decoder: simplify acquisition/release of spare surface.

Introduce gst_vaapi_surface_proxy_new_from_pool() to allocate a new surface
proxy from the context surface pool. This change also makes sure to retain
the parent surface pool in the proxy.

Besides, it was also totally useless to attach/detach parent context to
VA surface each time we acquire/release it. Since the whole context owns
all associated VA surfaces, we can mark this as such only once and for all.

1 files changed, 27 insertions, 9 deletions

diff --git a/gst-libs/gst/vaapi/gstvaapicontext.c b/gst-libs/gst/vaapi/gstvaapicontext.c
index 8d5a6d1d..44cafc46 100644
--- a/gst-libs/gst/vaapi/gstvaapicontext.c
+++ b/gst-libs/gst/vaapi/gstvaapicontext.c
@@ -32,6 +32,7 @@
 #include "gstvaapisurface.h"
 #include "gstvaapisurface_priv.h"
 #include "gstvaapisurfacepool.h"
+#include "gstvaapisurfaceproxy.h"
 #include "gstvaapiimage.h"
 #include "gstvaapisubpicture.h"
 #include "gstvaapiminiobject.h"
@@ -503,6 +504,7 @@ gst_vaapi_context_create_surfaces(GstVaapiContext *context)
         );
         if (!surface)
             return FALSE;
+        gst_vaapi_surface_set_parent_context(surface, context);
         g_ptr_array_add(priv->surfaces, surface);
         if (!gst_vaapi_video_pool_add_object(priv->surfaces_pool, surface))
             return FALSE;
@@ -999,6 +1001,30 @@ gst_vaapi_context_get_size(
 }
 
 /**
+ * gst_vaapi_context_get_surface_proxy:
+ * @context: a #GstVaapiContext
+ *
+ * Acquires a free surface, wrapped into a #GstVaapiSurfaceProxy. The
+ * returned surface will be automatically released when the proxy is
+ * destroyed. So, it is enough to call gst_vaapi_surface_proxy_unref()
+ * after usage.
+ *
+ * This function returns %NULL if there is no free surface available
+ * in the pool. The surfaces are pre-allocated during context creation
+ * though.
+ *
+ * Return value: a free surface, or %NULL if none is available
+ */
+GstVaapiSurfaceProxy *
+gst_vaapi_context_get_surface_proxy(GstVaapiContext *context)
+{
+    g_return_val_if_fail(GST_VAAPI_IS_CONTEXT(context), NULL);
+
+    return gst_vaapi_surface_proxy_new_from_pool(
+        GST_VAAPI_SURFACE_POOL(context->priv->surfaces_pool));
+}
+
+/**
  * gst_vaapi_context_get_surface:
  * @context: a #GstVaapiContext
  *
@@ -1012,16 +1038,9 @@ gst_vaapi_context_get_size(
 GstVaapiSurface *
 gst_vaapi_context_get_surface(GstVaapiContext *context)
 {
-    GstVaapiSurface *surface;
-
     g_return_val_if_fail(GST_VAAPI_IS_CONTEXT(context), NULL);
 
-    surface = gst_vaapi_video_pool_get_object(context->priv->surfaces_pool);
-    if (!surface)
-        return NULL;
-
-    gst_vaapi_surface_set_parent_context(surface, context);
-    return surface;
+    return gst_vaapi_video_pool_get_object(context->priv->surfaces_pool);
 }
 
 /**
@@ -1053,7 +1072,6 @@ gst_vaapi_context_put_surface(GstVaapiContext *context, GstVaapiSurface *surface
     g_return_if_fail(GST_VAAPI_IS_CONTEXT(context));
     g_return_if_fail(GST_VAAPI_IS_SURFACE(surface));
 
-    gst_vaapi_surface_set_parent_context(surface, NULL);
     gst_vaapi_video_pool_put_object(context->priv->surfaces_pool, surface);
 }