vo_gpu_next: don't set target peak for SDR output transfers

Author: kasper93

video/out/vo_gpu_next.c

@@ -813,6 +813,14 @@ static void apply_target_options(struct priv *p, struct pl_frame *target,
     // If swapchain returned a value use this, override is used in hint
     if (target_peak && !target->color.hdr.max_luma)
         target->color.hdr.max_luma = target_peak;
+    // Don't set a target peak for SDR output. It rarely makes sense. If there's
+    // a use case for it, we likely need separate options for SDR, as the target
+    // peak almost never matches what we have in HDR mode. The exception is inverse
+    // tone mapping mode, in which case we might want to upconvert SDR even
+    // while in SDR mode.
+    if (!pl_color_transfer_is_hdr(target->color.transfer) && !opts->tone_map.inverse)
+        target->color.hdr.max_luma = 0;
+    // Note that we still set min_luma in SDR mode, for bt.1886.
     if (!target->color.hdr.min_luma)
         apply_target_contrast(p, &target->color, min_luma);
     if (opts->target_gamut) {