avfilter: add ciescope filter

Signed-off-by: Paul B Mahol <onemda@gmail.com>

1 files changed, 1509 insertions, 0 deletions

diff --git a/libavfilter/vf_ciescope.c b/libavfilter/vf_ciescope.c
new file mode 100644
index 0000000..d693ff7
--- /dev/null
+++ b/libavfilter/vf_ciescope.c
@@ -0,0 +1,1509 @@
+/*
+ * Copyright (c) 2000 John Walker
+ * Copyright (c) 2016 Paul B Mahol
+ *
+ * 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 "libavutil/avassert.h"
+#include "libavutil/intreadwrite.h"
+#include "libavutil/opt.h"
+#include "libavutil/parseutils.h"
+#include "libavutil/pixdesc.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+enum CieSystem {
+    XYY,
+    UCS,
+    LUV,
+    NB_CIE
+};
+
+enum ColorsSystems {
+    NTSCsystem,
+    EBUsystem,
+    SMPTEsystem,
+    SMPTE240Msystem,
+    APPLEsystem,
+    wRGBsystem,
+    CIE1931system,
+    Rec709system,
+    Rec2020system,
+    NB_CS
+};
+
+typedef struct CiescopeContext {
+    const AVClass *class;
+    int color_system;
+    unsigned gamuts;
+    int size;
+    int show_white;
+    int correct_gamma;
+    int cie;
+    float intensity;
+    float contrast;
+    int background;
+
+    double log2lin[65536];
+    double igamma;
+    double i[3][3];
+    double m[3][3];
+    AVFrame *f;
+    void (*filter)(AVFilterContext *ctx, AVFrame *in, double *cx, double *cy, int x, int y);
+} CiescopeContext;
+
+#define OFFSET(x) offsetof(CiescopeContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+
+static const AVOption ciescope_options[] = {
+    { "system",     "set color system", OFFSET(color_system), AV_OPT_TYPE_INT, {.i64=Rec709system}, 0, NB_CS-1, FLAGS, "system" },
+    {   "ntsc",       "NTSC 1953 Y'I'O' (ITU-R BT.470 System M)", 0, AV_OPT_TYPE_CONST, {.i64=NTSCsystem},     0, 0, FLAGS, "system" },
+    {   "470m",       "NTSC 1953 Y'I'O' (ITU-R BT.470 System M)", 0, AV_OPT_TYPE_CONST, {.i64=NTSCsystem},     0, 0, FLAGS, "system" },
+    {   "ebu",        "EBU Y'U'V' (PAL/SECAM) (ITU-R BT.470 System B, G)", 0, AV_OPT_TYPE_CONST, {.i64=EBUsystem},      0, 0, FLAGS, "system" },
+    {   "470bg",      "EBU Y'U'V' (PAL/SECAM) (ITU-R BT.470 System B, G)", 0, AV_OPT_TYPE_CONST, {.i64=EBUsystem},      0, 0, FLAGS, "system" },
+    {   "smpte",      "SMPTE-C RGB",            0, AV_OPT_TYPE_CONST, {.i64=SMPTEsystem},    0, 0, FLAGS, "system" },
+    {   "240m",       "SMPTE-240M Y'PbPr",      0, AV_OPT_TYPE_CONST, {.i64=SMPTE240Msystem},0, 0, FLAGS, "system" },
+    {   "apple",      "Apple RGB",              0, AV_OPT_TYPE_CONST, {.i64=APPLEsystem},    0, 0, FLAGS, "system" },
+    {   "widergb",    "Adobe Wide Gamut RGB",   0, AV_OPT_TYPE_CONST, {.i64=wRGBsystem},     0, 0, FLAGS, "system" },
+    {   "cie1931",    "CIE 1931 RGB",           0, AV_OPT_TYPE_CONST, {.i64=CIE1931system},  0, 0, FLAGS, "system" },
+    {   "hdtv",       "ITU.BT-709 Y'CbCr",      0, AV_OPT_TYPE_CONST, {.i64=Rec709system},   0, 0, FLAGS, "system" },
+    {   "rec709",     "ITU.BT-709 Y'CbCr",      0, AV_OPT_TYPE_CONST, {.i64=Rec709system},   0, 0, FLAGS, "system" },
+    {   "uhdtv",      "ITU-R.BT-2020",          0, AV_OPT_TYPE_CONST, {.i64=Rec2020system},  0, 0, FLAGS, "system" },
+    {   "rec2020",    "ITU-R.BT-2020",          0, AV_OPT_TYPE_CONST, {.i64=Rec2020system},  0, 0, FLAGS, "system" },
+    { "cie",        "set cie system", OFFSET(cie), AV_OPT_TYPE_INT,   {.i64=XYY}, 0, NB_CIE-1, FLAGS, "cie" },
+    {   "xyy",      "CIE 1931 xyY", 0, AV_OPT_TYPE_CONST, {.i64=XYY}, 0, 0, FLAGS, "cie" },
+    {   "ucs",      "CIE 1960 UCS", 0, AV_OPT_TYPE_CONST, {.i64=UCS}, 0, 0, FLAGS, "cie" },
+    {   "luv",      "CIE 1976 Luv", 0, AV_OPT_TYPE_CONST, {.i64=LUV}, 0, 0, FLAGS, "cie" },
+    { "gamuts",     "set what gamuts to draw", OFFSET(gamuts), AV_OPT_TYPE_FLAGS, {.i64=0}, 0, 0xFFF, FLAGS, "gamuts" },
+    {   "ntsc",     NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<NTSCsystem},      0, 0, FLAGS, "gamuts" },
+    {   "470m",     NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<NTSCsystem},      0, 0, FLAGS, "gamuts" },
+    {   "ebu",      NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<EBUsystem},       0, 0, FLAGS, "gamuts" },
+    {   "470bg",    NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<EBUsystem},       0, 0, FLAGS, "gamuts" },
+    {   "smpte",    NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<SMPTEsystem},     0, 0, FLAGS, "gamuts" },
+    {   "240m",     NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<SMPTE240Msystem}, 0, 0, FLAGS, "gamuts" },
+    {   "apple",    NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<APPLEsystem},     0, 0, FLAGS, "gamuts" },
+    {   "widergb",  NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<wRGBsystem},      0, 0, FLAGS, "gamuts" },
+    {   "cie1931",  NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<CIE1931system},   0, 0, FLAGS, "gamuts" },
+    {   "hdtv",     NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<Rec709system},    0, 0, FLAGS, "gamuts" },
+    {   "rec709",   NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<Rec709system},    0, 0, FLAGS, "gamuts" },
+    {   "uhdtv",    NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<Rec2020system},   0, 0, FLAGS, "gamuts" },
+    {   "rec2020",  NULL, 0, AV_OPT_TYPE_CONST, {.i64=1<<Rec2020system},   0, 0, FLAGS, "gamuts" },
