*/
+/** @file src/subtitle.cc
+ * @brief Representations of subtitles.
+ */
+
#include "subtitle.h"
#include "image.h"
#include "exceptions.h"
-#include "film_state.h"
-using namespace std;
-using namespace boost;
+#include "i18n.h"
+
+using boost::shared_ptr;
+using libdcp::Size;
-Subtitle::Subtitle (AVSubtitle const & sub)
+/** 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)
{
- /* subtitle PTS in seconds */
- float const packet_time = (sub.pts / AV_TIME_BASE) + float (sub.pts % AV_TIME_BASE) / 1e6;
+ 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);
- _to = packet_time + (double (sub.end_display_time) / 1e3);
+ _from = (packet_time + (double (sub.start_display_time) / 1e3)) * TIME_HZ;
+ _to = (packet_time + (double (sub.end_display_time) / 1e3)) * TIME_HZ;
- for (unsigned int i = 0; i < sub.num_rects; ++i) {
- _images.push_back (shared_ptr<SubtitleImage> (new SubtitleImage (sub.rects[i])));
+ if (sub.num_rects > 1) {
+ throw DecodeError (_("multi-part subtitles not yet supported"));
}
-}
-/** @param t Time in seconds from the start of the film */
-bool
-Subtitle::displayed_at (double t)
-{
- return t >= _from && t <= _to;
-}
+ AVSubtitleRect const * rect = sub.rects[0];
-SubtitleImage::SubtitleImage (AVSubtitleRect const * rect)
- : _position (rect->x, rect->y)
- , _image (new SimpleImage (PIX_FMT_RGBA, Size (rect->w, rect->h)))
-{
if (rect->type != SUBTITLE_BITMAP) {
- throw DecodeError ("non-bitmap subtitles not yet supported");
+ 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];
+ 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_p++ = palette[*sub_line_p++];
+ *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;
}
-SubtitleTransform
-subtitle_transform (
- int target_base_width, int target_base_height,
+/** 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,
- Position sub_pos, int sub_width, int sub_height,
- shared_ptr<FilmState> fs
+ dcpomatic::Rect sub_area, int subtitle_offset, float subtitle_scale
)
{
- SubtitleTransform tx;
-
- Rectangle sub_area (sub_pos.x, sub_pos.y + fs->subtitle_offset, sub_width, sub_height);
-
- Rectangle cropped_target_area (
- fs->crop.left,
- fs->crop.top,
- target_base_width - (fs->crop.left + fs->crop.right),
- target_base_height - (fs->crop.top + fs->crop.bottom)
- );
+ 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.
+ */
- Rectangle cropped_sub_area = sub_area.intersection (cropped_target_area);
-
- tx.crop.x = cropped_sub_area.x - sub_area.x;
- tx.crop.y = cropped_sub_area.y - sub_area.y;
- tx.crop.w = cropped_sub_area.w;
- tx.crop.h = cropped_sub_area.h;
-
- tx.transformed.w = cropped_sub_area.w * target_x_scale * fs->subtitle_scale;
- tx.transformed.h = cropped_sub_area.h * target_y_scale * fs->subtitle_scale;
-
- tx.transformed.x = target_x_scale * ((sub_area.x - fs->crop.left) + (cropped_sub_area.w * (1 - fs->subtitle_scale) / 2));
- tx.transformed.y = target_y_scale * ((sub_area.y - fs->crop.top) + (cropped_sub_area.h * (1 - fs->subtitle_scale) / 2));
+ 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