From b06a8bffde11aec2b67fbef436f1160eeb35c77e Mon Sep 17 00:00:00 2001
From: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Date: Mon, 20 Nov 2017 21:09:28 -0500
Subject: [PATCH] waylandsink: Disable video-alignment from the pool

The SHM interface does not allow passing arbitrary strides and offsets,
for this reason, we simply disable this feature from the proposed pool.

This fixes video artifact seen when using the FFMPEG based video
decoder.

https://bugzilla.gnome.org/show_bug.cgi?id=790057
---
 ext/wayland/gstwaylandsink.c | 38 +++++++++++++++++++++++++++++++++++-
 1 file changed, 37 insertions(+), 1 deletion(-)

diff --git a/ext/wayland/gstwaylandsink.c b/ext/wayland/gstwaylandsink.c
index 6f9c976b6a..6a88533062 100644
--- a/ext/wayland/gstwaylandsink.c
+++ b/ext/wayland/gstwaylandsink.c
@@ -121,6 +121,42 @@ G_DEFINE_TYPE_WITH_CODE (GstWaylandSink, gst_wayland_sink, GST_TYPE_VIDEO_SINK,
     G_IMPLEMENT_INTERFACE (GST_TYPE_WAYLAND_VIDEO,
         gst_wayland_sink_waylandvideo_init));
 
+/* A tiny GstVideoBufferPool subclass that modify the options to remove
+ * VideoAlignment. To support VideoAlignment we would need to pass the padded
+ * width/height + stride and use the viewporter interface to crop, a bit like
+ * we use to do with XV. It would still be quite limited. It's a bit retro,
+ * hopefully there will be a better Wayland interface in the future. */
+typedef struct
+{
+  GstVideoBufferPool parent;
+} GstWaylandPool;
+
+typedef struct
+{
+  GstVideoBufferPoolClass parent;
+} GstWaylandPoolClass;
+
+G_DEFINE_TYPE (GstWaylandPool, gst_wayland_pool, GST_TYPE_VIDEO_BUFFER_POOL);
+
+static const gchar **
+gst_wayland_pool_get_options (GstBufferPool * pool)
+{
+  static const gchar *options[] = { GST_BUFFER_POOL_OPTION_VIDEO_META, NULL };
+  return options;
+}
+
+static void
+gst_wayland_pool_class_init (GstWaylandPoolClass * klass)
+{
+  GstBufferPoolClass *pool_class = GST_BUFFER_POOL_CLASS (klass);
+  pool_class->get_options = gst_wayland_pool_get_options;
+}
+
+static void
+gst_wayland_pool_init (GstWaylandPool * pool)
+{
+}
+
 static void
 gst_wayland_sink_class_init (GstWaylandSinkClass * klass)
 {
@@ -456,7 +492,7 @@ gst_wayland_create_pool (GstWaylandSink * sink, GstCaps * caps)
   GstStructure *structure;
   gsize size = sink->video_info.size;
 
-  pool = gst_video_buffer_pool_new ();
+  pool = g_object_new (gst_wayland_pool_get_type (), NULL);
 
   structure = gst_buffer_pool_get_config (pool);
   gst_buffer_pool_config_set_params (structure, caps, size, 2, 0);