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>
43 using std::make_shared;
47 using std::shared_ptr;
50 using boost::optional;
51 using namespace dcpomatic;
54 #if CAIROMM_MAJOR_VERSION == 1 && CAIROMM_MINOR_VERSION <= 14
55 #define DCPOMATIC_OLD_CAIROMM_API
58 #if PANGOMM_MAJOR_VERSION == 2 && PANGOMM_MINOR_VERSION <= 46
59 #define DCPOMATIC_OLD_PANGOMM_API
63 /** Create a Pango layout using a dummy context which we can use to calculate the size
64 * of the text we will render. Then we can transfer the layout over to the real context
65 * for the actual render.
67 static Glib::RefPtr<Pango::Layout>
68 create_layout(string font_name, string markup)
70 auto c_font_map = pango_cairo_font_map_new ();
71 DCPOMATIC_ASSERT (c_font_map);
72 auto font_map = Glib::wrap (c_font_map);
73 auto c_context = pango_font_map_create_context (c_font_map);
74 DCPOMATIC_ASSERT (c_context);
75 auto context = Glib::wrap (c_context);
76 auto layout = Pango::Layout::create(context);
78 #ifdef DCPOMATIC_OLD_PANGOMM_API
79 layout->set_alignment(Pango::ALIGN_LEFT);
81 layout->set_alignment(Pango::Alignment::LEFT);
83 Pango::FontDescription font (font_name);
84 layout->set_font_description (font);
85 layout->set_markup (markup);
92 marked_up(vector<StringText> subtitles, int target_height, float fade_factor, string font_name)
94 auto constexpr pixels_to_1024ths_point = 72 * 1024 / 96;
96 auto make_span = [target_height, fade_factor](StringText const& subtitle, string text, string extra_attribute) {
99 if (subtitle.italic()) {
100 span += "style=\"italic\" ";
102 if (subtitle.bold()) {
103 span += "weight=\"bold\" ";
105 if (subtitle.underline()) {
106 span += "underline=\"single\" ";
108 span += "size=\"" + dcp::raw_convert<string>(lrintf(subtitle.size_in_pixels(target_height) * pixels_to_1024ths_point)) + "\" ";
109 /* Between 1-65535 inclusive, apparently... */
110 span += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
111 span += "color=\"#" + subtitle.colour().to_rgb_string() + "\"";
112 if (!extra_attribute.empty()) {
113 span += " " + extra_attribute;
117 boost::algorithm::replace_all(text, "&", "&");
118 boost::algorithm::replace_all(text, "<", "<");
119 boost::algorithm::replace_all(text, ">", ">");
120 boost::algorithm::replace_all(text, "\n", "");
128 for (auto const& i: subtitles) {
129 if (std::abs(i.space_before()) > dcp::SPACE_BEFORE_EPSILON) {
130 /* We need to insert some horizontal space into the layout. The only way I can find to do this
131 * is to write a " " with some special letter_spacing. As far as I can see, such a space will
132 * be written with letter_spacing either side. This means that to get a horizontal space x we
133 * need to write a " " with letter spacing (x - s) / 2, where s is the width of the " ".
135 auto layout = create_layout(font_name, make_span(i, " ", {}));
138 layout->get_pixel_size(space_width, dummy);
139 auto spacing = ((i.space_before() * i.size_in_pixels(target_height) - space_width) / 2) * pixels_to_1024ths_point;
140 out += make_span(i, " ", "letter_spacing=\"" + dcp::raw_convert<string>(spacing) + "\"");
143 out += make_span(i, i.text(), {});
151 set_source_rgba (Cairo::RefPtr<Cairo::Context> context, dcp::Colour colour, float fade_factor)
153 context->set_source_rgba (float(colour.r) / 255, float(colour.g) / 255, float(colour.b) / 255, fade_factor);
157 static shared_ptr<Image>
158 create_image (dcp::Size size)
160 /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha.
