Support rgb -> xyz encoding.

14 files changed, 190 insertions, 32 deletions

diff --git a/src/colour_matrix.cc b/src/colour_matrix.cc
new file mode 100644
index 00000000..47ebf3e0
--- /dev/null
+++ b/src/colour_matrix.cc
@@ -0,0 +1,42 @@
+/*
+    Copyright (C) 2013 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
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+#include "colour_matrix.h"
+
+/* sRGB color matrix for XYZ -> RGB.  This is the same as the one used by the Fraunhofer
+   EasyDCP player, I think.
+*/
+
+float const libdcp::colour_matrix::xyz_to_rgb[3][3] = {
+	{  3.24096989631653,   -1.5373831987381,  -0.498610764741898 },
+	{ -0.96924364566803,    1.87596750259399,  0.0415550582110882 },
+	{  0.0556300804018974, -0.203976958990097, 1.05697154998779 }
+};
+
+float const libdcp::colour_matrix::srgb_to_xyz[3][3] = {
+	{0.4124564, 0.3575761, 0.1804375},
+	{0.2126729, 0.7151522, 0.0721750},
+	{0.0193339, 0.1191920, 0.9503041}
+};
+
+float const libdcp::colour_matrix::rec709_to_xyz[3][3] = {
+	{0.4124564, 0.3575761, 0.1804375},
+	{0.2126729, 0.7151522, 0.0721750},
+	{0.0193339, 0.1191920, 0.9503041}
+};
diff --git a/src/colour_matrix.h b/src/colour_matrix.h
new file mode 100644
index 00000000..13bbc821
--- /dev/null
+++ b/src/colour_matrix.h
@@ -0,0 +1,30 @@
+/*
+    Copyright (C) 2013 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
+    the Free Software Foundation; either version 2 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program; if not, write to the Free Software
+    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+*/
+
+namespace libdcp {
+
+namespace colour_matrix {
+
+extern float const xyz_to_rgb[3][3];
+extern float const srgb_to_xyz[3][3];
+extern float const rec709_to_xyz[3][3];
+
+}	
+
+}
diff --git a/src/gamma_lut.cc b/src/gamma_lut.cc
index 547601b9..80d9b902 100644
--- a/src/gamma_lut.cc
+++ b/src/gamma_lut.cc
@@ -26,7 +26,7 @@ using namespace libdcp;
 LUTCache<GammaLUT> GammaLUT::cache;
 
 GammaLUT::GammaLUT(int bits, float gamma)
-	: LUT<float> (bits, gamma)
+	: LUT (bits, gamma)
 {
 	int const bit_length = pow(2, bits);
 	for (int i = 0; i < bit_length; ++i) {
diff --git a/src/gamma_lut.h b/src/gamma_lut.h
index c844de44..32e4af02 100644
--- a/src/gamma_lut.h
+++ b/src/gamma_lut.h
@@ -25,7 +25,7 @@
 
 namespace libdcp {
 
-class GammaLUT : public LUT<float>
+class GammaLUT : public LUT
 {
 public:
 	GammaLUT (int bit_length, float gamma);
diff --git a/src/lut.h b/src/lut.h
index bdb5f37f..3efcaaed 100644
--- a/src/lut.h
+++ b/src/lut.h
@@ -24,7 +24,6 @@
 
 namespace libdcp {
 
-template<typename T>
 class LUT
 {
 public:
@@ -33,14 +32,14 @@ public:
 		, _bit_depth (bit_depth)
 		, _gamma (gamma)
 	{
-		_lut = new T[int(std::pow(2.0f, _bit_depth))];
+		_lut = new float[int(std::pow(2.0f, _bit_depth))];
 	}
 
 	virtual ~LUT() {
 		delete[] _lut;
 	}
 	
-	T const * lut() const {
+	float const * lut() const {
 		return _lut;
 	}
 
@@ -53,7 +52,7 @@ public:
 	}
 
 protected:
-	T* _lut;
+	float* _lut;
 	int _bit_depth;
 	float _gamma;
 };
diff --git a/src/rec709_linearised_gamma_lut.cc b/src/rec709_linearised_gamma_lut.cc
index f1ac0a6d..f14e4472 100644
--- a/src/rec709_linearised_gamma_lut.cc
+++ b/src/rec709_linearised_gamma_lut.cc
@@ -24,7 +24,7 @@ using namespace libdcp;
 LUTCache<Rec709LinearisedGammaLUT> Rec709LinearisedGammaLUT::cache;
 
