plugins: find the preferred format from right caps.

When the downstream has any caps, then raw video feature will
be used. At this situation, the preferred format should be chose
from caps which contains "vide/x-raw" feature instead of from
the fist allowed caps.

Fixes #142

diff --git a/gst/vaapi/gstvaapipluginutil.c b/gst/vaapi/gstvaapipluginutil.c
index 51fdf12..3599b6a 100644 (file)
--- a/gst/vaapi/gstvaapipluginutil.c
+++ b/gst/vaapi/gstvaapipluginutil.c
@@ -698,17 +698,28 @@ gst_vaapi_find_preferred_caps_feature (GstPad * pad, GstCaps * allowed_caps,
 find_format:
   if (out_format_ptr) {
     GstVideoFormat out_format;
-    GstStructure *structure;
+    GstStructure *structure = NULL;
     const GValue *format_list;
+    GstCapsFeatures *features;
 
-    /* if the best feature is SystemMemory, we should use the first
-     * caps in the filtered peer caps set, which is the preferred by
-     * downstream. */
-    if (feature == GST_VAAPI_CAPS_FEATURE_SYSTEM_MEMORY)
+    /* if the best feature is SystemMemory, we should choose the
+     * vidoe/x-raw caps in the filtered peer caps set. If not, use
+     * the first caps, which is the preferred by downstream. */
+    if (feature == GST_VAAPI_CAPS_FEATURE_SYSTEM_MEMORY) {
       gst_caps_replace (&caps, out_caps);
-
-    /* use the first caps, which is the preferred by downstream. */
-    structure = gst_caps_get_structure (caps, 0);
+      num_structures = gst_caps_get_size (caps);
+      for (i = 0; i < num_structures; i++) {
+        structure = gst_caps_get_structure (caps, i);
+        features = gst_caps_get_features (caps, i);
+        if (!gst_caps_features_is_any (features)
+            && gst_caps_features_contains (features,
+                gst_vaapi_caps_feature_to_string
+                (GST_VAAPI_CAPS_FEATURE_SYSTEM_MEMORY)))
+          break;
+      }
+    } else {
+      structure = gst_caps_get_structure (caps, 0);
+    }
     if (!structure)
       goto cleanup;
     format_list = gst_structure_get_value (structure, "format");