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 boost::optional;
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>
59 create_layout(string font_name, string markup)
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 auto layout = Pango::Layout::create(context);
69 layout->set_alignment (Pango::ALIGN_LEFT);
70 Pango::FontDescription font (font_name);
71 layout->set_font_description (font);
72 layout->set_markup (markup);
79 marked_up (list<StringText> subtitles, int target_height, float fade_factor, string font_name)
81 auto constexpr pixels_to_1024ths_point = 72 * 1024 / 96;
83 auto make_span = [target_height, fade_factor](StringText const& subtitle, string text, string extra_attribute) {
86 if (subtitle.italic()) {
87 span += "style=\"italic\" ";
89 if (subtitle.bold()) {
90 span += "weight=\"bold\" ";
92 if (subtitle.underline()) {
93 span += "underline=\"single\" ";
95 span += "size=\"" + dcp::raw_convert<string>(lrintf(subtitle.size_in_pixels(target_height) * pixels_to_1024ths_point)) + "\" ";
96 /* Between 1-65535 inclusive, apparently... */
97 span += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
98 span += "color=\"#" + subtitle.colour().to_rgb_string() + "\"";
99 if (!extra_attribute.empty()) {
100 span += " " + extra_attribute;
104 boost::algorithm::replace_all(text, "&", "&");
105 boost::algorithm::replace_all(text, "<", "<");
106 boost::algorithm::replace_all(text, ">", ">");
114 for (auto const& i: subtitles) {
115 if (std::abs(i.space_before()) > dcp::SPACE_BEFORE_EPSILON) {
116 /* We need to insert some horizontal space into the layout. The only way I can find to do this
117 * is to write a " " with some special letter_spacing. As far as I can see, such a space will
118 * be written with letter_spacing either side. This means that to get a horizontal space x we
119 * need to write a " " with letter spacing (x - s) / 2, where s is the width of the " ".
121 auto layout = create_layout(font_name, make_span(i, " ", {}));
124 layout->get_pixel_size(space_width, dummy);
125 auto spacing = ((i.space_before() * i.size_in_pixels(target_height) - space_width) / 2) * pixels_to_1024ths_point;
126 out += make_span(i, " ", "letter_spacing=\"" + dcp::raw_convert<string>(spacing) + "\"");
129 out += make_span(i, i.text(), {});
137 set_source_rgba (Cairo::RefPtr<Cairo::Context> context, dcp::Colour colour, float fade_factor)
139 context->set_source_rgba (float(colour.r) / 255, float(colour.g) / 255, float(colour.b) / 255, fade_factor);
143 static shared_ptr<Image>
144 create_image (dcp::Size size)
146 /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha.
147 * This must be COMPACT as we're using it with Cairo::ImageSurface::create
149 auto image = make_shared<Image>(AV_PIX_FMT_BGRA, size, Image::Alignment::COMPACT);
150 image->make_black ();
155 static Cairo::RefPtr<Cairo::ImageSurface>
156 create_surface (shared_ptr<Image> image)
158 /* XXX: I don't think it's guaranteed that format_stride_for_width will return a stride without any padding,
159 * so it's lucky that this works.
161 DCPOMATIC_ASSERT (image->alignment() == Image::Alignment::COMPACT);
162 DCPOMATIC_ASSERT (image->pixel_format() == AV_PIX_FMT_BGRA);
163 return Cairo::ImageSurface::create (
165 Cairo::FORMAT_ARGB32,
167 image->size().height,
168 /* Cairo ARGB32 means first byte blue, second byte green, third byte red, fourth byte alpha */
169 Cairo::ImageSurface::format_stride_for_width (Cairo::FORMAT_ARGB32, image->size().width)
175 setup_font(shared_ptr<const dcpomatic::Font> font)
177 auto font_file = default_font_file ();
179 if (font && font->file()) {
180 font_file = *font->file();
183 return FontConfig::instance()->make_font_available(font_file);
188 calculate_fade_factor (StringText const& first, DCPTime time, int frame_rate)
190 float fade_factor = 1;
192 /* Round the fade start/end to the nearest frame start. Otherwise if a subtitle starts just after
193 the start of a frame it will be faded out.
195 auto const fade_in_start = DCPTime::from_seconds(first.in().as_seconds()).round(frame_rate);
196 auto const fade_in_end = fade_in_start + DCPTime::from_seconds (first.fade_up_time().as_seconds ());
198 if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
199 fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
202 if (time < fade_in_start) {
206 /* first.out() may be zero if we don't know when this subtitle will finish. We can only think about
207 * fading out if we _do_ know when it will finish.