+    { "size",       "set ciescope size", OFFSET(size), AV_OPT_TYPE_INT, {.i64=512}, 256, 8192, FLAGS },
+    { "s",          "set ciescope size", OFFSET(size), AV_OPT_TYPE_INT, {.i64=512}, 256, 8192, FLAGS },
+    { "intensity",  "set ciescope intensity", OFFSET(intensity), AV_OPT_TYPE_FLOAT, {.dbl=0.001}, 0, 1, FLAGS },
+    { "i",          "set ciescope intensity", OFFSET(intensity), AV_OPT_TYPE_FLOAT, {.dbl=0.001}, 0, 1, FLAGS },
+    { "contrast",   NULL, OFFSET(contrast), AV_OPT_TYPE_FLOAT, {.dbl=0.75},  0, 1, FLAGS },
+    { "corrgamma",  NULL, OFFSET(correct_gamma), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
+    { "showwhite",  NULL, OFFSET(show_white), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS },
+    { "gamma",      NULL, OFFSET(igamma), AV_OPT_TYPE_DOUBLE, {.dbl=2.6}, 0.1, 6, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(ciescope);
+
+static const enum AVPixelFormat in_pix_fmts[] = {
+    AV_PIX_FMT_RGB24,
+    AV_PIX_FMT_RGBA,
+    AV_PIX_FMT_RGB48,
+    AV_PIX_FMT_RGBA64,
+    AV_PIX_FMT_XYZ12,
+    AV_PIX_FMT_NONE
+};
+
+static const enum AVPixelFormat out_pix_fmts[] = {
+    AV_PIX_FMT_RGBA64,
+    AV_PIX_FMT_NONE
+};
+
+static int query_formats(AVFilterContext *ctx)
+{
+    int ret;
+
+    if ((ret = ff_formats_ref(ff_make_format_list(in_pix_fmts), &ctx->inputs[0]->out_formats)) < 0)
+        return ret;
+
+    if ((ret = ff_formats_ref(ff_make_format_list(out_pix_fmts), &ctx->outputs[0]->in_formats)) < 0)
+        return ret;
+
+    return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    CiescopeContext *s = outlink->src->priv;
+
+    outlink->h = outlink->w = s->size;
+    outlink->sample_aspect_ratio = (AVRational){1,1};
+
+    return 0;
+}
+
+/* A  color  system is defined by the CIE x and y  coordinates of its
+   three primary illuminants and the x and y coordinates of the  white
+   point. */
+
+struct ColorSystem {
+    double xRed, yRed,                /* Red primary illuminant */
+           xGreen, yGreen,            /* Green primary illuminant */
+           xBlue, yBlue,              /* Blue primary illuminant */
+           xWhite, yWhite,            /* White point */
+           gamma;             /* gamma of nonlinear correction */
+};
+
+static float const spectral_chromaticity[][3] = {
+    { 0.175560, 0.005294, 0.819146 },
+    { 0.175483, 0.005286, 0.819231 },
+    { 0.175400, 0.005279, 0.819321 },
+    { 0.175317, 0.005271, 0.819412 },
+    { 0.175237, 0.005263, 0.819500 },
+    { 0.175161, 0.005256, 0.819582 },
+    { 0.175088, 0.005247, 0.819665 },
+    { 0.175015, 0.005236, 0.819749 },
+    { 0.174945, 0.005226, 0.819829 },
+    { 0.174880, 0.005221, 0.819899 },
+    { 0.174821, 0.005221, 0.819959 },
+    { 0.174770, 0.005229, 0.820001 },
+    { 0.174722, 0.005238, 0.820040 },
+    { 0.174665, 0.005236, 0.820098 },
+    { 0.174595, 0.005218, 0.820187 },
+    { 0.174510, 0.005182, 0.820309 },
+    { 0.174409, 0.005127, 0.820464 },
+    { 0.174308, 0.005068, 0.820624 },
+    { 0.174222, 0.005017, 0.820761 },
+    { 0.174156, 0.004981, 0.820863 },
+    { 0.174112, 0.004964, 0.820924 },
+    { 0.174088, 0.004964, 0.820948 },
+    { 0.174073, 0.004973, 0.820955 },
+    { 0.174057, 0.004982, 0.820961 },
+    { 0.174036, 0.004986, 0.820978 },
+    { 0.174008, 0.004981, 0.821012 },
+    { 0.173972, 0.004964, 0.821064 },
+    { 0.173932, 0.004943, 0.821125 },
+    { 0.173889, 0.004926, 0.821185 },
+    { 0.173845, 0.004916, 0.821239 },
+    { 0.173801, 0.004915, 0.821284 },
+    { 0.173754, 0.004925, 0.821321 },
+    { 0.173705, 0.004937, 0.821358 },
+    { 0.173655, 0.004944, 0.821401 },
+    { 0.173606, 0.004940, 0.821454 },
+    { 0.173560, 0.004923, 0.821517 },
+    { 0.173514, 0.004895, 0.821590 },
+    { 0.173468, 0.004865, 0.821667 },
+    { 0.173424, 0.004836, 0.821740 },
+    { 0.173380, 0.004813, 0.821807 },
+    { 0.173337, 0.004797, 0.821866 },
+    { 0.173291, 0.004786, 0.821923 },
+    { 0.173238, 0.004779, 0.821983 },
+    { 0.173174, 0.004775, 0.822051 },
+    { 0.173101, 0.004774, 0.822125 },
+    { 0.173021, 0.004775, 0.822204 },
+    { 0.172934, 0.004781, 0.822285 },
+    { 0.172843, 0.004791, 0.822366 },
+    { 0.172751, 0.004799, 0.822450 },
+    { 0.172662, 0.004802, 0.822536 },
+    { 0.172577, 0.004799, 0.822624 },
+    { 0.172489, 0.004795, 0.822715 },
+    { 0.172396, 0.004796, 0.822808 },
+    { 0.172296, 0.004803, 0.822901 },
+    { 0.172192, 0.004815, 0.822993 },
+    { 0.172087, 0.004833, 0.823081 },
+    { 0.171982, 0.004855, 0.823163 },
+    { 0.171871, 0.004889, 0.823240 },
+    { 0.171741, 0.004939, 0.823319 },
+    { 0.171587, 0.005010, 0.823402 },
+    { 0.171407, 0.005102, 0.823490 },
+    { 0.171206, 0.005211, 0.823583 },
+    { 0.170993, 0.005334, 0.823674 },
+    { 0.170771, 0.005470, 0.823759 },
+    { 0.170541, 0.005621, 0.823838 },
+    { 0.170301, 0.005789, 0.823911 },
+    { 0.170050, 0.005974, 0.823976 },
+    { 0.169786, 0.006177, 0.824037 },
+    { 0.169505, 0.006398, 0.824097 },
+    { 0.169203, 0.006639, 0.824158 },
+    { 0.168878, 0.006900, 0.824222 },
+    { 0.168525, 0.007184, 0.824291 },
+    { 0.168146, 0.007491, 0.824363 },
+    { 0.167746, 0.007821, 0.824433 },
+    { 0.167328, 0.008175, 0.824496 },
