v4l2object: allow to automatic selection of dmabuf

If the v4l2 queue support dmabuf select this buffer pool mode
and update the query with allocator.
This patch only concern exporting dmabuf and not importing dmabuf
fd from downstream element.

https://bugzilla.gnome.org/show_bug.cgi?id=699382

2 files changed, 8 insertions, 2 deletions

diff --git a/sys/v4l2/gstv4l2bufferpool.c b/sys/v4l2/gstv4l2bufferpool.c
index 2019072e7..2ea9eb58c 100644
--- a/sys/v4l2/gstv4l2bufferpool.c
+++ b/sys/v4l2/gstv4l2bufferpool.c
@@ -517,6 +517,8 @@ gst_v4l2_buffer_pool_set_config (GstBufferPool * bpool, GstStructure * config)
     gst_buffer_pool_config_set_params (config, caps, size, min_buffers,
         max_buffers);
 
+  gst_buffer_pool_config_set_allocator (config, pool->allocator, &params);
+
   /* keep a GstVideoInfo with defaults for the when we need to copy */
   gst_video_info_from_caps (&pool->caps_info, caps);
 
diff --git a/sys/v4l2/gstv4l2object.c b/sys/v4l2/gstv4l2object.c
index d70b53d6f..974624335 100644
--- a/sys/v4l2/gstv4l2object.c
+++ b/sys/v4l2/gstv4l2object.c
@@ -2362,8 +2362,12 @@ gst_v4l2_object_setup_pool (GstV4l2Object * v4l2object, GstCaps * caps)
     goto method_not_supported;
 
   if (v4l2object->vcap.capabilities & V4L2_CAP_STREAMING) {
-    if (v4l2object->req_mode == GST_V4L2_IO_AUTO)
-      mode = GST_V4L2_IO_MMAP;
+    if (v4l2object->req_mode == GST_V4L2_IO_AUTO) {
+      if (GST_V4L2_OBJECT_CAN_REQUEST (v4l2object, DMABUF))
+        mode = GST_V4L2_IO_DMABUF;
+      else
+        mode = GST_V4L2_IO_MMAP;
+    }
   } else if (v4l2object->req_mode == GST_V4L2_IO_MMAP)
     goto method_not_supported;