lavfi: add opencl tonemap filter

This filter does HDR(HDR10/HLG) to SDR conversion with tone-mapping.

An example command to use this filter with vaapi codecs:
FFMPEG -init_hw_device vaapi=va:/dev/dri/renderD128 -init_hw_device \
opencl=ocl@va -hwaccel vaapi -hwaccel_device va -hwaccel_output_format \
vaapi -i INPUT -filter_hw_device ocl -filter_complex \
'[0:v]hwmap,tonemap_opencl=t=bt2020:tonemap=linear:format=p010[x1]; \
[x1]hwmap=derive_device=vaapi:reverse=1' -c:v hevc_vaapi -profile 2 OUTPUT

Signed-off-by: Ruiling Song <ruiling.song@intel.com>

1 files changed, 90 insertions, 0 deletions

diff --git a/libavfilter/colorspace.c b/libavfilter/colorspace.c
new file mode 100644
index 0000000000..7fd7bdf0d9
--- /dev/null
+++ b/libavfilter/colorspace.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (c) 2016 Ronald S. Bultje <rsbultje@gmail.com>
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "colorspace.h"
+
+
+void invert_matrix3x3(const double in[3][3], double out[3][3])
+{
+    double m00 = in[0][0], m01 = in[0][1], m02 = in[0][2],
+           m10 = in[1][0], m11 = in[1][1], m12 = in[1][2],
+           m20 = in[2][0], m21 = in[2][1], m22 = in[2][2];
+    int i, j;
+    double det;
+
+    out[0][0] =  (m11 * m22 - m21 * m12);
+    out[0][1] = -(m01 * m22 - m21 * m02);
+    out[0][2] =  (m01 * m12 - m11 * m02);
+    out[1][0] = -(m10 * m22 - m20 * m12);
+    out[1][1] =  (m00 * m22 - m20 * m02);
+    out[1][2] = -(m00 * m12 - m10 * m02);
+    out[2][0] =  (m10 * m21 - m20 * m11);
+    out[2][1] = -(m00 * m21 - m20 * m01);
+    out[2][2] =  (m00 * m11 - m10 * m01);
+
+    det = m00 * out[0][0] + m10 * out[0][1] + m20 * out[0][2];
+    det = 1.0 / det;
+
+    for (i = 0; i < 3; i++) {
+        for (j = 0; j < 3; j++)
+            out[i][j] *= det;
+    }
+}
+
+void mul3x3(double dst[3][3], const double src1[3][3], const double src2[3][3])
+{
+    int m, n;
+
+    for (m = 0; m < 3; m++)
+        for (n = 0; n < 3; n++)
+            dst[m][n] = src2[m][0] * src1[0][n] +
+                        src2[m][1] * src1[1][n] +
+                        src2[m][2] * src1[2][n];
+}
+/*
+ * see e.g. http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
+ */
+void fill_rgb2xyz_table(const struct PrimaryCoefficients *coeffs,
+                        const struct WhitepointCoefficients *wp,
+                        double rgb2xyz[3][3])
+{
+    double i[3][3], sr, sg, sb, zw;
+
+    rgb2xyz[0][0] = coeffs->xr / coeffs->yr;
+    rgb2xyz[0][1] = coeffs->xg / coeffs->yg;
+    rgb2xyz[0][2] = coeffs->xb / coeffs->yb;
+    rgb2xyz[1][0] = rgb2xyz[1][1] = rgb2xyz[1][2] = 1.0;
+    rgb2xyz[2][0] = (1.0 - coeffs->xr - coeffs->yr) / coeffs->yr;
+    rgb2xyz[2][1] = (1.0 - coeffs->xg - coeffs->yg) / coeffs->yg;
+    rgb2xyz[2][2] = (1.0 - coeffs->xb - coeffs->yb) / coeffs->yb;
+    invert_matrix3x3(rgb2xyz, i);
+    zw = 1.0 - wp->xw - wp->yw;
+    sr = i[0][0] * wp->xw + i[0][1] * wp->yw + i[0][2] * zw;
+    sg = i[1][0] * wp->xw + i[1][1] * wp->yw + i[1][2] * zw;
+    sb = i[2][0] * wp->xw + i[2][1] * wp->yw + i[2][2] * zw;
+    rgb2xyz[0][0] *= sr;
+    rgb2xyz[0][1] *= sg;
+    rgb2xyz[0][2] *= sb;
+    rgb2xyz[1][0] *= sr;
+    rgb2xyz[1][1] *= sg;
+    rgb2xyz[1][2] *= sb;
+    rgb2xyz[2][0] *= sr;
+    rgb2xyz[2][1] *= sg;
+    rgb2xyz[2][2] *= sb;
+}