vo_gpu_next: add source-dynamic mode to colorspace hint

DOCS/man/options.rst

@@ -7032,7 +7032,7 @@ them.
         best choice. It depends on your compositor, driver, and display
         capabilities. However in most cases ``auto`` mode should work fine.
 
-``--target-colorspace-hint-mode=<target|source>``
+``--target-colorspace-hint-mode=<target|source|source-dynamic>``
     Select which metadata to use for the ``--target-colorspace-hint``.
     (Only for ``--vo=gpu-next``)
 
@@ -7048,6 +7048,13 @@ them.
         and display will handle the colorspace directly and perform any necessary
         mappings.
 
+    source-dynamic
+        The same as ``source``, but uses dynamic per-scene metadata instead of
+        static HDR10. This is experimental and depends on the display's ability
+        to react to metadata changes. Note that this does not send full HDR10+
+        or Dolby Vision metadata, but uses that information to produce HDR10
+        with per-scene luminance values.
+
     Default is ``target``. If target display parameters are not available, this
     will fall back to ``source``. Note that this is done on individual properties
     basis, i.e. it will merge source params into target for unknown properties,

video/out/vo_gpu_next.c

@@ -206,7 +206,7 @@ const struct m_sub_options gl_next_conf = {
         {"image-lut-type", OPT_CHOICE_C(image_lut.type, lut_types)},
         {"target-lut", OPT_STRING(target_lut.opt), .flags = M_OPT_FILE},
         {"target-colorspace-hint", OPT_CHOICE(target_hint, {"auto", -1}, {"no", 0}, {"yes", 1})},
-        {"target-colorspace-hint-mode", OPT_CHOICE(target_hint_mode, {"target", 0}, {"source", 1})},
+        {"target-colorspace-hint-mode", OPT_CHOICE(target_hint_mode, {"target", 0}, {"source", 1}, {"source-dynamic", 2})},
         // No `target-lut-type` because we don't support non-RGB targets
         {"libplacebo-opts", OPT_KEYVALUELIST(raw_opts)},
         {0},
@@ -1068,6 +1068,15 @@ static bool draw_frame(struct vo *vo, struct vo_frame *frame)
         hint = *(p->next_opts->target_hint_mode == 0 ? target : source);
         if (pl_color_transfer_is_hdr(hint.transfer) && !pl_primaries_valid(&hint.hdr.prim))
             pl_color_space_merge(&hint, source);
+        if (p->next_opts->target_hint_mode == 2) { // source-dynamic
+            pl_color_space_nominal_luma_ex(pl_nominal_luma_params(
+                .color      = &hint,
+                .metadata   = PL_HDR_METADATA_ANY,
+                .scaling    = PL_HDR_NITS,
+                .out_min    = &hint.hdr.min_luma,
+                .out_max    = &hint.hdr.max_luma,
+            ));
+        }
         // Infer missing bits now. This is important so that we don't lose
         // information after user option overrides. For example, if the user
         // sets target_trc to PQ, but the hint(source) is SDR, we want to fill