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"
29 #include <dcp/raw_convert.h>
30 #include <dcp/warnings.h>
31 #include <cairomm/cairomm.h>
32 LIBDCP_DISABLE_WARNINGS
34 LIBDCP_ENABLE_WARNINGS
35 #include <pango/pangocairo.h>
36 #include <boost/algorithm/string.hpp>
44 using std::make_shared;
48 using std::shared_ptr;
50 using namespace dcpomatic;
53 /** Create a Pango layout using a dummy context which we can use to calculate the size
54 * of the text we will render. Then we can transfer the layout over to the real context
55 * for the actual render.
57 static Glib::RefPtr<Pango::Layout>
60 auto c_font_map = pango_cairo_font_map_new ();
61 DCPOMATIC_ASSERT (c_font_map);
62 auto font_map = Glib::wrap (c_font_map);
63 auto c_context = pango_font_map_create_context (c_font_map);
64 DCPOMATIC_ASSERT (c_context);
65 auto context = Glib::wrap (c_context);
66 return Pango::Layout::create (context);
71 setup_layout (Glib::RefPtr<Pango::Layout> layout, string font_name, string markup)
73 layout->set_alignment (Pango::ALIGN_LEFT);
74 Pango::FontDescription font (font_name);
75 layout->set_font_description (font);
76 layout->set_markup (markup);
81 marked_up (list<StringText> subtitles, int target_height, float fade_factor, string font_name)
83 auto constexpr pixels_to_1024ths_point = 72 * 1024 / 96;
85 auto make_span = [target_height, fade_factor](StringText const& subtitle, string text, string extra_attribute) {
88 if (subtitle.italic()) {
89 span += "style=\"italic\" ";
91 if (subtitle.bold()) {
92 span += "weight=\"bold\" ";
94 if (subtitle.underline()) {
95 span += "underline=\"single\" ";
97 span += "size=\"" + dcp::raw_convert<string>(lrintf(subtitle.size_in_pixels(target_height) * pixels_to_1024ths_point)) + "\" ";
98 /* Between 1-65535 inclusive, apparently... */
99 span += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
100 span += "color=\"#" + subtitle.colour().to_rgb_string() + "\"";
101 if (!extra_attribute.empty()) {
102 span += " " + extra_attribute;
106 boost::algorithm::replace_all(text, "&", "&");
107 boost::algorithm::replace_all(text, "<", "<");
108 boost::algorithm::replace_all(text, ">", ">");
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(shared_ptr<const dcpomatic::Font> font)
180 auto font_file = default_font_file ();
182 if (font && font->file()) {
183 font_file = *font->file();
186 return FontConfig::instance()->make_font_available(font_file);
191 calculate_fade_factor (StringText const& first, DCPTime time, int frame_rate)
193 float fade_factor = 1;
195 /* Round the fade start/end to the nearest frame start. Otherwise if a subtitle starts just after
196 the start of a frame it will be faded out.
198 auto const fade_in_start = DCPTime::from_seconds(first.in().as_seconds()).round(frame_rate);
199 auto const fade_in_end = fade_in_start + DCPTime::from_seconds (first.fade_up_time().as_seconds ());
201 if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
202 fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
205 if (time < fade_in_start) {
209 /* first.out() may be zero if we don't know when this subtitle will finish. We can only think about
210 * fading out if we _do_ know when it will finish.
212 if (first.out() != dcp::Time()) {
213 auto const fade_out_end = DCPTime::from_seconds (first.out().as_seconds()).round(frame_rate);
214 auto const fade_out_start = fade_out_end - DCPTime::from_seconds(first.fade_down_time().as_seconds());
216 if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
217 fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
219 if (time > fade_out_end) {
229 x_position (StringText const& first, int target_width, int layout_width)
232 switch (first.h_align()) {
233 case dcp::HAlign::LEFT:
234 /* h_position is distance between left of frame and left of subtitle */
235 x = first.h_position() * target_width;
237 case dcp::HAlign::CENTER:
238 /* h_position is distance between centre of frame and centre of subtitle */
239 x = (0.5 + first.h_position()) * target_width - layout_width / 2;
241 case dcp::HAlign::RIGHT:
242 /* h_position is distance between right of frame and right of subtitle */
243 x = (1.0 - first.h_position()) * target_width - layout_width;
252 y_position (StringText const& first, int target_height, int baseline_to_bottom, int layout_height)
255 switch (first.valign_standard) {
256 case dcp::SubtitleStandard::INTEROP:
257 case dcp::SubtitleStandard::SMPTE_2014:
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::SubtitleStandard::SMPTE_2007:
274 case dcp::SubtitleStandard::SMPTE_2010:
275 switch (first.v_align()) {
276 case dcp::VAlign::TOP:
277 /* v_position is distance from top of frame to top of subtitle */
278 y = first.v_position() * target_height;
280 case dcp::VAlign::CENTER:
281 /* v_position is distance from centre of frame to centre of subtitle */
282 y = (0.5 + first.v_position()) * target_height - layout_height / 2;
284 case dcp::VAlign::BOTTOM:
285 /* v_position is distance from bottom of frame to bottom of subtitle */
286 y = (1.0 - first.v_position()) * target_height - layout_height;
295 /** @param subtitles A list of subtitles that are all on the same line,
296 * at the same time and with the same fade in/out.
