msdk: context: add job type to figure out if joining session is necessary

According to the driver's instruction, if there are two or more encoders
or decoders in a process, the session should be joined by
MFXJoinSession.

To achieve this successfully by GstContext, this patch adds job type
specified if it's encoder, decoder or vpp.

If a msdk element gets to know if joining session is needed by the
shared context,
it should create another instance of GstContext with joined session,
which
is not shared.

https://bugzilla.gnome.org/show_bug.cgi?id=790752

sys/msdk/gstmsdkcontext.c

@@ -53,6 +53,9 @@ struct _GstMsdkContextPrivate
 {
   mfxSession session;
   GList *cached_alloc_responses;
+  gboolean hardware;
+  gboolean is_joined;
+  GstMsdkContextJobType job_type;
 #ifndef _WIN32
   gint fd;
   VADisplay dpy;
@@ -113,10 +116,13 @@ failed:
 #endif
 
 static gboolean
-gst_msdk_context_open (GstMsdkContext * context, gboolean hardware)
+gst_msdk_context_open (GstMsdkContext * context, gboolean hardware,
+    GstMsdkContextJobType job_type)
 {
   GstMsdkContextPrivate *priv = context->priv;
 
+  priv->job_type = job_type;
+  priv->hardware = hardware;
   priv->session = msdk_open_session (hardware);
   if (!priv->session)
     goto failed;
@@ -151,6 +157,12 @@ gst_msdk_context_finalize (GObject * obj)
 {
   GstMsdkContext *context = GST_MSDK_CONTEXT_CAST (obj);
   GstMsdkContextPrivate *priv = context->priv;
+
+  if (priv->is_joined) {
+    MFXDisjoinSession (priv->session);
+    goto done;
+  }
+
   msdk_close_session (priv->session);
 
 #ifndef _WIN32
@@ -160,6 +172,7 @@ gst_msdk_context_finalize (GObject * obj)
     close (priv->fd);
 #endif
 
+done:
   G_OBJECT_CLASS (parent_class)->finalize (obj);
 }
 
@@ -173,11 +186,11 @@ gst_msdk_context_class_init (GstMsdkContextClass * klass)
 }
 
 GstMsdkContext *
-gst_msdk_context_new (gboolean hardware)
+gst_msdk_context_new (gboolean hardware, GstMsdkContextJobType job_type)
 {
   GstMsdkContext *obj = g_object_new (GST_TYPE_MSDK_CONTEXT, NULL);
 
-  if (obj && !gst_msdk_context_open (obj, hardware)) {
+  if (obj && !gst_msdk_context_open (obj, hardware, job_type)) {
     if (obj)
       gst_object_unref (obj);
     return NULL;
@@ -186,6 +199,42 @@ gst_msdk_context_new (gboolean hardware)
   return obj;
 }
 
+GstMsdkContext *
+gst_msdk_context_new_with_parent (GstMsdkContext * parent)
+{
+  mfxStatus status;
+  GstMsdkContext *obj = g_object_new (GST_TYPE_MSDK_CONTEXT, NULL);
+  GstMsdkContextPrivate *priv = obj->priv;
+  GstMsdkContextPrivate *parent_priv = parent->priv;
+
+  status = MFXCloneSession (parent_priv->session, &priv->session);
+  if (status != MFX_ERR_NONE) {
+    GST_ERROR ("Failed to clone mfx session");
+    return NULL;
+  }
+
+  status = MFXJoinSession (parent_priv->session, priv->session);
+  if (status != MFX_ERR_NONE) {
+    GST_ERROR ("Failed to join mfx session");
+    return NULL;
+  }
+
+  priv->is_joined = TRUE;
+  priv->hardware = parent_priv->hardware;
+  priv->job_type = parent_priv->job_type;
+#ifndef _WIN32
+  priv->dpy = parent_priv->dpy;
+  priv->fd = parent_priv->fd;
+
+  if (priv->hardware) {
+    status = MFXVideoCORE_SetHandle (priv->session, MFX_HANDLE_VA_DISPLAY,
+        (mfxHDL) parent_priv->dpy);
+  }
+#endif
+
+  return obj;
+}
+
 mfxSession
 gst_msdk_context_get_session (GstMsdkContext * context)
 {
@@ -286,3 +335,16 @@ gst_msdk_context_remove_alloc_response (GstMsdkContext * context,
 
