discoverer: Set number to stream infos

The idea is that we can reference to streams using this unique number,
within the context of that discoverer info. That number should always
be usable to reference the streams for a specific stream.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/897>

subprojects/gst-plugins-base/gst-libs/gst/pbutils/gstdiscoverer-types.c

@@ -50,7 +50,7 @@ G_DEFINE_TYPE (GstDiscovererStreamInfo, gst_discoverer_stream_info,
 static void
 gst_discoverer_stream_info_init (GstDiscovererStreamInfo * info)
 {
-  /* Nothing needs initialization */
+  info->stream_number = -1;
 }
 
 static void
@@ -143,6 +143,8 @@ gst_discoverer_info_copy_int (GstDiscovererStreamInfo * info,
   if (stream_map)
     g_hash_table_insert (stream_map, info, ret);
 
+  ret->stream_number = info->stream_number;
+
   return ret;
 }
 
@@ -718,6 +720,23 @@ gst_discoverer_stream_info_get_misc (GstDiscovererStreamInfo * info)
 }
 #endif
 
+/**
+ * gst_discoverer_stream_info_get_stream_number:
+ * @info: a #GstDiscovererStreamInfo
+ *
+ * Returns: the stream number, -1 if no index could be determined. This property
+ * acts as a unique identifier as a 'int' for the stream.
+ *
+ * Since: 1.20
+ */
+gint
+gst_discoverer_stream_info_get_stream_number (GstDiscovererStreamInfo * info)
+{
+  g_return_val_if_fail (GST_IS_DISCOVERER_STREAM_INFO (info), -1);
+
+  return info->stream_number;
+}
+
 /* GstDiscovererContainerInfo */
 
 /**

subprojects/gst-plugins-base/gst-libs/gst/pbutils/gstdiscoverer.c

@@ -1284,6 +1284,7 @@ parse_stream_topology (GstDiscoverer * dc, const GstStructure * topology,
     }
 
     if (add_to_list) {
+      res->stream_number = dc->priv->current_info->stream_count++;
       dc->priv->current_info->stream_list =
           g_list_append (dc->priv->current_info->stream_list, res);
     } else {
@@ -1476,9 +1477,13 @@ discoverer_collect (GstDiscoverer * dc)
     else
       dc->priv->current_info->live = TRUE;
 
-    if (dc->priv->current_topology)
+    if (dc->priv->current_topology) {
+      dc->priv->current_info->stream_count = 1;
       dc->priv->current_info->stream_info = parse_stream_topology (dc,
           dc->priv->current_topology, NULL);
+      if (dc->priv->current_info->stream_info)
+        dc->priv->current_info->stream_info->stream_number = 0;
+    }
 
     /*
      * Images need some special handling. They do not have a duration, have
@@ -2385,8 +2390,9 @@ _parse_discovery (GVariant * variant, GstDiscovererInfo * info)
   _parse_common_stream_info (sinfo, g_variant_get_child_value (common, 0),
       info);
 
-  if (!GST_IS_DISCOVERER_CONTAINER_INFO (sinfo))
+  if (!GST_IS_DISCOVERER_CONTAINER_INFO (sinfo)) {
     info->stream_list = g_list_append (info->stream_list, sinfo);
+  }
 
   if (!info->stream_info) {
     info->stream_info = sinfo;

subprojects/gst-plugins-base/gst-libs/gst/pbutils/gstdiscoverer.h

@@ -84,6 +84,9 @@ const GstStructure*      gst_discoverer_stream_info_get_misc(GstDiscovererStream
 GST_PBUTILS_API
 const gchar *            gst_discoverer_stream_info_get_stream_type_nick(GstDiscovererStreamInfo* info);
 
+GST_PBUTILS_API
+gint                     gst_discoverer_stream_info_get_stream_number(GstDiscovererStreamInfo *info);
+
 /**
  * GstDiscovererContainerInfo:
  *

subprojects/gst-plugins-base/gst-libs/gst/pbutils/pbutils-private.h

@@ -31,6 +31,7 @@ struct _GstDiscovererStreamInfo {
   GstToc                *toc;
   gchar                 *stream_id;
   GstStructure          *misc;
+  gint                  stream_number;
 };
 
 struct _GstDiscovererContainerInfo {
@@ -97,6 +98,8 @@ struct _GstDiscovererInfo {
   gboolean seekable;
   GPtrArray *missing_elements_details;
 
+  gint stream_count;
+
   gchar *cachefile;
   gpointer from_cache;
 };

subprojects/gst-plugins-base/tools/gst-discoverer.c

@@ -367,9 +367,9 @@ print_stream_info (GstDiscovererStreamInfo * info, void *depth)
     gst_caps_unref (caps);
   }
 
-  g_print ("%*s%s: %s\n", 2 * GPOINTER_TO_INT (depth), " ",
+  g_print ("%*s%s #%d: %s\n", 2 * GPOINTER_TO_INT (depth), " ",
       gst_discoverer_stream_info_get_stream_type_nick (info),
-      GST_STR_NULL (desc));
+      gst_discoverer_stream_info_get_stream_number (info), GST_STR_NULL (desc));
 
   if (desc) {
     g_free (desc);