wpevideosrc: Fix frame stuttering in GL rendering path

Make sure the EGLImage we're rendering to the GL memory stays alive long enough,
until the the GL memory has been destroyed.

This change fixes tearing and black flashes artefacts that were happening
because the EGLImage was sometimes destroyed before the sink actually rendered
the associated texture.

Fixes #889

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1354>

diff --git a/subprojects/gst-plugins-bad/ext/wpe/gstwpevideosrc.cpp b/subprojects/gst-plugins-bad/ext/wpe/gstwpevideosrc.cpp
index 770d10e..819da96 100644 (file)
--- a/subprojects/gst-plugins-bad/ext/wpe/gstwpevideosrc.cpp
+++ b/subprojects/gst-plugins-bad/ext/wpe/gstwpevideosrc.cpp
@@ -215,6 +215,16 @@ gst_wpe_video_src_create (GstBaseSrc * bsrc, guint64 offset, guint length,
   return ret;
 }
 
+static GQuark
+_egl_image_quark (void)
+{
+  static GQuark quark = 0;
+
+  if (!quark)
+    quark = g_quark_from_static_string ("GstWPEEGLImage");
+  return quark;
+}
+
 static gboolean
 gst_wpe_video_src_fill_memory (GstGLBaseSrc * bsrc, GstGLMemory * memory)
 {
@@ -240,6 +250,11 @@ gst_wpe_video_src_fill_memory (GstGLBaseSrc * bsrc, GstGLMemory * memory)
     return TRUE;
   }
 
+  // The EGLImage is implicitely associated with the memory we're filling, so we
+  // need to ensure their life cycles are tied.
+  gst_mini_object_set_qdata (GST_MINI_OBJECT_CAST (memory), _egl_image_quark (),
+      gst_egl_image_ref (locked_image), (GDestroyNotify) gst_egl_image_unref);
+
   gl->ActiveTexture (GL_TEXTURE0 + memory->plane);
   gl->BindTexture (GL_TEXTURE_2D, tex_id);
   gl->EGLImageTargetTexture2D (GL_TEXTURE_2D,