Various fixes to XYZ/RGB transforms.

[libdcp.git] / src / rgb_xyz.cc

diff --git a/src/rgb_xyz.cc b/src/rgb_xyz.cc
index 35332fc2baa969d6b728a975ac7ddeeda4103ae8..faddf013a2b4c9ac02c827daaf0b2c6d8e3d0225 100644 (file)
--- a/src/rgb_xyz.cc
+++ b/src/rgb_xyz.cc
@@ -61,8 +61,8 @@ dcp::xyz_to_rgba (
        shared_ptr<ARGBFrame> argb_frame (new ARGBFrame (xyz_frame->size ()));
        uint8_t* argb = argb_frame->data ();
        
-       float const * lut_in = conversion.in()->lut (16);
-       float const * lut_out = conversion.out()->lut (12);
+       double const * lut_in = conversion.in()->lut (16);
+       double const * lut_out = conversion.out()->lut (12);
        boost::numeric::ublas::matrix<double> matrix = conversion.matrix ();
 
        for (int y = 0; y < xyz_frame->size().height; ++y) {
@@ -96,9 +96,9 @@ dcp::xyz_to_rgba (
                        d.b = max (d.b, 0.0);
                        
                        /* Out gamma LUT */
-                       *argb_line++ = lut_out[(int) (d.b * max_colour)] * 0xff;
-                       *argb_line++ = lut_out[(int) (d.g * max_colour)] * 0xff;
-                       *argb_line++ = lut_out[(int) (d.r * max_colour)] * 0xff;
+                       *argb_line++ = lut_out[int(rint(d.b * max_colour))] * 0xff;
+                       *argb_line++ = lut_out[int(rint(d.g * max_colour))] * 0xff;
+                       *argb_line++ = lut_out[int(rint(d.r * max_colour))] * 0xff;
                        *argb_line++ = 0xff;
                }
                
@@ -110,21 +110,18 @@ dcp::xyz_to_rgba (
 
 /** Convert an openjpeg XYZ image to RGB.
  *  @param xyz_frame Frame in XYZ.
- *  @param lut_in Input Gamma LUT to use.
- *  @param lut_out Output Gamma LUT to use.
- *  @param buffer Buffer to write RGB data to; will be written
- *  as one byte R, one byte G, one byte B, one byte R etc. with
- *  no padding at line ends.
+ *  @param conversion Colour conversion to use.
+ *  @param buffer Buffer to write RGB data to; rgb will be packed RGB
+ *  16:16:16, 48bpp, 16R, 16G, 16B, with the 2-byte value for each
+ *  R/G/B component stored as little-endian; i.e. AV_PIX_FMT_RGB48LE.
  */
 void
 dcp::xyz_to_rgb (
        boost::shared_ptr<const XYZFrame> xyz_frame,
        ColourConversion const & conversion,
-       uint8_t* buffer
+       uint16_t* buffer
        )
 {
-       int const max_colour = pow (2, 12) - 1;
-
        struct {
                double x, y, z;
        } s;
@@ -132,21 +129,22 @@ dcp::xyz_to_rgb (
        struct {
                double r, g, b;
        } d;
-       
+
+       /* These should be 12-bit values from 0-4095 */
        int* xyz_x = xyz_frame->data (0);
        int* xyz_y = xyz_frame->data (1);
        int* xyz_z = xyz_frame->data (2);
 
-       float const * lut_in = conversion.in()->lut (16);
-       float const * lut_out = conversion.out()->lut (12);
+       double const * lut_in = conversion.in()->lut (12);
+       double const * lut_out = conversion.out()->lut (16);
        boost::numeric::ublas::matrix<double> matrix = conversion.matrix ();
        
        for (int y = 0; y < xyz_frame->size().height; ++y) {
-               uint8_t* buffer_line = buffer;
+               uint16_t* buffer_line = buffer;
                for (int x = 0; x < xyz_frame->size().width; ++x) {
 