209 if (first.out() != dcp::Time()) {
210 auto const fade_out_end = DCPTime::from_seconds (first.out().as_seconds()).round(frame_rate);
211 auto const fade_out_start = fade_out_end - DCPTime::from_seconds(first.fade_down_time().as_seconds());
213 if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
214 fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
216 if (time > fade_out_end) {
226 x_position(dcp::HAlign align, float position, int target_width, int layout_width)
230 case dcp::HAlign::LEFT:
231 /* h_position is distance between left of frame and left of subtitle */
232 x = position * target_width;
234 case dcp::HAlign::CENTER:
235 /* h_position is distance between centre of frame and centre of subtitle */
236 x = (0.5 + position) * target_width - layout_width / 2;
238 case dcp::HAlign::RIGHT:
239 /* h_position is distance between right of frame and right of subtitle */
240 x = (1.0 - position) * target_width - layout_width;
248 /** @param align_standard Standard with which to interpret this subtitle's position.
249 * @param align alignment.
250 * @param position position (between 0 and 1)
251 * @param target_height Height of the target screen (in pixels).
252 * @param baseline_to_bottom Distance from text baseline to the bottom of the bounding box (in pixels).
253 * @param layout_height Height of the subtitle bounding box (in pixels).
254 * @return y position of the top of the subtitle bounding box (in pixels) from the top of the screen.
257 y_position(dcp::SubtitleStandard standard, dcp::VAlign align, float position, int target_height, int baseline_to_bottom, int layout_height)
261 case dcp::SubtitleStandard::INTEROP:
262 case dcp::SubtitleStandard::SMPTE_2014:
264 case dcp::VAlign::TOP:
265 /* position is distance from top of frame to subtitle baseline */
266 y = position * target_height - (layout_height - baseline_to_bottom);
268 case dcp::VAlign::CENTER:
269 /* position is distance from centre of frame to subtitle baseline */
270 y = (0.5 + position) * target_height - (layout_height - baseline_to_bottom);
272 case dcp::VAlign::BOTTOM:
273 /* position is distance from bottom of frame to subtitle baseline */
274 y = (1.0 - position) * target_height - (layout_height - baseline_to_bottom);
278 case dcp::SubtitleStandard::SMPTE_2007:
279 case dcp::SubtitleStandard::SMPTE_2010:
281 case dcp::VAlign::TOP:
282 /* v_position is distance from top of frame to top of subtitle */
283 y = position * target_height;
285 case dcp::VAlign::CENTER:
286 /* v_position is distance from centre of frame to centre of subtitle */
287 y = (0.5 + position) * target_height - layout_height / 2;
289 case dcp::VAlign::BOTTOM:
290 /* v_position is distance from bottom of frame to bottom of subtitle */
291 y = (1.0 - position) * target_height - layout_height;
302 Position<int> position;
304 Glib::RefPtr<Pango::Layout> pango;
308 /** @param subtitles A list of subtitles that are all on the same line,
309 * at the same time and with the same fade in/out.
312 setup_layout(list<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
314 DCPOMATIC_ASSERT(!subtitles.empty());
315 auto const& first = subtitles.front();
317 auto const font_name = setup_font(first.font);
318 auto const fade_factor = calculate_fade_factor(first, time, frame_rate);
319 auto const markup = marked_up(subtitles, target.height, fade_factor, font_name);
320 auto layout = create_layout(font_name, markup);
321 auto ink = layout->get_ink_extents();
322 return { { ink.get_x() / Pango::SCALE, ink.get_y() / Pango::SCALE }, { ink.get_width() / Pango::SCALE, ink.get_height() / Pango::SCALE }, layout };
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, 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();
338 auto const fade_factor = calculate_fade_factor(first, time, frame_rate);
340 auto layout = setup_layout(subtitles, target, time, frame_rate);
342 /* Calculate x and y scale factors. These are only used to stretch
343 the font away from its normal aspect ratio.
