[telepathy-spec/master] ImmutableStreams MAY be undefined before RequestStreams

[Will Thompson]

---
 spec/Channel_Type_Streamed_Media_Future.xml |   22 ++++++++++++++++++++++
 1 files changed, 22 insertions(+), 0 deletions(-)

diff --git a/spec/Channel_Type_Streamed_Media_Future.xml b/spec/Channel_Type_Streamed_Media_Future.xml
index b534283..392ab1f 100644
--- a/spec/Channel_Type_Streamed_Media_Future.xml
+++ b/spec/Channel_Type_Streamed_Media_Future.xml
@@ -180,6 +180,28 @@
             started; the user interface will thus need to adapt in order to
             allow the user to place video calls.</p>
         </tp:rationale>
+
+        <p>For incoming channels, this property MUST be included in the channel's immutable properties
+          (as announced in <tp:dbus-ref
+            namespace="org.freedesktop.Telepathy.Connection.Interface.Requests">NewChannels</tp:dbus-ref>,
+          etc.). For outgoing calls, this property MAY be omitted from the
+          channel's immutable properties for calls without
+          <tp:member-ref>InitialAudio</tp:member-ref> or
+          <tp:member-ref>InitialVideo</tp:member-ref>, in which case its value
+          is undefined until <tp:dbus-ref
+            namespace='org.freedesktop.Telepathy.Channel.Type.StreamedMedia'>RequestStreams</tp:dbus-ref>
+          has been called at least once.</p>
+
+        <tp:rationale>
+          <p>The protocol mechanism used for the call might only be selected
+            when the CM knows what kind of call is desired. For example, if an
+            XMPP contact is signed in with Google Mail (with video support) and
+            Another client which supports modern Jingle (which supports
+            modifying the streams in a call) but only for audio calls, the
+            call's streams will be immutable if the UI requests Audio+Video,
+            but mutable if the UI just requests audio (a second audio stream
+            could be added, for instance).</p>
+        </tp:rationale>
       </tp:docstring>
     </property>
 
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1.5.6.5