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