2 Copyright (C) 2014-2021 Carl Hetherington <cth@carlh.net>
4 This file is part of DCP-o-matic.
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.
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.
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/>.
23 #include "dcpomatic_assert.h"
26 #include "render_text.h"
30 #include <dcp/raw_convert.h>
31 #include <fontconfig/fontconfig.h>
32 #include <cairomm/cairomm.h>
33 DCPOMATIC_DISABLE_WARNINGS
35 DCPOMATIC_ENABLE_WARNINGS
36 #include <pango/pangocairo.h>
37 #include <boost/algorithm/string.hpp>
45 using std::make_shared;
49 using std::shared_ptr;
51 using namespace dcpomatic;
54 static FcConfig* fc_config = nullptr;
55 static list<pair<boost::filesystem::path, string>> fc_config_fonts;
58 /** Create a Pango layout using a dummy context which we can use to calculate the size
59 * of the text we will render. Then we can transfer the layout over to the real context
60 * for the actual render.
62 static Glib::RefPtr<Pango::Layout>
65 auto c_font_map = pango_cairo_font_map_new ();
66 DCPOMATIC_ASSERT (c_font_map);
67 auto font_map = Glib::wrap (c_font_map);
68 auto c_context = pango_font_map_create_context (c_font_map);
69 DCPOMATIC_ASSERT (c_context);
70 auto context = Glib::wrap (c_context);
71 return Pango::Layout::create (context);
76 setup_layout (Glib::RefPtr<Pango::Layout> layout, string font_name, string markup)
78 layout->set_alignment (Pango::ALIGN_LEFT);
79 Pango::FontDescription font (font_name);
80 layout->set_font_description (font);
81 layout->set_markup (markup);
86 marked_up (list<StringText> subtitles, int target_height, float fade_factor, string font_name)
88 auto constexpr pixels_to_1024ths_point = 72 * 1024 / 96;
90 auto make_span = [target_height, fade_factor](StringText const& subtitle, string text, string extra_attribute) {
93 if (subtitle.italic()) {
94 span += "style=\"italic\" ";
96 if (subtitle.bold()) {
97 span += "weight=\"bold\" ";
99 if (subtitle.underline()) {
100 span += "underline=\"single\" ";
102 span += "size=\"" + dcp::raw_convert<string>(subtitle.size_in_pixels(target_height) * pixels_to_1024ths_point) + "\" ";
103 /* Between 1-65535 inclusive, apparently... */
104 span += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
105 span += "color=\"#" + subtitle.colour().to_rgb_string() + "\"";
106 if (!extra_attribute.empty()) {
107 span += " " + extra_attribute;
116 for (auto const& i: subtitles) {
117 if (std::abs(i.space_before()) > dcp::SPACE_BEFORE_EPSILON) {
118 /* We need to insert some horizontal space into the layout. The only way I can find to do this
119 * is to write a " " with some special letter_spacing. As far as I can see, such a space will
120 * be written with letter_spacing either side. This means that to get a horizontal space x we
121 * need to write a " " with letter spacing (x - s) / 2, where s is the width of the " ".
123 auto layout = create_layout();
124 setup_layout(layout, font_name, make_span(i, " ", {}));
127 layout->get_pixel_size(space_width, dummy);
128 auto spacing = ((i.space_before() * i.size_in_pixels(target_height) - space_width) / 2) * pixels_to_1024ths_point;
129 out += make_span(i, " ", "letter_spacing=\"" + dcp::raw_convert<string>(spacing) + "\"");
132 out += make_span(i, i.text(), {});
140 set_source_rgba (Cairo::RefPtr<Cairo::Context> context, dcp::Colour colour, float fade_factor)
142 context->set_source_rgba (float(colour.r) / 255, float(colour.g) / 255, float(colour.b) / 255, fade_factor);
146 static shared_ptr<Image>
147 create_image (dcp::Size size)
149 /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha.
150 * This must be COMPACT as we're using it with Cairo::ImageSurface::create
152 auto image = make_shared<Image>(AV_PIX_FMT_BGRA, size, Image::Alignment::COMPACT);
153 image->make_black ();
158 static Cairo::RefPtr<Cairo::ImageSurface>
159 create_surface (shared_ptr<Image> image)
161 /* XXX: I don't think it's guaranteed that format_stride_for_width will return a stride without any padding,
162 * so it's lucky that this works.
