WIP: use fraction for DCP frame rate.archive-frame-rates

This will allow archival rates to be expressed precisely.

14 files changed, 71 insertions, 44 deletions

diff --git a/src/lib/create_cli.cc b/src/lib/create_cli.cc
index 32834be23..1bc463371 100644
--- a/src/lib/create_cli.cc
+++ b/src/lib/create_cli.cc
@@ -177,7 +177,7 @@ CreateCLI::CreateCLI(int argc, char* argv[])
 	optional<string> dcp_content_type_string;
 	string container_ratio_string;
 	optional<string> standard_string;
-	int dcp_frame_rate_int = 0;
+	string dcp_frame_rate_string;
 	string template_name_string;
 	int64_t video_bit_rate_int = 0;
 	optional<int> audio_channels;
@@ -257,7 +257,7 @@ CreateCLI::CreateCLI(int argc, char* argv[])
 		argument_option(i, argc, argv, "-t", "--template",         &claimed, &error, &template_name_string);
 		/* See comment below about --cpl */
 		argument_option(i, argc, argv, "-c", "--dcp-content-type", &claimed, &error, &dcp_content_type_string, string_to_string);
-		argument_option(i, argc, argv, "-f", "--dcp-frame-rate",   &claimed, &error, &dcp_frame_rate_int);
+		argument_option(i, argc, argv, "-f", "--dcp-frame-rate",   &claimed, &error, &dcp_frame_rate_string);
 		argument_option(i, argc, argv, "",   "--container-ratio",  &claimed, &error, &container_ratio_string);
 		argument_option(i, argc, argv, "-s", "--still-length",     &claimed, &error, &still_length, string_to_nonzero_int);
 		argument_option(i, argc, argv, "",   "--auto-crop-threshold", &claimed, &error, &auto_crop_threshold, string_to_int);
@@ -356,8 +356,18 @@ CreateCLI::CreateCLI(int argc, char* argv[])
 		_template_name = template_name_string;
 	}
 
-	if (dcp_frame_rate_int) {
-		dcp_frame_rate = dcp_frame_rate_int;
+	if (!dcp_frame_rate_string.empty()) {
+		vector<string> parts;
+		boost::split(parts, dcp_frame_rate_string, boost::is_any_of("/"));
+		if (parts.empty() || parts.size() > 2) {
+			error = fmt::format("{}: unrecognised DCP frame rate '{}'", argv[0], dcp_frame_rate_string);
+			return;
+		}
+		if (parts.size() == 1) {
+			dcp_frame_rate = dcp::Fraction(dcp::raw_convert<int>(parts[0]), 1);
+		} else {
+			dcp_frame_rate = dcp::Fraction(dcp::raw_convert<int>(parts[0]), dcp::raw_convert<int>(parts[1]));
+		}
 	}
 
 	if (video_bit_rate_int) {
diff --git a/src/lib/create_cli.h b/src/lib/create_cli.h
index 00abf85e5..b3cc8074d 100644
--- a/src/lib/create_cli.h
+++ b/src/lib/create_cli.h
@@ -52,7 +52,7 @@ public:
 	};
 
