X-Git-Url: https://main.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Fsubtitle.cc;h=b4ac14285714b1e085a9fffcee5d80daf1906fc9;hb=7deb94e3cb9048891664f74d9c8a534ca6a24748;hp=040a057fcf3ee040af1767db95eadfa519de2e88;hpb=b1fc0de953b1c2fce8a31b267b63dfcaf67830c7;p=dcpomatic.git diff --git a/src/lib/subtitle.cc b/src/lib/subtitle.cc index 040a057fc..b4ac14285 100644 --- a/src/lib/subtitle.cc +++ b/src/lib/subtitle.cc @@ -17,109 +17,131 @@ */ +/** @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; -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 (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); - for (unsigned int i = 0; i < sub.num_rects; ++i) { - _images.push_back (shared_ptr (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"); } + + shared_ptr 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); } -} -SubtitleTransform -subtitle_transform ( - int target_base_width, int target_base_height, - float target_x_scale, float target_y_scale, - Position sub_pos, int sub_width, int sub_height, - shared_ptr fs - ) + _subtitle.reset (new Subtitle (Position (rect->x, rect->y), image)); +} + +/** @param t Time in seconds from the start of the source */ +bool +TimedSubtitle::displayed_at (double t) const { - SubtitleTransform tx; + return t >= _from && t <= _to; +} - /* The area of the original subtitle, in the coordinate space of the source video frame */ - Rectangle sub_area (sub_pos.x, sub_pos.y + fs->subtitle_offset, sub_width, sub_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 i) + : _position (p) + , _image (i) +{ - /* The cropped area of the source video frame, in the same coordinate space */ - 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) - ); +} - /* Hence the area of the cropped subtitle, in the same coordinate space */ - Rectangle cropped_sub_area = sub_area.intersection (cropped_target_area); +/** 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. + */ +Rect +subtitle_transformed_area ( + float target_x_scale, float target_y_scale, + Rect sub_area, int subtitle_offset, float subtitle_scale + ) +{ + Rect tx; - /* The crop that should be applied to the subtitle, in its coordinate space */ - 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; + 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.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.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 - fs->crop_left) * target_x_scale and (sub_area.y - fs->crop_top) * target_y_scale. + * sub_area.x * target_x_scale and sub_area.y * target_y_scale. * - * 2. that to shift the origin of the scale by fs->subtitle_scale to the centre of the subtitle; this will be - * (width_before_subtitle_scale * (1 - fs->subtitle_scale) / 2) and - * (height_before_subtitle_scale * (1 - fs->subtitle_scale) / 2). + * 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.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 = target_x_scale * (sub_area.x + (sub_area.width * (1 - subtitle_scale) / 2)); + tx.y = 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 */ +Rect +Subtitle::area () const +{ + return Rect (_position.x, _position.y, _image->size().width, _image->size().height); +}