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 #include <pangommconfig.h>
35 LIBDCP_ENABLE_WARNINGS
36 #include <pango/pangocairo.h>
37 #include <boost/algorithm/string.hpp>
44 using std::make_shared;
48 using std::shared_ptr;
51 using boost::optional;
52 using namespace dcpomatic;
55 #if CAIROMM_MAJOR_VERSION == 1 && CAIROMM_MINOR_VERSION <= 14
56 #define DCPOMATIC_OLD_CAIROMM_API
59 #if PANGOMM_MAJOR_VERSION == 2 && PANGOMM_MINOR_VERSION <= 46
60 #define DCPOMATIC_OLD_PANGOMM_API
64 /** Create a Pango layout using a dummy context which we can use to calculate the size
65 * of the text we will render. Then we can transfer the layout over to the real context
66 * for the actual render.
68 static Glib::RefPtr<Pango::Layout>
69 create_layout(string font_name, string markup)
71 auto c_font_map = pango_cairo_font_map_new ();
72 DCPOMATIC_ASSERT (c_font_map);
73 auto font_map = Glib::wrap (c_font_map);
74 auto c_context = pango_font_map_create_context (c_font_map);
75 DCPOMATIC_ASSERT (c_context);
76 auto context = Glib::wrap (c_context);
77 auto layout = Pango::Layout::create(context);
79 #ifdef DCPOMATIC_OLD_PANGOMM_API
80 layout->set_alignment(Pango::ALIGN_LEFT);
82 layout->set_alignment(Pango::Alignment::LEFT);
84 Pango::FontDescription font (font_name);
85 layout->set_font_description (font);
86 layout->set_markup (markup);
93 marked_up(vector<StringText> subtitles, int target_height, float fade_factor, string font_name)
95 auto constexpr pixels_to_1024ths_point = 72 * 1024 / 96;
97 auto make_span = [target_height, fade_factor](StringText const& subtitle, string text, string extra_attribute) {
100 if (subtitle.italic()) {
101 span += "style=\"italic\" ";
103 if (subtitle.bold()) {
104 span += "weight=\"bold\" ";
106 if (subtitle.underline()) {
107 span += "underline=\"single\" ";
109 span += "size=\"" + dcp::raw_convert<string>(lrintf(subtitle.size_in_pixels(target_height) * pixels_to_1024ths_point)) + "\" ";
110 /* Between 1-65535 inclusive, apparently... */
111 span += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
112 span += "color=\"#" + subtitle.colour().to_rgb_string() + "\"";
113 if (!extra_attribute.empty()) {
114 span += " " + extra_attribute;
118 boost::algorithm::replace_all(text, "&", "&");
119 boost::algorithm::replace_all(text, "<", "<");
120 boost::algorithm::replace_all(text, ">", ">");
121 boost::algorithm::replace_all(text, "\n", "");
129 for (auto const& i: subtitles) {
130 if (std::abs(i.space_before()) > dcp::SPACE_BEFORE_EPSILON) {
131 /* We need to insert some horizontal space into the layout. The only way I can find to do this
132 * is to write a " " with some special letter_spacing. As far as I can see, such a space will
133 * be written with letter_spacing either side. This means that to get a horizontal space x we
134 * need to write a " " with letter spacing (x - s) / 2, where s is the width of the " ".
136 auto layout = create_layout(font_name, make_span(i, " ", {}));
139 layout->get_pixel_size(space_width, dummy);
140 auto spacing = ((i.space_before() * i.size_in_pixels(target_height) - space_width) / 2) * pixels_to_1024ths_point;
141 out += make_span(i, " ", "letter_spacing=\"" + dcp::raw_convert<string>(spacing) + "\"");
144 out += make_span(i, i.text(), {});
152 set_source_rgba (Cairo::RefPtr<Cairo::Context> context, dcp::Colour colour, float fade_factor)
154 context->set_source_rgba (float(colour.r) / 255, float(colour.g) / 255, float(colour.b) / 255, fade_factor);
158 static shared_ptr<Image>
159 create_image (dcp::Size size)
161 /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha.
