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"
25 #include "font_config.h"
27 #include "render_text.h"
30 #include <dcp/raw_convert.h>
31 #include <dcp/warnings.h>
32 #include <cairomm/cairomm.h>
33 LIBDCP_DISABLE_WARNINGS
35 LIBDCP_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 /** Create a Pango layout using a dummy context which we can use to calculate the size
55 * of the text we will render. Then we can transfer the layout over to the real context
56 * for the actual render.
58 static Glib::RefPtr<Pango::Layout>
61 auto c_font_map = pango_cairo_font_map_new ();
62 DCPOMATIC_ASSERT (c_font_map);
63 auto font_map = Glib::wrap (c_font_map);
64 auto c_context = pango_font_map_create_context (c_font_map);
65 DCPOMATIC_ASSERT (c_context);
66 auto context = Glib::wrap (c_context);
67 return Pango::Layout::create (context);
72 setup_layout (Glib::RefPtr<Pango::Layout> layout, string font_name, string markup)
74 layout->set_alignment (Pango::ALIGN_LEFT);
75 Pango::FontDescription font (font_name);
76 layout->set_font_description (font);
77 layout->set_markup (markup);
82 marked_up (list<StringText> subtitles, int target_height, float fade_factor, string font_name)
84 auto constexpr pixels_to_1024ths_point = 72 * 1024 / 96;
86 auto make_span = [target_height, fade_factor](StringText const& subtitle, string text, string extra_attribute) {
89 if (subtitle.italic()) {
90 span += "style=\"italic\" ";
92 if (subtitle.bold()) {
93 span += "weight=\"bold\" ";
95 if (subtitle.underline()) {
96 span += "underline=\"single\" ";
98 span += "size=\"" + dcp::raw_convert<string>(lrintf(subtitle.size_in_pixels(target_height) * pixels_to_1024ths_point)) + "\" ";
99 /* Between 1-65535 inclusive, apparently... */
100 span += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
101 span += "color=\"#" + subtitle.colour().to_rgb_string() + "\"";
102 if (!extra_attribute.empty()) {
103 span += " " + extra_attribute;
107 boost::algorithm::replace_all(text, "&", "&");
108 boost::algorithm::replace_all(text, "<", "<");
109 boost::algorithm::replace_all(text, ">", ">");
117 for (auto const& i: subtitles) {
118 if (std::abs(i.space_before()) > dcp::SPACE_BEFORE_EPSILON) {
119 /* We need to insert some horizontal space into the layout. The only way I can find to do this
120 * is to write a " " with some special letter_spacing. As far as I can see, such a space will
121 * be written with letter_spacing either side. This means that to get a horizontal space x we
122 * need to write a " " with letter spacing (x - s) / 2, where s is the width of the " ".
124 auto layout = create_layout();
125 setup_layout(layout, font_name, make_span(i, " ", {}));
128 layout->get_pixel_size(space_width, dummy);
129 auto spacing = ((i.space_before() * i.size_in_pixels(target_height) - space_width) / 2) * pixels_to_1024ths_point;
130 out += make_span(i, " ", "letter_spacing=\"" + dcp::raw_convert<string>(spacing) + "\"");
133 out += make_span(i, i.text(), {});
141 set_source_rgba (Cairo::RefPtr<Cairo::Context> context, dcp::Colour colour, float fade_factor)
143 context->set_source_rgba (float(colour.r) / 255, float(colour.g) / 255, float(colour.b) / 255, fade_factor);
147 static shared_ptr<Image>
148 create_image (dcp::Size size)
150 /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha.
151 * This must be COMPACT as we're using it with Cairo::ImageSurface::create
153 auto image = make_shared<Image>(AV_PIX_FMT_BGRA, size, Image::Alignment::COMPACT);
154 image->make_black ();
159 static Cairo::RefPtr<Cairo::ImageSurface>
160 create_surface (shared_ptr<Image> image)
162 /* XXX: I don't think it's guaranteed that format_stride_for_width will return a stride without any padding,
163 * so it's lucky that this works.