164 DCPOMATIC_ASSERT (image->alignment() == Image::Alignment::COMPACT);
165 DCPOMATIC_ASSERT (image->pixel_format() == AV_PIX_FMT_BGRA);
166 return Cairo::ImageSurface::create (
168 Cairo::FORMAT_ARGB32,
170 image->size().height,
171 /* Cairo ARGB32 means first byte blue, second byte green, third byte red, fourth byte alpha */
172 Cairo::ImageSurface::format_stride_for_width (Cairo::FORMAT_ARGB32, image->size().width)
178 setup_font (StringText const& subtitle, list<shared_ptr<Font>> const& fonts)
181 fc_config = FcInitLoadConfig ();
184 auto font_file = default_font_file ();
186 for (auto i: fonts) {
187 if (i->id() == subtitle.font() && i->file()) {
188 font_file = i->file().get();
192 auto existing = fc_config_fonts.cbegin ();
193 while (existing != fc_config_fonts.end() && existing->first != font_file) {
198 if (existing != fc_config_fonts.end ()) {
199 font_name = existing->second;
201 /* Make this font available to DCP-o-matic */
202 FcConfigAppFontAddFile (fc_config, reinterpret_cast<FcChar8 const *>(font_file.string().c_str()));
203 auto pattern = FcPatternBuild (
204 0, FC_FILE, FcTypeString, font_file.string().c_str(), static_cast<char *>(0)
206 auto object_set = FcObjectSetBuild (FC_FAMILY, FC_STYLE, FC_LANG, FC_FILE, static_cast<char *> (0));
207 auto font_set = FcFontList (fc_config, pattern, object_set);
209 for (int i = 0; i < font_set->nfont; ++i) {
210 FcPattern* font = font_set->fonts[i];
215 FcPatternGetString (font, FC_FILE, 0, &file) == FcResultMatch &&
216 FcPatternGetString (font, FC_FAMILY, 0, &family) == FcResultMatch &&
217 FcPatternGetString (font, FC_STYLE, 0, &style) == FcResultMatch
219 font_name = reinterpret_cast<char const *> (family);
223 FcFontSetDestroy (font_set);
226 FcObjectSetDestroy (object_set);
227 FcPatternDestroy (pattern);
229 fc_config_fonts.push_back (make_pair(font_file, font_name));
232 FcConfigSetCurrent (fc_config);
238 calculate_fade_factor (StringText const& first, DCPTime time, int frame_rate)
240 float fade_factor = 1;
242 /* Round the fade start/end to the nearest frame start. Otherwise if a subtitle starts just after
243 the start of a frame it will be faded out.
245 auto const fade_in_start = DCPTime::from_seconds(first.in().as_seconds()).round(frame_rate);
246 auto const fade_in_end = fade_in_start + DCPTime::from_seconds (first.fade_up_time().as_seconds ());
248 if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
249 fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
252 if (time < fade_in_start) {
256 /* first.out() may be zero if we don't know when this subtitle will finish. We can only think about
257 * fading out if we _do_ know when it will finish.
259 if (first.out() != dcp::Time()) {
260 auto const fade_out_end = DCPTime::from_seconds (first.out().as_seconds()).round(frame_rate);
261 auto const fade_out_start = fade_out_end - DCPTime::from_seconds(first.fade_down_time().as_seconds());
263 if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
264 fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
266 if (time > fade_out_end) {
276 x_position (StringText const& first, int target_width, int layout_width)
279 switch (first.h_align()) {
280 case dcp::HAlign::LEFT:
281 /* h_position is distance between left of frame and left of subtitle */
282 x = first.h_position() * target_width;
284 case dcp::HAlign::CENTER:
285 /* h_position is distance between centre of frame and centre of subtitle */
286 x = (0.5 + first.h_position()) * target_width - layout_width / 2;
288 case dcp::HAlign::RIGHT:
289 /* h_position is distance between right of frame and right of subtitle */
290 x = (1.0 - first.h_position()) * target_width - layout_width;
299 y_position (StringText const& first, int target_height, int layout_height)
302 switch (first.v_align()) {
303 case dcp::VAlign::TOP:
304 /* SMPTE says that v_position is the distance between top
305 of frame and top of subtitle, but this doesn't always seem to be
306 the case in practice; Gunnar Ásgeirsson's Dolby server appears
307 to put VAlign::TOP subs with v_position as the distance between top
308 of frame and bottom of subtitle.
