[mutter] screen-cast-stream: Check for a modifier in the format negotiation via pipewire

[Marge Bot <marge-bot src gnome org>]

commit b34ca56cae169c8ecb06e5292265902a8d1bce92
Author: columbarius <co1umbarius protonmail com>
Date:   Sat Nov 13 16:34:40 2021 +0100

    screen-cast-stream: Check for a modifier in the format negotiation via pipewire
    
    Announce SPA_PARAM_BUFFERS_dataType accordingly if the modifier key
    exists in the returned SPA_PARAM_Format.
    
    Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1939>

 src/backends/meta-screen-cast-stream-src.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
---
diff --git a/src/backends/meta-screen-cast-stream-src.c b/src/backends/meta-screen-cast-stream-src.c
index 7e6fdcec44..2efe7bc238 100644
--- a/src/backends/meta-screen-cast-stream-src.c
+++ b/src/backends/meta-screen-cast-stream-src.c
@@ -772,6 +772,7 @@ on_stream_param_changed (void                 *data,
   struct spa_pod_builder pod_builder;
   const struct spa_pod *params[3];
   const int bpp = 4;
+  int buffer_types;
 
   if (!format || id != SPA_PARAM_Format)
     return;
@@ -788,6 +789,11 @@ on_stream_param_changed (void                 *data,
 
   pod_builder = SPA_POD_BUILDER_INIT (params_buffer, sizeof (params_buffer));
 
+  if (!spa_pod_find_prop (format, NULL, SPA_FORMAT_VIDEO_modifier))
+    buffer_types = 1 << SPA_DATA_MemFd;
+  else
+    buffer_types = 1 << SPA_DATA_DmaBuf;
+
   params[0] = spa_pod_builder_add_object (
     &pod_builder,
     SPA_TYPE_OBJECT_ParamBuffers, SPA_PARAM_Buffers,
@@ -795,7 +801,8 @@ on_stream_param_changed (void                 *data,
     SPA_PARAM_BUFFERS_blocks, SPA_POD_Int (1),
     SPA_PARAM_BUFFERS_size, SPA_POD_Int (size),
     SPA_PARAM_BUFFERS_stride, SPA_POD_Int (stride),
-    SPA_PARAM_BUFFERS_align, SPA_POD_Int (16));
+    SPA_PARAM_BUFFERS_align, SPA_POD_Int (16),
+    SPA_PARAM_BUFFERS_dataType, SPA_POD_CHOICE_FLAGS_Int (buffer_types));
 
   params[1] = spa_pod_builder_add_object (
     &pod_builder,