 Rec709LinearisedGammaLUT::Rec709LinearisedGammaLUT (int bits, float gamma)
-	: LUT<float> (bits, gamma)
+	: LUT (bits, gamma)
 {
 	int const bit_length = pow (2, bits);
 	for (int i = 0; i < bit_length; ++i) {
diff --git a/src/rec709_linearised_gamma_lut.h b/src/rec709_linearised_gamma_lut.h
index 75e71f74..af0158a5 100644
--- a/src/rec709_linearised_gamma_lut.h
+++ b/src/rec709_linearised_gamma_lut.h
@@ -22,7 +22,7 @@
 
 namespace libdcp {
 
-class Rec709LinearisedGammaLUT : public LUT<float>
+class Rec709LinearisedGammaLUT : public LUT
 {
 public:
 	Rec709LinearisedGammaLUT (int bit_length, float gamma);
diff --git a/src/rgb_xyz.cc b/src/rgb_xyz.cc
index 6be7180f..22b2bdec 100644
--- a/src/rgb_xyz.cc
+++ b/src/rgb_xyz.cc
@@ -21,31 +21,23 @@
 #include "argb_frame.h"
 #include "xyz_frame.h"
 #include "gamma_lut.h"
+#include "image.h"
+#include "colour_matrix.h"
 
 using std::min;
 using std::max;
 using boost::shared_ptr;
 using namespace libdcp;
 
+#define DCI_COEFFICIENT (48.0 / 52.37)
+
 /** Convert an openjpeg XYZ image to RGB.
  *  @param xyz_frame Frame in XYZ.
  *  @return RGB image.
  */
 shared_ptr<ARGBFrame>
-libdcp::xyz_to_rgb (shared_ptr<const XYZFrame> xyz_frame, shared_ptr<const GammaLUT> lut_in, shared_ptr<const GammaLUT> lut_out)
+libdcp::xyz_to_rgb (shared_ptr<const XYZFrame> xyz_frame, shared_ptr<const LUT> lut_in, shared_ptr<const LUT> lut_out)
 {
-	float const dci_coefficient = 48.0 / 52.37;
-
-        /* sRGB color matrix for XYZ -> RGB.  This is the same as the one used by the Fraunhofer
-	   EasyDCP player, I think.
-	*/
-
-	float const colour_matrix[3][3] = {
-		{  3.24096989631653,   -1.5373831987381,  -0.498610764741898 },
-		{ -0.96924364566803,    1.87596750259399,  0.0415550582110882 },
-		{  0.0556300804018974, -0.203976958990097, 1.05697154998779 }
-	};
-
 	int const max_colour = pow (2, lut_out->bit_depth()) - 1;
 
 	struct {
@@ -76,14 +68,14 @@ libdcp::xyz_to_rgb (shared_ptr<const XYZFrame> xyz_frame, shared_ptr<const Gamma
 			s.z = lut_in->lut()[*xyz_z++];
 
 			/* DCI companding */
-			s.x /= dci_coefficient;
-			s.y /= dci_coefficient;
-			s.z /= dci_coefficient;
-			
+			s.x /= DCI_COEFFICIENT;
+			s.y /= DCI_COEFFICIENT;
+			s.z /= DCI_COEFFICIENT;
+
 			/* XYZ to RGB */
-			d.r = ((s.x * colour_matrix[0][0]) + (s.y * colour_matrix[0][1]) + (s.z * colour_matrix[0][2]));
-			d.g = ((s.x * colour_matrix[1][0]) + (s.y * colour_matrix[1][1]) + (s.z * colour_matrix[1][2]));
-			d.b = ((s.x * colour_matrix[2][0]) + (s.y * colour_matrix[2][1]) + (s.z * colour_matrix[2][2]));
+			d.r = ((s.x * colour_matrix::xyz_to_rgb[0][0]) + (s.y * colour_matrix::xyz_to_rgb[0][1]) + (s.z * colour_matrix::xyz_to_rgb[0][2]));
+			d.g = ((s.x * colour_matrix::xyz_to_rgb[1][0]) + (s.y * colour_matrix::xyz_to_rgb[1][1]) + (s.z * colour_matrix::xyz_to_rgb[1][2]));
+			d.b = ((s.x * colour_matrix::xyz_to_rgb[2][0]) + (s.y * colour_matrix::xyz_to_rgb[2][1]) + (s.z * colour_matrix::xyz_to_rgb[2][2]));
 			
