mxfdemux: Handle sub-descriptor in generic descriptors

Specificied in S377-1 (2019) B.2 Generic Descriptor

This is one of the ways to store more "sub descriptors" for a single track

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/3899>

subprojects/gst-plugins-bad/gst/mxf/mxfdemux.c

@@ -1201,9 +1201,21 @@ gst_mxf_demux_show_topology (GstMXFDemux * demux)
       }
       for (di = 0; di < track->n_descriptor; di++) {
         MXFMetadataFileDescriptor *desc = track->descriptor[di];
+        MXFMetadataGenericDescriptor *generic =
+            (MXFMetadataGenericDescriptor *) desc;
+        guint subdi;
+
         GST_DEBUG_OBJECT (demux, "      Descriptor %s %s",
             g_type_name (G_OBJECT_TYPE (desc)),
             mxf_ul_to_string (&desc->essence_container, str));
+        for (subdi = 0; subdi < generic->n_sub_descriptors; subdi++) {
+          MXFMetadataGenericDescriptor *subdesc =
+              generic->sub_descriptors[subdi];
+          if (subdesc) {
+            GST_DEBUG_OBJECT (demux, "        Sub-Descriptor %s",
+                g_type_name (G_OBJECT_TYPE (subdesc)));
+          }
+        }
       }
       GST_DEBUG_OBJECT (demux,
           "      Sequence duration:%" G_GINT64_FORMAT

subprojects/gst-plugins-bad/gst/mxf/mxfmetadata.c

@@ -3912,6 +3912,11 @@ mxf_metadata_generic_descriptor_finalize (GObject * object)
   g_free (self->locators);
   self->locators = NULL;
 
+  g_free (self->sub_descriptors_uids);
+  self->sub_descriptors_uids = NULL;
+  g_free (self->sub_descriptors);
+  self->sub_descriptors = NULL;
+
   G_OBJECT_CLASS (mxf_metadata_generic_descriptor_parent_class)->finalize
       (object);
 }
@@ -3946,11 +3951,31 @@ mxf_metadata_generic_descriptor_handle_tag (MXFMetadataBase * metadata,
 #endif
       break;
     default:
-      ret =
+    {
-          MXF_METADATA_BASE_CLASS
+      MXFUL *tag_ul = mxf_primer_tag_to_ul (primer, tag);
-          (mxf_metadata_generic_descriptor_parent_class)->handle_tag (metadata,
+      if (tag_ul && mxf_ul_is_equal (tag_ul, MXF_UL (SUB_DESCRIPTORS_ARRAY))) {
-          primer, tag, tag_data, tag_size);
+        if (!mxf_uuid_array_parse (&self->sub_descriptors_uids,
+                &self->n_sub_descriptors, tag_data, tag_size))
+          goto error;
+
+        GST_DEBUG ("  number of sub_descriptors = %u", self->n_sub_descriptors);
+#ifndef GST_DISABLE_GST_DEBUG
+        {
+          guint i;
+          for (i = 0; i < self->n_sub_descriptors; i++) {
+            GST_DEBUG ("  sub descriptor %u = %s", i,
+                mxf_uuid_to_string (&self->sub_descriptors_uids[i], str));
+          }
+        }
+#endif
+      } else {
+        ret =
+            MXF_METADATA_BASE_CLASS
+            (mxf_metadata_generic_descriptor_parent_class)->handle_tag
+            (metadata, primer, tag, tag_data, tag_size);
+      }
       break;
+    }
   }
 
   return ret;
@@ -4000,6 +4025,29 @@ mxf_metadata_generic_descriptor_resolve (MXFMetadataBase * m,
     return FALSE;
   }
 
+  /* this memory reuse is done in the same way as for locators, but the reason
+   * isn't 100% clear. This might not be needed anymore */
+  if (self->sub_descriptors)
+    memset (self->sub_descriptors, 0,
+        sizeof (gpointer) * self->n_sub_descriptors);
+  else
+    self->sub_descriptors =
+        g_new0 (MXFMetadataGenericDescriptor *, self->n_sub_descriptors);
+  for (i = 0; i < self->n_sub_descriptors; i++) {
+    current = g_hash_table_lookup (metadata, &self->sub_descriptors_uids[i]);
+    if (current && MXF_IS_METADATA_GENERIC_DESCRIPTOR (current)) {
+      if (mxf_metadata_base_resolve (current, metadata)) {
+        self->sub_descriptors[i] = MXF_METADATA_GENERIC_DESCRIPTOR (current);
+      } else {
+        GST_WARNING ("Couldn't resolve sub_descriptor %s",
+            mxf_uuid_to_string (&self->sub_descriptors_uids[i], str));
+      }
+    } else {
+      GST_WARNING ("Sub_Descriptor %s not found",
+          mxf_uuid_to_string (&self->sub_descriptors_uids[i], str));
+    }
+  }
+
   return
       MXF_METADATA_BASE_CLASS
       (mxf_metadata_generic_descriptor_parent_class)->resolve (m, metadata);

subprojects/gst-plugins-bad/gst/mxf/mxfmetadata.h

@@ -625,6 +625,10 @@ struct _MXFMetadataGenericDescriptor {
   guint32 n_locators;
   MXFUUID *locators_uids;
   MXFMetadataLocator **locators;
+
+  MXFUUID *sub_descriptors_uids;
+  guint32 n_sub_descriptors;
+  MXFMetadataGenericDescriptor **sub_descriptors;
 };
 
 struct _MXFMetadataFileDescriptor {

subprojects/gst-plugins-bad/gst/mxf/mxful.c

@@ -275,6 +275,9 @@ const MXFUL _mxf_ul_table[] = {
   /* LOCATORS */
   {{0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x02,
           0x06, 0x01, 0x01, 0x04, 0x06, 0x03, 0x00, 0x00}},
+  /* SUB_DESCRIPTORS_ARRAY */
+  {{0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x09,
+          0x06, 0x01, 0x01, 0x04, 0x06, 0x10, 0x00, 0x00}},
   /* File descriptor */
   /* LINKED_TRACK_ID */
   {{0x06, 0x0E, 0x2B, 0x34, 0x01, 0x01, 0x01, 0x05,

subprojects/gst-plugins-bad/gst/mxf/mxful.h

@@ -106,6 +106,7 @@ typedef enum {
   MXF_UL_DM_SEGMENT_TRACK_IDS,
   MXF_UL_DM_FRAMEWORK,
   MXF_UL_LOCATORS,
+  MXF_UL_SUB_DESCRIPTORS_ARRAY,
   MXF_UL_LINKED_TRACK_ID,
   MXF_UL_SAMPLE_RATE,
   MXF_UL_CONTAINER_DURATION,