Used to test XYZ JPEG2000 output
before his introduction in avscale?
---
 libavfilter/Makefile     |    1 +
 libavfilter/allfilters.c |    1 +
 libavfilter/version.h    |    2 +-
 libavfilter/vf_xyz2rgb.c |  250 ++++++++++++++++++++++++++++++++++++++++++++++
 4 files changed, 253 insertions(+), 1 deletion(-)
 create mode 100644 libavfilter/vf_xyz2rgb.c

diff --git a/libavfilter/Makefile b/libavfilter/Makefile
index 4a3331a..748141d 100644
--- a/libavfilter/Makefile
+++ b/libavfilter/Makefile
@@ -55,6 +55,7 @@ OBJS-$(CONFIG_FPS_FILTER)                    += vf_fps.o
 OBJS-$(CONFIG_FREI0R_FILTER)                 += vf_frei0r.o
 OBJS-$(CONFIG_GRADFUN_FILTER)                += vf_gradfun.o
 OBJS-$(CONFIG_HFLIP_FILTER)                  += vf_hflip.o
+OBJS-$(CONFIG_XYZ2RGB_FILTER)                += vf_xyz2rgb.o
 OBJS-$(CONFIG_HQDN3D_FILTER)                 += vf_hqdn3d.o
 OBJS-$(CONFIG_LUT_FILTER)                    += vf_lut.o
 OBJS-$(CONFIG_LUTRGB_FILTER)                 += vf_lut.o
diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c
index f3ce91c..8c98abb 100644
--- a/libavfilter/allfilters.c
+++ b/libavfilter/allfilters.c
@@ -99,6 +99,7 @@ void avfilter_register_all(void)
     REGISTER_FILTER(VFLIP,          vflip,          vf);
     REGISTER_FILTER(YADIF,          yadif,          vf);
 
+    REGISTER_FILTER(XYZ2RGB,        xyz2rgb,        vf);
     REGISTER_FILTER(COLOR,          color,          vsrc);
     REGISTER_FILTER(FREI0R,         frei0r_src,     vsrc);
     REGISTER_FILTER(MOVIE,          movie,          vsrc);
diff --git a/libavfilter/version.h b/libavfilter/version.h
index a07af2b..1a5ec42 100644
--- a/libavfilter/version.h
+++ b/libavfilter/version.h
@@ -29,7 +29,7 @@
 #include "libavutil/avutil.h"
 
 #define LIBAVFILTER_VERSION_MAJOR  3
-#define LIBAVFILTER_VERSION_MINOR  5
+#define LIBAVFILTER_VERSION_MINOR  6
 #define LIBAVFILTER_VERSION_MICRO  0
 
