From f0fd2aeb0469fa15bd2932aedf3e682004107890 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADctor=20Manuel=20J=C3=A1quez=20Leal?=
 <vjaquez@igalia.com>
Date: Thu, 15 Feb 2018 19:28:33 +0100
Subject: [PATCH] plugins: store the first downstream allocator if available

The allocator will be required if we need to allocate a buffer
to store the frame with the expected strides.

https://bugzilla.gnome.org/show_bug.cgi?id=785054
---
 gst/vaapi/gstvaapipluginbase.c | 17 ++++++++++++++++-
 gst/vaapi/gstvaapipluginbase.h |  2 ++
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/gst/vaapi/gstvaapipluginbase.c b/gst/vaapi/gstvaapipluginbase.c
index 7bc7178dad..0183579cf1 100644
--- a/gst/vaapi/gstvaapipluginbase.c
+++ b/gst/vaapi/gstvaapipluginbase.c
@@ -327,6 +327,7 @@ gst_vaapi_plugin_base_close (GstVaapiPluginBase * plugin)
 
   g_clear_object (&plugin->sinkpad_allocator);
   g_clear_object (&plugin->srcpad_allocator);
+  g_clear_object (&plugin->other_srcpad_allocator);
 
   gst_caps_replace (&plugin->srcpad_caps, NULL);
   gst_video_info_init (&plugin->srcpad_info);
@@ -929,10 +930,24 @@ gst_vaapi_plugin_base_decide_allocation (GstVaapiPluginBase * plugin,
   num_allocators = gst_query_get_n_allocation_params (query);
   for (i = 0; i < num_allocators; i++) {
     GstAllocator *allocator = NULL;
+    GstAllocationParams params;
 
-    gst_query_parse_nth_allocation_param (query, i, &allocator, NULL);
+    gst_query_parse_nth_allocation_param (query, i, &allocator, &params);
     if (!allocator)
       continue;
+
+    /* Let's keep the the first allocator if it is not VA-API. It
+     * might be used if it is required to copy the output frame to a
+     * new buffer */
+    if (i == 0
+        && g_strcmp0 (allocator->mem_type, GST_VAAPI_VIDEO_MEMORY_NAME) != 0) {
+      if (plugin->other_srcpad_allocator)
+        gst_object_unref (plugin->other_srcpad_allocator);
+      plugin->other_srcpad_allocator = allocator;
+      plugin->other_allocator_params = params;
+      continue;
+    }
+
     if (g_strcmp0 (allocator->mem_type, GST_VAAPI_VIDEO_MEMORY_NAME) == 0) {
       GST_DEBUG_OBJECT (plugin, "found vaapi allocator in query %"
           GST_PTR_FORMAT, allocator);
diff --git a/gst/vaapi/gstvaapipluginbase.h b/gst/vaapi/gstvaapipluginbase.h
index f08548260f..81b5f4eddb 100644
--- a/gst/vaapi/gstvaapipluginbase.h
+++ b/gst/vaapi/gstvaapipluginbase.h
@@ -147,6 +147,8 @@ struct _GstVaapiPluginBase
   gboolean srcpad_can_dmabuf;
 
   gboolean enable_direct_rendering;
+  GstAllocator *other_srcpad_allocator;
+  GstAllocationParams other_allocator_params;
 };
 
 struct _GstVaapiPluginBaseClass