161 * This must be COMPACT as we're using it with Cairo::ImageSurface::create
163 auto image = make_shared<Image>(AV_PIX_FMT_BGRA, size, Image::Alignment::COMPACT);
164 image->make_black ();
169 static Cairo::RefPtr<Cairo::ImageSurface>
170 create_surface (shared_ptr<Image> image)
172 /* XXX: I don't think it's guaranteed that format_stride_for_width will return a stride without any padding,
173 * so it's lucky that this works.
175 DCPOMATIC_ASSERT (image->alignment() == Image::Alignment::COMPACT);
176 DCPOMATIC_ASSERT (image->pixel_format() == AV_PIX_FMT_BGRA);
177 return Cairo::ImageSurface::create (
179 #ifdef DCPOMATIC_OLD_CAIROMM_API
180 Cairo::FORMAT_ARGB32,
182 Cairo::ImageSurface::Format::ARGB32,
185 image->size().height,
186 /* Cairo ARGB32 means first byte blue, second byte green, third byte red, fourth byte alpha */
187 Cairo::ImageSurface::format_stride_for_width(
188 #ifdef DCPOMATIC_OLD_CAIROMM_API
189 Cairo::FORMAT_ARGB32,
191 Cairo::ImageSurface::Format::ARGB32,
200 calculate_fade_factor (StringText const& first, DCPTime time, int frame_rate)
202 float fade_factor = 1;
204 /* Round the fade start/end to the nearest frame start. Otherwise if a subtitle starts just after
205 the start of a frame it will be faded out.
207 auto const fade_in_start = DCPTime::from_seconds(first.in().as_seconds()).round(frame_rate);
208 auto const fade_in_end = fade_in_start + DCPTime::from_seconds (first.fade_up_time().as_seconds ());
210 if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
211 fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
214 if (time < fade_in_start) {
218 /* first.out() may be zero if we don't know when this subtitle will finish. We can only think about
219 * fading out if we _do_ know when it will finish.
221 if (first.out() != dcp::Time()) {
222 auto const fade_out_end = DCPTime::from_seconds (first.out().as_seconds()).round(frame_rate);
223 auto const fade_out_start = fade_out_end - DCPTime::from_seconds(first.fade_down_time().as_seconds());
225 if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
226 fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
228 if (time > fade_out_end) {
238 x_position(dcp::HAlign align, float position, int target_width, int layout_width)
242 case dcp::HAlign::LEFT:
243 /* h_position is distance between left of frame and left of subtitle */
244 x = position * target_width;
246 case dcp::HAlign::CENTER:
247 /* h_position is distance between centre of frame and centre of subtitle */
248 x = (0.5 + position) * target_width - layout_width / 2;
250 case dcp::HAlign::RIGHT:
251 /* h_position is distance between right of frame and right of subtitle */
252 x = (1.0 - position) * target_width - layout_width;
260 /** @param align_standard Standard with which to interpret this subtitle's position.
261 * @param align alignment.
262 * @param position position (between 0 and 1)
263 * @param target_height Height of the target screen (in pixels).
264 * @param baseline_to_bottom Distance from text baseline to the bottom of the bounding box (in pixels).
265 * @param layout_height Height of the subtitle bounding box (in pixels).
266 * @return y position of the top of the subtitle bounding box (in pixels) from the top of the screen.
