+++ /dev/null
-/*
- Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
-
- This program is free software; you can redistribute it and/or modify
- it under the terms of the GNU General Public License as published by
- the Free Software Foundation; either version 2 of the License, or
- (at your option) any later version.
-
- This program is distributed in the hope that it will be useful,
- but WITHOUT ANY WARRANTY; without even the implied warranty of
- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- GNU General Public License for more details.
-
- You should have received a copy of the GNU General Public License
- along with this program; if not, write to the Free Software
- Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
-
-*/
-
-/** @file src/subtitle.cc
- * @brief Representations of subtitles.
- */
-
-#include "subtitle.h"
-#include "image.h"
-#include "exceptions.h"
-
-#include "i18n.h"
-
-using boost::shared_ptr;
-using libdcp::Size;
-
-/** Construct a TimedSubtitle. This is a subtitle image, position,
- * and a range of time over which it should be shown.
- * @param sub AVSubtitle to read.
- */
-TimedSubtitle::TimedSubtitle (AVSubtitle const & sub)
-{
- assert (sub.num_rects > 0);
-
- /* Subtitle PTS in seconds (within the source, not taking into account any of the
- source that we may have chopped off for the DCP)
- */
- double const packet_time = static_cast<double> (sub.pts) / AV_TIME_BASE;
-
- /* hence start time for this sub */
- _from = (packet_time + (double (sub.start_display_time) / 1e3)) * TIME_HZ;
- _to = (packet_time + (double (sub.end_display_time) / 1e3)) * TIME_HZ;
-
- if (sub.num_rects > 1) {
- throw DecodeError (_("multi-part subtitles not yet supported"));
- }
-
- AVSubtitleRect const * rect = sub.rects[0];
-
- if (rect->type != SUBTITLE_BITMAP) {
- throw DecodeError (_("non-bitmap subtitles not yet supported"));
- }
-
- shared_ptr<Image> image (new SimpleImage (PIX_FMT_RGBA, libdcp::Size (rect->w, rect->h), true));
-
- /* Start of the first line in the subtitle */
- uint8_t* sub_p = rect->pict.data[0];
- /* sub_p looks up into a RGB palette which is here */
- uint32_t const * palette = (uint32_t *) rect->pict.data[1];
- /* Start of the output data */
- uint32_t* out_p = (uint32_t *) image->data()[0];
-
- for (int y = 0; y < rect->h; ++y) {
- uint8_t* sub_line_p = sub_p;
- uint32_t* out_line_p = out_p;
- for (int x = 0; x < rect->w; ++x) {
- *out_line_p++ = palette[*sub_line_p++];
- }
- sub_p += rect->pict.linesize[0];
- out_p += image->stride()[0] / sizeof (uint32_t);
- }
-
- _subtitle.reset (new Subtitle (Position (rect->x, rect->y), image));
-}
-
-/** @param t Time from the start of the source */
-bool
-TimedSubtitle::displayed_at (Time t) const
-{
- return t >= _from && t <= _to;
-}
-
-/** Construct a subtitle, which is an image and a position.
- * @param p Position within the (uncropped) source frame.
- * @param i Image of the subtitle (should be RGBA).
- */
-Subtitle::Subtitle (Position p, shared_ptr<Image> i)
- : _position (p)
- , _image (i)
-{
-
-}
-
-/** Given the area of a subtitle, work out the area it should
- * take up when its video frame is scaled up, and it is optionally
- * itself scaled and offset.
- * @param target_x_scale the x scaling of the video frame that the subtitle is in.
- * @param target_y_scale the y scaling of the video frame that the subtitle is in.
- * @param sub_area The area of the subtitle within the original source.
- * @param subtitle_offset y offset to apply to the subtitle position (+ve is down)
- * in the coordinate space of the source.
- * @param subtitle_scale scaling factor to apply to the subtitle image.
- */
-dcpomatic::Rect
-subtitle_transformed_area (
- float target_x_scale, float target_y_scale,
- dcpomatic::Rect sub_area, int subtitle_offset, float subtitle_scale
- )
-{
- dcpomatic::Rect tx;
-
- sub_area.y += subtitle_offset;
-
- /* We will scale the subtitle by the same amount as the video frame, and also by the additional
- subtitle_scale
- */
- tx.width = sub_area.width * target_x_scale * subtitle_scale;
- tx.height = sub_area.height * target_y_scale * subtitle_scale;
-
- /* Then we need a corrective translation, consisting of two parts:
- *
- * 1. that which is the result of the scaling of the subtitle by target_x_scale and target_y_scale; this will be
- * sub_area.x * target_x_scale and sub_area.y * target_y_scale.
- *
- * 2. that to shift the origin of the scale by subtitle_scale to the centre of the subtitle; this will be
- * (width_before_subtitle_scale * (1 - subtitle_scale) / 2) and
- * (height_before_subtitle_scale * (1 - subtitle_scale) / 2).
- *
- * Combining these two translations gives these expressions.
- */
-
- tx.x = rint (target_x_scale * (sub_area.x + (sub_area.width * (1 - subtitle_scale) / 2)));
- tx.y = rint (target_y_scale * (sub_area.y + (sub_area.height * (1 - subtitle_scale) / 2)));
-
- return tx;
-}
-
-/** @return area that this subtitle takes up, in the original uncropped source's coordinate space */
-dcpomatic::Rect
-Subtitle::area () const
-{
- return dcpomatic::Rect (_position.x, _position.y, _image->size().width, _image->size().height);
-}
projects / dcpomatic.git / blobdiff