+    { 0.166895, 0.008556, 0.824549 },
+    { 0.166446, 0.008964, 0.824589 },
+    { 0.165977, 0.009402, 0.824622 },
+    { 0.165483, 0.009865, 0.824652 },
+    { 0.164963, 0.010351, 0.824687 },
+    { 0.164412, 0.010858, 0.824731 },
+    { 0.163828, 0.011385, 0.824787 },
+    { 0.163210, 0.011937, 0.824853 },
+    { 0.162552, 0.012520, 0.824928 },
+    { 0.161851, 0.013137, 0.825011 },
+    { 0.161105, 0.013793, 0.825102 },
+    { 0.160310, 0.014491, 0.825199 },
+    { 0.159466, 0.015232, 0.825302 },
+    { 0.158573, 0.016015, 0.825412 },
+    { 0.157631, 0.016840, 0.825529 },
+    { 0.156641, 0.017705, 0.825654 },
+    { 0.155605, 0.018609, 0.825786 },
+    { 0.154525, 0.019556, 0.825920 },
+    { 0.153397, 0.020554, 0.826049 },
+    { 0.152219, 0.021612, 0.826169 },
+    { 0.150985, 0.022740, 0.826274 },
+    { 0.149691, 0.023950, 0.826359 },
+    { 0.148337, 0.025247, 0.826416 },
+    { 0.146928, 0.026635, 0.826437 },
+    { 0.145468, 0.028118, 0.826413 },
+    { 0.143960, 0.029703, 0.826337 },
+    { 0.142405, 0.031394, 0.826201 },
+    { 0.140796, 0.033213, 0.825991 },
+    { 0.139121, 0.035201, 0.825679 },
+    { 0.137364, 0.037403, 0.825233 },
+    { 0.135503, 0.039879, 0.824618 },
+    { 0.133509, 0.042692, 0.823798 },
+    { 0.131371, 0.045876, 0.822753 },
+    { 0.129086, 0.049450, 0.821464 },
+    { 0.126662, 0.053426, 0.819912 },
+    { 0.124118, 0.057803, 0.818079 },
+    { 0.121469, 0.062588, 0.815944 },
+    { 0.118701, 0.067830, 0.813468 },
+    { 0.115807, 0.073581, 0.810612 },
+    { 0.112776, 0.079896, 0.807328 },
+    { 0.109594, 0.086843, 0.803563 },
+    { 0.106261, 0.094486, 0.799253 },
+    { 0.102776, 0.102864, 0.794360 },
+    { 0.099128, 0.112007, 0.788865 },
+    { 0.095304, 0.121945, 0.782751 },
+    { 0.091294, 0.132702, 0.776004 },
+    { 0.087082, 0.144317, 0.768601 },
+    { 0.082680, 0.156866, 0.760455 },
+    { 0.078116, 0.170420, 0.751464 },
+    { 0.073437, 0.185032, 0.741531 },
+    { 0.068706, 0.200723, 0.730571 },
+    { 0.063993, 0.217468, 0.718539 },
+    { 0.059316, 0.235254, 0.705430 },
+    { 0.054667, 0.254096, 0.691238 },
+    { 0.050031, 0.274002, 0.675967 },
+    { 0.045391, 0.294976, 0.659633 },
+    { 0.040757, 0.316981, 0.642262 },
+    { 0.036195, 0.339900, 0.623905 },
+    { 0.031756, 0.363598, 0.604646 },
+    { 0.027494, 0.387921, 0.584584 },
+    { 0.023460, 0.412703, 0.563837 },
+    { 0.019705, 0.437756, 0.542539 },
+    { 0.016268, 0.462955, 0.520777 },
+    { 0.013183, 0.488207, 0.498610 },
+    { 0.010476, 0.513404, 0.476120 },
+    { 0.008168, 0.538423, 0.453409 },
+    { 0.006285, 0.563068, 0.430647 },
+    { 0.004875, 0.587116, 0.408008 },
+    { 0.003982, 0.610447, 0.385570 },
+    { 0.003636, 0.633011, 0.363352 },
+    { 0.003859, 0.654823, 0.341318 },
+    { 0.004646, 0.675898, 0.319456 },
+    { 0.006011, 0.696120, 0.297869 },
+    { 0.007988, 0.715342, 0.276670 },
+    { 0.010603, 0.733413, 0.255984 },
+    { 0.013870, 0.750186, 0.235943 },
+    { 0.017766, 0.765612, 0.216622 },
+    { 0.022244, 0.779630, 0.198126 },
+    { 0.027273, 0.792104, 0.180623 },
+    { 0.032820, 0.802926, 0.164254 },
+    { 0.038852, 0.812016, 0.149132 },
+    { 0.045328, 0.819391, 0.135281 },
+    { 0.052177, 0.825164, 0.122660 },
+    { 0.059326, 0.829426, 0.111249 },
+    { 0.066716, 0.832274, 0.101010 },
+    { 0.074302, 0.833803, 0.091894 },
+    { 0.082053, 0.834090, 0.083856 },
+    { 0.089942, 0.833289, 0.076769 },
+    { 0.097940, 0.831593, 0.070468 },
+    { 0.106021, 0.829178, 0.064801 },
+    { 0.114161, 0.826207, 0.059632 },
+    { 0.122347, 0.822770, 0.054882 },
+    { 0.130546, 0.818928, 0.050526 },
+    { 0.138702, 0.814774, 0.046523 },
+    { 0.146773, 0.810395, 0.042832 },
+    { 0.154722, 0.805864, 0.039414 },
+    { 0.162535, 0.801238, 0.036226 },
+    { 0.170237, 0.796519, 0.033244 },
+    { 0.177850, 0.791687, 0.030464 },
+    { 0.185391, 0.786728, 0.027881 },
+    { 0.192876, 0.781629, 0.025495 },
+    { 0.200309, 0.776399, 0.023292 },
+    { 0.207690, 0.771055, 0.021255 },
+    { 0.215030, 0.765595, 0.019375 },
+    { 0.222337, 0.760020, 0.017643 },
+    { 0.229620, 0.754329, 0.016051 },
+    { 0.236885, 0.748524, 0.014591 },
+    { 0.244133, 0.742614, 0.013253 },
+    { 0.251363, 0.736606, 0.012031 },
+    { 0.258578, 0.730507, 0.010916 },
+    { 0.265775, 0.724324, 0.009901 },
+    { 0.272958, 0.718062, 0.008980 },
+    { 0.280129, 0.711725, 0.008146 },
+    { 0.287292, 0.705316, 0.007391 },
+    { 0.294450, 0.698842, 0.006708 },
+    { 0.301604, 0.692308, 0.006088 },
+    { 0.308760, 0.685712, 0.005528 },
+    { 0.315914, 0.679063, 0.005022 },
+    { 0.323066, 0.672367, 0.004566 },
+    { 0.330216, 0.665628, 0.004156 },
+    { 0.337363, 0.658848, 0.003788 },
+    { 0.344513, 0.652028, 0.003459 },
+    { 0.351664, 0.645172, 0.003163 },
+    { 0.358814, 0.638287, 0.002899 },
+    { 0.365959, 0.631379, 0.002662 },
+    { 0.373102, 0.624451, 0.002448 },
+    { 0.380244, 0.617502, 0.002254 },
+    { 0.387379, 0.610542, 0.002079 },
+    { 0.394507, 0.603571, 0.001922 },
+    { 0.401626, 0.596592, 0.001782 },
+    { 0.408736, 0.589607, 0.001657 },
+    { 0.415836, 0.582618, 0.001546 },
+    { 0.422921, 0.575631, 0.001448 },
+    { 0.429989, 0.568649, 0.001362 },
+    { 0.437036, 0.561676, 0.001288 },
+    { 0.444062, 0.554714, 0.001224 },
