Specifies that you are finished defining a playback session and ready to perform the playback. If the playback target is to a file, this command starts the playback. If the playback target is to a client, this command initializes playback so that the hs_playback_sample command with a default step returns the first sample in the playback session.
The hs_create_playback_session command and one or more successful hs_create_playback_view commands must precede the hs_initiate_playback command.
If no views were created before the hs_initiate_playback command, then hs_initiate_playback returns an error. The user may still attempt an hs_create_playback_view command, or may cancel the playback session with the hs_terminate_playback command.