162 * This must be COMPACT as we're using it with Cairo::ImageSurface::create
164 auto image = make_shared<Image>(AV_PIX_FMT_BGRA, size, Image::Alignment::COMPACT);
165 image->make_black ();
170 static Cairo::RefPtr<Cairo::ImageSurface>
171 create_surface (shared_ptr<Image> image)
173 /* XXX: I don't think it's guaranteed that format_stride_for_width will return a stride without any padding,
174 * so it's lucky that this works.
176 DCPOMATIC_ASSERT (image->alignment() == Image::Alignment::COMPACT);
177 DCPOMATIC_ASSERT (image->pixel_format() == AV_PIX_FMT_BGRA);
178 return Cairo::ImageSurface::create (
180 #ifdef DCPOMATIC_OLD_CAIROMM_API
181 Cairo::FORMAT_ARGB32,
183 Cairo::ImageSurface::Format::ARGB32,
186 image->size().height,
187 /* Cairo ARGB32 means first byte blue, second byte green, third byte red, fourth byte alpha */
188 Cairo::ImageSurface::format_stride_for_width(
189 #ifdef DCPOMATIC_OLD_CAIROMM_API
190 Cairo::FORMAT_ARGB32,
192 Cairo::ImageSurface::Format::ARGB32,
201 calculate_fade_factor (StringText const& first, DCPTime time, int frame_rate)
203 float fade_factor = 1;
205 /* Round the fade start/end to the nearest frame start. Otherwise if a subtitle starts just after
206 the start of a frame it will be faded out.
208 auto const fade_in_start = DCPTime::from_seconds(first.in().as_seconds()).round(frame_rate);
209 auto const fade_in_end = fade_in_start + DCPTime::from_seconds (first.fade_up_time().as_seconds ());
211 if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
212 fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
215 if (time < fade_in_start) {
219 /* first.out() may be zero if we don't know when this subtitle will finish. We can only think about
220 * fading out if we _do_ know when it will finish.
222 if (first.out() != dcp::Time()) {
223 auto const fade_out_end = DCPTime::from_seconds (first.out().as_seconds()).round(frame_rate);
224 auto const fade_out_start = fade_out_end - DCPTime::from_seconds(first.fade_down_time().as_seconds());
226 if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
227 fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
229 if (time > fade_out_end) {
239 x_position(dcp::HAlign align, float position, int target_width, int layout_width)
243 case dcp::HAlign::LEFT:
244 /* h_position is distance between left of frame and left of subtitle */
245 x = position * target_width;
247 case dcp::HAlign::CENTER:
248 /* h_position is distance between centre of frame and centre of subtitle */
249 x = (0.5 + position) * target_width - layout_width / 2;
251 case dcp::HAlign::RIGHT:
252 /* h_position is distance between right of frame and right of subtitle */
253 x = (1.0 - position) * target_width - layout_width;
261 /** @param align_standard Standard with which to interpret this subtitle's position.
262 * @param align alignment.
263 * @param position position (between 0 and 1)
264 * @param target_height Height of the target screen (in pixels).
265 * @param baseline_to_bottom Distance from text baseline to the bottom of the bounding box (in pixels).
266 * @param layout_height Height of the subtitle bounding box (in pixels).
267 * @return y position of the top of the subtitle bounding box (in pixels) from the top of the screen.
270 y_position(dcp::SubtitleStandard standard, dcp::VAlign align, float position, int target_height, int baseline_to_bottom, int layout_height)
274 case dcp::SubtitleStandard::INTEROP:
275 case dcp::SubtitleStandard::SMPTE_2014:
277 case dcp::VAlign::TOP:
278 /* position is distance from top of frame to subtitle baseline */
279 y = position * target_height - (layout_height - baseline_to_bottom);
281 case dcp::VAlign::CENTER:
282 /* position is distance from centre of frame to subtitle baseline */
283 y = (0.5 + position) * target_height - (layout_height - baseline_to_bottom);
285 case dcp::VAlign::BOTTOM:
286 /* position is distance from bottom of frame to subtitle baseline */
287 y = (1.0 - position) * target_height - (layout_height - baseline_to_bottom);
291 case dcp::SubtitleStandard::SMPTE_2007:
292 case dcp::SubtitleStandard::SMPTE_2010:
294 case dcp::VAlign::TOP:
295 /* v_position is distance from top of frame to top of subtitle */
296 y = position * target_height;
298 case dcp::VAlign::CENTER:
299 /* v_position is distance from centre of frame to centre of subtitle */
300 y = (0.5 + position) * target_height - layout_height / 2;
302 case dcp::VAlign::BOTTOM:
303 /* v_position is distance from bottom of frame to bottom of subtitle */
304 y = (1.0 - position) * target_height - layout_height;
315 Position<int> position;
316 int baseline_position;
318 Glib::RefPtr<Pango::Layout> pango;
320 int baseline_to_bottom(int border_width)
322 return position.y + size.height - baseline_position - border_width;
327 /** @param subtitles A list of subtitles that are all on the same line,
328 * at the same time and with the same fade in/out.
