Optimise image scaling for the preview.

7 files changed, 49 insertions, 21 deletions

diff --git a/src/lib/dcp_video.cc b/src/lib/dcp_video.cc
index cd7d5229e..fbe863a8e 100644
--- a/src/lib/dcp_video.cc
+++ b/src/lib/dcp_video.cc
@@ -1,6 +1,5 @@
 /*
-    Copyright (C) 2012-2015 Carl Hetherington <cth@carlh.net>
-    Taken from code Copyright (C) 2010-2011 Terrence Meiczinger
+    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -99,7 +98,7 @@ DCPVideo::convert_to_xyz (shared_ptr<const PlayerVideo> frame, dcp::NoteHandler
 {
 	shared_ptr<dcp::OpenJPEGImage> xyz;
 
-	shared_ptr<Image> image = frame->image (note);
+	shared_ptr<Image> image = frame->image (note, bind (&PlayerVideo::keep_xyz_or_rgb, _1), true, false);
 	if (frame->colour_conversion()) {
 		xyz = dcp::rgb_to_xyz (
 			image->data()[0],
diff --git a/src/lib/dcp_video.h b/src/lib/dcp_video.h
index a61a757bd..3809d2792 100644
--- a/src/lib/dcp_video.h
+++ b/src/lib/dcp_video.h
@@ -1,6 +1,5 @@
 /*
-    Copyright (C) 2012-2014 Carl Hetherington <cth@carlh.net>
-    Taken from code Copyright (C) 2010-2011 Terrence Meiczinger
+    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
diff --git a/src/lib/image.cc b/src/lib/image.cc
index 9ddccb75f..92b850a62 100644
--- a/src/lib/image.cc
+++ b/src/lib/image.cc
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012-2015 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -110,10 +110,13 @@ Image::planes () const
 	return d->nb_components;
 }
 
-/** Crop this image, scale it to `inter_size' and then place it in a black frame of `out_size' */
+/** Crop this image, scale it to `inter_size' and then place it in a black frame of `out_size'.
+ *  @param fast Try to be fast at the possible expense of quality; at present this means using
+ *  fast bilinear rather than bicubic scaling.
+ */
 shared_ptr<Image>
 Image::crop_scale_window (
-	Crop crop, dcp::Size inter_size, dcp::Size out_size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat out_format, bool out_aligned
+	Crop crop, dcp::Size inter_size, dcp::Size out_size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat out_format, bool out_aligned, bool fast
 	) const
 {
 	/* Empirical testing suggests that sws_scale() will crash if
@@ -156,7 +159,7 @@ Image::crop_scale_window (
 	struct SwsContext* scale_context = sws_getContext (
 			cropped_size.width, cropped_size.height, pixel_format(),
 			inter_size.width, inter_size.height, out_format,
-			SWS_BICUBIC, 0, 0, 0
+			fast ? SWS_FAST_BILINEAR : SWS_BICUBIC, 0, 0, 0
 		);
 
 	if (!scale_context) {
@@ -213,8 +216,11 @@ Image::crop_scale_window (
 	return out;
 }
 
+/** @param fast Try to be fast at the possible expense of quality; at present this means using
+ *  fast bilinear rather than bicubic scaling.
+ */
 shared_ptr<Image>
-Image::scale (dcp::Size out_size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat out_format, bool out_aligned) const
+Image::scale (dcp::Size out_size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat out_format, bool out_aligned, bool fast) const
 {
 	/* Empirical testing suggests that sws_scale() will crash if
 	   the input image is not aligned.
@@ -226,7 +232,7 @@ Image::scale (dcp::Size out_size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat out_fo
 	struct SwsContext* scale_context = sws_getContext (
 		size().width, size().height, pixel_format(),
 		out_size.width, out_size.height, out_format,
-		SWS_BICUBIC, 0, 0, 0
+		fast ? SWS_FAST_BILINEAR : SWS_BICUBIC, 0, 0, 0
 		);
 
 	DCPOMATIC_ASSERT (yuv_to_rgb < dcp::YUV_TO_RGB_COUNT);
diff --git a/src/lib/image.h b/src/lib/image.h
index 416ee3a8d..b8d48275a 100644
--- a/src/lib/image.h
+++ b/src/lib/image.h
@@ -1,5 +1,5 @@
 /*
-    Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
+    Copyright (C) 2012-2016 Carl Hetherington <cth@carlh.net>
 
     This program is free software; you can redistribute it and/or modify
     it under the terms of the GNU General Public License as published by
@@ -57,8 +57,10 @@ public:
 	int line_factor (int) const;
 	dcp::Size sample_size (int) const;
 