165 DCPOMATIC_ASSERT (image->alignment() == Image::Alignment::COMPACT);
166 DCPOMATIC_ASSERT (image->pixel_format() == AV_PIX_FMT_BGRA);
167 return Cairo::ImageSurface::create (
169 Cairo::FORMAT_ARGB32,
171 image->size().height,
172 /* Cairo ARGB32 means first byte blue, second byte green, third byte red, fourth byte alpha */
173 Cairo::ImageSurface::format_stride_for_width (Cairo::FORMAT_ARGB32, image->size().width)
179 setup_font(shared_ptr<const dcpomatic::Font> font)
181 auto font_file = default_font_file ();
183 if (font && font->file()) {
184 font_file = *font->file();
187 return FontConfig::instance()->make_font_available(font_file);
192 calculate_fade_factor (StringText const& first, DCPTime time, int frame_rate)
194 float fade_factor = 1;
196 /* Round the fade start/end to the nearest frame start. Otherwise if a subtitle starts just after
197 the start of a frame it will be faded out.
199 auto const fade_in_start = DCPTime::from_seconds(first.in().as_seconds()).round(frame_rate);
200 auto const fade_in_end = fade_in_start + DCPTime::from_seconds (first.fade_up_time().as_seconds ());
202 if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
203 fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
206 if (time < fade_in_start) {
210 /* first.out() may be zero if we don't know when this subtitle will finish. We can only think about
211 * fading out if we _do_ know when it will finish.
213 if (first.out() != dcp::Time()) {
214 auto const fade_out_end = DCPTime::from_seconds (first.out().as_seconds()).round(frame_rate);
215 auto const fade_out_start = fade_out_end - DCPTime::from_seconds(first.fade_down_time().as_seconds());
217 if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
218 fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
220 if (time > fade_out_end) {
230 x_position (StringText const& first, int target_width, int layout_width)
233 switch (first.h_align()) {
234 case dcp::HAlign::LEFT:
235 /* h_position is distance between left of frame and left of subtitle */
236 x = first.h_position() * target_width;
238 case dcp::HAlign::CENTER:
239 /* h_position is distance between centre of frame and centre of subtitle */
240 x = (0.5 + first.h_position()) * target_width - layout_width / 2;
242 case dcp::HAlign::RIGHT:
243 /* h_position is distance between right of frame and right of subtitle */
244 x = (1.0 - first.h_position()) * target_width - layout_width;
253 y_position (StringText const& first, int target_height, int baseline_to_bottom, int layout_height)
256 switch (first.valign_standard) {
257 case dcp::Standard::INTEROP:
258 switch (first.v_align()) {
259 case dcp::VAlign::TOP:
260 /* v_position is distance from top of frame to subtitle baseline */
261 y = first.v_position() * target_height - (layout_height - baseline_to_bottom);
263 case dcp::VAlign::CENTER:
264 /* v_position is distance from centre of frame to subtitle baseline */
265 y = (0.5 + first.v_position()) * target_height - (layout_height - baseline_to_bottom);
267 case dcp::VAlign::BOTTOM:
268 /* v_position is distance from bottom of frame to subtitle baseline */
269 y = (1.0 - first.v_position()) * target_height - (layout_height - baseline_to_bottom);
273 case dcp::Standard::SMPTE:
274 switch (first.v_align()) {
275 case dcp::VAlign::TOP:
276 /* v_position is distance from top of frame to top of subtitle */
277 y = first.v_position() * target_height;
279 case dcp::VAlign::CENTER:
280 /* v_position is distance from centre of frame to centre of subtitle */
281 y = (0.5 + first.v_position()) * target_height - layout_height / 2;
283 case dcp::VAlign::BOTTOM:
284 /* v_position is distance from bottom of frame to bottom of subtitle */
285 y = (1.0 - first.v_position()) * target_height - layout_height;
294 /** @param subtitles A list of subtitles that are all on the same line,
295 * at the same time and with the same fade in/out.
298 render_line (list<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
300 /* XXX: this method can only handle italic / bold changes mid-line,
304 DCPOMATIC_ASSERT (!subtitles.empty ());
305 auto const& first = subtitles.front ();
307 auto const font_name = setup_font(first.font);
308 auto const fade_factor = calculate_fade_factor (first, time, frame_rate);
309 auto const markup = marked_up (subtitles, target.height, fade_factor, font_name);
310 auto layout = create_layout ();
311 setup_layout (layout, font_name, markup);
312 auto ink = layout->get_ink_extents();
313 dcp::Size size{ink.get_width() / Pango::SCALE, ink.get_height() / Pango::SCALE};
315 /* Calculate x and y scale factors. These are only used to stretch
316 the font away from its normal aspect ratio.
