ios - DLNA/UPNP video cast error of DMR -

i ios developer. developing dlna/upnp ios application. target directly cast video iphone samsung smart tv without middleware. using upnpx library that. wireframe below. iphone download videolink server. , directly cast video tv. of course, server not dms. in here issue videos played on tv. videos not played on tv. audio played. miss on implementing app? hope best solution everybody. thank you.

this how selected dmr:

mediarenderer1device *render = (mediarenderer1device*)device;         [[playback getinstance] setrenderer:render];         [[playback getinstance] play:0]; 

/*choosed dmr urn 'urn:schemas-upnp-org:device:mediarenderer:1' */

//play func  -(int)play:(nsinteger)position {        if([[renderer  avtransportservice]isobserver:basicupnpserviceobserver*)self]== no){             [[renderer avtransportservice] addobserver:(basicupnpserviceobserver*)self];         }           nsstring *uri = @"http://parstvco.files.wordpress.com/2015/11/dandoon-tala-10.mp4"; // uri played on tv(dmr)          nsstring *iid = @"0";          [[renderer avtransport] setplaymodewithinstanceid:iid newplaymode:@"normal"];          [[renderer avtransport] setavtransporturiwithinstanceid:iid currenturi:uri      currenturimetadata:@"video/mp4"];           [[renderer avtransport] playwithinstanceid:iid speed:@"1"];  } 

//result log

2016-06-11 09:33:16.120 upnpxdemo[841:8340] error (soapaction): got non 200 response: 500. data:

<?xml version="1.0"?> <soap-env:envelope xmlns:soap-env="http://schemas.xmlsoap.org/soap/envelope/" soap-env:encodingstyle="http://schemas.xmlsoap.org/soap/encoding/"><soap-env:body><soap-env:fault><faultcode>soap-env:client</faultcode><faultstring>upnperror</faultstring><detail><u:upnperror xmlns:u="urn:schemas-upnp-org:control-1-0"><u:errorcode>701</u:errorcode><u:errordescription>transition not available</u:errordescription></u:upnperror></detail></soap-env:fault></soap-env:body></soap-env:envelope> 

the error message unlikely related videos not playing (i suspect that's codec incompatibility), following error message:

avtransport service may fail 701 in several cases if cannot make state transition ask (e.g. if try pause() while stopped). avtransport service definition document lists cases 701 may happen -- of course samsung might returning in different situations :/

i can't see in code might trigger described above suggest trying monitor transportstate of service before call fails 701: guess service still e.g. transitioning , won't take commands until it's stopped or playing.