glupload: Do prepend the preferred caps

The direct dmabuf upload does color conversion, so when it transforms
the caps, it replaces the format with all formats found through the
format query. When this uploader can't be used, it makes the upstream
source pick a unsupported format.

To fix this, we only append the caps with a list of format. So the
source will only pick one of these formats if the downstream preferred
format is not supported. A negotiation failure after this would be
normal.

This fixes pipelines without a glcolorconvert element.

https://bugzilla.gnome.org/show_bug.cgi?id=783521

diff --git a/gst-libs/gst/gl/gstglupload.c b/gst-libs/gst/gl/gstglupload.c
index 51322bbf36f2a84a10d562d5246b98263eea7f59..e32f6846689124e19be874669f1b7fcbdb2fea30 100644 (file)
--- a/gst-libs/gst/gl/gstglupload.c
+++ b/gst-libs/gst/gl/gstglupload.c
@@ -848,7 +848,9 @@ _direct_dma_buf_upload_transform_caps (gpointer impl, GstGLContext * context,
 
     g_value_init (&formats, GST_TYPE_LIST);
     gst_value_deserialize (&formats, format_str);
-    gst_caps_set_value (ret, "format", &formats);
+    tmp = gst_caps_copy (ret);
+    gst_caps_set_value (tmp, "format", &formats);
+    gst_caps_append (ret, tmp);
     g_free (format_str);
     g_value_unset (&formats);