 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
diff --git a/libavfilter/vf_xyz2rgb.c b/libavfilter/vf_xyz2rgb.c
new file mode 100644
index 0000000..13d2b5e
--- /dev/null
+++ b/libavfilter/vf_xyz2rgb.c
@@ -0,0 +1,250 @@
+/*
+ * XYZ to RGB filter
+ * Copyright (c) 2012 Matthias Buercher
+ * Copyright (c) 2013 Nicolas Bertrand <[email protected]>
+ *
+ * This file is part of Libav.
+ *
+ * Libav is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * Libav 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
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * xyz2rgb filter
+ * Converts from XYZ to RGB space
+ * Useful to convert jpeg2000 files from MXF containers in DCP
+ * The filter has no parameters
+ */
+
+#include <string.h>
+
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/internal.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/imgutils.h"
+
+typedef struct {
+    int xyzgamma[4096];
+    int rgbgamma[4096];
+    int matrix[3][3];
+} XYZ2RGBContext;
+
+static int query_formats(AVFilterContext * ctx)
+{
+    AVFilterFormats *formats;
+    int ret = -1 ;
+
+    if (ctx->inputs[0]) {
+        formats = NULL;
+        ret = ff_add_format(&formats, AV_PIX_FMT_XYZ12);
+        ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
+    }
+    if (ctx->outputs[0]) {
+        formats = NULL;
+        ret = ff_add_format(&formats, AV_PIX_FMT_RGB48);
+        ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
+    }
+    return ret;
+}
+
+/**
+ * The gamma values is precalculated in an array
+ * XYZ uses projector gamma 2.6
+ * sRGB uses gamma 2.2
+ * The gamma function is the inverse power function, calculated in [0..1] and 
scaled to 12 bitdepth [0.4095]
+ * 0.5 is added for rounding
+ *
+ * The matrix multipliers are precalculated and scaled to 12bit bitdepth (4096 
values)
+ * For documentation see 
+ * http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
+ * http://en.wikipedia.org/wiki/SRGB
+*/
+
+static int config_props(AVFilterLink * inlink)
+{
+    XYZ2RGBContext *settings = inlink->dst->priv;
+    int i;
+    double xyzgamma = 2.6;
+    double rgbgamma = 1.0 / 2.2;
+
+    for (i = 0; i < 4096; i++) {
+        settings->xyzgamma[i] =
+            (int) (pow(i / 4095.0, xyzgamma) * 4095.0 + 0.5);
+        settings->rgbgamma[i] =
+            (int) (pow(i / 4095.0, rgbgamma) * 4095.0 + 0.5);
+    }
+
+    settings->matrix[0][0] = (int) (3.2404542 * 4095.0 + 0.5);
+    settings->matrix[0][1] = (int) (-1.5371385 * 4095.0 - 0.5);
+    settings->matrix[0][2] = (int) (-0.4985314 * 4095.0 - 0.5);
+    settings->matrix[1][0] = (int) (-0.9692660 * 4095.0 - 0.5);
+    settings->matrix[1][1] = (int) (1.8760108 * 4095.0 + 0.5);
+    settings->matrix[1][2] = (int) (0.0415560 * 4095.0 + 0.5);
+    settings->matrix[2][0] = (int) (0.0556434 * 4095.0 + 0.5);
+    settings->matrix[2][1] = (int) (-0.2040259 * 4095.0 - 0.5);
+    settings->matrix[2][2] = (int) (1.0572252 * 4095.0 + 0.5);
+    return 0;
+}
+
+static int filter_frame(AVFilterLink * inlink, AVFrame * in)
+{
+    AVFilterLink *outlink = inlink->dst->outputs[0];
+    XYZ2RGBContext *settings = inlink->dst->priv;
+
+    AVFrame *out;
+    uint8_t *inrow, *outrow;
+    int i, j;
+    int r, g, b, x, y, z;
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out) {
+        av_frame_free(&in);
+        return AVERROR(ENOMEM);
+    }
+
+    out->pts = in->pts;
+    inrow = in->data[0];
+    outrow = out->data[0];
+
+    /*
+     * The calculation is separated on input-format RB24 or RGB48LE
+     * In both cases the XYZ-values are scaled to 12bit bitdepth,
+     * then transformed to sRGB and and scaled back to the original bitdepth
+     */
+    for (i = 0; i < inlink->h; i++) {
+        if (inlink->format == AV_PIX_FMT_RGB24) {
+            for (j = 0; j < inlink->w * 3; j += 3) {
+    
+                // scale from 8bit to 12bit
+                x = inrow[j] << 4;
+                y = inrow[j + 1] << 4;
+                z = inrow[j + 2] << 4;
+
+                // convert from XYZ to XYZlinear
+                x = settings->xyzgamma[x];
+                y = settings->xyzgamma[y];
+                z = settings->xyzgamma[z];
+
+                // convert from XYZlinear to sRGBlinear
+                r = settings->matrix[0][0] * x +
+                    settings->matrix[0][1] * y +
