From 3fb8caf63572fbe0421bcccb015fb3efde05b6f9 Mon Sep 17 00:00:00 2001
From: Seungha Yang <seungha@centricular.com>
Date: Fri, 31 Jul 2020 03:46:39 +0900
Subject: [PATCH] mfvideosrc: Handle I420/IYUV subtypes for UWP cases

Microsoft defines two I420 formats, one is I420, and the other is
IYUV (but both are same, just names are different).
Since both will be converted to GST_VIDEO_FORMAT_I420,
we should check both I420 and IYUV subtypes during
GstVideoFormat to Microsoft's format conversion.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/1478>
---
 sys/mediafoundation/mediacapturewrapper.cpp | 26 ++++++++++++++++-----
 1 file changed, 20 insertions(+), 6 deletions(-)

diff --git a/sys/mediafoundation/mediacapturewrapper.cpp b/sys/mediafoundation/mediacapturewrapper.cpp
index 6023c987b9..657673a416 100644
--- a/sys/mediafoundation/mediacapturewrapper.cpp
+++ b/sys/mediafoundation/mediacapturewrapper.cpp
@@ -74,7 +74,8 @@ gst_media_capture_subtype_to_video_format (const std::string &subtype)
     return "NV12";
   else if (g_ascii_strcasecmp (subtype.c_str(), "YV12") == 0)
     return "YV12";
-  else if (g_ascii_strcasecmp (subtype.c_str(), "IYUV") == 0)
+  else if (g_ascii_strcasecmp (subtype.c_str(), "IYUV") == 0 ||
+           g_ascii_strcasecmp (subtype.c_str(), "I420") == 0)
     return "I420";
   else if (g_ascii_strcasecmp (subtype.c_str(), "YUY2") == 0)
     return "YUY2";
@@ -654,6 +655,8 @@ MediaCaptureWrapper::mediaCaptureInitPost (ComPtr<IAsyncAction> init_async,
   UINT32 count = 0;
   GstVideoInfo videoInfo;
   HRESULT hr;
+  bool is_I420_subtype = false;
+  std::string target_subtype;
   ComPtr<ITypedEventHandler<MediaFrameReader*, MediaFrameArrivedEventArgs*>>
       frame_arrived_handler = Callback<ITypedEventHandler<MediaFrameReader*,
           MediaFrameArrivedEventArgs*>> ([&]
@@ -676,6 +679,12 @@ MediaCaptureWrapper::mediaCaptureInitPost (ComPtr<IAsyncAction> init_async,
     goto done;
   }
 
+  /* Windows defines two I420 format, one is I420 and the other is IYUV.
+   * So, if requested video format was I420, we should accept both I420 and
+   * IYUV formats */
+  is_I420_subtype = GST_VIDEO_INFO_FORMAT (&videoInfo) == GST_VIDEO_FORMAT_I420;
+  target_subtype = convert_hstring_to_string (&media_desc_->subtype_);
+
   hr = media_capture.As (&media_capture5);
   if (!gst_mf_result (hr))
     goto done;
@@ -809,11 +818,16 @@ MediaCaptureWrapper::mediaCaptureInitPost (ComPtr<IAsyncAction> init_async,
     if (!gst_mf_result (hr))
       continue;
 
-    if (wcscmp (subtype.GetRawBuffer (nullptr),
-        media_desc_->subtype_.GetRawBuffer (nullptr))) {
-      std::string cur_subtype = convert_hstring_to_string (&subtype);
-      std::string target_subtype =
-          convert_hstring_to_string (&media_desc_->subtype_);
+    std::string cur_subtype = convert_hstring_to_string (&subtype);
+
+    if (is_I420_subtype) {
+      /* Special handling for I420 */
+      if (cur_subtype != "I420" && cur_subtype != "IYUV") {
+        GST_LOG ("IMediaFrameFormat[%d], subtype %s is not equal to target %s",
+          i, cur_subtype.c_str (), target_subtype.c_str ());
+        continue;
+      }
+    } else if (cur_subtype != target_subtype) {
       GST_LOG ("IMediaFrameFormat[%d], subtype %s is not equal to target %s",
           i, cur_subtype.c_str (), target_subtype.c_str ());
       continue;