347 if (fabs (first.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
348 if (first.aspect_adjust() < 1) {
349 x_scale = max (0.25f, first.aspect_adjust ());
353 y_scale = 1 / min (4.0f, first.aspect_adjust ());
357 auto const border_width = first.effect() == dcp::Effect::BORDER ? (first.outline_width * target.width / 2048.0) : 0;
358 layout.size.width += 2 * ceil (border_width);
359 layout.size.height += 2 * ceil (border_width);
361 layout.size.width *= x_scale;
362 layout.size.height *= y_scale;
364 /* Shuffle the subtitle over by the border width (if we have any) so it's not cut off */
365 int const x_offset = -layout.position.x + ceil(border_width);
366 int const y_offset = -layout.position.y + ceil(border_width);
368 auto image = create_image(layout.size);
369 auto surface = create_surface (image);
370 auto context = Cairo::Context::create (surface);
372 context->set_line_width (1);
373 context->scale (x_scale, y_scale);
374 layout.pango->update_from_cairo_context(context);
376 if (first.effect() == dcp::Effect::SHADOW) {
377 /* Drop-shadow effect */
378 set_source_rgba (context, first.effect_colour(), fade_factor);
379 context->move_to (x_offset + 4, y_offset + 4);
380 layout.pango->add_to_cairo_context(context);
384 if (first.effect() == dcp::Effect::BORDER) {
386 set_source_rgba (context, first.effect_colour(), fade_factor);
387 context->set_line_width (border_width);
388 context->set_line_join (Cairo::LINE_JOIN_ROUND);
389 context->move_to (x_offset, y_offset);
390 layout.pango->add_to_cairo_context (context);
394 /* The actual subtitle */
396 set_source_rgba (context, first.colour(), fade_factor);
398 context->move_to (x_offset, y_offset);
399 layout.pango->add_to_cairo_context (context);
402 context->set_line_width (0.5);
403 context->move_to (x_offset, y_offset);
404 layout.pango->add_to_cairo_context (context);
407 int const x = x_position(first.h_align(), first.h_position(), target.width, layout.size.width);
408 int const y = y_position(first.valign_standard, first.v_align(), first.v_position(), target.height, layout.position.y, layout.size.height);
409 return PositionImage (image, Position<int>(max (0, x), max(0, y)));
413 /** @param time Time of the frame that these subtitles are going on.
414 * @param target Size of the container that this subtitle will end up in.
415 * @param frame_rate DCP frame rate.
418 render_text (list<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
420 list<StringText> pending;
421 list<PositionImage> images;
423 for (auto const& i: subtitles) {
424 if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
425 images.push_back(render_line(pending, target, time, frame_rate));
428 pending.push_back (i);
431 if (!pending.empty()) {
432 images.push_back(render_line(pending, target, time, frame_rate));
439 list<dcpomatic::Rect<int>>
440 bounding_box(list<StringText> subtitles, dcp::Size target, optional<dcp::SubtitleStandard> override_standard)
442 list<StringText> pending;
443 list<dcpomatic::Rect<int>> rects;
445 auto use_pending = [&pending, &rects, target, override_standard]() {
446 auto const& subtitle = pending.front();
447 auto standard = override_standard.get_value_or(subtitle.valign_standard);
448 /* We can provide dummy values for time and frame rate here as they are only used to calculate fades */
449 auto layout = setup_layout(pending, target, DCPTime(), 24);
450 int const x = x_position(subtitle.h_align(), subtitle.h_position(), target.width, layout.size.width);
451 int const y = y_position(standard, subtitle.v_align(), subtitle.v_position(), target.height, layout.position.y, layout.size.height);
452 rects.push_back({Position<int>(x, y), layout.size.width, layout.size.height});
455 for (auto const& i: subtitles) {
456 if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
460 pending.push_back(i);
463 if (!pending.empty()) {
472 FontMetrics::height(StringText const& subtitle)
474 return get(subtitle)->second.second;
479 FontMetrics::baseline_to_bottom(StringText const& subtitle)
481 return get(subtitle)->second.first;
485 FontMetrics::Cache::iterator
486 FontMetrics::get(StringText const& subtitle)
488 auto id = Identifier(subtitle);
490 auto iter = _cache.find(id);
491 if (iter != _cache.end()) {
495 auto const font_name = setup_font(subtitle.font);
496 auto copy = subtitle;
497 copy.set_text("Qypjg");
498 auto layout = create_layout(font_name, marked_up({copy}, _target_height, 1, font_name));
499 auto ink = layout->get_ink_extents();
500 auto const scale = float(_target_height * Pango::SCALE);
501 return _cache.insert({id, { ink.get_y() / scale, ink.get_height() / scale}}).first;
505 FontMetrics::Identifier::Identifier(StringText const& subtitle)
506 : font(subtitle.font)
507 , size(subtitle.size())
508 , aspect_adjust(subtitle.aspect_adjust())
515 FontMetrics::Identifier::operator<(FontMetrics::Identifier const& other) const
517 if (font != other.font) {
518 return font < other.font;
521 if (size != other.size) {
522 return size < other.size;
525 return aspect_adjust < other.aspect_adjust;