iphone - Save the The Stream From URL -

in project connecting url , watching video mpmovieplayerviewcontroller. not enough me. want save file iphone. have buttons. 1 watch video, other save video. when push button watch watchng it. unable save it. want able watch video later. in view want see saved videos etc. there 1 can me or can show way ? have tried following code phrase when code started, works while (probably download time), when time save bad exc_bad_access error .thanks every one.
here code .

cfstringref *docsdirectory =  (cfstringref)[nstemporarydirectory() stringbyappendingpathcomponent: @"recordedfile.mp4"];   nsstring *tempath=nstemporarydirectory(); nsstring *tempfile=[tempath stringbyappendingpathcomponent:@"recode.mp4"];   nslog(@" dosya adi madi %@",docsdirectory);   nsfilemanager *filemanager = [nsfilemanager defaultmanager]; nserror *error = [[nserror alloc] init];  [filemanager removeitematpath:docsdirectory error:&error];  nsurl *url = [nsurl urlwithstring:@"http://video.teknomart.com.tr/3-13-2.mp4"];  nsmutableurlrequest *liverequest = [[nsmutableurlrequest alloc] initwithurl:url]; [liverequest setcachepolicy:nsurlrequestreloadignoringcachedata];  [liverequest setvalue:@"headervalue" forhttpheaderfield:@"headerfield"];  nsurlresponse *response; nsdata *mydata = [nsurlconnection sendsynchronousrequest:liverequest returningresponse:&response error:&error]; nsdata *mydata2 = [nsdata datawithcontentsofurl:[nsurl urlwithstring:@"http://video.teknomart.com.tr/3-13-2.mp4"]];  nsstring *mystring=[[nsstring alloc] initwithdata:mydata encoding:nsasciistringencoding];  nslog(@"gelen sey %@",mystring);  [mystring writetofile:tempfile writetofile:tempfile automatically:yes encoding:nsasciistringencoding error:nil];   [mystring release]; return true; 

-(void)viewdidload {      nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);         nsstring *documentsdirectory = [paths objectatindex:0];         if (!documentsdirectory) {             nslog(@"documents directory not found!");         }         nsarray *mywords = [songnamestring componentsseparatedbycharactersinset:[nscharacterset charactersetwithcharactersinstring:@"/"]];         nsstring *appfile = [documentsdirectory stringbyappendingpathcomponent:[mywords lastobject]];         nslog(@"%@",[mywords lastobject]);         nsurl *url = [nsurl fileurlwithpath:appfile];         nslog(@"%@",url);         [[uiapplication sharedapplication] setstatusbarhidden:yes];         self.navigationcontroller.navigationbarhidden=yes;         currenttimer=[nstimer scheduledtimerwithtimeinterval:1 target:self selector:@selector(showcurrenttime) userinfo:nil repeats:yes];         alarmtimelabel.text =alarmtimestring;         alarmsonglabel.text = [mywords lastobject] ;         [self performselector:@selector(loadvideoinbackground)];         //[nsthread detachnewthreadselector:@selector(loadvideoinbackground) totarget:self withobject:nil];       }      -(void)loadvideoinbackground     {         nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);         nsstring *documentsdirectory = [paths objectatindex:0];         if (!documentsdirectory) {             nslog(@"documents directory not found!");         }         nsstring *appfile;         nsarray *mywords = [songnamestring componentsseparatedbycharactersinset:[nscharacterset charactersetwithcharactersinstring:@"/"]];         appfile = [documentsdirectory stringbyappendingpathcomponent:[mywords lastobject]];         nsfilemanager *filemgr=[nsfilemanager defaultmanager];         if (![filemgr fileexistsatpath:appfile]) {             alarmcanplay = false;             nsurl *imageurl = [[[nsurl alloc] initwithstring:songnamestring]autorelease];             nsurlrequest *imagerequest = [nsurlrequest requestwithurl:imageurl                                                            cachepolicy:nsurlrequestreturncachedataelseload timeoutinterval:120.0];             imageconnection = [[nsurlconnection alloc] initwithrequest:imagerequest delegate:self];              if(imageconnection)             {                 videodata = [[nsmutabledata data] retain];             }          }     }       - (void)connection:(nsurlconnection *)connection didreceiveresponse:(nsurlresponse *)response     {          // method called when server has determined         // has enough information create nsurlresponse         // can called multiple times, example in case of         // redirect, each time reset data.         // receiveddata declared method instance elsewhere         [videodata setlength:0];      }     - (void)connection:(nsurlconnection *)connection didreceivedata:(nsdata *)data     {         // append new data receiveddata         // receiveddata declared method instance elsewhere         //nslog(@"%d",[data size]);         [videodata appenddata:data];     }      - (void)connection:(nsurlconnection *)connection didfailwitherror:(nserror *)error     {         // release data object         [videodata release];          // inform user         nslog(@"connection failed! error - %@ %@", [error localizeddescription], [[error userinfo] objectforkey:nserrorfailingurlstringkey]);         //workinprogress = no;     }      - (void)connectiondidfinishloading:(nsurlconnection *)connection     {         nsarray *paths = nssearchpathfordirectoriesindomains(nsdocumentdirectory, nsuserdomainmask, yes);         nsstring *documentsdirectory = [paths objectatindex:0];         if (!documentsdirectory) {             nslog(@"documents directory not found!");         }         nsstring *appfile;         nsarray *mywords = [songnamestring componentsseparatedbycharactersinset:[nscharacterset charactersetwithcharactersinstring:@"/"]];         appfile = [documentsdirectory stringbyappendingpathcomponent:[mywords lastobject]];         [videodata writetofile:appfile atomically:yes];         alarmcanplay = true;     }