vo_gpu_next: add --tone-mapping-visualize

DOCS/interface-changes.rst

@@ -54,6 +54,7 @@ Interface changes
     - undeprecate vf_sub
     - add `--tone-mapping=st2094-40` and `--tone-mapping=st2094-10`
     - change `--screenshot-jxl-effort` default from `3` to `4`.
+    - add `--tone-mapping-visualize`
  --- mpv 0.35.0 ---
     - add the `--vo=gpu-next` video output driver, as well as the options
       `--allow-delayed-peak-detect`, `--builtin-scalers`,

DOCS/man/options.rst

@@ -6524,6 +6524,16 @@ them.
         reductions to account for brightness-related perceptual nonuniformity.
         (``--vo=gpu-next`` only)
 
+``--tone-mapping-visualize``
+    Display a (PQ-PQ) graph of the active tone-mapping LUT. Intended only for
+    debugging purposes. The X axis shows PQ input values, the Y axis shows PQ
+    output values. The tone-mapping curve is shown in green/yellow. Yellow
+    means the brightness has been boosted from the source, dark blue regions
+    show where the brightness has been reduced. The extra colored regions and
+    lines indicate various monitor limits, as well a reference diagonal
+    (neutral tone-mapping) and source scene average brightness information (if
+    available). (``--vo=gpu-next`` only)
+
 ``--gamut-mapping-mode``
     Specifies the algorithm used for reducing the gamut of images for the
     target display, after any tone mapping is done.

video/out/gpu/video.c

@@ -399,6 +399,7 @@ const struct m_sub_options gl_video_conf = {
             {"max",         TONE_MAP_MODE_MAX},
             {"hybrid",      TONE_MAP_MODE_HYBRID},
             {"luma",        TONE_MAP_MODE_LUMA})},
+        {"tone-mapping-visualize", OPT_FLAG(tone_map.visualize)},
         {"gamut-mapping-mode", OPT_CHOICE(tone_map.gamut_mode,
             {"auto",        GAMUT_AUTO},
             {"clip",        GAMUT_CLIP},

video/out/gpu/video.h

@@ -130,6 +130,7 @@ struct gl_tone_map_opts {
     float scene_threshold_low;
     float scene_threshold_high;
     int gamut_mode;
+    int visualize;
 };
 
 struct gl_video_opts {

video/out/vo_gpu_next.c

@@ -1878,6 +1878,9 @@ static void update_render_options(struct vo *vo)
         p->color_map.tone_mapping_param = 0.0;
     if (opts->tone_map.gamut_mode != GAMUT_AUTO)
         p->color_map.gamut_mode = gamut_modes[opts->tone_map.gamut_mode];
+#if PL_API_VER >= 247
+    p->color_map.visualize_lut = opts->tone_map.visualize;
+#endif
 
     switch (opts->dither_algo) {
     case DITHER_NONE: