Set up seek position correctly when a seek skips over a reel in

[dcpomatic.git] / src / lib / render_subtitles.cc

diff --git a/src/lib/render_subtitles.cc b/src/lib/render_subtitles.cc
index fa1cf4766906e3e48840e79a94081d6d4d1a6be0..5f587c3137504c759df8ba29306e4e0b99fb0926 100644 (file)
--- a/src/lib/render_subtitles.cc
+++ b/src/lib/render_subtitles.cc
@@ -65,7 +65,8 @@ marked_up (list<SubtitleString> subtitles, int target_height, float fade_factor)
                        out += "underline=\"single\" ";
                }
                out += "size=\"" + dcp::raw_convert<string>(i.size_in_pixels(target_height) * 72 * 1024 / 96) + "\" ";
-               out += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65535))) + "\" ";
+               /* Between 1-65535 inclusive, apparently... */
+               out += "alpha=\"" + dcp::raw_convert<string>(int(floor(fade_factor * 65534)) + 1) + "\" ";
                out += "color=\"#" + i.colour().to_rgb_string() + "\">";
                out += i.text ();
                out += "</span>";
@@ -84,7 +85,7 @@ set_source_rgba (Cairo::RefPtr<Cairo::Context> context, dcp::Colour colour, floa
  *  at the same time and with the same fade in/out.
  */
 static PositionImage
-render_line (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target, DCPTime time)
+render_line (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target, DCPTime time, int frame_rate)
 {
        /* XXX: this method can only handle italic / bold changes mid-line,
           nothing else yet.
@@ -122,7 +123,8 @@ render_line (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp:
        /* ...and add a bit more for luck */
        height += target.height / 11;
 
-       shared_ptr<Image> image (new Image (AV_PIX_FMT_RGBA, dcp::Size (target.width, height), false));
+       /* FFmpeg BGRA means first byte blue, second byte green, third byte red, fourth byte alpha */
+       shared_ptr<Image> image (new Image (AV_PIX_FMT_BGRA, dcp::Size (target.width, height), false));
        image->make_black ();
 
 #ifdef DCPOMATIC_HAVE_FORMAT_STRIDE_FOR_WIDTH
@@ -131,6 +133,7 @@ render_line (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp:
                Cairo::FORMAT_ARGB32,
                image->size().width,
                image->size().height,
+               /* Cairo ARGB32 means first byte blue, second byte green, third byte red, fourth byte alpha */
                Cairo::ImageSurface::format_stride_for_width (Cairo::FORMAT_ARGB32, image->size().width)
                );
 #else
@@ -239,15 +242,21 @@ render_line (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp:
        /* Compute fade factor */
        float fade_factor = 1;
 
-       DCPTime const fade_in_start = DCPTime::from_seconds (subtitles.front().in().as_seconds ());
+       /* Round the fade start/end to the nearest frame start.  Otherwise if a subtitle starts just after
+          the start of a frame it will be faded out.
+       */
+       DCPTime const fade_in_start = DCPTime::from_seconds(subtitles.front().in().as_seconds()).round(frame_rate);
        DCPTime const fade_in_end = fade_in_start + DCPTime::from_seconds (subtitles.front().fade_up_time().as_seconds ());
-       DCPTime const fade_out_end =  DCPTime::from_seconds (subtitles.front().out().as_seconds ());
+       DCPTime const fade_out_end =  DCPTime::from_seconds (subtitles.front().out().as_seconds()).round(frame_rate);
        DCPTime const fade_out_start = fade_out_end - DCPTime::from_seconds (subtitles.front().fade_down_time().as_seconds ());
+
        if (fade_in_start <= time && time <= fade_in_end && fade_in_start != fade_in_end) {
-               fade_factor = DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
-       } else if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
-               fade_factor = 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
-       } else if (time < fade_in_start || time > fade_out_end) {
+               fade_factor *= DCPTime(time - fade_in_start).seconds() / DCPTime(fade_in_end - fade_in_start).seconds();
+       }
+       if (fade_out_start <= time && time <= fade_out_end && fade_out_start != fade_out_end) {
+               fade_factor *= 1 - DCPTime(time - fade_out_start).seconds() / DCPTime(fade_out_end - fade_out_start).seconds();
+       }
+       if (time < fade_in_start || time > fade_out_end) {
                fade_factor = 0;
        }
 
@@ -276,7 +285,6 @@ render_line (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp:
        }
 
        if (subtitles.front().effect() == dcp::BORDER) {
-               cout << "border it " << (subtitles.front().outline_width * target.width) << " " << fade_factor << ".\n";
                /* Border effect; stroke the subtitle with a large (arbitrarily chosen) line width */
                set_source_rgba (context, subtitles.front().effect_colour(), fade_factor);
                context->set_line_width (subtitles.front().outline_width * target.width / 2048.0);
@@ -342,23 +350,25 @@ render_line (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp:
        return PositionImage (image, Position<int> (max (0, x), max (0, y)));
 }
 
-/** @param time Time of the frame that these subtitles are going on */
+/** @param time Time of the frame that these subtitles are going on.
+ *  @param frame_rate DCP frame rate.
+ */
 list<PositionImage>
-render_subtitles (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target, DCPTime time)
+render_subtitles (list<SubtitleString> subtitles, list<shared_ptr<Font> > fonts, dcp::Size target, DCPTime time, int frame_rate)
 {
        list<SubtitleString> pending;
        list<PositionImage> images;
 
        BOOST_FOREACH (SubtitleString const & i, subtitles) {
                if (!pending.empty() && fabs (i.v_position() - pending.back().v_position()) > 1e-4) {
-                       images.push_back (render_line (pending, fonts, target, time));
+                       images.push_back (render_line (pending, fonts, target, time, frame_rate));
                        pending.clear ();
                }
                pending.push_back (i);
        }
 
        if (!pending.empty ()) {
-               images.push_back (render_line (pending, fonts, target, time));
+               images.push_back (render_line (pending, fonts, target, time, frame_rate));
        }
 
        return images;