269 y_position(dcp::SubtitleStandard standard, dcp::VAlign align, float position, int target_height, int baseline_to_bottom, int layout_height)
273 case dcp::SubtitleStandard::INTEROP:
274 case dcp::SubtitleStandard::SMPTE_2014:
276 case dcp::VAlign::TOP:
277 /* position is distance from top of frame to subtitle baseline */
278 y = position * target_height - (layout_height - baseline_to_bottom);
280 case dcp::VAlign::CENTER:
281 /* position is distance from centre of frame to subtitle baseline */
282 y = (0.5 + position) * target_height - (layout_height - baseline_to_bottom);
284 case dcp::VAlign::BOTTOM:
285 /* position is distance from bottom of frame to subtitle baseline */
286 y = (1.0 - position) * target_height - (layout_height - baseline_to_bottom);
290 case dcp::SubtitleStandard::SMPTE_2007:
291 case dcp::SubtitleStandard::SMPTE_2010:
293 case dcp::VAlign::TOP:
294 /* v_position is distance from top of frame to top of subtitle */
295 y = position * target_height;
297 case dcp::VAlign::CENTER:
298 /* v_position is distance from centre of frame to centre of subtitle */
299 y = (0.5 + position) * target_height - layout_height / 2;
301 case dcp::VAlign::BOTTOM:
302 /* v_position is distance from bottom of frame to bottom of subtitle */
303 y = (1.0 - position) * target_height - layout_height;
314 Position<int> position;
315 int baseline_position;
317 Glib::RefPtr<Pango::Layout> pango;
319 int baseline_to_bottom(int border_width)
321 return position.y + size.height - baseline_position - border_width;
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 setup_layout(vector<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
332 DCPOMATIC_ASSERT(!subtitles.empty());
333 auto const& first = subtitles.front();
335 auto const font_name = FontConfig::instance()->make_font_available(first.font);
336 auto const fade_factor = calculate_fade_factor(first, time, frame_rate);
337 auto const markup = marked_up(subtitles, target.height, fade_factor, font_name);
338 auto layout = create_layout(font_name, markup);
339 auto ink = layout->get_ink_extents();
342 description.position = { ink.get_x() / Pango::SCALE, ink.get_y() / Pango::SCALE };
343 description.baseline_position = layout->get_baseline() / Pango::SCALE;
344 description.size = { ink.get_width() / Pango::SCALE, ink.get_height() / Pango::SCALE };
345 description.pango = layout;
353 border_width_for_subtitle(StringText const& subtitle, dcp::Size target)
355 return subtitle.effect() == dcp::Effect::BORDER ? (subtitle.outline_width * target.width / 2048.0) : 0;
359 /** @param subtitles A list of subtitles that are all on the same line,
360 * at the same time and with the same fade in/out.
363 render_line(vector<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
365 /* XXX: this method can only handle italic / bold changes mid-line,
369 DCPOMATIC_ASSERT(!subtitles.empty ());
370 auto const& first = subtitles.front();
371 auto const fade_factor = calculate_fade_factor(first, time, frame_rate);
373 auto layout = setup_layout(subtitles, target, time, frame_rate);
375 /* Calculate x and y scale factors. These are only used to stretch
376 the font away from its normal aspect ratio.
380 if (fabs (first.aspect_adjust() - 1.0) > dcp::ASPECT_ADJUST_EPSILON) {
381 if (first.aspect_adjust() < 1) {
382 x_scale = max (0.25f, first.aspect_adjust ());
386 y_scale = 1 / min (4.0f, first.aspect_adjust ());
390 auto const border_width = border_width_for_subtitle(first, target);
391 layout.size.width += 2 * ceil (border_width);
392 layout.size.height += 2 * ceil (border_width);
394 layout.size.width *= x_scale;
395 layout.size.height *= y_scale;
397 /* Shuffle the subtitle over by the border width (if we have any) so it's not cut off */
398 int const x_offset = -layout.position.x + ceil(border_width);
399 int const y_offset = -layout.position.y + ceil(border_width);
401 auto image = create_image(layout.size);
402 auto surface = create_surface (image);
403 auto context = Cairo::Context::create (surface);
405 context->set_line_width (1);
406 context->scale (x_scale, y_scale);
407 layout.pango->update_from_cairo_context(context);
409 if (first.effect() == dcp::Effect::SHADOW) {
410 /* Drop-shadow effect */
411 set_source_rgba (context, first.effect_colour(), fade_factor);
412 context->move_to (x_offset + 4, y_offset + 4);
413 layout.pango->add_to_cairo_context(context);
417 if (first.effect() == dcp::Effect::BORDER) {
419 set_source_rgba (context, first.effect_colour(), fade_factor);
420 context->set_line_width (border_width);
421 #ifdef DCPOMATIC_OLD_CAIROMM_API
422 context->set_line_join (Cairo::LINE_JOIN_ROUND);
424 context->set_line_join (Cairo::Context::LineJoin::ROUND);
426 context->move_to (x_offset, y_offset);
427 layout.pango->add_to_cairo_context (context);
431 /* The actual subtitle */
433 set_source_rgba (context, first.colour(), fade_factor);
435 context->move_to (x_offset, y_offset);
436 layout.pango->add_to_cairo_context (context);
439 context->set_line_width (0.5);
440 context->move_to (x_offset, y_offset);
441 layout.pango->add_to_cairo_context (context);
444 int const x = x_position(first.h_align(), first.h_position(), target.width, layout.size.width);
445 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);
446 return PositionImage (image, Position<int>(max (0, x), max(0, y)));
450 /** @param time Time of the frame that these subtitles are going on.