331 setup_layout(vector<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
333 DCPOMATIC_ASSERT(!subtitles.empty());
334 auto const& first = subtitles.front();
336 auto const font_name = FontConfig::instance()->make_font_available(first.font);
337 auto const fade_factor = calculate_fade_factor(first, time, frame_rate);
338 auto const markup = marked_up(subtitles, target.height, fade_factor, font_name);
339 auto layout = create_layout(font_name, markup);
340 auto ink = layout->get_ink_extents();
343 description.position = { ink.get_x() / Pango::SCALE, ink.get_y() / Pango::SCALE };
344 description.baseline_position = layout->get_baseline() / Pango::SCALE;
345 description.size = { ink.get_width() / Pango::SCALE, ink.get_height() / Pango::SCALE };
346 description.pango = layout;
354 border_width_for_subtitle(StringText const& subtitle, dcp::Size target)
356 return subtitle.effect() == dcp::Effect::BORDER ? (subtitle.outline_width * target.width / 2048.0) : 0;
360 /** @param subtitles A list of subtitles that are all on the same line,
361 * at the same time and with the same fade in/out.
364 render_line(vector<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
366 /* XXX: this method can only handle italic / bold changes mid-line,
370 DCPOMATIC_ASSERT(!subtitles.empty ());
371 auto const& first = subtitles.front();
372 auto const fade_factor = calculate_fade_factor(first, time, frame_rate);
374 auto layout = setup_layout(subtitles, target, time, frame_rate);
376 /* Calculate x and y scale factors. These are only used to stretch
377 the font away from its normal aspect ratio.
381 if (fabs (first.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
382 if (first.aspect_adjust() < 1) {
383 x_scale = max (0.25f, first.aspect_adjust ());
387 y_scale = 1 / min (4.0f, first.aspect_adjust ());
391 auto const border_width = border_width_for_subtitle(first, target);
392 layout.size.width += 2 * ceil (border_width);
393 layout.size.height += 2 * ceil (border_width);
395 layout.size.width *= x_scale;
396 layout.size.height *= y_scale;
398 /* Shuffle the subtitle over by the border width (if we have any) so it's not cut off */
399 int const x_offset = -layout.position.x + ceil(border_width);
400 int const y_offset = -layout.position.y + ceil(border_width);
402 auto image = create_image(layout.size);
403 auto surface = create_surface (image);
404 auto context = Cairo::Context::create (surface);
406 context->set_line_width (1);
407 context->scale (x_scale, y_scale);
408 layout.pango->update_from_cairo_context(context);
410 if (first.effect() == dcp::Effect::SHADOW) {
411 /* Drop-shadow effect */
412 set_source_rgba (context, first.effect_colour(), fade_factor);
413 context->move_to (x_offset + 4, y_offset + 4);
414 layout.pango->add_to_cairo_context(context);
418 if (first.effect() == dcp::Effect::BORDER) {
420 set_source_rgba (context, first.effect_colour(), fade_factor);
421 context->set_line_width (border_width);
422 #ifdef DCPOMATIC_OLD_CAIROMM_API
423 context->set_line_join (Cairo::LINE_JOIN_ROUND);
425 context->set_line_join (Cairo::Context::LineJoin::ROUND);
427 context->move_to (x_offset, y_offset);
428 layout.pango->add_to_cairo_context (context);
432 /* The actual subtitle */
434 set_source_rgba (context, first.colour(), fade_factor);
436 context->move_to (x_offset, y_offset);
437 layout.pango->add_to_cairo_context (context);
440 context->set_line_width (0.5);
441 context->move_to (x_offset, y_offset);
442 layout.pango->add_to_cairo_context (context);
445 int const x = x_position(first.h_align(), first.h_position(), target.width, layout.size.width);
446 int const y = y_position(first.valign_standard, first.v_align(), first.v_position(), target.height, layout.baseline_to_bottom(border_width), layout.size.height);
447 return PositionImage (image, Position<int>(max (0, x), max(0, y)));
451 /** @param time Time of the frame that these subtitles are going on.