+                    settings->matrix[0][2] * z >> 12;
+                g = settings->matrix[1][0] * x +
+                    settings->matrix[1][1] * y +
+                    settings->matrix[1][2] * z >> 12;
+                b = settings->matrix[2][0] * x +
+                    settings->matrix[1][2] * y +
+                    settings->matrix[2][2] * z >> 12;
+
+                // limit values to 12bit legal values [0..0495]
+                if (r > 4095)
+                    r = 4095;
+                if (r < 0)
+                    r = 0;
+                if (g > 4095)
+                    g = 4095;
+                if (g < 0)
+                    g = 0;
+                if (b > 4095)
+                    b = 4095;
+                if (b < 0)
+                    b = 0;
+
+                // convert from sRGBlinear to RGB and scale from 12bit to 8bit
+                r = settings->rgbgamma[r] >> 4; // /16 12bit->8bit
+                g = settings->rgbgamma[g] >> 4;
+                b = settings->rgbgamma[b] >> 4;
+
+                outrow[j]     = (uint8_t) r;
+                outrow[j + 1] = (uint8_t) g;
+                outrow[j + 2] = (uint8_t) b;
+            }
+        } else {                 //  16bits case so XYZ input format
+            for (j = 0; j < inlink->w * 6; j += 6) {
+                // read low endian and scale from 16bit to 12bit
+                x = (inrow[j]     + (inrow[j + 1] << 8)) >> 4;
+                y = (inrow[j + 2] + (inrow[j + 3] << 8)) >> 4;
+                z = (inrow[j + 4] + (inrow[j + 5] << 8)) >> 4;
+
+                // convert from XYZ to XYZlinear
+                x = settings->xyzgamma[x];
+                y = settings->xyzgamma[y];
+                z = settings->xyzgamma[z];
+
+                // convert from XYZlinear to sRGBlinear
+                r = settings->matrix[0][0] * x +
+                    settings->matrix[0][1] * y +
+                    settings->matrix[0][2] * z >> 12;
+                g = settings->matrix[1][0] * x +
+                    settings->matrix[1][1] * y +
+                    settings->matrix[1][2] * z >> 12;
+                b = settings->matrix[2][0] * x +
+                    settings->matrix[1][2] * y +
+                    settings->matrix[2][2] * z >> 12;
+
+                // limit values to 12bit legal values [0..0495]
+                if (r > 4095)
+                    r = 4095;
+                if (r < 0)
+                    r = 0;
+                if (g > 4095)
+                    g = 4095;
+                if (g < 0)
+                    g = 0;
+                if (b > 4095)
+                    b = 4095;
+                if (b < 0)
+                    b = 0;
+
+                // convert from sRGBlinear to RGB and scale from 12bit to 16bit
+                r = settings->rgbgamma[r] << 4;
+                g = settings->rgbgamma[g] << 4;
+                b = settings->rgbgamma[b] << 4;
+
+                // write low endian
+                outrow[j]     = (uint8_t) (r & 255);
+                outrow[j + 1] = (uint8_t) (r >> 8);
+                outrow[j + 2] = (uint8_t) (g & 255);
+                outrow[j + 3] = (uint8_t) (g >> 8);
+                outrow[j + 4] = (uint8_t) (b & 255);
+                outrow[j + 5] = (uint8_t) (b >> 8);
+            }
+        }
+        inrow += in->linesize[0];
+        outrow += out->linesize[0];
+    }
+    av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+}
+
+AVFilter avfilter_vf_xyz2rgb = {
+    .name = "xyz2rgb",
+    .description = NULL_IF_CONFIG_SMALL("Converts XYZ to RGB."),
+    .priv_size = sizeof(XYZ2RGBContext),
+    .query_formats = query_formats,
+    .inputs = (const AVFilterPad[]) {{.name = "default",
+                                      .type = AVMEDIA_TYPE_VIDEO,
+                                      .filter_frame = filter_frame,
+                                      .config_props = config_props,
+                                      .min_perms = AV_PERM_READ,},
+                                     {.name = NULL}},
+    .outputs = (const AVFilterPad[]) {{.name = "default",
+                                       .type = AVMEDIA_TYPE_VIDEO,},
+                                      {.name = NULL}},
+};
-- 
1.7.9.5

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