vaapidecode: return sink caps template if decoder is in NULL state.

Otherwise, the decoder would always create its own X display instead
of probing it from the downstream element, which is not reliable.
e.g. DISPLAY is not :0 or when running on Wayland.

Signed-off-by: Gwenole Beauchesne <gwenole.beauchesne@intel.com>

diff --git a/gst/vaapi/gstvaapidecode.c b/gst/vaapi/gstvaapidecode.c
index 63f29fc..ffba8fb 100644 (file)
--- a/gst/vaapi/gstvaapidecode.c
+++ b/gst/vaapi/gstvaapidecode.c
@@ -455,6 +455,9 @@ gst_vaapidecode_change_state(GstElement *element, GstStateChange transition)
     GstStateChangeReturn ret = GST_STATE_CHANGE_SUCCESS;
 
     switch (transition) {
+    case GST_STATE_CHANGE_NULL_TO_READY:
+        decode->is_ready = TRUE;
+        break;
     case GST_STATE_CHANGE_READY_TO_PAUSED:
         break;
     case GST_STATE_CHANGE_PAUSED_TO_PLAYING:
@@ -472,6 +475,14 @@ gst_vaapidecode_change_state(GstElement *element, GstStateChange transition)
         break;
     case GST_STATE_CHANGE_PAUSED_TO_READY:
         break;
+    case GST_STATE_CHANGE_READY_TO_NULL:
+        gst_vaapidecode_destroy(decode);
+        if (decode->display) {
+            g_object_unref(decode->display);
+            decode->display = NULL;
+        }
+        decode->is_ready = FALSE;
+        break;
     default:
         break;
     }
@@ -570,6 +581,9 @@ gst_vaapidecode_get_caps(GstPad *pad)
 {
     GstVaapiDecode * const decode = GST_VAAPIDECODE(GST_OBJECT_PARENT(pad));
 
+    if (!decode->is_ready)
+        return gst_static_pad_template_get_caps(&gst_vaapidecode_sink_factory);
+
     if (!gst_vaapidecode_ensure_allowed_caps(decode))
         return gst_caps_new_empty();
 
@@ -660,6 +674,7 @@ gst_vaapidecode_init(GstVaapiDecode *decode, GstVaapiDecodeClass *klass)
     decode->decoder_caps        = NULL;
     decode->allowed_caps        = NULL;
     decode->use_ffmpeg          = TRUE;
+    decode->is_ready            = FALSE;
 
     /* Pad through which data comes in to the element */
     decode->sinkpad = gst_pad_new_from_template(

diff --git a/gst/vaapi/gstvaapidecode.h b/gst/vaapi/gstvaapidecode.h
index e2788a5..f288583 100644 (file)
--- a/gst/vaapi/gstvaapidecode.h
+++ b/gst/vaapi/gstvaapidecode.h
@@ -72,6 +72,7 @@ struct _GstVaapiDecode {
     GstCaps            *decoder_caps;
     GstCaps            *allowed_caps;
     unsigned int        use_ffmpeg      : 1;
+    unsigned int        is_ready        : 1;
 };
 
 struct _GstVaapiDecodeClass {