 	bool version;
-	boost::optional<int> dcp_frame_rate;
+	boost::optional<dcp::Fraction> dcp_frame_rate;
 	boost::optional<int> still_length;
 	boost::optional<int> auto_crop_threshold;
 	boost::optional<boost::filesystem::path> config_dir;
diff --git a/src/lib/dcp_video.cc b/src/lib/dcp_video.cc
index 775298091..a1dfd7c49 100644
--- a/src/lib/dcp_video.cc
+++ b/src/lib/dcp_video.cc
@@ -79,7 +79,7 @@ using namespace boost::placeholders;
  *  @param bit_rate Video bit rate to use.
  */
 DCPVideo::DCPVideo(
-	shared_ptr<const PlayerVideo> frame, int index, int dcp_fps, int64_t bit_rate, Resolution r
+	shared_ptr<const PlayerVideo> frame, int index, dcp::Fraction dcp_fps, int64_t bit_rate, Resolution r
 	)
 	: _frame(frame)
 	, _index(index)
diff --git a/src/lib/dcp_video.h b/src/lib/dcp_video.h
index 6afbedfad..b3e73de4a 100644
--- a/src/lib/dcp_video.h
+++ b/src/lib/dcp_video.h
@@ -49,7 +49,7 @@ class PlayerVideo;
 class DCPVideo
 {
 public:
-	DCPVideo(std::shared_ptr<const PlayerVideo>, int index, int dcp_fps, int64_t bit_rate, Resolution r);
+	DCPVideo(std::shared_ptr<const PlayerVideo>, int index, dcp::Fraction dcp_fps, int64_t bit_rate, Resolution r);
 	DCPVideo(std::shared_ptr<const PlayerVideo>, cxml::ConstNodePtr);
 
 	DCPVideo(DCPVideo const&) = default;
@@ -76,10 +76,10 @@ private:
 	void add_metadata(xmlpp::Element *) const;
 
 	std::shared_ptr<const PlayerVideo> _frame;
-	int _index;			 ///< frame index within the DCP's intrinsic duration
-	int _frames_per_second;		 ///< Frames per second that we will use for the DCP
-	int64_t _video_bit_rate;	 ///< Video bit rate to use
-	Resolution _resolution;          ///< Resolution (2K or 4K)
+	int _index;			  ///< frame index within the DCP's intrinsic duration
+	dcp::Fraction _frames_per_second; ///< Frames per second that we will use for the DCP
+	int64_t _video_bit_rate;	  ///< Video bit rate to use
+	Resolution _resolution;           ///< Resolution (2K or 4K)
 };
 
 #endif
diff --git a/src/lib/dcpomatic_time.h b/src/lib/dcpomatic_time.h
index 0d15028c6..a388b6dc6 100644
--- a/src/lib/dcpomatic_time.h
+++ b/src/lib/dcpomatic_time.h
@@ -30,6 +30,7 @@
 
 #include "dcpomatic_assert.h"
 #include "frame_rate_change.h"
+#include <dcp/types.h>
 #include <boost/optional.hpp>
 #include <stdint.h>
 #include <cmath>
@@ -178,6 +179,10 @@ public:
 		return Time<S, O>(llrint(HZ * frames_round(r) / r));
 	}
 
+	Time<S, O> round(dcp::Fraction r) const {
+		return Time<S, O>(llrint(HZ * frames_round(r) * r.denominator / r.numerator));
+	}
+
 	double seconds() const {
 		return double(_t) / HZ;
 	}
@@ -195,11 +200,23 @@ public:
 		return llrint(_t * double(r) / HZ);
 	}
 
+	int64_t frames_round(dcp::Fraction r) const {
+		/* We must cast to double here otherwise if T is integer
+		   the calculation will round down before we get the chance
+		   to llrint().
+		*/
+		return llrint(_t * double(r.numerator) / (HZ * r.denominator));
+	}
+
 	template <typename T>
 	int64_t frames_floor(T r) const {
 		return ::floor(_t * r / HZ);
 	}
 
+	int64_t frames_floor(dcp::Fraction r) const {
+		return ::floor(_t * r.numerator / (HZ * r.denominator));
+	}
+
 	template <typename T>
 	int64_t frames_ceil(T r) const {
 		/* We must cast to double here otherwise if T is integer
@@ -252,6 +269,11 @@ public:
 		return Time<S, O>(f * HZ / r);
 	}
 