   return TRUE;
 }
+
+GstMsdkContextJobType
+gst_msdk_context_get_job_type (GstMsdkContext * context)
+{
+  return context->priv->job_type;
+}
+
+void
+gst_msdk_context_add_job_type (GstMsdkContext * context,
+    GstMsdkContextJobType job_type)
+{
+  context->priv->job_type |= job_type;
+}

sys/msdk/gstmsdkcontext.h

@@ -58,6 +58,12 @@ typedef struct _GstMsdkContext GstMsdkContext;
 typedef struct _GstMsdkContextClass GstMsdkContextClass;
 typedef struct _GstMsdkContextPrivate GstMsdkContextPrivate;
 
+typedef enum {
+  GST_MSDK_JOB_DECODER = 0x01,
+  GST_MSDK_JOB_ENCODER = 0x02,
+  GST_MSDK_JOB_VPP = 0x04,
+} GstMsdkContextJobType;
+
 /*
  * GstMsdkContext:
  */
@@ -78,7 +84,8 @@ struct _GstMsdkContextClass
 
 GType gst_msdk_context_get_type (void);
 
-GstMsdkContext * gst_msdk_context_new (gboolean hardware);
+GstMsdkContext * gst_msdk_context_new (gboolean hardware, GstMsdkContextJobType job_type);
+GstMsdkContext * gst_msdk_context_new_with_parent (GstMsdkContext * parent);
 mfxSession gst_msdk_context_get_session (GstMsdkContext * context);
 
 gpointer gst_msdk_context_get_handle (GstMsdkContext * context);
@@ -112,6 +119,12 @@ gboolean
 gst_msdk_context_remove_alloc_response (GstMsdkContext * context,
     mfxFrameAllocResponse * resp);
 
+GstMsdkContextJobType
+gst_msdk_context_get_job_type (GstMsdkContext * context);
+
+void
+gst_msdk_context_add_job_type (GstMsdkContext * context, GstMsdkContextJobType job_type);
+
 G_END_DECLS
 
 #endif /* GST_MSDK_CONTEXT_H */

sys/msdk/gstmsdkcontextutil.c

@@ -215,11 +215,12 @@ gst_msdk_context_propagate (GstElement * element, GstMsdkContext * msdk_context)
 }
 
 gboolean
-gst_msdk_context_ensure_context (GstElement * element, gboolean hardware)
+gst_msdk_context_ensure_context (GstElement * element, gboolean hardware,
+    GstMsdkContextJobType job)
 {
   GstMsdkContext *msdk_context;
 
-  msdk_context = gst_msdk_context_new (hardware);
+  msdk_context = gst_msdk_context_new (hardware, job);
   if (!msdk_context) {
     GST_ERROR_OBJECT (element, "Context creation failed");
     return FALSE;

sys/msdk/gstmsdkcontextutil.h

@@ -50,7 +50,7 @@ gboolean
 gst_msdk_context_get_context (GstContext * context, GstMsdkContext ** msdk_context);
 
 gboolean
-gst_msdk_context_ensure_context (GstElement * element, gboolean hardware);
+gst_msdk_context_ensure_context (GstElement * element, gboolean hardware, GstMsdkContextJobType job);
 
 G_END_DECLS
 

sys/msdk/gstmsdkdec.c

@@ -243,7 +243,7 @@ gst_msdkdec_init_decoder (GstMsdkDec * thiz)
   /* make sure that the decoder is closed */
   gst_msdkdec_close_decoder (thiz);
 
-  thiz->context = gst_msdk_context_new (thiz->hardware);
+  thiz->context = gst_msdk_context_new (thiz->hardware, GST_MSDK_JOB_DECODER);
   if (!thiz->context) {
     GST_ERROR_OBJECT (thiz, "Context creation failed");
     return FALSE;

sys/msdk/gstmsdkenc.c

@@ -169,7 +169,7 @@ gst_msdkenc_init_encoder (GstMsdkEnc * thiz)
   /* make sure that the encoder is closed */
   gst_msdkenc_close_encoder (thiz);
 
-  thiz->context = gst_msdk_context_new (thiz->hardware);
+  thiz->context = gst_msdk_context_new (thiz->hardware, GST_MSDK_JOB_ENCODER);
   if (!thiz->context) {
     GST_ERROR_OBJECT (thiz, "Context creation failed");
     return FALSE;