452 * @param target Size of the container that this subtitle will end up in.
453 * @param frame_rate DCP frame rate.
455 vector<PositionImage>
456 render_text(vector<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
458 vector<StringText> pending;
459 vector<PositionImage> images;
461 for (auto const& i: subtitles) {
462 if (!pending.empty()) {
463 auto const last = pending.back();
464 auto const different_v = i.v_align() != last.v_align() || fabs(i.v_position() - last.v_position()) > 1e-4;
465 auto const different_h = i.h_align() != last.h_align() || fabs(i.h_position() - pending.back().h_position()) > 1e-4;
466 if (different_v || different_h) {
467 /* We need a new line if any new positioning (horizontal or vertical) changes for this section */
468 images.push_back(render_line(pending, target, time, frame_rate));
472 pending.push_back (i);
475 if (!pending.empty()) {
476 images.push_back(render_line(pending, target, time, frame_rate));
483 vector<dcpomatic::Rect<int>>
484 bounding_box(vector<StringText> subtitles, dcp::Size target, optional<dcp::SubtitleStandard> override_standard)
486 vector<StringText> pending;
487 vector<dcpomatic::Rect<int>> rects;
489 auto use_pending = [&pending, &rects, target, override_standard]() {
490 auto const& subtitle = pending.front();
491 auto standard = override_standard.get_value_or(subtitle.valign_standard);
492 /* We can provide dummy values for time and frame rate here as they are only used to calculate fades */
493 auto layout = setup_layout(pending, target, DCPTime(), 24);
494 int const x = x_position(subtitle.h_align(), subtitle.h_position(), target.width, layout.size.width);
495 auto const border_width = border_width_for_subtitle(subtitle, target);
496 int const y = y_position(standard, subtitle.v_align(), subtitle.v_position(), target.height, layout.baseline_to_bottom(border_width), layout.size.height);
497 rects.push_back({Position<int>(x, y), layout.size.width, layout.size.height});
500 for (auto const& i: subtitles) {
501 if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
505 pending.push_back(i);
508 if (!pending.empty()) {
517 FontMetrics::height(StringText const& subtitle)
519 return get(subtitle)->second.second;
524 FontMetrics::baseline_to_bottom(StringText const& subtitle)
526 return get(subtitle)->second.first;
530 FontMetrics::Cache::iterator
531 FontMetrics::get(StringText const& subtitle)
533 auto id = Identifier(subtitle);
535 auto iter = _cache.find(id);
536 if (iter != _cache.end()) {
540 auto const font_name = FontConfig::instance()->make_font_available(subtitle.font);
541 auto copy = subtitle;
542 copy.set_text("Qypjg");
543 auto layout = create_layout(font_name, marked_up({copy}, _target_height, 1, font_name));
544 auto ink = layout->get_ink_extents();
545 auto const scale = float(_target_height * Pango::SCALE);
546 return _cache.insert({id, { ink.get_y() / scale, ink.get_height() / scale}}).first;
550 FontMetrics::Identifier::Identifier(StringText const& subtitle)
551 : font(subtitle.font)
552 , size(subtitle.size())
553 , aspect_adjust(subtitle.aspect_adjust())
560 FontMetrics::Identifier::operator<(FontMetrics::Identifier const& other) const
562 if (font != other.font) {
563 return font < other.font;
566 if (size != other.size) {
567 return size < other.size;
570 return aspect_adjust < other.aspect_adjust;