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