[gnome-remote-desktop] pipewire-utils: Add functions to check whether PipeWire buffer has data

[Jonas Ådahl <jadahl src gnome org>]

commit 7421a47e957b345851f87d7e29f5627d18e9d388
Author: Pascal Nowack <Pascal Nowack gmx de>
Date:   Mon Jan 31 13:31:04 2022 +0100

    pipewire-utils: Add functions to check whether PipeWire buffer has data
    
    These two functions check whether a PipeWire buffer has frame data or
    a mouse pointer bitmap.
    In the next commits, they are used to determine the latest PipeWire
    buffer with frame data and the latest PipeWire buffer with a mouse
    pointer bitmap.

 src/grd-pipewire-utils.c | 31 ++++++++++++++++++++++++++++++-
 src/grd-pipewire-utils.h |  5 +++++
 2 files changed, 35 insertions(+), 1 deletion(-)
---
diff --git a/src/grd-pipewire-utils.c b/src/grd-pipewire-utils.c
index 46634e62..84b36c19 100644
--- a/src/grd-pipewire-utils.c
+++ b/src/grd-pipewire-utils.c
@@ -23,7 +23,6 @@
 #include "grd-pipewire-utils.h"
 
 #include <drm_fourcc.h>
-#include <pipewire/pipewire.h>
 #include <spa/param/video/raw.h>
 
 static gboolean is_pipewire_initialized = FALSE;
@@ -38,6 +37,36 @@ grd_maybe_initialize_pipewire (void)
     }
 }
 
+gboolean
+grd_pipewire_buffer_has_pointer_bitmap (struct pw_buffer *buffer)
+{
+  struct spa_meta_cursor *spa_meta_cursor;
+
+  spa_meta_cursor = spa_buffer_find_meta_data (buffer->buffer, SPA_META_Cursor,
+                                               sizeof *spa_meta_cursor);
+  if (spa_meta_cursor && spa_meta_cursor_is_valid (spa_meta_cursor))
+    {
+      struct spa_meta_bitmap *spa_meta_bitmap = NULL;
+
+      if (spa_meta_cursor->bitmap_offset)
+        {
+          spa_meta_bitmap = SPA_MEMBER (spa_meta_cursor,
+                                        spa_meta_cursor->bitmap_offset,
+                                        struct spa_meta_bitmap);
+        }
+      if (spa_meta_bitmap)
+        return TRUE;
+    }
+
+  return FALSE;
+}
+
+gboolean
+grd_pipewire_buffer_has_frame_data (struct pw_buffer *buffer)
+{
+  return buffer->buffer->datas[0].chunk->size > 0;
+}
+
 gboolean
 grd_spa_pixel_format_to_grd_pixel_format (uint32_t        spa_format,
                                           GrdPixelFormat *out_format)
diff --git a/src/grd-pipewire-utils.h b/src/grd-pipewire-utils.h
index 830db6de..072f9949 100644
--- a/src/grd-pipewire-utils.h
+++ b/src/grd-pipewire-utils.h
@@ -21,6 +21,7 @@
 #define GRD_PIPEWIRE_UTILS_H
 
 #include <gio/gio.h>
+#include <pipewire/pipewire.h>
 #include <stdint.h>
 #include <spa/param/video/format-utils.h>
 
@@ -39,6 +40,10 @@ typedef struct _GrdPipeWireSource
 
 void grd_maybe_initialize_pipewire (void);
 
+gboolean grd_pipewire_buffer_has_pointer_bitmap (struct pw_buffer *buffer);
+
+gboolean grd_pipewire_buffer_has_frame_data (struct pw_buffer *buffer);
+
 gboolean grd_spa_pixel_format_to_grd_pixel_format (uint32_t        spa_format,
                                                    GrdPixelFormat *out_format);