The subscriber sends a SUBSCRIBE_TRACKS control message on a new bidirectional stream to a publisher to request PUBLISH messages for all tracks within matching namespaces, as well as future track publications within those namespaces.
SUBSCRIBE_TRACKS Message {
Type (vi64) = 0x51,
Length (16),
Request ID (vi64),
Track Namespace Prefix (..),
Number of Parameters (vi64),
Parameters (..) ...
}
-
Request ID: See Section 6.4.2.1.
-
Track Namespace Prefix: A Track Namespace structure as described in Section 8.7. This prefix is matched against track namespaces known to the publisher.
-
Parameters: The parameters are defined in Section 9.20, though they are handled differently from the same Parameters on Subscriptions, as outlined below. The parameters that can appear in a SUBSCRIBE_TRACKS are AUTHORIZATION_TOKEN, FORWARD, GROUP_ORDER, SUBGROUP_FILTER, OBJECTID_FILTER, PRIORITY_FILTER, OBJECT_PROPERTY_FILTER, TRACK_PROPERTY_FILTER and INCLUDE_PROPERTIES.