+	static Time<S, O> from_frames(int64_t f, dcp::Fraction r) {
+		DCPOMATIC_ASSERT(r.numerator > 0);
+		return Time<S, O>(f * HZ * r.denominator / r.numerator);
+	}
+
 	static Time<S, O> delta() {
 		return Time<S, O>(1);
 	}
diff --git a/src/lib/ffmpeg_file_encoder.h b/src/lib/ffmpeg_file_encoder.h
index a975d4519..b4289be6f 100644
--- a/src/lib/ffmpeg_file_encoder.h
+++ b/src/lib/ffmpeg_file_encoder.h
@@ -59,7 +59,7 @@ class FFmpegFileEncoder
 public:
 	FFmpegFileEncoder(
 		dcp::Size video_frame_size,
-		int video_frame_rate,
+		dcp::Fraction video_frame_rate,
 		int audio_frame_rate,
 		int channels,
 		ExportFormat,
@@ -99,7 +99,7 @@ private:
 
 	boost::filesystem::path _output;
 	dcp::Size _video_frame_size;
-	int _video_frame_rate;
+	dcp::Fraction _video_frame_rate;
 	int _audio_frame_rate;
 
 	int64_t _audio_frames = 0;
diff --git a/src/lib/ffmpeg_film_encoder.cc b/src/lib/ffmpeg_film_encoder.cc
index 9a9cba79c..602524fdf 100644
--- a/src/lib/ffmpeg_film_encoder.cc
+++ b/src/lib/ffmpeg_film_encoder.cc
@@ -247,7 +247,7 @@ FFmpegFilmEncoder::frames_done() const
 
 FFmpegFilmEncoder::FileEncoderSet::FileEncoderSet(
 	dcp::Size video_frame_size,
-	int video_frame_rate,
+	dcp::Fraction video_frame_rate,
 	int audio_frame_rate,
 	int channels,
 	ExportFormat format,
diff --git a/src/lib/ffmpeg_film_encoder.h b/src/lib/ffmpeg_film_encoder.h
index 2e06b770e..a1b1656ac 100644
--- a/src/lib/ffmpeg_film_encoder.h
+++ b/src/lib/ffmpeg_film_encoder.h
@@ -57,7 +57,7 @@ private:
 	public:
 		FileEncoderSet(
 			dcp::Size video_frame_size,
-			int video_frame_rate,
+			dcp::Fraction video_frame_rate,
 			int audio_frame_rate,
 			int channels,
 			ExportFormat,
diff --git a/src/lib/film.h b/src/lib/film.h
index 142f6c374..694c2dbb4 100644
--- a/src/lib/film.h
+++ b/src/lib/film.h
@@ -151,8 +151,8 @@ public:
 
 	ContentList content() const;
 	dcpomatic::DCPTime length() const;
-	int best_video_frame_rate() const;
-	FrameRateChange active_frame_rate_change(dcpomatic::DCPTime) const;
+	dcp::Fraction best_video_frame_rate() const;
+	dcp::Fraction active_frame_rate_change(dcpomatic::DCPTime) const;
 	std::pair<double, double> speed_up_range(int dcp_frame_rate) const;
 
 	dcp::DecryptedKDM make_kdm(boost::filesystem::path cpl_file, dcp::LocalTime from, dcp::LocalTime until) const;
@@ -253,7 +253,7 @@ public:
 	}
 
 	/** @return The frame rate of the DCP */
-	int video_frame_rate() const {
+	dcp::Fraction video_frame_rate() const {
 		return _video_frame_rate;
 	}
 
@@ -406,7 +406,7 @@ public:
 	void set_encrypt_sound(bool);
 	void set_encrypt_text(bool);
 	void set_video_bit_rate(VideoEncoding encoding, int64_t);
-	void set_video_frame_rate(int rate, bool user_explicit = true);
+	void set_video_frame_rate(dcp::Fraction rate, bool user_explicit = true);
 	void set_audio_channels(int);
 	void set_three_d(bool);
 	void set_isdcf_date_today();
@@ -534,7 +534,7 @@ private:
 	/** bit rate for encoding video using in bits per second */
 	EnumIndexedVector<int64_t, VideoEncoding> _video_bit_rate;
 	/** Frames per second to run our DCP at */
-	int _video_frame_rate;
+	dcp::Fraction _video_frame_rate;
 	/** The date that we should use in a ISDCF name */
 	boost::gregorian::date _isdcf_date;
 	/** Number of audio channels requested for the DCP */
diff --git a/src/lib/frame_rate_change.cc b/src/lib/frame_rate_change.cc
index 48f5b9881..8f6397d56 100644
--- a/src/lib/frame_rate_change.cc
+++ b/src/lib/frame_rate_change.cc
@@ -22,6 +22,7 @@
 #include "content.h"
 #include "film.h"
 #include "frame_rate_change.h"
+#include <dcp/types.h>
 #include <cmath>
 
