From 09b6fee360acb1b0d0ecc4b07a624713cfdc0483 Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Tue, 7 Nov 2023 13:42:38 +1100
Subject: [PATCH] [host] dxgi: fix HDR content downsampling

---
 host/platform/Windows/capture/DXGI/src/dxgi.c | 29 ++++++++++---------
 .../Windows/capture/DXGI/src/pp/downsample.c  |  2 +-
 host/platform/Windows/capture/DXGI/src/util.c | 28 ++++++++++++++++++
 host/platform/Windows/capture/DXGI/src/util.h |  5 ++++
 4 files changed, 49 insertions(+), 15 deletions(-)

diff --git a/host/platform/Windows/capture/DXGI/src/dxgi.c b/host/platform/Windows/capture/DXGI/src/dxgi.c
index f455e451..73a07aea 100644
--- a/host/platform/Windows/capture/DXGI/src/dxgi.c
+++ b/host/platform/Windows/capture/DXGI/src/dxgi.c
@@ -739,28 +739,29 @@ static bool dxgi_init(void)
   if (!initVertexShader())
     goto fail;
 
-  if (!ppInit(&DXGIPP_Downsample,
-      this->backend != &copyBackendD3D11 && !this->hdr))
-  {
-    DEBUG_ERROR("Failed to intiailize the downsample post processor");
-    goto fail;
-  }
-
-  // if HDR add the SDRWhiteLevel post processor to correct the output
+  bool shareable = this->backend != &copyBackendD3D11;
   if (this->hdr)
   {
-    if (!ppInit(&DXGIPP_SDRWhiteLevel, this->backend != &copyBackendD3D11))
+    //HDR content needs to be corrected and converted to HDR10
+    if (!ppInit(&DXGIPP_SDRWhiteLevel, shareable))
     {
       DEBUG_ERROR("Failed to initialize the SDRWhiteLevel post processor");
       goto fail;
     }
   }
-  else
+
+  //Downsampling must happen before conversion to RGB24
+  if (!ppInit(&DXGIPP_Downsample, shareable))
   {
-    // only support DX11 for this atm
-    if (this->backend == &copyBackendD3D11)
-      if (!ppInit(&DXGIPP_RGB24, false))
-        DEBUG_WARN("Failed to initialize the RGB24 post processor");
+    DEBUG_ERROR("Failed to intiailize the downsample post processor");
+    goto fail;
+  }
+
+  //If not HDR, pack to RGB24
+  if (!this->hdr)
+  {
+    if (!ppInit(&DXGIPP_RGB24, shareable))
+      DEBUG_WARN("Failed to initialize the RGB24 post processor");
   }
 
   for (int i = 0; i < LGMP_Q_FRAME_LEN; ++i)
diff --git a/host/platform/Windows/capture/DXGI/src/pp/downsample.c b/host/platform/Windows/capture/DXGI/src/pp/downsample.c
index 6cb0e009..9626517c 100644
--- a/host/platform/Windows/capture/DXGI/src/pp/downsample.c
+++ b/host/platform/Windows/capture/DXGI/src/pp/downsample.c
@@ -171,7 +171,7 @@ static bool downsample_configure(void * opaque,
     .SampleDesc.Count   = 1,
     .SampleDesc.Quality = 0,
     .Usage              = D3D11_USAGE_DEFAULT,
-    .Format             = DXGI_FORMAT_B8G8R8A8_UNORM,
+    .Format             = getDXGIFormat(*format),
     .BindFlags          = D3D11_BIND_RENDER_TARGET |
                           D3D11_BIND_SHADER_RESOURCE,
     .CPUAccessFlags     = 0,
diff --git a/host/platform/Windows/capture/DXGI/src/util.c b/host/platform/Windows/capture/DXGI/src/util.c
index 6036ecb6..bc765513 100644
--- a/host/platform/Windows/capture/DXGI/src/util.c
+++ b/host/platform/Windows/capture/DXGI/src/util.c
@@ -18,6 +18,7 @@
  * Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 
+#include "util.h"
 #include "common/debug.h"
 
 #include <d3d11.h>
@@ -320,3 +321,30 @@ float getSDRWhiteLevel(const DISPLAYCONFIG_PATH_INFO * displayPathInfo)
 
   return nits;
 }
+
+DXGI_FORMAT getDXGIFormat(CaptureFormat format)
+{
+  switch(format)
+  {
+    case CAPTURE_FMT_RGBA:
+      return DXGI_FORMAT_R8G8B8A8_UNORM;
+
+    case CAPTURE_FMT_BGRA:
+      return DXGI_FORMAT_B8G8R8A8_UNORM;
+
+    case CAPTURE_FMT_RGBA10:
+      return DXGI_FORMAT_R10G10B10A2_UNORM;
+
+    case CAPTURE_FMT_RGBA16F:
+      return DXGI_FORMAT_R16G16B16A16_FLOAT;
+
+    case CAPTURE_FMT_BGR:
+      return DXGI_FORMAT_B8G8R8A8_UNORM;
+
+    default:
+      break;
+  }
+
+  DEBUG_ASSERT("Invalid capture format for DXGI");
+  return 0;
+}
diff --git a/host/platform/Windows/capture/DXGI/src/util.h b/host/platform/Windows/capture/DXGI/src/util.h
index 2e23700f..c02d0878 100644
--- a/host/platform/Windows/capture/DXGI/src/util.h
+++ b/host/platform/Windows/capture/DXGI/src/util.h
@@ -19,8 +19,11 @@
  */
 
 #include <windows.h>
+#include <d3dcommon.h>
 #include <dxgi.h>
 
+#include "interface/capture.h"
+
 const char * getDXGIFormatStr(DXGI_FORMAT format);
 const char * getDXGIColorSpaceTypeStr(DXGI_COLOR_SPACE_TYPE type);
 
@@ -30,3 +33,5 @@ bool compileShader(ID3DBlob ** dst, const char * entry, const char * target,
 bool getDisplayPathInfo(HMONITOR monitor, DISPLAYCONFIG_PATH_INFO * info);
 
 float getSDRWhiteLevel(const DISPLAYCONFIG_PATH_INFO * displayPathInfo);
+
+DXGI_FORMAT getDXGIFormat(CaptureFormat format);