mssdemux: PlayReady WRM parsing support

If the manifest has a ProtectionHeader node then parse it and emit
protection events according to the specified protection SystemID.

https://bugzilla.gnome.org/show_bug.cgi?id=753613

ext/smoothstreaming/gstmssdemux.c

@@ -367,12 +367,34 @@ _create_pad (GstMssDemux * mssdemux, GstMssStream * manifeststream)
   return srcpad;
 }
 
+static void
+gst_mss_demux_apply_protection_system (GstCaps * caps,
+    const gchar * selected_system)
+{
+  GstStructure *s;
+
+  g_return_if_fail (selected_system);
+  s = gst_caps_get_structure (caps, 0);
+  gst_structure_set (s,
+      "original-media-type", G_TYPE_STRING, gst_structure_get_name (s),
+      GST_PROTECTION_SYSTEM_ID_CAPS_FIELD, G_TYPE_STRING, selected_system,
+      NULL);
+  gst_structure_set_name (s, "application/x-cenc");
+
+}
+
 static gboolean
 gst_mss_demux_setup_streams (GstAdaptiveDemux * demux)
 {
   GstMssDemux *mssdemux = GST_MSS_DEMUX_CAST (demux);
   GSList *streams = gst_mss_manifest_get_streams (mssdemux->manifest);
   GSList *iter;
+  const gchar *protection_system_id =
+      gst_mss_manifest_get_protection_system_id (mssdemux->manifest);
+  const gchar *protection_data =
+      gst_mss_manifest_get_protection_data (mssdemux->manifest);
+  gboolean protected = protection_system_id && protection_data;
+  const gchar *selected_system = NULL;
 
   if (streams == NULL) {
     GST_INFO_OBJECT (mssdemux, "No streams found in the manifest");
@@ -382,6 +404,17 @@ gst_mss_demux_setup_streams (GstAdaptiveDemux * demux)
     return FALSE;
   }
 
+  if (protected) {
+    const gchar *sys_ids[2] = { protection_system_id, NULL };
+
+    selected_system = gst_protection_select_system (sys_ids);
+    if (!selected_system) {
+      GST_ERROR_OBJECT (mssdemux, "stream is protected, but no "
+          "suitable decryptor element has been found");
+      return FALSE;
+    }
+  }
+
   GST_INFO_OBJECT (mssdemux, "Changing max bitrate to %u",
       demux->connection_speed);
   gst_mss_manifest_change_bitrate (mssdemux->manifest, demux->connection_speed);
@@ -404,7 +437,13 @@ gst_mss_demux_setup_streams (GstAdaptiveDemux * demux)
         srcpad);
     stream->manifest_stream = manifeststream;
     gst_mss_stream_set_active (manifeststream, TRUE);
+
     caps = gst_mss_stream_get_caps (stream->manifest_stream);
+
+    if (protected) {
+      gst_mss_demux_apply_protection_system (caps, selected_system);
+    }
+
     gst_adaptive_demux_stream_set_caps (GST_ADAPTIVE_DEMUX_STREAM_CAST (stream),
         create_mss_caps (stream, caps));
     gst_caps_unref (caps);
@@ -417,6 +456,22 @@ gst_mss_demux_setup_streams (GstAdaptiveDemux * demux)
       gst_adaptive_demux_stream_set_tags (GST_ADAPTIVE_DEMUX_STREAM_CAST
           (stream), tags);
     }
+
+    if (protected) {
+      gsize protection_data_len;
+      guchar *decoded_data =
+          g_base64_decode (protection_data, &protection_data_len);
+      GstBuffer *protection_buffer =
+          gst_buffer_new_wrapped (decoded_data, protection_data_len);
+      GstEvent *event =
+          gst_event_new_protection (protection_system_id, protection_buffer,
+          "smooth-streaming");
+
+      GST_LOG_OBJECT (stream, "Queuing Protection event on source pad");
+      gst_adaptive_demux_stream_queue_event ((GstAdaptiveDemuxStream *) stream,
+          event);
+      gst_buffer_unref (protection_buffer);
+    }
   }
 
   return TRUE;
@@ -476,10 +531,31 @@ gst_mss_demux_stream_select_bitrate (GstAdaptiveDemuxStream * stream,
   if (gst_mss_stream_select_bitrate (mssstream->manifest_stream, bitrate)) {
     GstCaps *caps;
     GstCaps *msscaps;
+    GstMssDemux *mssdemux = GST_MSS_DEMUX_CAST (stream->demux);
+    const gchar *protection_system_id =
+        gst_mss_manifest_get_protection_system_id (mssdemux->manifest);
+    const gchar *protection_data =
+        gst_mss_manifest_get_protection_data (mssdemux->manifest);
+    gboolean protected = protection_system_id && protection_data;
+
     caps = gst_mss_stream_get_caps (mssstream->manifest_stream);
 
