wrappercamerabinsrc: Add video-source-filter during construction

By adding the video-source-filter during construction time, rather then
patching it in later (*), we can greatly reduce the amount of caps involved
in negotation, speeding up pipeline creation.

I wrote this while working on speeding up the startup of cheese. My cheese
has been modified to add a capsfilter, filtering for only the configured
resolution, with that cheese patch + this patch, the pipeline creation time
goes from aprox 1.1 seconds to aprox 350ms. This is with a Logitech 9000
pro camera, which supports lots of different resolutions at many different
framerates per resolution, causing a caps "explosion" if not filtered.

*) Note the code for this is left in, as it is still necessary if the
video-source-filter is changed between a stop + re-start.

https://bugzilla.gnome.org/show_bug.cgi?id=701953

1 files changed, 10 insertions, 0 deletions

diff --git a/gst/camerabin2/gstwrappercamerabinsrc.c b/gst/camerabin2/gstwrappercamerabinsrc.c
index 3f94428e2..2e3dda64f 100644
--- a/gst/camerabin2/gstwrappercamerabinsrc.c
+++ b/gst/camerabin2/gstwrappercamerabinsrc.c
@@ -552,6 +552,16 @@ gst_wrapper_camera_bin_src_construct_pipeline (GstBaseCameraSrc * bcamsrc)
             "src-videoconvert"))
       goto done;
 
+    if (self->app_vid_filter) {
+      self->video_filter = gst_object_ref (self->app_vid_filter);
+
+      if (!gst_camerabin_add_element (cbin, self->video_filter))
+        goto done;
+      if (!gst_camerabin_create_and_add_element (cbin, "videoconvert",
+              "filter-videoconvert"))
+        goto done;
+    }
+
     if (!(self->src_filter =
             gst_camerabin_create_and_add_element (cbin, "capsfilter",
                 "src-capsfilter")))