msdk: don't reset the external frame allocator

In gst-msdk, a mfx session may be shared between different gst
elements, each element tries to set the frame allocator. However, per
the MSDK documation[1], the behavior is undefined if reset the frame
allocator while the previous allocator is in use. Fortunately all
elements use the same frame allocator, so we can avoid to call
MFXVideoCORE_SetFrameAllocator again.

[1]: https://software.intel.com/en-us/node/628430#MFXVideoCORE3

4 files changed, 29 insertions, 4 deletions

diff --git a/sys/msdk/gstmsdkallocator_d3d.c b/sys/msdk/gstmsdkallocator_d3d.c
index 75b147e86..27e457288 100644
--- a/sys/msdk/gstmsdkallocator_d3d.c
+++ b/sys/msdk/gstmsdkallocator_d3d.c
@@ -75,6 +75,5 @@ gst_msdk_set_frame_allocator (GstMsdkContext * context)
     .Free = gst_msdk_frame_free,
   };
 
-  MFXVideoCORE_SetFrameAllocator (gst_msdk_context_get_session (context),
-      &gst_msdk_frame_allocator);
+  gst_msdk_context_set_frame_allocator (context, &gst_msdk_frame_allocator);
 }
diff --git a/sys/msdk/gstmsdkallocator_libva.c b/sys/msdk/gstmsdkallocator_libva.c
index 74be0dffc..e5200a3fe 100644
--- a/sys/msdk/gstmsdkallocator_libva.c
+++ b/sys/msdk/gstmsdkallocator_libva.c
@@ -366,8 +366,7 @@ gst_msdk_set_frame_allocator (GstMsdkContext * context)
     .Free = gst_msdk_frame_free,
   };
 
-  MFXVideoCORE_SetFrameAllocator (gst_msdk_context_get_session (context),
-      &gst_msdk_frame_allocator);
+  gst_msdk_context_set_frame_allocator (context, &gst_msdk_frame_allocator);
 }
 
 gboolean
diff --git a/sys/msdk/gstmsdkcontext.c b/sys/msdk/gstmsdkcontext.c
index ae7b305fd..f1615ad60 100644
--- a/sys/msdk/gstmsdkcontext.c
+++ b/sys/msdk/gstmsdkcontext.c
@@ -47,6 +47,7 @@ struct _GstMsdkContextPrivate
   GList *cached_alloc_responses;
   gboolean hardware;
   gboolean is_joined;
+  gboolean has_frame_allocator;
   GstMsdkContextJobType job_type;
   gint shared_async_depth;
   GMutex mutex;
@@ -597,3 +598,25 @@ gst_msdk_context_add_shared_async_depth (GstMsdkContext * context,
 {
   context->priv->shared_async_depth += async_depth;
 }
+
+void
+gst_msdk_context_set_frame_allocator (GstMsdkContext * context,
+    mfxFrameAllocator * allocator)
+{
+  GstMsdkContextPrivate *priv = context->priv;
+
+  g_mutex_lock (&priv->mutex);
+
+  if (!priv->has_frame_allocator) {
+    mfxStatus status;
+
+    status = MFXVideoCORE_SetFrameAllocator (priv->session, allocator);
+
+    if (status != MFX_ERR_NONE)
+      GST_ERROR ("Failed to set frame allocator");
+    else
+      priv->has_frame_allocator = 1;
+  }
+
+  g_mutex_unlock (&priv->mutex);
+}
diff --git a/sys/msdk/gstmsdkcontext.h b/sys/msdk/gstmsdkcontext.h
index cbaf68937..6abfa86ef 100644
--- a/sys/msdk/gstmsdkcontext.h
+++ b/sys/msdk/gstmsdkcontext.h
@@ -142,6 +142,10 @@ gst_msdk_context_get_shared_async_depth (GstMsdkContext * context);
 void
 gst_msdk_context_add_shared_async_depth (GstMsdkContext * context, gint async_depth);
 
+void
+gst_msdk_context_set_frame_allocator (GstMsdkContext * context,
+    mfxFrameAllocator * allocator);
+
 G_END_DECLS
 
 #endif /* GST_MSDK_CONTEXT_H */