+    { 0.451065, 0.547766, 0.001169 },
+    { 0.458041, 0.540837, 0.001123 },
+    { 0.464986, 0.533930, 0.001084 },
+    { 0.471899, 0.527051, 0.001051 },
+    { 0.478775, 0.520202, 0.001023 },
+    { 0.485612, 0.513389, 0.001000 },
+    { 0.492405, 0.506615, 0.000980 },
+    { 0.499151, 0.499887, 0.000962 },
+    { 0.505845, 0.493211, 0.000944 },
+    { 0.512486, 0.486591, 0.000923 },
+    { 0.519073, 0.480029, 0.000899 },
+    { 0.525600, 0.473527, 0.000872 },
+    { 0.532066, 0.467091, 0.000843 },
+    { 0.538463, 0.460725, 0.000812 },
+    { 0.544787, 0.454434, 0.000779 },
+    { 0.551031, 0.448225, 0.000744 },
+    { 0.557193, 0.442099, 0.000708 },
+    { 0.563269, 0.436058, 0.000673 },
+    { 0.569257, 0.430102, 0.000641 },
+    { 0.575151, 0.424232, 0.000616 },
+    { 0.580953, 0.418447, 0.000601 },
+    { 0.586650, 0.412758, 0.000591 },
+    { 0.592225, 0.407190, 0.000586 },
+    { 0.597658, 0.401762, 0.000580 },
+    { 0.602933, 0.396497, 0.000571 },
+    { 0.608035, 0.391409, 0.000556 },
+    { 0.612977, 0.386486, 0.000537 },
+    { 0.617779, 0.381706, 0.000516 },
+    { 0.622459, 0.377047, 0.000493 },
+    { 0.627037, 0.372491, 0.000472 },
+    { 0.631521, 0.368026, 0.000453 },
+    { 0.635900, 0.363665, 0.000435 },
+    { 0.640156, 0.359428, 0.000416 },
+    { 0.644273, 0.355331, 0.000396 },
+    { 0.648233, 0.351395, 0.000372 },
+    { 0.652028, 0.347628, 0.000344 },
+    { 0.655669, 0.344018, 0.000313 },
+    { 0.659166, 0.340553, 0.000281 },
+    { 0.662528, 0.337221, 0.000251 },
+    { 0.665764, 0.334011, 0.000226 },
+    { 0.668874, 0.330919, 0.000207 },
+    { 0.671859, 0.327947, 0.000194 },
+    { 0.674720, 0.325095, 0.000185 },
+    { 0.677459, 0.322362, 0.000179 },
+    { 0.680079, 0.319747, 0.000174 },
+    { 0.682582, 0.317249, 0.000170 },
+    { 0.684971, 0.314863, 0.000167 },
+    { 0.687250, 0.312586, 0.000164 },
+    { 0.689426, 0.310414, 0.000160 },
+    { 0.691504, 0.308342, 0.000154 },
+    { 0.693490, 0.306366, 0.000145 },
+    { 0.695389, 0.304479, 0.000133 },
+    { 0.697206, 0.302675, 0.000119 },
+    { 0.698944, 0.300950, 0.000106 },
+    { 0.700606, 0.299301, 0.000093 },
+    { 0.702193, 0.297725, 0.000083 },
+    { 0.703709, 0.296217, 0.000074 },
+    { 0.705163, 0.294770, 0.000067 },
+    { 0.706563, 0.293376, 0.000061 },
+    { 0.707918, 0.292027, 0.000055 },
+    { 0.709231, 0.290719, 0.000050 },
+    { 0.710500, 0.289453, 0.000047 },
+    { 0.711724, 0.288232, 0.000044 },
+    { 0.712901, 0.287057, 0.000041 },
+    { 0.714032, 0.285929, 0.000040 },
+    { 0.715117, 0.284845, 0.000038 },
+    { 0.716159, 0.283804, 0.000036 },
+    { 0.717159, 0.282806, 0.000035 },
+    { 0.718116, 0.281850, 0.000034 },
+    { 0.719033, 0.280935, 0.000032 },
+    { 0.719912, 0.280058, 0.000030 },
+    { 0.720753, 0.279219, 0.000028 },
+    { 0.721555, 0.278420, 0.000026 },
+    { 0.722315, 0.277662, 0.000023 },
+    { 0.723032, 0.276948, 0.000020 },
+    { 0.723702, 0.276282, 0.000016 },
+    { 0.724328, 0.275660, 0.000012 },
+    { 0.724914, 0.275078, 0.000007 },
+    { 0.725467, 0.274530, 0.000003 },
+    { 0.725992, 0.274008, 0.000000 },
+    { 0.726495, 0.273505, 0.000000 },
+    { 0.726975, 0.273025, 0.000000 },
+    { 0.727432, 0.272568, 0.000000 },
+    { 0.727864, 0.272136, 0.000000 },
+    { 0.728272, 0.271728, 0.000000 },
+    { 0.728656, 0.271344, 0.000000 },
+    { 0.729020, 0.270980, 0.000000 },
+    { 0.729361, 0.270639, 0.000000 },
+    { 0.729678, 0.270322, 0.000000 },
+    { 0.729969, 0.270031, 0.000000 },
+    { 0.730234, 0.269766, 0.000000 },
+    { 0.730474, 0.269526, 0.000000 },
+    { 0.730693, 0.269307, 0.000000 },
+    { 0.730896, 0.269104, 0.000000 },
+    { 0.731089, 0.268911, 0.000000 },
+    { 0.731280, 0.268720, 0.000000 },
+    { 0.731467, 0.268533, 0.000000 },
+    { 0.731650, 0.268350, 0.000000 },
+    { 0.731826, 0.268174, 0.000000 },
+    { 0.731993, 0.268007, 0.000000 },
+    { 0.732150, 0.267850, 0.000000 },
+    { 0.732300, 0.267700, 0.000000 },
+    { 0.732443, 0.267557, 0.000000 },
+    { 0.732581, 0.267419, 0.000000 },
+    { 0.732719, 0.267281, 0.000000 },
+    { 0.732859, 0.267141, 0.000000 },
+    { 0.733000, 0.267000, 0.000000 },
+    { 0.733142, 0.266858, 0.000000 },
+    { 0.733281, 0.266719, 0.000000 },
+    { 0.733417, 0.266583, 0.000000 },
+    { 0.733551, 0.266449, 0.000000 },
+    { 0.733683, 0.266317, 0.000000 },
+    { 0.733813, 0.266187, 0.000000 },
+    { 0.733936, 0.266064, 0.000000 },
+    { 0.734047, 0.265953, 0.000000 },
+    { 0.734143, 0.265857, 0.000000 },
+    { 0.734221, 0.265779, 0.000000 },
+    { 0.734286, 0.265714, 0.000000 },
+    { 0.734341, 0.265659, 0.000000 },
+    { 0.734390, 0.265610, 0.000000 },
+    { 0.734438, 0.265562, 0.000000 },
+    { 0.734482, 0.265518, 0.000000 },
+    { 0.734523, 0.265477, 0.000000 },
+    { 0.734560, 0.265440, 0.000000 },
+    { 0.734592, 0.265408, 0.000000 },
+    { 0.734621, 0.265379, 0.000000 },
+    { 0.734649, 0.265351, 0.000000 },
+    { 0.734673, 0.265327, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+    { 0.734690, 0.265310, 0.000000 },
+};
+
+
+/* Standard white point chromaticities. */
+
+#define C     0.310063, 0.316158
+#define E     1.0/3.0, 1.0/3.0
+#define D50   0.34570, 0.3585
+#define D65   0.312713, 0.329016
+
+/* Gamma of nonlinear correction.