 #include "i18n.h"
@@ -32,29 +33,30 @@ using std::string;
 
 
 FrameRateChange::FrameRateChange()
+	: dcp(24, 1)
 {
 
 }
 
 
-FrameRateChange::FrameRateChange(double source_, int dcp_)
+FrameRateChange::FrameRateChange(double source_, dcp::Fraction dcp_)
 	: source(source_)
 	, dcp(dcp_)
 {
-	if (fabs(source / 2.0 - dcp) < fabs(source - dcp)) {
+	if (fabs(source / 2.0 - dcp.as_float()) < fabs(source - dcp.as_float())) {
 		/* The difference between source and DCP frame rate will be lower
 		   (i.e. better) if we skip.
 		*/
 		skip = true;
-	} else if (fabs(source * 2 - dcp) < fabs(source - dcp)) {
+	} else if (fabs(source * 2 - dcp.as_float()) < fabs(source - dcp.as_float())) {
 		/* The difference between source and DCP frame rate would be better
 		   if we repeated each frame once; it may be better still if we
 		   repeated more than once.  Work out the required repeat.
 		*/
-		repeat = round(dcp / source);
+		repeat = round(dcp.as_float() / source);
 	}
 
-	speed_up = dcp / (source * factor());
+	speed_up = dcp.as_float() / (source * factor());
 
 	auto about_equal = [](double a, double b) {
 		return (fabs(a - b) < VIDEO_FRAME_RATE_EPSILON);
@@ -95,7 +97,7 @@ FrameRateChange::description() const
 		}
 
 		if (change_speed) {
-			double const pc = dcp * 100 / (source * factor());
+			double const pc = dcp.as_float() * 100 / (source * factor());
 			char buffer[256];
 			snprintf(buffer, sizeof(buffer), _("DCP will run at %.1f%% of the content speed.\n"), pc);
 			description += buffer;
diff --git a/src/lib/frame_rate_change.h b/src/lib/frame_rate_change.h
index 84c4c340d..9b01a0e1a 100644
--- a/src/lib/frame_rate_change.h
+++ b/src/lib/frame_rate_change.h
@@ -23,6 +23,7 @@
 #define DCPOMATIC_FRAME_RATE_CHANGE_H
 
 
+#include <dcp/types.h>
 #include <memory>
 #include <string>
 
@@ -35,7 +36,7 @@ class FrameRateChange
 {
 public:
 	FrameRateChange();
-	FrameRateChange(double, int);
+	FrameRateChange(double, dcp::Fraction);
 	FrameRateChange(std::shared_ptr<const Film> film, std::shared_ptr<const Content> content);
 	FrameRateChange(std::shared_ptr<const Film> film, Content const * content);
 
@@ -51,7 +52,7 @@ public:
 	}
 
 	double source = 24;
-	int dcp = 24;
+	dcp::Fraction dcp;
 