320 if (fabs (first.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
321 if (first.aspect_adjust() < 1) {
322 x_scale = max (0.25f, first.aspect_adjust ());
326 y_scale = 1 / min (4.0f, first.aspect_adjust ());
330 auto const border_width = first.effect() == dcp::Effect::BORDER ? (first.outline_width * target.width / 2048.0) : 0;
331 size.width += 2 * ceil (border_width);
332 size.height += 2 * ceil (border_width);
334 size.width *= x_scale;
335 size.height *= y_scale;
337 /* Shuffle the subtitle over by the border width (if we have any) so it's not cut off */
338 int const x_offset = (-ink.get_x() / Pango::SCALE) + ceil(border_width);
339 int const y_offset = -ink.get_y() / Pango::SCALE + ceil(border_width);
341 auto image = create_image (size);
342 auto surface = create_surface (image);
343 auto context = Cairo::Context::create (surface);
345 context->set_line_width (1);
346 context->scale (x_scale, y_scale);
347 layout->update_from_cairo_context (context);
349 if (first.effect() == dcp::Effect::SHADOW) {
350 /* Drop-shadow effect */
351 set_source_rgba (context, first.effect_colour(), fade_factor);
352 context->move_to (x_offset + 4, y_offset + 4);
353 layout->add_to_cairo_context (context);
357 if (first.effect() == dcp::Effect::BORDER) {
359 set_source_rgba (context, first.effect_colour(), fade_factor);
360 context->set_line_width (border_width);
361 context->set_line_join (Cairo::LINE_JOIN_ROUND);
362 context->move_to (x_offset, y_offset);
363 layout->add_to_cairo_context (context);
367 /* The actual subtitle */
369 set_source_rgba (context, first.colour(), fade_factor);
371 context->move_to (x_offset, y_offset);
372 layout->add_to_cairo_context (context);
375 context->set_line_width (0.5);
376 context->move_to (x_offset, y_offset);
377 layout->add_to_cairo_context (context);
380 int const x = x_position (first, target.width, size.width);
381 int const y = y_position (first, target.height, ink.get_y() / Pango::SCALE, size.height);
382 return PositionImage (image, Position<int>(max (0, x), max(0, y)));
386 /** @param time Time of the frame that these subtitles are going on.
387 * @param target Size of the container that this subtitle will end up in.
388 * @param frame_rate DCP frame rate.
391 render_text (list<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
393 list<StringText> pending;
394 list<PositionImage> images;
396 for (auto const& i: subtitles) {
397 if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
398 images.push_back(render_line(pending, target, time, frame_rate));
401 pending.push_back (i);
404 if (!pending.empty()) {
405 images.push_back(render_line(pending, target, time, frame_rate));
413 FontMetrics::height(StringText const& subtitle)
415 return get(subtitle)->second.second;
420 FontMetrics::baseline_to_bottom(StringText const& subtitle)
422 return get(subtitle)->second.first;
426 FontMetrics::Cache::iterator
427 FontMetrics::get(StringText const& subtitle)
429 auto id = Identifier(subtitle);
431 auto iter = _cache.find(id);
432 if (iter != _cache.end()) {
436 auto const font_name = setup_font(subtitle.font);
437 auto layout = create_layout();
438 auto copy = subtitle;
439 copy.set_text("Qypjg");
440 setup_layout(layout, font_name, marked_up({copy}, _target_height, 1, font_name));
441 auto ink = layout->get_ink_extents();
442 auto const scale = float(_target_height * Pango::SCALE);
443 return _cache.insert({id, { ink.get_y() / scale, ink.get_height() / scale}}).first;
447 FontMetrics::Identifier::Identifier(StringText const& subtitle)
448 : font(subtitle.font)
449 , size(subtitle.size())
450 , aspect_adjust(subtitle.aspect_adjust())
457 FontMetrics::Identifier::operator<(FontMetrics::Identifier const& other) const
459 if (font != other.font) {
460 return font < other.font;
463 if (size != other.size) {
464 return size < other.size;
467 return aspect_adjust < other.aspect_adjust;