<extension name="Local_Extension">

    <condition field="destination_number" expression="^(10[0-9][0-9])$">                           

      <action application="set" data="hangup_after_bridge=true"/>                                           

      <action application="set" data="continue_on_fail=false"/>

      <action application="log" data="INFO: read_codec=${read_codec}"/>                  

      <action application="bridge" data="user/$1@${domain}"/>                   

    </condition>                                                                                        

  </extension> 

In the example above, read_codec of call leg A will be logged

Now I want to print the read_codec/write_codec of outbound call leg in this dialplan. How can I achieve it?