 	/** true to skip every other frame */
 	bool skip = false;
diff --git a/src/lib/grok/context.h b/src/lib/grok/context.h
index b31867cf6..106c4e828 100644
--- a/src/lib/grok/context.h
+++ b/src/lib/grok/context.h
@@ -226,7 +226,7 @@ public:
 					12,
 					device,
 					_dcpomatic_context->film->resolution() == Resolution::FOUR_K,
-					_dcpomatic_context->film->video_frame_rate(),
+					std::round(_dcpomatic_context->film->video_frame_rate().as_float()),
 					_dcpomatic_context->film->video_bit_rate(VideoEncoding::JPEG2000),
 					grok.licence_server,
 					grok.licence)) {
diff --git a/src/lib/hints.cc b/src/lib/hints.cc
index 99882ec0e..73d31ce5b 100644
--- a/src/lib/hints.cc
+++ b/src/lib/hints.cc
@@ -181,13 +181,8 @@ Hints::check_high_video_bit_rate()
 void
 Hints::check_frame_rate()
 {
-	auto f = film();
-	switch (f->video_frame_rate()) {
-	case 24:
-		/* Fine */
-		break;
-	case 25:
-	{
+	auto const vfr = film()->video_frame_rate();
+	if (vfr == dcp::Fraction(25, 1)) {
 		/* You might want to go to 24 */
 		string base = fmt::format(_("You are set up for a DCP at a frame rate of {} fps.  This frame rate is not supported by all projectors.  You may want to consider changing your frame rate to {} fps."), 25, 24);
 		if (f->interop()) {
@@ -196,16 +191,13 @@ Hints::check_frame_rate()
 		}
 		hint(base);
 		break;
-	}
-	case 30:
+	} else if (vfr == dcp::Fraction(30, 1)) {
 		/* 30fps: we can't really offer any decent solutions */
 		hint(_("You are set up for a DCP frame rate of 30fps, which is not supported by all projectors.  Be aware that you may have compatibility problems."));
 		break;
-	case 48:
-	case 50:
-	case 60:
+	} else if (vfr == dcp::Fraction(48, 1) || vfr == dcp::Fraction(50, 1) || vfr == dcp::Fraction(60, 1)) {
 		/* You almost certainly want to go to half frame rate */
-		hint(fmt::format(_("You are set up for a DCP at a frame rate of {} fps.  This frame rate is not supported by all projectors.  It is advisable to change the DCP frame rate to {} fps."), f->video_frame_rate(), f->video_frame_rate() / 2));
+		hint(fmt::format(_("You are set up for a DCP at a frame rate of {} fps.  This frame rate is not supported by all projectors.  It is advisable to change the DCP frame rate to {} fps."), vfr.numerator, vfr.numerator / 2));
 		break;
 	}
 }
@@ -624,7 +616,7 @@ Hints::open_subtitle(PlayerText text, DCPTimePeriod period)
 		hint(_("It is advisable to put your first subtitle at least 4 seconds after the start of the DCP to make sure it is seen."));
 	}
 
-	int const vfr = film()->video_frame_rate();
+	auto const vfr = film()->video_frame_rate();
 
 	if (period.duration().frames_round(vfr) < 15 && !_short_subtitle) {
 		_short_subtitle = true;
diff --git a/src/lib/referenced_reel_asset.cc b/src/lib/referenced_reel_asset.cc
index 5ef3b9ae7..62b7c4c93 100644
--- a/src/lib/referenced_reel_asset.cc
+++ b/src/lib/referenced_reel_asset.cc
@@ -83,7 +83,7 @@ get_referenced_reel_assets(shared_ptr<const Film> film, shared_ptr<const Playlis
 		auto const frame_rate = film->video_frame_rate();
 		DCPOMATIC_ASSERT (dcp->video_frame_rate());
 		/* We should only be referencing if the DCP rate is the same as the film rate */
-		DCPOMATIC_ASSERT (std::round(dcp->video_frame_rate().get()) == frame_rate);
+		DCPOMATIC_ASSERT(std::abs(dcp->video_frame_rate().get() - frame_rate.as_float()) < 1e-3);
 
 		Frame const trim_start = dcp->trim_start().frames_round(frame_rate);
 		Frame const trim_end = dcp->trim_end().frames_round(frame_rate);