udp - GStreamer UDPSink blocksize property not working? -

i'm using gstreamer , sending audio using pipeline:

gst-launch-1.0 -v filesrc location=soundfile.mp3 ! mad ! audioconvert ! audio/x-raw, layout=interleaved, format=f32le, channels=2 ! udpsink blocksize=512 port=5005 host=127.0.0.1

however, blocksize doesn't appear working @ all. doc udpsink, accessed gst-inspect udpsink:

element properties:   name                : name of object                         flags: readable, writable                         string. default: "udpsink0"   preroll-queue-len   : number of buffers queue during preroll                         flags: readable, writable                         unsigned integer. range: 0 - 4294967295 default: 0    sync                : sync on clock                         flags: readable, writable                         boolean. default: true   max-lateness        : maximum number of nanoseconds buffer can late before dropped (-1 unlimited)                         flags: readable, writable                         integer64. range: -1 - 9223372036854775807 default: -1    qos                 : generate quality-of-service events upstream                         flags: readable, writable                         boolean. default: false   async               : go asynchronously paused                         flags: readable, writable                         boolean. default: true   ts-offset           : timestamp offset in nanoseconds                         flags: readable, writable                         integer64. range: -9223372036854775808 - 9223372036854775807 default: 0    enable-last-buffer  : enable last-buffer property                         flags: readable, writable                         boolean. default: true   last-buffer         : last buffer received in sink                         flags: readable                         miniobject of type "gstbuffer"   blocksize           : size in bytes pull per buffer (0 = default)                         flags: readable, writable                         unsigned integer. range: 0 - 4294967295 default: 4096    render-delay        : additional render delay of sink in nanoseconds                         flags: readable, writable                         unsigned integer64. range: 0 - 18446744073709551615 default: 0    throttle-time       : time keep between rendered buffers (unused)                         flags: readable, writable                         unsigned integer64. range: 0 - 18446744073709551615 default: 0    bytes-to-serve      : number of bytes received serve clients                         flags: readable                         unsigned integer64. range: 0 - 18446744073709551615 default: 0    bytes-served        : total number of bytes sent clients                         flags: readable                         unsigned integer64. range: 0 - 18446744073709551615 default: 0    sockfd              : socket use udp sending. (-1 == allocate)                         flags: readable, writable                         integer. range: -1 - 2147483647 default: -1    closefd             : close sockfd if passed property on state change                         flags: readable, writable                         boolean. default: true   sock                : socket in use udp sending. (-1 == no socket)                         flags: readable                         integer. range: -1 - 2147483647 default: -1    clients             : comma separated list of host:port pairs destinations                         flags: readable, writable                         string. default: "localhost:4951"   auto-multicast      : automatically join/leave multicast groups, false means user has himself                         flags: readable, writable                         boolean. default: true   ttl                 : used setting unicast ttl parameter                         flags: readable, writable                         integer. range: 0 - 255 default: 64    ttl-mc              : used setting multicast ttl parameter                         flags: readable, writable                         integer. range: 0 - 255 default: 1    loop                : used setting multicast loop parameter. true = enable, false = disable                         flags: readable, writable                         boolean. default: true   qos-dscp            : quality of service, differentiated services code point (-1 default)                         flags: readable, writable                         integer. range: -1 - 63 default: -1    send-duplicates     : when distination/port pair added multiple times, send packets multiple times                         flags: readable, writable                         boolean. default: true   buffer-size         : size of kernel send buffer in bytes, 0=default                         flags: readable, writable                         integer. range: 0 - 2147483647 default: 0    host                : host/ip/multicast group send packets                         flags: readable, writable                         string. default: "localhost"   port                : port send packets                         flags: readable, writable                         integer. range: 0 - 65535 default: 4951  

this confusing, default value blocksize listed both 0 , 4096. seems 4096, however, udp packet size no matter value use blocksize. what's more confusing can scarcely find mention of blocksize property anywhere online, in gstreamer's own documentation: http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-plugins-good-plugins/html/gst-plugins-good-plugins-udpsink.html

the properties mentioned host , port. has blocksize been deprecated or something? , if so, there way control amount of data sent in each udp packet? i've tried using mtu property in rtp no luck (see here: gstreamer rtp packet size) , kind of @ wits' end this.