pbutils: allow describing unfixed caps if they share the same media type

Caps description and missing plugin code does not really need caps to
be fixed, and indeed they may not be if giving encodebin unfixed caps
that correspond to an unknown encoder or muxer.

So we relax the check, and allow unfixed caps if all the structures
refer to the same media type.

3 files changed, 24 insertions, 4 deletions

diff --git a/gst-libs/gst/pbutils/descriptions.c b/gst-libs/gst/pbutils/descriptions.c
index ac27e7dfc..9591f5906 100644
--- a/gst-libs/gst/pbutils/descriptions.c
+++ b/gst-libs/gst/pbutils/descriptions.c
@@ -839,7 +839,7 @@ gst_pb_utils_get_decoder_description (const GstCaps * caps)
 
   tmp = copy_and_clean_caps (caps);
 
-  g_return_val_if_fail (gst_caps_is_fixed (tmp), NULL);
+  g_return_val_if_fail (has_single_media_type (tmp), NULL);
 
   /* special-case RTP caps */
   if (caps_are_rtp_caps (tmp, "video", &str)) {
@@ -890,7 +890,7 @@ gst_pb_utils_get_encoder_description (const GstCaps * caps)
   g_return_val_if_fail (caps != NULL, NULL);
   g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
   tmp = copy_and_clean_caps (caps);
-  g_return_val_if_fail (gst_caps_is_fixed (tmp), NULL);
+  g_return_val_if_fail (has_single_media_type (tmp), NULL);
 
   /* special-case RTP caps */
   if (caps_are_rtp_caps (tmp, "video", &str)) {
@@ -1021,7 +1021,7 @@ gst_pb_utils_get_codec_description (const GstCaps * caps)
   g_return_val_if_fail (caps != NULL, NULL);
   g_return_val_if_fail (GST_IS_CAPS (caps), NULL);
   tmp = copy_and_clean_caps (caps);
-  g_return_val_if_fail (gst_caps_is_fixed (tmp), NULL);
+  g_return_val_if_fail (has_single_media_type (tmp), NULL);
 
   info = find_format_info (tmp);
 
diff --git a/gst-libs/gst/pbutils/missing-plugins.c b/gst-libs/gst/pbutils/missing-plugins.c
index 7d7f2f4f9..6ff16d5fb 100644
--- a/gst-libs/gst/pbutils/missing-plugins.c
+++ b/gst-libs/gst/pbutils/missing-plugins.c
@@ -156,6 +156,25 @@ copy_and_clean_caps (const GstCaps * caps)
   return ret;
 }
 
+gboolean
+has_single_media_type (const GstCaps * caps)
+{
+  guint n, ns;
+  const char *name0, *namen;
+
+  g_return_val_if_fail (GST_IS_CAPS (caps), FALSE);
+
+  name0 = gst_structure_get_name (gst_caps_get_structure (caps, 0));
+  ns = gst_caps_get_size (caps);
+  for (n = 1; n < ns; ++n) {
+    namen = gst_structure_get_name (gst_caps_get_structure (caps, n));
+    if (strcmp (name0, namen)) {
+      return FALSE;
+    }
+  }
+  return TRUE;
+}
+
 /**
  * gst_missing_uri_source_message_new:
  * @element: the #GstElement posting the message
@@ -319,7 +338,7 @@ gst_missing_encoder_message_new (GstElement * element,
   g_return_val_if_fail (GST_IS_CAPS (encode_caps), NULL);
   g_return_val_if_fail (!gst_caps_is_any (encode_caps), NULL);
   g_return_val_if_fail (!gst_caps_is_empty (encode_caps), NULL);
-  g_return_val_if_fail (gst_caps_is_fixed (encode_caps), NULL);
+  g_return_val_if_fail (has_single_media_type (encode_caps), NULL);
 
   description = gst_pb_utils_get_encoder_description (encode_caps);
   caps = copy_and_clean_caps (encode_caps);
diff --git a/gst-libs/gst/pbutils/pbutils-private.h b/gst-libs/gst/pbutils/pbutils-private.h
index 82fd22c89..bb475a337 100644
--- a/gst-libs/gst/pbutils/pbutils-private.h
+++ b/gst-libs/gst/pbutils/pbutils-private.h
@@ -107,3 +107,4 @@ struct _GstDiscovererInfo {
 /* missing-plugins.c */
 
 GstCaps *copy_and_clean_caps (const GstCaps * caps);
+gboolean has_single_media_type (const GstCaps * caps);