+   See Charles Poynton's ColorFAQ Item 45 and GammaFAQ Item 6 at
+   http://www.inforamp.net/~poynton/ColorFAQ.html
+   http://www.inforamp.net/~poynton/GammaFAQ.html
+*/
+
+#define GAMMA_REC709    0.      /* Rec. 709 */
+
+static const struct ColorSystem color_systems[] = {
+    [NTSCsystem] = {
+        0.67,  0.33,  0.21,  0.71,  0.14,  0.08,
+        C, GAMMA_REC709
+    },
+    [EBUsystem] = {
+        0.64,  0.33,  0.29,  0.60,  0.15,  0.06,
+        D65, GAMMA_REC709
+    },
+    [SMPTEsystem] = {
+        0.630, 0.340, 0.310, 0.595, 0.155, 0.070,
+        D65, GAMMA_REC709
+    },
+    [SMPTE240Msystem] = {
+        0.670, 0.330, 0.210, 0.710, 0.150, 0.060,
+        D65, GAMMA_REC709
+    },
+    [APPLEsystem] = {
+        0.625, 0.340, 0.280, 0.595, 0.115, 0.070,
+        D65, GAMMA_REC709
+    },
+    [wRGBsystem] = {
+        0.7347, 0.2653, 0.1152, 0.8264, 0.1566, 0.0177,
+        D50, GAMMA_REC709
+    },
+    [CIE1931system] = {
+        0.7347, 0.2653, 0.2738, 0.7174, 0.1666, 0.0089,
+        E, GAMMA_REC709
+    },
+    [Rec709system] = {
+        0.64,  0.33,  0.30,  0.60,  0.15,  0.06,
+        D65, GAMMA_REC709
+    },
+    [Rec2020system] = {
+        0.708,  0.292,  0.170,  0.797,  0.131,  0.046,
+        D65, GAMMA_REC709
+    },
+};
+
+/*
+static struct ColorSystem CustomSystem = {
+    "Custom",
+    0.64,  0.33,  0.30,  0.60,  0.15,  0.06,
+    D65, GAMMA_REC709
+};
+*/
+
+static void
+uv_to_xy(double   const u,
+         double   const v,
+         double * const xc,
+         double * const yc)
+{
+/*
+    Given 1970 coordinates u, v, determine 1931 chromaticities x, y
+*/
+    *xc = 3*u / (2*u - 8*v + 4);
+    *yc = 2*v / (2*u - 8*v + 4);
+}
+
+static void
+upvp_to_xy(double   const up,
+           double   const vp,
+           double * const xc,
+           double * const yc)
+{
+/*
+    Given 1976 coordinates u', v', determine 1931 chromaticities x, y
+*/
+    *xc = 9*up / (6*up - 16*vp + 12);
+    *yc = 4*vp / (6*up - 16*vp + 12);
+}
+
+static void
+xy_to_upvp(double xc,
+           double yc,
+           double * const up,
+           double * const vp)
+{
+/*
+    Given 1931 chromaticities x, y, determine 1976 coordinates u', v'
+*/
+    *up = 4*xc / (- 2*xc + 12*yc + 3);
+    *vp = 9*yc / (- 2*xc + 12*yc + 3);
+}
+
+static void
+xy_to_uv(double xc,
+         double yc,
+         double * const u,
+         double * const v)
+{
+/*
+    Given 1931 chromaticities x, y, determine 1960 coordinates u, v
+*/
+    *u = 4*xc / (- 2*xc + 12*yc + 3);
+    *v = 6*yc / (- 2*xc + 12*yc + 3);
+}
+
+static void
+xyz_to_rgb(const double m[3][3],
+           double xc, double yc, double zc,
+           double * const r, double * const g, double * const b)
+{
+    *r = m[0][0]*xc + m[0][1]*yc + m[0][2]*zc;
+    *g = m[1][0]*xc + m[1][1]*yc + m[1][2]*zc;
+    *b = m[2][0]*xc + m[2][1]*yc + m[2][2]*zc;
+}
+
+static void invert_matrix3x3(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;
+
+    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);
+
+    double 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;
+    }
+}
+
+static void get_rgb2xyz_matrix(struct ColorSystem system, double m[3][3])
+{
+    double S[3], X[4], Z[4];
+    int i;
+
+    X[0] = system.xRed   / system.yRed;
+    X[1] = system.xGreen / system.yGreen;
+    X[2] = system.xBlue  / system.yBlue;
+    X[3] = system.xWhite / system.yWhite;
+
+    Z[0] = (1 - system.xRed   - system.yRed)   / system.yRed;
+    Z[1] = (1 - system.xGreen - system.yGreen) / system.yGreen;
+    Z[2] = (1 - system.xBlue  - system.yBlue)  / system.yBlue;
+    Z[3] = (1 - system.xWhite - system.yWhite) / system.yWhite;
+
+    for (i = 0; i < 3; i++) {
+        m[0][i] = X[i];
+        m[1][i] = 1;
+        m[2][i] = Z[i];
+    }
+
+    invert_matrix3x3(m, m);
+
+    for (i = 0; i < 3; i++)
+        S[i] = m[i][0] * X[3] + m[i][1] * 1 + m[i][2] * Z[3];
+
+    for (i = 0; i < 3; i++) {
+        m[0][i] = S[i] * X[i];
+        m[1][i] = S[i] * 1;
+        m[2][i] = S[i] * Z[i];
+    }
+}
+
+static void
+rgb_to_xy(double rc,
+          double gc,
+          double bc,
+          double * const x,
+          double * const y,
+          double * const z,
+          const double m[3][3])
+{
+    double sum;
+
+    *x = m[0][0] * rc + m[0][1] * gc + m[0][2] * bc;
+    *y = m[1][0] * rc + m[1][1] * gc + m[1][2] * bc;
+    *z = m[2][0] * rc + m[2][1] * gc + m[2][2] * bc;
+
+    sum = *x + *y + *z;
+
+    *x = *x / sum;
+    *y = *y / sum;
+}
+
+static int
+constrain_rgb(double * const r,
+              double * const g,
+              double * const b)
+{
+/*----------------------------------------------------------------------------
+    If  the  requested RGB shade contains a negative weight for one of
+    the primaries, it lies outside the color  gamut  accessible  from
+    the  given  triple  of  primaries.  Desaturate it by adding white,
+    equal quantities of R, G, and B, enough to make RGB all positive.
+-----------------------------------------------------------------------------*/
+    double w;
+
+    /* Amount of white needed is w = - min(0, *r, *g, *b) */
+    w = (0 < *r) ? 0 : *r;
+    w = (w < *g) ? w : *g;
+    w = (w < *b) ? w : *b;
+    w = - w;
+
+    /* Add just enough white to make r, g, b all positive. */
+    if (w > 0) {
+        *r += w;  *g += w; *b += w;
+
+        return 1;                     /* Color modified to fit RGB gamut */
+    }
+
+    return 0;                         /* Color within RGB gamut */
+}
+
+static void
+gamma_correct(const struct ColorSystem * const cs,
+              double *                   const c)
+{
+/*----------------------------------------------------------------------------
+    Transform linear RGB values to nonlinear RGB values.