299 render_line (list<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
301 /* XXX: this method can only handle italic / bold changes mid-line,
305 DCPOMATIC_ASSERT (!subtitles.empty ());
306 auto const& first = subtitles.front ();
308 auto const font_name = setup_font(first.font);
309 auto const fade_factor = calculate_fade_factor (first, time, frame_rate);
310 auto const markup = marked_up (subtitles, target.height, fade_factor, font_name);
311 auto layout = create_layout ();
312 setup_layout (layout, font_name, markup);
313 auto ink = layout->get_ink_extents();
314 dcp::Size size{ink.get_width() / Pango::SCALE, ink.get_height() / Pango::SCALE};
316 /* Calculate x and y scale factors. These are only used to stretch
317 the font away from its normal aspect ratio.
321 if (fabs (first.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
322 if (first.aspect_adjust() < 1) {
323 x_scale = max (0.25f, first.aspect_adjust ());
327 y_scale = 1 / min (4.0f, first.aspect_adjust ());
331 auto const border_width = first.effect() == dcp::Effect::BORDER ? (first.outline_width * target.width / 2048.0) : 0;
332 size.width += 2 * ceil (border_width);
333 size.height += 2 * ceil (border_width);
335 size.width *= x_scale;
336 size.height *= y_scale;
338 /* Shuffle the subtitle over by the border width (if we have any) so it's not cut off */
339 int const x_offset = (-ink.get_x() / Pango::SCALE) + ceil(border_width);
340 int const y_offset = -ink.get_y() / Pango::SCALE + ceil(border_width);
342 auto image = create_image (size);
343 auto surface = create_surface (image);
344 auto context = Cairo::Context::create (surface);
346 context->set_line_width (1);
347 context->scale (x_scale, y_scale);
348 layout->update_from_cairo_context (context);
350 if (first.effect() == dcp::Effect::SHADOW) {
351 /* Drop-shadow effect */
352 set_source_rgba (context, first.effect_colour(), fade_factor);
353 context->move_to (x_offset + 4, y_offset + 4);
354 layout->add_to_cairo_context (context);
358 if (first.effect() == dcp::Effect::BORDER) {
360 set_source_rgba (context, first.effect_colour(), fade_factor);
361 context->set_line_width (border_width);
362 context->set_line_join (Cairo::LINE_JOIN_ROUND);
363 context->move_to (x_offset, y_offset);
364 layout->add_to_cairo_context (context);
368 /* The actual subtitle */
370 set_source_rgba (context, first.colour(), fade_factor);
372 context->move_to (x_offset, y_offset);
373 layout->add_to_cairo_context (context);
376 context->set_line_width (0.5);
377 context->move_to (x_offset, y_offset);
378 layout->add_to_cairo_context (context);
381 int const x = x_position (first, target.width, size.width);
382 int const y = y_position (first, target.height, ink.get_y() / Pango::SCALE, size.height);
383 return PositionImage (image, Position<int>(max (0, x), max(0, y)));
387 /** @param time Time of the frame that these subtitles are going on.
388 * @param target Size of the container that this subtitle will end up in.
389 * @param frame_rate DCP frame rate.
392 render_text (list<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
394 list<StringText> pending;
395 list<PositionImage> images;
397 for (auto const& i: subtitles) {
398 if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
399 images.push_back(render_line(pending, target, time, frame_rate));
402 pending.push_back (i);
405 if (!pending.empty()) {
406 images.push_back(render_line(pending, target, time, frame_rate));
414 FontMetrics::height(StringText const& subtitle)
416 return get(subtitle)->second.second;
421 FontMetrics::baseline_to_bottom(StringText const& subtitle)
423 return get(subtitle)->second.first;
427 FontMetrics::Cache::iterator
428 FontMetrics::get(StringText const& subtitle)
430 auto id = Identifier(subtitle);
432 auto iter = _cache.find(id);
433 if (iter != _cache.end()) {
437 auto const font_name = setup_font(subtitle.font);
438 auto layout = create_layout();
439 auto copy = subtitle;
440 copy.set_text("Qypjg");
441 setup_layout(layout, font_name, marked_up({copy}, _target_height, 1, font_name));
442 auto ink = layout->get_ink_extents();
443 auto const scale = float(_target_height * Pango::SCALE);
444 return _cache.insert({id, { ink.get_y() / scale, ink.get_height() / scale}}).first;
448 FontMetrics::Identifier::Identifier(StringText const& subtitle)
449 : font(subtitle.font)
450 , size(subtitle.size())
451 , aspect_adjust(subtitle.aspect_adjust())
458 FontMetrics::Identifier::operator<(FontMetrics::Identifier const& other) const
460 if (font != other.font) {
461 return font < other.font;
464 if (size != other.size) {
465 return size < other.size;
468 return aspect_adjust < other.aspect_adjust;