-	boost::shared_ptr<Image> scale (dcp::Size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat, bool aligned) const;
-	boost::shared_ptr<Image> crop_scale_window (Crop c, dcp::Size, dcp::Size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat, bool aligned) const;
+	boost::shared_ptr<Image> scale (dcp::Size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat, bool aligned, bool fast) const;
+	boost::shared_ptr<Image> crop_scale_window (
+		Crop c, dcp::Size, dcp::Size, dcp::YUVToRGB yuv_to_rgb, AVPixelFormat, bool aligned, bool fast)
+		const;
 
 	void make_black ();
 	void make_transparent ();
diff --git a/src/lib/player.cc b/src/lib/player.cc
index 30f36107f..d35c1b76b 100644
--- a/src/lib/player.cc
+++ b/src/lib/player.cc
@@ -318,7 +318,8 @@ Player::transform_image_subtitles (list<ImageSubtitle> subs) const
 					scaled_size,
 					dcp::YUV_TO_RGB_REC601,
 					i->image->pixel_format (),
-					true
+					true,
+					_fast
 					),
 				Position<int> (
 					lrint (_video_container_size.width * i->rectangle.x),
diff --git a/src/lib/player_video.cc b/src/lib/player_video.cc
index ba4503d8e..3129a1717 100644
--- a/src/lib/player_video.cc
+++ b/src/lib/player_video.cc
@@ -34,6 +34,7 @@ using std::cout;
 using boost::shared_ptr;
 using boost::dynamic_pointer_cast;
 using boost::optional;
+using boost::function;
 using dcp::Data;
 
 PlayerVideo::PlayerVideo (
@@ -94,8 +95,14 @@ PlayerVideo::set_subtitle (PositionImage image)
 	_subtitle = image;
 }
 
+/** Create an image for this frame.
+ *  @param note Handler for any notes that are made during the process.
+ *  @param pixel_format Function which is called to decide what pixel format the output image should be;
+ *  it is passed the pixel format of the input image from the ImageProxy, and should return the desired
+ *  output pixel format.  Two functions always_rgb and keep_xyz_or_rgb are provided for use here.
+ */
 shared_ptr<Image>
-PlayerVideo::image (dcp::NoteHandler note) const
+PlayerVideo::image (dcp::NoteHandler note, function<AVPixelFormat (AVPixelFormat)> pixel_format, bool aligned, bool fast) const
 {
 	shared_ptr<Image> im = _in->image (optional<dcp::NoteHandler> (note));
 
@@ -122,10 +129,9 @@ PlayerVideo::image (dcp::NoteHandler note) const
 		yuv_to_rgb = _colour_conversion.get().yuv_to_rgb();
 	}
 
-	/* If the input is XYZ, keep it otherwise convert to RGB */
-	AVPixelFormat const p = _in->pixel_format() == AV_PIX_FMT_XYZ12LE ? AV_PIX_FMT_XYZ12LE : AV_PIX_FMT_RGB48LE;
-
-	shared_ptr<Image> out = im->crop_scale_window (total_crop, _inter_size, _out_size, yuv_to_rgb, p, true);
+	shared_ptr<Image> out = im->crop_scale_window (
+		total_crop, _inter_size, _out_size, yuv_to_rgb, pixel_format (_in->pixel_format()), aligned, fast
+		);
 
 	if (_subtitle) {
 		out->alpha_blend (_subtitle->image, _subtitle->position);
@@ -230,3 +236,15 @@ PlayerVideo::same (shared_ptr<const PlayerVideo> other) const
 
 	return _in->same (other->_in);
 }
+
+AVPixelFormat
+PlayerVideo::always_rgb (AVPixelFormat)
+{
+	return AV_PIX_FMT_RGB24;
+}
+
+AVPixelFormat
+PlayerVideo::keep_xyz_or_rgb (AVPixelFormat p)
+{
+	return p == AV_PIX_FMT_XYZ12LE ? AV_PIX_FMT_XYZ12LE : AV_PIX_FMT_RGB48LE;
+}
diff --git a/src/lib/player_video.h b/src/lib/player_video.h
index 01b1c74f5..8bd1c7be3 100644
--- a/src/lib/player_video.h
+++ b/src/lib/player_video.h
@@ -54,7 +54,10 @@ public:
 
 	void set_subtitle (PositionImage);
 
-	boost::shared_ptr<Image> image (dcp::NoteHandler note) const;
+	boost::shared_ptr<Image> image (dcp::NoteHandler note, boost::function<AVPixelFormat (AVPixelFormat)> pixel_format, bool aligned, bool fast) const;
+
+	static AVPixelFormat always_rgb (AVPixelFormat);
+	static AVPixelFormat keep_xyz_or_rgb (AVPixelFormat);
 
 	void add_metadata (xmlpp::Node* node) const;
 	void send_binary (boost::shared_ptr<Socket> socket) const;