+
+    Rec. 709 is ITU-R Recommendation BT. 709 (1990)
+    ``Basic Parameter Values for the HDTV Standard for the Studio and for
+    International Programme Exchange'', formerly CCIR Rec. 709.
+
+    For details see
+       http://www.inforamp.net/~poynton/ColorFAQ.html
+       http://www.inforamp.net/~poynton/GammaFAQ.html
+-----------------------------------------------------------------------------*/
+    double gamma;
+    double cc;
+
+    gamma = cs->gamma;
+
+    if (gamma == 0.) {
+        /* Rec. 709 gamma correction. */
+        cc = 0.018;
+        if (*c < cc) {
+            *c *= (1.099 * pow(cc, 0.45) - 0.099) / cc;
+        } else {
+            *c = 1.099 * pow(*c, 0.45) - 0.099;
+        }
+    } else {
+    /* Nonlinear color = (Linear color)^(1/gamma) */
+        *c = pow(*c, 1./gamma);
+    }
+}
+
+
+
+static void
+gamma_correct_rgb(const struct ColorSystem * const cs,
+                  double * const r,
+                  double * const g,
+                  double * const b)
+{
+    gamma_correct(cs, r);
+    gamma_correct(cs, g);
+    gamma_correct(cs, b);
+}
+
+/* Sz(X) is the displacement in pixels of a displacement of X normalized
+   distance units.  (A normalized distance unit is 1/512 of the smaller
+   dimension of the canvas)
+*/
+#define Sz(x) (((x) * (int)FFMIN(w, h)) / 512)
+
+static void
+monochrome_color_location(double waveLength, int w, int h,
+                          int cie, int *xP, int *yP)
+{
+    const int ix = waveLength - 360;
+    const double pX = spectral_chromaticity[ix][0];
+    const double pY = spectral_chromaticity[ix][1];
+    const double pZ = spectral_chromaticity[ix][2];
+    const double px = pX / (pX + pY + pZ);
+    const double py = pY / (pX + pY + pZ);
+
+    if (cie == LUV) {
+        double up, vp;
+
+        xy_to_upvp(px, py, &up, &vp);
+        *xP = up * (w - 1);
+        *yP = (h - 1) - vp * (h - 1);
+    } else if (cie == UCS) {
+        double u, v;
+
+        xy_to_uv(px, py, &u, &v);
+        *xP = u * (w - 1);
+        *yP = (h - 1) - v * (h - 1);
+    } else if (cie == XYY) {
+        *xP = px * (w - 1);
+        *yP = (h - 1) - py * (h - 1);
+    } else {
+        av_assert0(0);
+    }
+}
+
+static void
+find_tongue(uint16_t* const pixels,
+            int       const w,
+            int       const linesize,
+            int       const row,
+            int *     const presentP,
+            int *     const leftEdgeP,
+            int *     const rightEdgeP)
+{
+    int i;
+
+    for (i = 0; i < w && pixels[row * linesize + i * 4 + 0] == 0; i++)
+        ;
+
+    if (i >= w) {
+        *presentP = 0;
+    } else {
+        int j;
+        int const leftEdge = i;
+
+        *presentP = 1;
+
+        for (j = w - 1; j >= leftEdge && pixels[row * linesize + j * 4 + 0] == 0; j--)
+            ;
+
+        *rightEdgeP = j;
+        *leftEdgeP = leftEdge;
+    }
+}
+
+static void draw_line(uint16_t *const pixels, int linesize,
+                      int x0, int y0, int x1, int y1,
+                      int w, int h,
+                      const uint16_t *const rgbcolor)
+{
+    int dx  = FFABS(x1 - x0), sx = x0 < x1 ? 1 : -1;
+    int dy  = FFABS(y1 - y0), sy = y0 < y1 ? 1 : -1;
+    int err = (dx > dy ? dx : -dy) / 2, e2;
+
+    for (;;) {
+        pixels[y0 * linesize + x0 * 4 + 0] = rgbcolor[0];
+        pixels[y0 * linesize + x0 * 4 + 1] = rgbcolor[1];
+        pixels[y0 * linesize + x0 * 4 + 2] = rgbcolor[2];
+        pixels[y0 * linesize + x0 * 4 + 3] = rgbcolor[3];
+
+        if (x0 == x1 && y0 == y1)
+            break;
+
+        e2 = err;
+
+        if (e2 >-dx) {
+            err -= dy;
+            x0 += sx;
+        }
+
+        if (e2 < dy) {
+            err += dx;
+            y0 += sy;
+        }
+    }
+}
+
+static void draw_rline(uint16_t *const pixels, int linesize,
+                       int x0, int y0, int x1, int y1,
+                       int w, int h)
+{
+    int dx  = FFABS(x1 - x0), sx = x0 < x1 ? 1 : -1;
+    int dy  = FFABS(y1 - y0), sy = y0 < y1 ? 1 : -1;
+    int err = (dx > dy ? dx : -dy) / 2, e2;
+
+    for (;;) {
+        pixels[y0 * linesize + x0 * 4 + 0] = 65535 - pixels[y0 * linesize + x0 * 4 + 0];
+        pixels[y0 * linesize + x0 * 4 + 1] = 65535 - pixels[y0 * linesize + x0 * 4 + 1];
+        pixels[y0 * linesize + x0 * 4 + 2] = 65535 - pixels[y0 * linesize + x0 * 4 + 2];
+        pixels[y0 * linesize + x0 * 4 + 3] = 65535;
+
+        if (x0 == x1 && y0 == y1)
+            break;
+
+        e2 = err;
+
+        if (e2 >-dx) {
+            err -= dy;
+            x0 += sx;
+        }
+
+        if (e2 < dy) {
+            err += dx;
+            y0 += sy;
+        }
+    }
+}
+
+static void
+tongue_outline(uint16_t* const pixels,
+               int       const linesize,
+               int       const w,
+               int       const h,
+               uint16_t  const maxval,
+               int       const cie)
+{
+    const uint16_t rgbcolor[4] = { maxval, maxval, maxval, maxval };
+    int wavelength;
+    int lx, ly;
+    int fx, fy;
+
+    for (wavelength = 360; wavelength <= 830; wavelength++) {
+        int icx, icy;
+
+        monochrome_color_location(wavelength, w, h, cie,
+                                  &icx, &icy);
+
+        if (wavelength > 360)
+            draw_line(pixels, linesize, lx, ly, icx, icy, w, h, rgbcolor);
+        else {
+            fx = icx;
+            fy = icy;
+        }
+        lx = icx;
+        ly = icy;
+    }
+    draw_line(pixels, linesize, lx, ly, fx, fy, w, h, rgbcolor);
+}
+
+static void
+fill_in_tongue(uint16_t*                  const pixels,
+               int                        const linesize,
+               int                        const w,
+               int                        const h,
+               uint16_t                   const maxval,
+               const struct ColorSystem * const cs,
+               double                     const m[3][3],
+               int                        const cie,
+               int                        const correct_gamma,
+               float                      const contrast)
+{
+    int y;
+
+    /* Scan the image line by line and  fill  the  tongue  outline
+       with the RGB values determined by the color system for the x-y
+       co-ordinates within the tongue.
