Try to improve hint when making a DCP which is not 24 or 48fps.

5 files changed, 53 insertions, 6 deletions

diff --git a/src/lib/film.cc b/src/lib/film.cc
index 218dc58ef..df19af77f 100644
--- a/src/lib/film.cc
+++ b/src/lib/film.cc
@@ -1584,3 +1584,9 @@ Film::use_template (string name)
 	_reel_length = _template_film->_reel_length;
 	_upload_after_make_dcp = _template_film->_upload_after_make_dcp;
 }
+
+pair<double, double>
+Film::speed_up_range (int dcp_frame_rate) const
+{
+	return _playlist->speed_up_range (dcp_frame_rate);
+}
diff --git a/src/lib/film.h b/src/lib/film.h
index 9f473d711..fdd4674d5 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -120,6 +120,7 @@ public:
 	DCPTime length () const;
 	int best_video_frame_rate () const;
 	FrameRateChange active_frame_rate_change (DCPTime) const;
+	std::pair<double, double> speed_up_range (int dcp_frame_rate) const;
 
 	dcp::EncryptedKDM make_kdm (
 		dcp::Certificate recipient,
diff --git a/src/lib/hints.cc b/src/lib/hints.cc
index 219b5139c..1cdc10bd0 100644
--- a/src/lib/hints.cc
+++ b/src/lib/hints.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2016 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2016-2017 Carl Hetherington <cth@carlh.net>
 
     This file is part of DCP-o-matic.
 
@@ -32,12 +32,16 @@
 #include <dcp/raw_convert.h>
 #include <boost/foreach.hpp>
 #include <boost/algorithm/string.hpp>
+#include <iostream>
 
 #include "i18n.h"
 
 using std::vector;
 using std::string;
+using std::pair;
+using std::min;
 using std::max;
+using std::cout;
 using boost::shared_ptr;
 using boost::optional;
 
@@ -99,16 +103,28 @@ get_hints (shared_ptr<const Film> film)
 		hints.push_back (_("Your DCP uses an unusual container ratio.  This may cause problems on some projectors.  If possible, use Flat or Scope for the DCP container ratio"));
 	}
 
-	if (film->video_frame_rate() != 24 && film->video_frame_rate() != 48) {
-		hints.push_back (String::compose (_("Your DCP frame rate (%1 fps) may cause problems in a few (mostly older) projectors.  Use 24 or 48 frames per second to be on the safe side."), film->video_frame_rate()));
-	}
-
 	if (film->j2k_bandwidth() >= 245000000) {
 		hints.push_back (_("A few projectors have problems playing back very high bit-rate DCPs.  It is a good idea to drop the JPEG2000 bandwidth down to about 200Mbit/s; this is unlikely to have any visible effect on the image."));
 	}
 
 	if (film->interop() && film->video_frame_rate() != 24 && film->video_frame_rate() != 48) {
-		hints.push_back (_("You are set up for an Interop DCP at a frame rate which is not officially supported.  You are advised to make a SMPTE DCP instead."));
+		string base = _("You are set up for an Interop DCP at a frame rate which is not officially supported.  You are advised either to change the frame rate of your DCP or to make a SMPTE DCP instead.");
+		base += "  ";
+		pair<double, double> range24 = film->speed_up_range (24);
+		pair<double, double> range48 = film->speed_up_range (48);
+		pair<double, double> range (max (range24.first, range48.first), min (range24.second, range48.second));
+		string h;
+		if (range.second > (29.0/24)) {
+			h = base;
+			h += _("However, setting your DCP frame rate to 24 or 48 will cause a significant speed-up of your content, and SMPTE DCPs are not be supported by all projectors.");
+		} else if (range.first < (24.0/29)) {
+			h = base;
+			h += _("However, setting your DCP frame rate to 24 or 48 will cause a significant slowdown of your content, and SMPTE DCPs are not supported by all projectors.");
+		} else {
+			h = _("You are set up for an Interop DCP at a frame rate which is not officially supported.  You are advised either to change the frame rate of your DCP or to make a SMPTE DCP instead (although SMPTE DCPs are not supported by all projectors).");
+		}
+
+		hints.push_back (h);
 	}
 
 	int vob = 0;
diff --git a/src/lib/playlist.cc b/src/lib/playlist.cc
index aa365ead4..09b67e921 100644
--- a/src/lib/playlist.cc
+++ b/src/lib/playlist.cc
@@ -554,3 +554,26 @@ Playlist::video_content_at (DCPTime time) const
 
 	return false;
 }
+
+pair<double, double>
+Playlist::speed_up_range (int dcp_video_frame_rate) const
+{
+	pair<double, double> range (DBL_MAX, -DBL_MAX);
+
+	BOOST_FOREACH (shared_ptr<Content> i, _content) {
+		if (!i->video) {
+			continue;
+		}
+		if (i->video_frame_rate()) {
+			FrameRateChange const frc (i->video_frame_rate().get(), dcp_video_frame_rate);
+			range.first = min (range.first, frc.speed_up);
+			range.second = max (range.second, frc.speed_up);
+		} else {
+			FrameRateChange const frc (dcp_video_frame_rate, dcp_video_frame_rate);
+			range.first = min (range.first, frc.speed_up);
+			range.second = max (range.second, frc.speed_up);
+		}
+	}
+
+	return range;
+}
diff --git a/src/lib/playlist.h b/src/lib/playlist.h
index 0b19a6e44..1ce5f247a 100644
--- a/src/lib/playlist.h
+++ b/src/lib/playlist.h
@@ -68,6 +68,7 @@ public:
 	DCPTime subtitle_end () const;
 	FrameRateChange active_frame_rate_change (DCPTime, int dcp_frame_rate) const;
 	std::string content_summary (DCPTimePeriod period) const;
+	std::pair<double, double> speed_up_range (int dcp_video_frame_rate) const;
 
 	void set_sequence (bool);
 	void maybe_sequence ();