Add support for obtaining a frame as RGBA.

1 files changed, 87 insertions, 0 deletions

diff --git a/src/picture_frame.cc b/src/picture_frame.cc
index d2ef698f..844f0183 100644
--- a/src/picture_frame.cc
+++ b/src/picture_frame.cc
@@ -17,12 +17,16 @@
 
 */
 
+#include <openjpeg.h>
 #include "AS_DCP.h"
 #include "KM_fileio.h"
 #include "picture_frame.h"
 #include "exceptions.h"
+#include "rgba_frame.h"
+#include "lut.h"
 
 using namespace std;
+using namespace boost;
 using namespace libdcp;
 
 PictureFrame::PictureFrame (string mxf_path, int n)
@@ -56,3 +60,86 @@ PictureFrame::size () const
 {
 	return _buffer->Size ();
 }
+
+shared_ptr<RGBAFrame>
+PictureFrame::rgba_frame () const
+{
+	/* JPEG2000 -> decompressed XYZ */
+	
+	opj_dinfo_t* decoder = opj_create_decompress (CODEC_J2K);
+	opj_dparameters_t parameters;
+	opj_set_default_decoder_parameters (&parameters);
+	opj_setup_decoder (decoder, &parameters);
+	opj_cio_t* cio = opj_cio_open ((opj_common_ptr) decoder, const_cast<unsigned char *> (data()), size());
+	opj_image_t* xyz_frame = opj_decode (decoder, cio);
+	if (!xyz_frame) {
+		opj_destroy_decompress (decoder);
+		opj_cio_close (cio);
+		throw DCPReadError ("could not decode JPEG2000 codestream");
+	}
+	
+	assert (xyz_frame->numcomps == 3);
+	
+	/* XYZ -> RGB */
+	
+	struct {
+		double x, y, z;
+	} s;
+	
+	struct {
+		double r, g, b;
+	} d;
+	
+	int* xyz_x = xyz_frame->comps[0].data;
+	int* xyz_y = xyz_frame->comps[1].data;
+	int* xyz_z = xyz_frame->comps[2].data;
+
+	shared_ptr<RGBAFrame> rgba_frame (new RGBAFrame (xyz_frame->x1, xyz_frame->y1));
+	
+	uint8_t* rgba = rgba_frame->data ();
+	
+	for (int y = 0; y < xyz_frame->y1; ++y) {
+		uint8_t* rgba_line = rgba;
+		for (int x = 0; x < xyz_frame->x1; ++x) {
+			
+			assert (*xyz_x >= 0 && *xyz_y >= 0 && *xyz_z >= 0 && *xyz_x < 4096 && *xyz_x < 4096 && *xyz_z < 4096);
+			
+			/* In gamma LUT */
+			s.x = lut_in[*xyz_x++];
+			s.y = lut_in[*xyz_y++];
+			s.z = lut_in[*xyz_z++];
+			
+			/* DCI companding */
+			s.x /= DCI_COEFFICIENT;
+			s.y /= DCI_COEFFICIENT;
+			s.z /= DCI_COEFFICIENT;
+			
+			/* XYZ to RGB */
+			d.r = ((s.x * color_matrix[0][0]) + (s.y * color_matrix[0][1]) + (s.z * color_matrix[0][2]));
+			d.g = ((s.x * color_matrix[1][0]) + (s.y * color_matrix[1][1]) + (s.z * color_matrix[1][2]));
+			d.b = ((s.x * color_matrix[2][0]) + (s.y * color_matrix[2][1]) + (s.z * color_matrix[2][2]));
+			
+			d.r = min (d.r, 1.0);
+			d.r = max (d.r, 0.0);
+			
+			d.g = min (d.g, 1.0);
+			d.g = max (d.g, 0.0);
+			
+			d.b = min (d.b, 1.0);
+			d.b = max (d.b, 0.0);
+			
+			/* Out gamma LUT */
+			*rgba_line++ = lut_out[(int) (d.r * COLOR_DEPTH)];
+			*rgba_line++ = lut_out[(int) (d.g * COLOR_DEPTH)];
+			*rgba_line++ = lut_out[(int) (d.b * COLOR_DEPTH)];
+			*rgba_line++ = 0xff;
+		}
+		
+		rgba += rgba_frame->stride ();
+	}
+	
+	opj_cio_close (cio);
+	opj_image_destroy (xyz_frame);
+
+	return rgba_frame;
+}