commit f9062b696444f35c4385d207e6cafbb99ed8828f
author Sasha McIntosh <sashamcintosh@google.com> Tue Nov 12 10:55:06 2024 -0500
committer Sasha McIntosh <sashamcintosh@google.com> Thu Jan 30 23:09:52 2025 -0500
tree b43b33c85597cc83acd2c71e43224d5cd18ec53c
parent f8c14115ec4b02a1af33e90a1ec40f9fe59d8fa8

drm_hwcomposer: Set HDR metadata on the connector

Implement a function to set HDR metadata on the connector. Support HDR10
and HLG, which are common HDR types.

Change-Id: Id3dbe8eea2ee6b8ba700af23845a43e2070dd14e
Signed-off-by: Sasha McIntosh <sashamcintosh@google.com>

hwc2_device/HwcDisplay.cpp

diff --git a/hwc2_device/HwcDisplay.cpp b/hwc2_device/HwcDisplay.cpp
index a0c200e..5abbc4d 100644
--- a/hwc2_device/HwcDisplay.cpp
+++ b/hwc2_device/HwcDisplay.cpp
@@ -24,6 +24,7 @@
 #include <xf86drmMode.h>
 
 #include <hardware/gralloc.h>
+#include <ui/ColorSpace.h>
 #include <ui/GraphicBufferAllocator.h>
 #include <ui/GraphicBufferMapper.h>
 #include <ui/PixelFormat.h>
@@ -39,6 +40,7 @@
 #include "utils/properties.h"
 
 using ::android::DrmDisplayPipeline;
+using ColorGamut = ::android::ColorSpace;
 
 namespace android {
 
@@ -787,6 +789,7 @@
   args.color_matrix = color_matrix_;
   args.content_type = content_type_;
   args.colorspace = colorspace_;
+  args.hdr_metadata = hdr_metadata_;
 
   std::vector<LayerData> composition_layers;
   if (modeset_layer) {
@@ -816,6 +819,7 @@
   a_args.color_matrix = color_matrix_;
   a_args.content_type = content_type_;
   a_args.colorspace = colorspace_;
+  a_args.hdr_metadata = hdr_metadata_;
 
   uint32_t prev_vperiod_ns = 0;
   GetDisplayVsyncPeriod(&prev_vperiod_ns);
@@ -979,6 +983,18 @@
   staged_mode_change_time_ = change_time;
   staged_mode_config_id_ = config;
 
+  std::vector<ui::Hdr> hdr_types;
+  GetEdid()->GetSupportedHdrTypes(hdr_types);
+  if (hdr_types.empty()) {
+    hdr_metadata_.reset();
+    colorspace_ = Colorspace::kDefault;
+  } else {
+    auto ret = SetHdrOutputMetadata(hdr_types.front());
+    if (ret != HWC2::Error::None)
+      return ret;
+    colorspace_ = Colorspace::kBt2020Rgb;
+  }
+
   return HWC2::Error::None;
 }
 
@@ -1246,6 +1262,61 @@
                              (int32_t *)(outVsyncPeriod));
 }
 
+// Display primary values are coded as unsigned 16-bit values in units of
+// 0.00002, where 0x0000 represents zero and 0xC350 represents 1.0000.
+static uint64_t ToU16ColorValue(float in) {
+  constexpr float kPrimariesFixedPoint = 50000.F;
+  return static_cast<uint64_t>(kPrimariesFixedPoint * in);
+}
+
+HWC2::Error HwcDisplay::SetHdrOutputMetadata(ui::Hdr type) {
+  hdr_metadata_ = std::make_shared<hdr_output_metadata>();
+  hdr_metadata_->metadata_type = 0;
+  auto *m = &hdr_metadata_->hdmi_metadata_type1;
+  m->metadata_type = 0;
+
+  switch (type) {
+    case ui::Hdr::HDR10:
+      m->eotf = 2;  // PQ
+      break;
+    case ui::Hdr::HLG:
+      m->eotf = 3;  // HLG
+      break;
+    default:
+      return HWC2::Error::Unsupported;
+  }
+
+  // Most luminance values are coded as an unsigned 16-bit value in units of 1
+  // cd/m2, where 0x0001 represents 1 cd/m2 and 0xFFFF represents 65535 cd/m2.
+  std::vector<ui::Hdr> types;
+  float hdr_luminance[3]{0.F, 0.F, 0.F};
+  GetEdid()->GetHdrCapabilities(types, &hdr_luminance[0], &hdr_luminance[1],
+                                &hdr_luminance[2]);
+  m->max_display_mastering_luminance = m->max_cll = static_cast<uint64_t>(
+      hdr_luminance[0]);
+  m->max_fall = static_cast<uint64_t>(hdr_luminance[1]);
+  // The min luminance value is coded as an unsigned 16-bit value in units of
+  // 0.0001 cd/m2, where 0x0001 represents 0.0001 cd/m2 and 0xFFFF
+  // represents 6.5535 cd/m2.
+  m->min_display_mastering_luminance = static_cast<uint64_t>(hdr_luminance[2] *
+                                                             10000.F);
+
+  auto gamut = ColorGamut::BT2020();
+  auto primaries = gamut.getPrimaries();
+  m->display_primaries[0].x = ToU16ColorValue(primaries[0].x);
+  m->display_primaries[0].y = ToU16ColorValue(primaries[0].y);
+  m->display_primaries[1].x = ToU16ColorValue(primaries[1].x);
+  m->display_primaries[1].y = ToU16ColorValue(primaries[1].y);
+  m->display_primaries[2].x = ToU16ColorValue(primaries[2].x);
+  m->display_primaries[2].y = ToU16ColorValue(primaries[2].y);
+
+  auto whitePoint = gamut.getWhitePoint();
+  m->white_point.x = ToU16ColorValue(whitePoint.x);
+  m->white_point.y = ToU16ColorValue(whitePoint.y);
+
+  return HWC2::Error::None;
+}
+
 #if __ANDROID_API__ > 29
 HWC2::Error HwcDisplay::GetDisplayConnectionType(uint32_t *outType) {
   if (IsInHeadlessMode()) {