vaapidecode: generate source pad caps

Just as vaapipostproc, VA decoder's context can be queried to get the possible
raw formats, so, the src caps can negotiate the exact caps that the context
supports.

2 files changed, 53 insertions, 4 deletions

diff --git a/gst/vaapi/gstvaapidecode.c b/gst/vaapi/gstvaapidecode.c
index 51001ef0..a1f9b2fe 100644
--- a/gst/vaapi/gstvaapidecode.c
+++ b/gst/vaapi/gstvaapidecode.c
@@ -201,11 +201,58 @@ gst_vaapidecode_update_sink_caps (GstVaapiDecode * decode, GstCaps * caps)
 }
 
 static gboolean
+gst_vaapidecode_ensure_allowed_srcpad_caps (GstVaapiDecode * decode)
+{
+  GstCaps *out_caps, *raw_caps;
+
+  if (decode->allowed_srcpad_caps)
+    return TRUE;
+
+  if (!GST_VAAPI_PLUGIN_BASE_DISPLAY (decode))
+    return FALSE;
+
+  /* Create VA caps */
+  out_caps = gst_caps_from_string (GST_VAAPI_MAKE_SURFACE_CAPS ";"
+      GST_VAAPI_MAKE_GLTEXUPLOAD_CAPS);
+  if (!out_caps) {
+    GST_WARNING_OBJECT (decode, "failed to create VA/GL source caps");
+    return FALSE;
+  }
+
+  raw_caps = gst_vaapi_plugin_base_get_allowed_raw_caps
+      (GST_VAAPI_PLUGIN_BASE (decode));
+  if (!raw_caps) {
+    gst_caps_unref (out_caps);
+    GST_WARNING_OBJECT (decode, "failed to create raw sink caps");
+    return FALSE;
+  }
+
+  out_caps = gst_caps_make_writable (out_caps);
+  gst_caps_append (out_caps, gst_caps_copy (raw_caps));
+  decode->allowed_srcpad_caps = out_caps;
+
+  GST_INFO_OBJECT (decode, "allowed srcpad caps: %" GST_PTR_FORMAT,
+      decode->allowed_srcpad_caps);
+
+  return TRUE;
+}
+
+static GstCaps *
+gst_vaapidecode_get_allowed_srcpad_caps (GstVaapiDecode * decode)
+{
+  GstPad *const srcpad = GST_VIDEO_DECODER_SRC_PAD (decode);
+
+  if (gst_vaapidecode_ensure_allowed_srcpad_caps (decode))
+    return gst_caps_ref (decode->allowed_srcpad_caps);
+  return gst_pad_get_pad_template_caps (srcpad);
+}
+
+static gboolean
 gst_vaapidecode_update_src_caps (GstVaapiDecode * decode)
 {
   GstVideoDecoder *const vdec = GST_VIDEO_DECODER (decode);
   GstPad *const srcpad = GST_VIDEO_DECODER_SRC_PAD (vdec);
-  GstCaps *templ;
+  GstCaps *allowed;
   GstVideoCodecState *state, *ref_state;
   GstVaapiCapsFeature feature;
   GstCapsFeatures *features;
@@ -223,9 +270,9 @@ gst_vaapidecode_update_src_caps (GstVaapiDecode * decode)
   ref_state = decode->input_state;
 
   format = GST_VIDEO_INFO_FORMAT (&decode->decoded_info);
-  templ = gst_pad_get_pad_template_caps (srcpad);
-  feature = gst_vaapi_find_preferred_caps_feature (srcpad, templ, &format);
-  gst_caps_unref (templ);
+  allowed = gst_vaapidecode_get_allowed_srcpad_caps (decode);
+  feature = gst_vaapi_find_preferred_caps_feature (srcpad, allowed, &format);
+  gst_caps_unref (allowed);
 
   if (feature == GST_VAAPI_CAPS_FEATURE_NOT_NEGOTIATED)
     return FALSE;
@@ -934,6 +981,7 @@ gst_vaapidecode_close (GstVideoDecoder * vdec)
   GstVaapiDecode *const decode = GST_VAAPIDECODE (vdec);
 
   gst_vaapidecode_destroy (decode);
+  gst_caps_replace (&decode->allowed_srcpad_caps, NULL);
   gst_vaapi_plugin_base_close (GST_VAAPI_PLUGIN_BASE (decode));
   return TRUE;
 }
diff --git a/gst/vaapi/gstvaapidecode.h b/gst/vaapi/gstvaapidecode.h
index 41d85640..cb2a2f1d 100644
--- a/gst/vaapi/gstvaapidecode.h
+++ b/gst/vaapi/gstvaapidecode.h
@@ -47,6 +47,7 @@ struct _GstVaapiDecode {
     GCond               surface_ready;
     GstCaps            *decoder_caps;
     GstCaps            *allowed_sinkpad_caps;
+    GstCaps            *allowed_srcpad_caps;
     guint               current_frame_size;
     guint               has_texture_upload_meta : 1;