seek (sp.front().from, true);
  94         }
  95
  96         /* Now enough pass() calls will either:
  97          *  (a) give us what we want, or
  98          *  (b) hit the end of the decoder.
  99          */
 100         while (!_parent->pass(Decoder::PASS_REASON_SUBTITLE, accurate) && (subs.empty() || (subs.back().period().to < sp.back().to))) {}
 101
 102         /* Now look for what we wanted in the data we have collected */
 103         /* XXX: inefficient */
 104
 105         list<T> out;
 106         for (typename list<T>::const_iterator i = subs.begin(); i != subs.end(); ++i) {
 107                 if ((starting && period.contains(i->period().from)) || (!starting && period.overlap(i->period()))) {
 108                         out.push_back (*i);
 109                 }
 110         }
 111
 112         /* Discard anything in _decoded_image_subtitles that is outside 5 seconds either side of period */
 113
 114         list<ContentImageSubtitle>::iterator i = _decoded_image.begin();
 115         while (i != _decoded_image.end()) {
 116                 list<ContentImageSubtitle>::iterator tmp = i;
 117                 ++tmp;
 118
 119                 if (
 120                         i->period().to < (period.from - ContentTime::from_seconds (5)) ||
 121                         i->period().from > (period.to + ContentTime::from_seconds (5))
 122                         ) {
 123                         _decoded_image.erase (i);
 124                 }
 125
 126                 i = tmp;
 127         }
 128
 129         return out;
 130 }
 131
 132 list<ContentTextSubtitle>
 133 SubtitleDecoder::get_text (ContentTimePeriod period, bool starting, bool accurate)
 134 {
 135         return get<ContentTextSubtitle> (_decoded_text, _text_during (period, starting), period, starting, accurate);
 136 }
 137
 138 list<ContentImageSubtitle>
 139 SubtitleDecoder::get_image (ContentTimePeriod period, bool starting, bool accurate)
 140 {
 141         return get<ContentImageSubtitle> (_decoded_image, _image_during (period, starting), period, starting, accurate);
 142 }
 143
 144 void
 145 SubtitleDecoder::seek (ContentTime, bool)
 146 {
 147         reset ();
 148 }
 149
 150 void
 151 SubtitleDecoder::reset ()
 152 {
 153         _decoded_text.clear ();
 154         _decoded_image.clear ();
 155 }
 156
 157 void
 158 SubtitleDecoder::give_text (ContentTimePeriod period, sub::Subtitle const & subtitle)
 159 {
 160         /* See if our next subtitle needs to be placed on screen by us */
 161         bool needs_placement = false;
 162         optional<int> bottom_line;
 163         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 164                 if (!i.vertical_position.reference || i.vertical_position.reference.get() == sub::TOP_OF_SUBTITLE) {
 165                         needs_placement = true;
 166                         DCPOMATIC_ASSERT (i.vertical_position.line);
 167                         if (!bottom_line || bottom_line.get() < i.vertical_position.line.get()) {
 168                                 bottom_line = i.vertical_position.line.get();
 169                         }
 170                 }
 171         }
 172
 173         /* Find the lowest proportional postion */
 174         optional<float> lowest_proportional;
 175         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 176                 if (i.vertical_position.proportional) {
 177                         if (!lowest_proportional) {
 178                                 lowest_proportional = i.vertical_position.proportional;
 179                         } else {
 180                                 lowest_proportional = min (lowest_proportional.get(), i.vertical_position.proportional.get());
 181                         }
 182                 }
 183         }
 184
 185         list<dcp::SubtitleString> out;
 186         BOOST_FOREACH (sub::Line i, subtitle.lines) {
 187                 BOOST_FOREACH (sub::Block j, i.blocks) {
 188
 189                         if (!j.font_size.specified()) {
 190                                 /* Fallback default font size if none other has been specified */
 191                                 j.font_size.set_points (48);
 192                         }
 193
 194                         float v_position;
 195                         dcp::VAlign v_align;
 196                         if (needs_placement) {
 197                                 DCPOMATIC_ASSERT (i.vertical_position.line);
 198                                 /* This 1.015 is an arbitrary value to lift the bottom sub off the bottom
 199                                    of the screen a bit to a pleasing degree.
 200                                 */
 201                                 v_position = 1.015 -
 202                                         (1 + bottom_line.get() - i.vertical_position.line.get())
 203                                         * 1.2 * content()->line_spacing() * content()->y_scale() * j.font_size.proportional (72 * 11);
 204
 205                                 v_align = dcp::VALIGN_TOP;
 206                         } else {
 207                                 DCPOMATIC_ASSERT (i.vertical_position.proportional);
 208                                 DCPOMATIC_ASSERT (i.vertical_position.reference);
 209                                 v_position = i.vertical_position.proportional.get();
 210
 211                                 if (lowest_proportional) {
 212                                         /* Adjust line spacing */
 213                                         v_position = ((v_position - lowest_proportional.get()) * content()->line_spacing()) + lowest_proportional.get();
 214                                 }
 215
 216                                 switch (i.vertical_position.reference.get()) {
 217                                 case sub::TOP_OF_SCREEN:
 218                                         v_align = dcp::VALIGN_TOP;
 219                                         break;
 220                                 case sub::CENTRE_OF_SCREEN:
 221                                         v_align = dcp::VALIGN_CENTER;
 222                                         break;
 223                                 case sub::BOTTOM_OF_SCREEN:
 224                                         v_align = dcp::VALIGN_BOTTOM;
 225                                         break;
 226                                 default:
 227                                         v_align = dcp::VALIGN_TOP;
 228                                         break;
 229                                 }
 230                         }
 231
 232                         dcp::Effect effect = dcp::NONE;
 233                         if (content()->outline()) {
 234                                 effect = dcp::BORDER;
 235                         } else if (content()->shadow()) {
 236                                 effect = dcp::SHADOW;
 237                         }
 238
 239                         out.push_back (
 240                                 dcp::SubtitleString (
 241                                         string(TEXT_FONT_ID),
 242                                         j.italic,
 243                                         j.bold,
 244                                         j.underline,
 245                                         /* force the colour to whatever is configured */
 246                                         content()->colour(),
 247                                         j.font_size.points (72 * 11),
 248                                         1.0,
 249                                         dcp::Time (period.from.seconds(), 1000),
 250                                         dcp::Time (period.to.seconds(), 1000),
 251                                         0,
 252                                         dcp::HALIGN_CENTER,
 253                                         v_position,
 254                                         v_align,
 255                                         dcp::DIRECTION_LTR,
 256                                         j.text,
 257                                         effect,
 258                                         content()->effect_colour(),
 259                                         dcp::Time (content()->fade_in().seconds(), 1000),
 260                                         dcp::Time (content()->fade_out().seconds(), 1000)
 261                                         )
 262                                 );
 263                 }
 264         }
 265
 266         give_text (period, out);
 267 }