 			d.r = min (d.r, 1.0);
 			d.r = max (d.r, 0.0);
@@ -107,3 +99,58 @@ libdcp::xyz_to_rgb (shared_ptr<const XYZFrame> xyz_frame, shared_ptr<const Gamma
 	return argb_frame;
 }
 
+shared_ptr<libdcp::XYZFrame>
+libdcp::rgb_to_xyz (shared_ptr<const Image> rgb, shared_ptr<const LUT> lut_in, shared_ptr<const LUT> lut_out, float const colour_matrix[3][3])
+{
+	assert (lut_in->bit_depth() == 12);
+	assert (lut_out->bit_depth() == 16);
+	
+	shared_ptr<XYZFrame> xyz (new XYZFrame (rgb->size ()));
+
+	struct {
+		double r, g, b;
+	} s;
+
+	struct {
+		double x, y, z;
+	} d;
+
+	int jn = 0;
+	for (int y = 0; y < rgb->size().height; ++y) {
+		uint8_t* p = rgb->data()[0] + y * rgb->stride()[0];
+		for (int x = 0; x < rgb->size().width; ++x) {
+
+			/* In gamma LUT (converting 8-bit input to 12-bit) */
+			s.r = lut_in->lut()[*p++ << 4];
+			s.g = lut_in->lut()[*p++ << 4];
+			s.b = lut_in->lut()[*p++ << 4];
+			
+			/* RGB to XYZ Matrix */
+			d.x = ((s.r * colour_matrix[0][0]) +
+			       (s.g * colour_matrix[0][1]) +
+			       (s.b * colour_matrix[0][2]));
+			
+			d.y = ((s.r * colour_matrix[1][0]) +
+			       (s.g * colour_matrix[1][1]) +
+			       (s.b * colour_matrix[1][2]));
+			
+			d.z = ((s.r * colour_matrix[2][0]) +
+			       (s.g * colour_matrix[2][1]) +
+			       (s.b * colour_matrix[2][2]));
+			
+			/* DCI companding */
+			d.x = d.x * DCI_COEFFICIENT * 65535;
+			d.y = d.y * DCI_COEFFICIENT * 65535;
+			d.z = d.z * DCI_COEFFICIENT * 65535;
+			
+			/* Out gamma LUT */
+			xyz->data(0)[jn] = lut_out->lut()[(int) d.x] * 4096;
+			xyz->data(1)[jn] = lut_out->lut()[(int) d.y] * 4096;
+			xyz->data(2)[jn] = lut_out->lut()[(int) d.z] * 4096;
+
+			++jn;
+		}
+	}
+
+	return xyz;
+}
diff --git a/src/rgb_xyz.h b/src/rgb_xyz.h
index 123e055a..d85e5a1f 100644
--- a/src/rgb_xyz.h
+++ b/src/rgb_xyz.h
@@ -23,10 +23,15 @@ namespace libdcp {
 
 class ARGBFrame;	
 class XYZFrame;
-class GammaLUT;
+class LUT;
+class Image;
 	
 extern boost::shared_ptr<ARGBFrame> xyz_to_rgb (
-	boost::shared_ptr<const XYZFrame>, boost::shared_ptr<const GammaLUT>, boost::shared_ptr<const GammaLUT>
+	boost::shared_ptr<const XYZFrame>, boost::shared_ptr<const LUT>, boost::shared_ptr<const LUT>
 	);
 
+extern boost::shared_ptr<XYZFrame> rgb_to_xyz (
+	boost::shared_ptr<const Image>, boost::shared_ptr<const LUT>, boost::shared_ptr<const LUT>, float const colour_matrix[3][3]
+	);
+	
 }
diff --git a/src/srgb_linearised_gamma_lut.cc b/src/srgb_linearised_gamma_lut.cc
index 1c10e118..0d3650f4 100644
--- a/src/srgb_linearised_gamma_lut.cc
+++ b/src/srgb_linearised_gamma_lut.cc
@@ -24,7 +24,7 @@ using namespace libdcp;
 LUTCache<SRGBLinearisedGammaLUT> SRGBLinearisedGammaLUT::cache;
 