+    */
+
+    for (y = 0; y < h; ++y) {
+        int  present;  /* There is some tongue on this line */
+        int leftEdge; /* x position of leftmost pixel in tongue on this line */
+        int rightEdge; /* same, but rightmost */
+
+        find_tongue(pixels, w, linesize, y, &present, &leftEdge, &rightEdge);
+
+        if (present) {
+            int x;
+
+            for (x = leftEdge; x <= rightEdge; ++x) {
+                double cx, cy, cz, jr, jg, jb, jmax;
+                int r, g, b, mx = maxval;
+
+                if (cie == LUV) {
+                    double up, vp;
+                    up = ((double) x) / (w - 1);
+                    vp = 1.0 - ((double) y) / (h - 1);
+                    upvp_to_xy(up, vp, &cx, &cy);
+                    cz = 1.0 - (cx + cy);
+                } else if (cie == UCS) {
+                    double u, v;
+                    u = ((double) x) / (w - 1);
+                    v = 1.0 - ((double) y) / (h - 1);
+                    uv_to_xy(u, v, &cx, &cy);
+                    cz = 1.0 - (cx + cy);
+                } else if (cie == XYY) {
+                    cx = ((double) x) / (w - 1);
+                    cy = 1.0 - ((double) y) / (h - 1);
+                    cz = 1.0 - (cx + cy);
+                } else {
+                    av_assert0(0);
+                }
+
+                xyz_to_rgb(m, cx, cy, cz, &jr, &jg, &jb);
+
+                /* Check whether the requested color  is  within  the
+                   gamut  achievable with the given color system.  If
+                   not, draw it in a reduced  intensity,  interpolated
+                   by desaturation to the closest within-gamut color. */
+
+                if (constrain_rgb(&jr, &jg, &jb))
+                    mx *= contrast;
+
+                jmax = FFMAX3(jr, jg, jb);
+                if (jmax > 0) {
+                    jr = jr / jmax;
+                    jg = jg / jmax;
+                    jb = jb / jmax;
+                }
+                /* gamma correct from linear rgb to nonlinear rgb. */
+                if (correct_gamma)
+                    gamma_correct_rgb(cs, &jr, &jg, &jb);
+                r = mx * jr;
+                g = mx * jg;
+                b = mx * jb;
+                pixels[y * linesize + x * 4 + 0] = r;
+                pixels[y * linesize + x * 4 + 1] = g;
+                pixels[y * linesize + x * 4 + 2] = b;
+                pixels[y * linesize + x * 4 + 3] = 65535;
+            }
+        }
+    }
+}
+
+static void
+plot_white_point(uint16_t*      pixels,
+                 int      const linesize,
+                 int      const w,
+                 int      const h,
+                 int      const maxval,
+                 int      const color_system,
+                 int      const cie)
+{
+    const struct ColorSystem *cs = &color_systems[color_system];
+    int wx, wy;
+
+    if (cie == LUV) {
+        double wup, wvp;
+        xy_to_upvp(cs->xWhite, cs->yWhite, &wup, &wvp);
+        wx = wup;
+        wy = wvp;
+        wx = (w - 1) * wup;
+        wy = (h - 1) - ((int) ((h - 1) * wvp));
+    } else if (cie == UCS) {
+        double wu, wv;
+        xy_to_uv(cs->xWhite, cs->yWhite, &wu, &wv);
+        wx = wu;
+        wy = wv;
+        wx = (w - 1) * wu;
+        wy = (h - 1) - ((int) ((h - 1) * wv));
+    } else if (cie == XYY) {
+        wx = (w - 1) * cs->xWhite;
+        wy = (h - 1) - ((int) ((h - 1) * cs->yWhite));
+    } else {
+        av_assert0(0);
+    }
+
+    draw_rline(pixels, linesize,
+               wx + Sz(3), wy, wx + Sz(10), wy,
+               w, h);
+    draw_rline(pixels, linesize,
+               wx - Sz(3), wy, wx - Sz(10), wy,
+               w, h);
+    draw_rline(pixels, linesize,
+               wx, wy + Sz(3), wx, wy + Sz(10),
+               w, h);
+    draw_rline(pixels, linesize,
+               wx, wy - Sz(3), wx, wy - Sz(10),
+               w, h);
+}
+
+static int draw_background(AVFilterContext *ctx)
+{
+    CiescopeContext *s = ctx->priv;
+    const struct ColorSystem *cs = &color_systems[s->color_system];
+    AVFilterLink *outlink = ctx->outputs[0];
+    int w = s->size;
+    int h = s->size;
+    uint16_t *pixels;
+
+    if ((s->f = ff_get_video_buffer(outlink, outlink->w, outlink->h)) == NULL)
+        return AVERROR(ENOMEM);
+    pixels = (uint16_t *)s->f->data[0];
+
+    tongue_outline(pixels, s->f->linesize[0] / 2, w, h, 65535, s->cie);
+
+    fill_in_tongue(pixels, s->f->linesize[0] / 2, w, h, 65535, cs, s->i, s->cie,
+                   s->correct_gamma, s->contrast);
+
+    return 0;
+}
+
+static void filter_rgb48(AVFilterContext *ctx, AVFrame *in, double *cx, double *cy, int x, int y)
+{
+    CiescopeContext *s = ctx->priv;
+    const uint16_t* src = (const uint16_t*)(in->data[0] + in->linesize[0] * y + x * 6);
+    double r = src[0] / 65535.;
+    double g = src[1] / 65535.;
+    double b = src[2] / 65535.;
+    double cz;
+
+    rgb_to_xy(r, g, b, cx, cy, &cz, s->m);
+}
+
+static void filter_rgba64(AVFilterContext *ctx, AVFrame *in, double *cx, double *cy, int x, int y)
+{
+    CiescopeContext *s = ctx->priv;
+    const uint16_t* src = (const uint16_t*)(in->data[0] + in->linesize[0] * y + x * 8);
+    double r = src[0] / 65535.;
+    double g = src[1] / 65535.;
+    double b = src[2] / 65535.;
+    double cz;
+
+    rgb_to_xy(r, g, b, cx, cy, &cz, s->m);
+}
+
+static void filter_rgb24(AVFilterContext *ctx, AVFrame *in, double *cx, double *cy, int x, int y)
+{
+    CiescopeContext *s = ctx->priv;
+    const uint8_t* src = in->data[0] + in->linesize[0] * y + x * 3;
+    double r = src[0] / 255.;
+    double g = src[1] / 255.;
+    double b = src[2] / 255.;
+    double cz;
+
+    rgb_to_xy(r, g, b, cx, cy, &cz, s->m);
+}
+
+static void filter_rgba(AVFilterContext *ctx, AVFrame *in, double *cx, double *cy, int x, int y)
+{
+    CiescopeContext *s = ctx->priv;
+    const uint8_t* src = in->data[0] + in->linesize[0] * y + x * 4;
+    double r = src[0] / 255.;
+    double g = src[1] / 255.;
+    double b = src[2] / 255.;
+    double cz;
+
+    rgb_to_xy(r, g, b, cx, cy, &cz, s->m);
+}
+
+static void filter_xyz(AVFilterContext *ctx, AVFrame *in, double *cx, double *cy, int x, int y)
+{
+    CiescopeContext *s = ctx->priv;
+    const uint16_t* src = (uint16_t *)(in->data[0] + in->linesize[0] * y + x * 6);
+    double lx = s->log2lin[src[0]];