451 * @param target Size of the container that this subtitle will end up in.
452 * @param frame_rate DCP frame rate.
454 vector<PositionImage>
455 render_text(vector<StringText> subtitles, dcp::Size target, DCPTime time, int frame_rate)
457 vector<StringText> pending;
458 vector<PositionImage> images;
460 for (auto const& i: subtitles) {
461 if (!pending.empty()) {
462 auto const last = pending.back();
463 auto const different_v = i.v_align() != last.v_align() || fabs(i.v_position() - last.v_position()) > 1e-4;
464 auto const different_h = i.h_align() != last.h_align() || fabs(i.h_position() - pending.back().h_position()) > 1e-4;
465 if (different_v || different_h) {
466 /* We need a new line if any new positioning (horizontal or vertical) changes for this section */
467 images.push_back(render_line(pending, target, time, frame_rate));
471 pending.push_back (i);
474 if (!pending.empty()) {
475 images.push_back(render_line(pending, target, time, frame_rate));
482 vector<dcpomatic::Rect<int>>
483 bounding_box(vector<StringText> subtitles, dcp::Size target, optional<dcp::SubtitleStandard> override_standard)
485 vector<StringText> pending;
486 vector<dcpomatic::Rect<int>> rects;
488 auto use_pending = [&pending, &rects, target, override_standard]() {
489 auto const& subtitle = pending.front();
490 auto standard = override_standard.get_value_or(subtitle.valign_standard);
491 /* We can provide dummy values for time and frame rate here as they are only used to calculate fades */
492 auto layout = setup_layout(pending, target, DCPTime(), 24);
493 int const x = x_position(subtitle.h_align(), subtitle.h_position(), target.width, layout.size.width);
494 auto const border_width = border_width_for_subtitle(subtitle, target);
495 int const y = y_position(standard, subtitle.v_align(), subtitle.v_position(), target.height, layout.baseline_to_bottom(border_width), layout.size.height);
496 rects.push_back({Position<int>(x, y), layout.size.width, layout.size.height});
499 for (auto const& i: subtitles) {
500 if (!pending.empty() && (i.v_align() != pending.back().v_align() || fabs(i.v_position() - pending.back().v_position()) > 1e-4)) {
504 pending.push_back(i);
507 if (!pending.empty()) {
516 FontMetrics::height(StringText const& subtitle)
518 return get(subtitle)->second.second;
523 FontMetrics::baseline_to_bottom(StringText const& subtitle)
525 return get(subtitle)->second.first;
529 FontMetrics::Cache::iterator
530 FontMetrics::get(StringText const& subtitle)
532 auto id = Identifier(subtitle);
534 auto iter = _cache.find(id);
535 if (iter != _cache.end()) {
539 auto const font_name = FontConfig::instance()->make_font_available(subtitle.font);
540 auto copy = subtitle;
541 copy.set_text("Qypjg");
542 auto layout = create_layout(font_name, marked_up({copy}, _target_height, 1, font_name));
543 auto ink = layout->get_ink_extents();
544 auto const scale = float(_target_height * Pango::SCALE);
545 return _cache.insert({id, { ink.get_y() / scale, ink.get_height() / scale}}).first;
549 FontMetrics::Identifier::Identifier(StringText const& subtitle)
550 : font(subtitle.font)
551 , size(subtitle.size())
552 , aspect_adjust(subtitle.aspect_adjust())
559 FontMetrics::Identifier::operator<(FontMetrics::Identifier const& other) const
561 if (font != other.font) {
562 return font < other.font;
565 if (size != other.size) {
566 return size < other.size;
569 return aspect_adjust < other.aspect_adjust;