X-Git-Url: https://git.carlh.net/gitweb/?a=blobdiff_plain;f=src%2Flib%2Frender_subtitles.cc;h=5f587c3137504c759df8ba29306e4e0b99fb0926;hb=565490c24a46d0aa941f75cf2a03b195246008b4;hp=9426427fd507385a12973e0b02823af4c15b19da;hpb=b064fa7e95ad31accffafc21a28fa7ede0161212;p=dcpomatic.git

diff --git a/src/lib/render_subtitles.cc b/src/lib/render_subtitles.cc
index 9426427fd..5f587c313 100644
--- a/src/lib/render_subtitles.cc
+++ b/src/lib/render_subtitles.cc
@@ -85,7 +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.
@@ -123,7 +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
@@ -132,6 +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
@@ -240,15 +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;
 	}
 
@@ -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;