+    double ly = s->log2lin[src[1]];
+    double lz = s->log2lin[src[2]];
+    double sum = lx + ly + lz;
+
+    if (sum == 0)
+        sum = 1;
+    *cx = lx / sum;
+    *cy = ly / sum;
+}
+
+static void plot_gamuts(uint16_t *pixels, int linesize, int w, int h,
+                        int cie, int gamuts)
+{
+    int i;
+
+    for (i = 0; i < NB_CS; i++) {
+        const struct ColorSystem *cs = &color_systems[i];
+        int rx, ry, gx, gy, bx, by;
+
+        if (!((1 << i) & gamuts))
+            continue;
+        if (cie == LUV) {
+            double wup, wvp;
+            xy_to_upvp(cs->xRed, cs->yRed, &wup, &wvp);
+            rx = (w - 1) * wup;
+            ry = (h - 1) - ((int) ((h - 1) * wvp));
+            xy_to_upvp(cs->xGreen, cs->yGreen, &wup, &wvp);
+            gx = (w - 1) * wup;
+            gy = (h - 1) - ((int) ((h - 1) * wvp));
+            xy_to_upvp(cs->xBlue, cs->yBlue, &wup, &wvp);
+            bx = (w - 1) * wup;
+            by = (h - 1) - ((int) ((h - 1) * wvp));
+        } else if (cie == UCS) {
+            double wu, wv;
+            xy_to_uv(cs->xRed, cs->yRed, &wu, &wv);
+            rx = (w - 1) * wu;
+            ry = (h - 1) - ((int) ((h - 1) * wv));
+            xy_to_uv(cs->xGreen, cs->yGreen, &wu, &wv);
+            gx = (w - 1) * wu;
+            gy = (h - 1) - ((int) ((h - 1) * wv));
+            xy_to_uv(cs->xBlue, cs->yBlue, &wu, &wv);
+            bx = (w - 1) * wu;
+            by = (h - 1) - ((int) ((h - 1) * wv));
+        } else if (cie == XYY) {
+            rx = (w - 1) * cs->xRed;
+            ry = (h - 1) - ((int) ((h - 1) * cs->yRed));
+            gx = (w - 1) * cs->xGreen;
+            gy = (h - 1) - ((int) ((h - 1) * cs->yGreen));
+            bx = (w - 1) * cs->xBlue;
+            by = (h - 1) - ((int) ((h - 1) * cs->yBlue));
+        } else {
+            av_assert0(0);
+        }
+
+        draw_rline(pixels, linesize, rx, ry, gx, gy, w, h);
+        draw_rline(pixels, linesize, gx, gy, bx, by, w, h);
+        draw_rline(pixels, linesize, bx, by, rx, ry, w, h);
+    }
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    AVFilterContext *ctx  = inlink->dst;
+    CiescopeContext *s = ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[0];
+    int i = s->intensity * 65535;
+    int w = outlink->w;
+    int h = outlink->h;
+    AVFrame *out;
+    int ret, x, y;
+
+    out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
+    if (!out) {
+        av_frame_free(&in);
+        return AVERROR(ENOMEM);
+    }
+    out->pts = in->pts;
+
+    if (!s->background) {
+        ret = draw_background(ctx);
+        if (ret < 0)
+            return ret;
+        s->background = 1;
+    }
+    for (y = 0; y < outlink->h; y++) {
+        memset(out->data[0] + y * out->linesize[0], 0, outlink->w * 8);
+    }
+
+    for (y = 0; y < in->height; y++) {
+        for (x = 0; x < in->width; x++) {
+            double cx, cy;
+            uint16_t *dst;
+            int wx, wy;
+
+            s->filter(ctx, in, &cx, &cy, x, y);
+
+            if (s->cie == LUV) {
+                double up, vp;
+                xy_to_upvp(cx, cy, &up, &vp);
+                cx = up;
+                cy = vp;
+            } else if (s->cie == UCS) {
+                double u, v;
+                xy_to_uv(cx, cy, &u, &v);
+                cx = u;
+                cy = v;
+            }
+
+            wx = (w - 1) * cx;
+            wy = (h - 1) - ((h - 1) * cy);
+
+            if (wx < 0 || wx >= w ||
+                wy < 0 || wy >= h)
+                continue;
+
+            dst = (uint16_t *)(out->data[0] + wy * out->linesize[0] + wx * 8 + 0);
+            dst[0] = FFMIN(dst[0] + i, 65535);
+            dst[1] = FFMIN(dst[1] + i, 65535);
+            dst[2] = FFMIN(dst[2] + i, 65535);
+            dst[3] = 65535;
+        }
+    }
+
+    for (y = 0; y < outlink->h; y++) {
+        uint16_t *dst = (uint16_t *)(out->data[0] + y * out->linesize[0]);
+        const uint16_t *src = (const uint16_t *)(s->f->data[0] + y * s->f->linesize[0]);
+        for (x = 0; x < outlink->w; x++) {
+            const int xx = x * 4;
+            if (dst[xx + 3] == 0) {
+                dst[xx + 0] = src[xx + 0];
+                dst[xx + 1] = src[xx + 1];
+                dst[xx + 2] = src[xx + 2];
+                dst[xx + 3] = src[xx + 3];
+            }
+        }
+    }
+
+    if (s->show_white)
+        plot_white_point((uint16_t *)out->data[0], out->linesize[0] / 2,
+                         outlink->w, outlink->h, 65535,
+                         s->color_system, s->cie);
+
+    plot_gamuts((uint16_t *)out->data[0], out->linesize[0] / 2,
+                outlink->w, outlink->h,
+                s->cie, s->gamuts);
+
+    av_frame_free(&in);
+    return ff_filter_frame(outlink, out);
+}
+
+static void av_cold uninit(AVFilterContext *ctx)
+{
+    CiescopeContext *s = ctx->priv;
+
+    av_frame_free(&s->f);
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+    CiescopeContext *s = inlink->dst->priv;
+    int i;
+
+    get_rgb2xyz_matrix(color_systems[s->color_system], s->m);
+    invert_matrix3x3(s->m, s->i);
+
+    switch (inlink->format) {
+    case AV_PIX_FMT_RGB24:
+        s->filter = filter_rgb24;
+        break;
+    case AV_PIX_FMT_RGBA:
+        s->filter = filter_rgba;
+        break;
+    case AV_PIX_FMT_RGB48:
+        s->filter = filter_rgb48;
+        break;
+    case AV_PIX_FMT_RGBA64:
+        s->filter = filter_rgba64;
+        break;
+    case AV_PIX_FMT_XYZ12:
+        s->filter = filter_xyz;
+        for (i = 0; i < 65536; i++)
+            s->log2lin[i] = pow(i / 65535., s->igamma) * 65535.;
+        break;
+    default:
+        av_assert0(0);
+    }
+
+    return 0;
+}
+
+static const AVFilterPad inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+        .config_props = config_input,
+    },
+    { NULL }
+};
+
+static const AVFilterPad outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_output,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_ciescope = {
+    .name          = "ciescope",
+    .description   = NULL_IF_CONFIG_SMALL("Video CIE scope."),
+    .priv_size     = sizeof(CiescopeContext),
+    .priv_class    = &ciescope_class,
+    .query_formats = query_formats,
+    .uninit        = uninit,
+    .inputs        = inputs,
+    .outputs       = outputs,
+};