                        DCP_ASSERT (*xyz_x >= 0 && *xyz_y >= 0 && *xyz_z >= 0 && *xyz_x < 4096 && *xyz_y < 4096 && *xyz_z < 4096);
-                       
+
                        /* In gamma LUT */
                        s.x = lut_in[*xyz_x++];
                        s.y = lut_in[*xyz_y++];
@@ -170,11 +168,10 @@ dcp::xyz_to_rgb (
                        
                        d.b = min (d.b, 1.0);
                        d.b = max (d.b, 0.0);
-                       
-                       /* Out gamma LUT */
-                       *buffer_line++ = lut_out[(int) (d.r * max_colour)] * 0xff;
-                       *buffer_line++ = lut_out[(int) (d.g * max_colour)] * 0xff;
-                       *buffer_line++ = lut_out[(int) (d.b * max_colour)] * 0xff;
+
+                       *buffer_line++ = rint(lut_out[int(rint(d.r * 65535))] * 65535);
+                       *buffer_line++ = rint(lut_out[int(rint(d.g * 65535))] * 65535);
+                       *buffer_line++ = rint(lut_out[int(rint(d.b * 65535))] * 65535);
                }
                
                buffer += xyz_frame->size().width * 3;
@@ -200,20 +197,20 @@ dcp::rgb_to_xyz (
                double x, y, z;
        } d;
 
-       float const * lut_in = conversion.in()->lut (12);
-       float const * lut_out = conversion.out()->lut (16);
+       double const * lut_in = conversion.in()->lut (12);
+       double const * lut_out = conversion.out()->lut (16);
        boost::numeric::ublas::matrix<double> matrix = conversion.matrix ();
 
        int jn = 0;
        for (int y = 0; y < rgb->size().height; ++y) {
-               uint16_t* p = reinterpret_cast<uint16_t *> (rgb->data()[0] + y * rgb->stride()[0]);
+               uint16_t* p = rgb->data()[0] + y * rgb->stride()[0] / 2;
                for (int x = 0; x < rgb->size().width; ++x) {
 
                        /* In gamma LUT (converting 16-bit to 12-bit) */
                        s.r = lut_in[*p++ >> 4];
                        s.g = lut_in[*p++ >> 4];
                        s.b = lut_in[*p++ >> 4];
-                       
+
                        /* RGB to XYZ Matrix */
                        d.x = ((s.r * matrix(0, 0)) + (s.g * matrix(0, 1)) + (s.b * matrix(0, 2)));
                        d.y = ((s.r * matrix(1, 0)) + (s.g * matrix(1, 1)) + (s.b * matrix(1, 2)));
@@ -229,9 +226,9 @@ dcp::rgb_to_xyz (
                        DCP_ASSERT (d.z >= 0 && d.z < 65536);
                        
                        /* Out gamma LUT */
-                       xyz->data(0)[jn] = lut_out[(int) d.x] * 4096;
-                       xyz->data(1)[jn] = lut_out[(int) d.y] * 4096;
-                       xyz->data(2)[jn] = lut_out[(int) d.z] * 4096;
+                       xyz->data(0)[jn] = lut_out[int(rint(d.x))] * 4095;
+                       xyz->data(1)[jn] = lut_out[int(rint(d.y))] * 4095;
+                       xyz->data(2)[jn] = lut_out[int(rint(d.z))] * 4095;
 
                        ++jn;
                }
@@ -251,7 +248,7 @@ dcp::xyz_to_xyz (shared_ptr<const Image> xyz_16)
 
        int jn = 0;
        for (int y = 0; y < xyz_16->size().height; ++y) {
-               uint16_t* p = reinterpret_cast<uint16_t *> (xyz_16->data()[0] + y * xyz_16->stride()[0]);
+               uint16_t* p = xyz_16->data()[0] + y * xyz_16->stride()[0] / 2;
                for (int x = 0; x < xyz_16->size().width; ++x) {
                        /* Truncate 16-bit to 12-bit */
                        xyz_12->data(0)[jn] = *p++ >> 4;