ios - video zoom in and zoom out while recording iphone -

i working on app in user have facility zoom in , zoom out video. using av foundation record video not able zoom in , zoom out video when user recording video.

i using following code record video

    - (void) startcamera     nslog(@"setting capture session");         capturesession = [[avcapturesession alloc] init];          //----- add inputs -----         nslog(@"adding video input");          //add video input         avcapturedevice *videodevice = [avcapturedevice defaultdevicewithmediatype:avmediatypevideo];         if (videodevice)         {             nserror *error;             videoinputdevice = [avcapturedeviceinput deviceinputwithdevice:videodevice error:&error];             if (!error)             {                 if ([capturesession canaddinput:videoinputdevice])                     [capturesession addinput:videoinputdevice];                 else                     nslog(@"couldn't add video input");             }             else             {                 nslog(@"couldn't create video input");             }         }         else         {             nslog(@"couldn't create video capture device");         }          //add audio input         nslog(@"adding audio input");         avcapturedevice *audiocapturedevice = [avcapturedevice defaultdevicewithmediatype:avmediatypeaudio];         nserror *error = nil;         avcapturedeviceinput *audioinput = [avcapturedeviceinput deviceinputwithdevice:audiocapturedevice error:&error];         if (audioinput)         {             [capturesession addinput:audioinput];         }           //----- add outputs -----          //add video preview layer         nslog(@"adding video preview layer");         [self setpreviewlayer:[[avcapturevideopreviewlayer alloc] initwithsession:capturesession]];          previewlayer.orientation = avcapturevideoorientationportrait;       //<<set orientation.  can deliberatly set wrong flip image , may need set wrong right image          [[self previewlayer] setvideogravity:avlayervideogravityresizeaspectfill];           //add movie file output         nslog(@"adding movie file output");         moviefileoutput = [[avcapturemoviefileoutput alloc] init];          float64 totalseconds = 60;          //total seconds         int32_t preferredtimescale = 30;    //frames per second         cmtime maxduration = cmtimemakewithseconds(totalseconds, preferredtimescale);   //<<set max duration         moviefileoutput.maxrecordedduration = maxduration;          moviefileoutput.minfreediskspacelimit = 1024 * 1024;                        //<<set min free space in bytes recording continue on volume          if ([capturesession canaddoutput:moviefileoutput])             [capturesession addoutput:moviefileoutput];          //set connection properties (output properties)         [self camerasetoutputproperties];           //(we call method has done after changing camera)            //----- set image quality / resolution -----         //options:         //  avcapturesessionpresethigh - highest recording quality (varies per device)         //  avcapturesessionpresetmedium - suitable wifi sharing (actual values may change)         //  avcapturesessionpresetlow - suitable 3g sharing (actual values may change)         //  avcapturesessionpreset640x480 - 640x480 vga (check supported before setting it)         //  avcapturesessionpreset1280x720 - 1280x720 720p hd (check supported before setting it)         //  avcapturesessionpresetphoto - full photo resolution (not supported video output)         nslog(@"setting image quality");         [capturesession setsessionpreset:avcapturesessionpresetmedium];         if ([capturesession cansetsessionpreset:avcapturesessionpreset640x480])     //check size based configs supported before setting them             [capturesession setsessionpreset:avcapturesessionpreset640x480];            //----- display preview layer -----         //display full screen under out view controller existing controls         nslog(@"display preview layer");         cgrect layerrect;         layerrect = cgrectmake(284, 0, 200, 200);          [previewlayer setbounds:layerrect];         [previewlayer setposition:cgpointmake(cgrectgetmidx(layerrect),                                               cgrectgetmidy(layerrect))];         //[[[self view] layer] addsublayer:[[self capturemanager] previewlayer]];         //we use instead goes on layer behind our ui controls (avoids having manually bring each control front):         uiview *cameraview = [[uiview alloc] init];         [[self view] addsubview:cameraview];         [self.view sendsubviewtoback:cameraview];          [[cameraview layer] addsublayer:previewlayer];           //----- start capture session running -----         [capturesession startrunning]; }  //********** camera set output properties ********** - (void) camerasetoutputproperties {     //set connection properties (output properties)     avcaptureconnection *captureconnection = [moviefileoutput connectionwithmediatype:avmediatypevideo];      //set landscape (if required)     if ([captureconnection isvideoorientationsupported])     {         avcapturevideoorientation orientation = avcapturevideoorientationportrait;      //<<<<<set video orientation if landscape         [captureconnection setvideoorientation:orientation];     }      //set frame rate (if requried)     cmtimeshow(captureconnection.videominframeduration);     cmtimeshow(captureconnection.videomaxframeduration);      if (captureconnection.supportsvideominframeduration)         captureconnection.videominframeduration = cmtimemake(1, capture_frames_per_second);     if (captureconnection.supportsvideomaxframeduration)         captureconnection.videomaxframeduration = cmtimemake(1, capture_frames_per_second);      cmtimeshow(captureconnection.videominframeduration);     cmtimeshow(captureconnection.videomaxframeduration); }  //********** did finish recording output file @ url ********** - (void)captureoutput:(avcapturefileoutput *)captureoutput didfinishrecordingtooutputfileaturl:(nsurl *)outputfileurl       fromconnections:(nsarray *)connections                 error:(nserror *)error {      nslog(@"didfinishrecordingtooutputfileaturl - enter");      bool recordedsuccessfully = yes;     if ([error code] != noerr)     {         // problem occurred: find out if recording successful.         id value = [[error userinfo] objectforkey:averrorrecordingsuccessfullyfinishedkey];         if (value)         {             recordedsuccessfully = [value boolvalue];         }     }     if (recordedsuccessfully)     {         //----- recorded sucessfully -----         nslog(@"didfinishrecordingtooutputfileaturl - success");         alassetslibrary *library = [[alassetslibrary alloc] init];         if ([library videoatpathiscompatiblewithsavedphotosalbum:outputfileurl])         {             [library writevideoatpathtosavedphotosalbum:outputfileurl                                         completionblock:^(nsurl *asseturl, nserror *error)              {                  if (error)                  {                   }              }];         }      } } 

any great

you cannot zoom iphone camera, @ best can while taking pictures use cameraviewtransform: , apply transform live view of camera, still doesn't affect final picture taken