310 y = first.v_position() * target_height - layout_height;
312 case dcp::VAlign::CENTER:
313 /* v_position is distance between centre of frame and centre of subtitle */
314 y = (0.5 + first.v_position()) * target_height - layout_height / 2;
316 case dcp::VAlign::BOTTOM:
317 /* v_position is distance between bottom of frame and bottom of subtitle */
318 y = (1.0 - first.v_position()) * target_height - layout_height;
326 /** @param subtitles A list of subtitles that are all on the same line,
327 * at the same time and with the same fade in/out.
330 render_line (list<StringText> subtitles, list<shared_ptr<Font>> fonts, dcp::Size target, DCPTime time, int frame_rate)
332 /* XXX: this method can only handle italic / bold changes mid-line,
336 DCPOMATIC_ASSERT (!subtitles.empty ());
337 auto const& first = subtitles.front ();
339 auto const font_name = setup_font (first, fonts);
340 auto const fade_factor = calculate_fade_factor (first, time, frame_rate);
341 auto const markup = marked_up (subtitles, target.height, fade_factor, font_name);
342 auto layout = create_layout ();
343 setup_layout (layout, font_name, markup);
345 layout->get_pixel_size (size.width, size.height);
347 /* Calculate x and y scale factors. These are only used to stretch
348 the font away from its normal aspect ratio.
352 if (fabs (first.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
353 if (first.aspect_adjust() < 1) {
354 x_scale = max (0.25f, first.aspect_adjust ());
358 y_scale = 1 / min (4.0f, first.aspect_adjust ());
362 auto const border_width = first.effect() == dcp::Effect::BORDER ? (first.outline_width * target.width / 2048.0) : 0;
363 size.width += 2 * ceil (border_width);
364 size.height += 2 * ceil (border_width);
366 size.width *= x_scale;
367 size.height *= y_scale;
369 /* Shuffle the subtitle over by the border width (if we have any) so it's not cut off */
370 int const x_offset = ceil (border_width);
371 /* Move down a bit so that accents on capital letters can be seen */
372 int const y_offset = target.height / 100.0;
374 size.width += x_offset;
375 size.height += y_offset;
377 auto image = create_image (size);
378 auto surface = create_surface (image);
379 auto context = Cairo::Context::create (surface);
381 context->set_line_width (1);
382 context->scale (x_scale, y_scale);
383 layout->update_from_cairo_context (context);
385 if (first.effect() == dcp::Effect::SHADOW) {
386 /* Drop-shadow effect */
387 set_source_rgba (context, first.effect_colour(), fade_factor);
388 context->move_to (x_offset + 4, y_offset + 4);
389 layout->add_to_cairo_context (context);
393 if (first.effect() == dcp::Effect::BORDER) {
395 set_source_rgba (context, first.effect_colour(), fade_factor);
396 context->set_line_width (border_width);
397 context->set_line_join (Cairo::LINE_JOIN_ROUND);
398 context->move_to (x_offset, y_offset);
399 layout->add_to_cairo_context (context);
403 /* The actual subtitle */
405 set_source_rgba (context, first.colour(), fade_factor);
407 context->move_to (x_offset, y_offset);
408 layout->add_to_cairo_context (context);
411 context->set_line_width (0.5);
412 context->move_to (x_offset, y_offset);
413 layout->add_to_cairo_context (context);
416 int const x = x_position (first, target.width, size.width);
417 int const y = y_position (first, target.height, size.height);
418 return PositionImage (image, Position<int>(max (0, x), max(0, y)));
422 /** @param time Time of the frame that these subtitles are going on.
423 * @param target Size of the container that this subtitle will end up in.
424 * @param frame_rate DCP frame rate.
427 render_text (list<StringText> subtitles, list<shared_ptr<Font>> fonts, dcp::Size target, DCPTime time, int frame_rate)
429 list<StringText> pending;
430 list<PositionImage> images;
432 for (auto const& i: subtitles) {
433 if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
434 images.push_back (render_line (pending, fonts, target, time, frame_rate));
437 pending.push_back (i);
440 if (!pending.empty()) {
441 images.push_back (render_line (pending, fonts, target, time, frame_rate));