 SRGBLinearisedGammaLUT::SRGBLinearisedGammaLUT (int bits, float gamma)
-	: LUT<float> (bits, gamma)
+	: LUT (bits, gamma)
 {
 	int const bit_length = pow (2, bits);
 	for (int i = 0; i < bit_length; ++i) {
diff --git a/src/srgb_linearised_gamma_lut.h b/src/srgb_linearised_gamma_lut.h
index 9e32463a..34800c66 100644
--- a/src/srgb_linearised_gamma_lut.h
+++ b/src/srgb_linearised_gamma_lut.h
@@ -22,7 +22,7 @@
 
 namespace libdcp {
 
-class SRGBLinearisedGammaLUT : public LUT<float>
+class SRGBLinearisedGammaLUT : public LUT
 {
 public:
 	SRGBLinearisedGammaLUT (int bit_length, float gamma);
diff --git a/src/wscript b/src/wscript
index 3b23443c..4d51bbe4 100644
--- a/src/wscript
+++ b/src/wscript
@@ -13,11 +13,13 @@ def build(bld):
                  argb_frame.cc
                  asset.cc
                  certificates.cc
+                 colour_matrix.cc
                  crypt_chain.cc
                  cpl.cc
                  dcp.cc        
                  dcp_time.cc
                  gamma_lut.cc
+                 image.cc
                  kdm.cc
                  metadata.cc
                  mxf_asset.cc
@@ -43,13 +45,16 @@ def build(bld):
     headers = """
               asset.h
               certificates.h
+              colour_matrix.h
               cpl.h
               crypt_chain.h
               dcp.h
               dcp_time.h
               exceptions.h
               gamma_lut.h
+              image.h
               kdm.h
+              lut.h
               metadata.h
               mxf_asset.h
               picture_asset.h
diff --git a/src/xyz_frame.cc b/src/xyz_frame.cc
index 78df3f33..f5b0ee86 100644
--- a/src/xyz_frame.cc
+++ b/src/xyz_frame.cc
@@ -18,6 +18,7 @@
 */
 
 #include <cassert>
+#include <stdexcept>
 #include "xyz_frame.h"
 
 using namespace libdcp;
@@ -29,6 +30,34 @@ XYZFrame::XYZFrame (opj_image_t* image)
 	assert (_opj_image->numcomps == 3);
 }
 
+XYZFrame::XYZFrame (Size size)
+{
+	opj_image_cmptparm_t cmptparm[3];
+	
+	for (int i = 0; i < 3; ++i) {
+		cmptparm[i].dx = 1;
+		cmptparm[i].dy = 1;
+		cmptparm[i].w = size.width;
+		cmptparm[i].h = size.height;
+		cmptparm[i].x0 = 0;
+		cmptparm[i].y0 = 0;
+		cmptparm[i].prec = 12;
+		cmptparm[i].bpp = 12;
+		cmptparm[i].sgnd = 0;
+	}
+
+	/* XXX: is this _SRGB right? */
+	_opj_image = opj_image_create (3, &cmptparm[0], CLRSPC_SRGB);
+	if (_opj_image == 0) {
+		throw std::runtime_error ("could not create libopenjpeg image");
+	}
+
+	_opj_image->x0 = 0;
+	_opj_image->y0 = 0;
+	_opj_image->x1 = size.width;
+	_opj_image->y1 = size.height;
+}
+
 XYZFrame::~XYZFrame ()
 {
 	opj_image_destroy (_opj_image);
diff --git a/src/xyz_frame.h b/src/xyz_frame.h
index 9a10d1e3..a4dcb2c0 100644
--- a/src/xyz_frame.h
+++ b/src/xyz_frame.h
@@ -26,6 +26,7 @@ class XYZFrame
 {
 public:
 	XYZFrame (opj_image_t *);
+	XYZFrame (Size);
 	~XYZFrame ();
 
 	int* data (int) const;