     GST_DEBUG_OBJECT (stream->pad,
         "Starting streams reconfiguration due to bitrate changes");
+
+    if (protected) {
+      const gchar *sys_ids[2] = { protection_system_id, NULL };
+      const gchar *selected_system = gst_protection_select_system (sys_ids);
+
+      if (!selected_system) {
+        GST_ERROR_OBJECT (mssdemux, "stream is protected, but no "
+            "suitable decryptor element has been found");
+        return FALSE;
+      }
+
+      gst_mss_demux_apply_protection_system (caps, selected_system);
+    }
+
     msscaps = create_mss_caps (mssstream, caps);
 
     GST_DEBUG_OBJECT (stream->pad,

ext/smoothstreaming/gstmssdemux.h

@@ -27,6 +27,7 @@
 #include <gst/adaptivedemux/gstadaptivedemux.h>
 #include <gst/base/gstadapter.h>
 #include <gst/base/gstdataqueue.h>
+#include <gst/gstprotection.h>
 #include "gstmssmanifest.h"
 #include <gst/uridownloader/gsturidownloader.h>
 

ext/smoothstreaming/gstmssmanifest.c

@@ -95,6 +95,9 @@ struct _GstMssManifest
 
   gboolean is_live;
 
+  GString *protection_system_id;
+  gchar *protection_data;
+
   GSList *streams;
 };
 
@@ -267,6 +270,41 @@ _gst_mss_stream_init (GstMssStream * stream, xmlNodePtr node)
   stream->regex_position = g_regex_new ("\\{start[ _]time\\}", 0, 0, NULL);
 }
 
+
+static void
+_gst_mss_parse_protection (GstMssManifest * manifest,
+    xmlNodePtr protection_node)
+{
+  xmlNodePtr nodeiter;
+
+  for (nodeiter = protection_node->children; nodeiter;
+      nodeiter = nodeiter->next) {
+    if (nodeiter->type == XML_ELEMENT_NODE
+        && (strcmp ((const char *) nodeiter->name, "ProtectionHeader") == 0)) {
+      xmlChar *system_id_attribute =
+          xmlGetProp (nodeiter, (xmlChar *) "SystemID");
+      gchar *value = (gchar *) system_id_attribute;
+      int id_len = strlen (value);
+      GString *system_id;
+
+      if (value[0] == '{') {
+        value++;
+        id_len--;
+      }
+
+      system_id = g_string_new (value);
+      system_id = g_string_ascii_down (system_id);
+      if (value[id_len - 1] == '}')
+        system_id = g_string_truncate (system_id, id_len - 1);
+
+      manifest->protection_system_id = system_id;
+      manifest->protection_data = (gchar *) xmlNodeGetContent (nodeiter);
+      xmlFree (system_id_attribute);
+      break;
+    }
+  }
+}
+
 GstMssManifest *
 gst_mss_manifest_new (GstBuffer * data)
 {
@@ -300,6 +338,11 @@ gst_mss_manifest_new (GstBuffer * data)
       manifest->streams = g_slist_append (manifest->streams, stream);
       _gst_mss_stream_init (stream, nodeiter);
     }
+
+    if (nodeiter->type == XML_ELEMENT_NODE
+        && (strcmp ((const char *) nodeiter->name, "Protection") == 0)) {
+      _gst_mss_parse_protection (manifest, nodeiter);
+    }
   }
 
   gst_buffer_unmap (data, &mapinfo);
@@ -327,10 +370,28 @@ gst_mss_manifest_free (GstMssManifest * manifest)
 
   g_slist_free_full (manifest->streams, (GDestroyNotify) gst_mss_stream_free);
 
+  if (manifest->protection_system_id != NULL)
+    g_string_free (manifest->protection_system_id, TRUE);
+  xmlFree (manifest->protection_data);
+
   xmlFreeDoc (manifest->xml);
   g_free (manifest);
 }
 
+const gchar *
+gst_mss_manifest_get_protection_system_id (GstMssManifest * manifest)
+{
+  if (manifest->protection_system_id != NULL)
+    return manifest->protection_system_id->str;
+  return NULL;
+}
+
+const gchar *
+gst_mss_manifest_get_protection_data (GstMssManifest * manifest)
+{
+  return manifest->protection_data;
+}
+
 GSList *
 gst_mss_manifest_get_streams (GstMssManifest * manifest)
 {

ext/smoothstreaming/gstmssmanifest.h

@@ -52,6 +52,8 @@ gint64 gst_mss_manifest_get_dvr_window_length (GstMssManifest * manifest);
 gint gst_mss_manifest_get_look_ahead_fragments_count (GstMssManifest * manifest);
 void gst_mss_manifest_reload_fragments (GstMssManifest * manifest, GstBuffer * data);
 GstClockTime gst_mss_manifest_get_min_fragment_duration (GstMssManifest * manifest);
+const gchar * gst_mss_manifest_get_protection_system_id (GstMssManifest * manifest);
+const gchar * gst_mss_manifest_get_protection_data (GstMssManifest * manifest);
 
 GstMssStreamType gst_mss_stream_get_type (GstMssStream *stream);
 GstCaps * gst_mss_stream_get_caps (GstMssStream * stream);