ios6 - Toggle camera using AVFoundation iOS 6 -

i want toggle camera using avfoundation. here code have subclass of nsobject

@interface capturesessionmanager : nsobject

@property (retain) avcapturevideopreviewlayer *previewlayer; @property (retain) avcapturesession *capturesession; @property (retain) avcapturestillimageoutput *stillimageoutput; @property (nonatomic, retain) uiimage *stillimage; 

in @implementation capturesessionmanager

    - (id)init {     if ((self = [super init])) {         [self setcapturesession:[[avcapturesession alloc] init]];     }     return self; }  - (void)addvideopreviewlayer {     [self setpreviewlayer:[[[avcapturevideopreviewlayer alloc] initwithsession:[self capturesession]] autorelease]];     [[self previewlayer] setvideogravity:avlayervideogravityresizeaspectfill];  }  - (void)addvideoinputfrontcamera:(bool)front {     nsarray *devices = [avcapturedevice devices];     avcapturedevice *frontcamera;     avcapturedevice *backcamera;      (avcapturedevice *device in devices) {          nslog(@"device name: %@", [device localizedname]);          if ([device hasmediatype:avmediatypevideo]) {              if ([device position] == avcapturedevicepositionback) {                 nslog(@"device position : back");                 backcamera = device;             }             else {                 nslog(@"device position : front");                 frontcamera = device;             }         }     }      nserror *error = nil;      if (front) {         avcapturedeviceinput *frontfacingcameradeviceinput = [avcapturedeviceinput deviceinputwithdevice:frontcamera error:&error];         if (!error) {             if ([[self capturesession] canaddinput:frontfacingcameradeviceinput]) {                 [[self capturesession] addinput:frontfacingcameradeviceinput];             } else {                 nslog(@"couldn't add front facing video input");             }         }     } else {         avcapturedeviceinput *backfacingcameradeviceinput = [avcapturedeviceinput deviceinputwithdevice:backcamera error:&error];         if (!error) {             if ([[self capturesession] canaddinput:backfacingcameradeviceinput]) {                 [[self capturesession] addinput:backfacingcameradeviceinput];             } else {                 nslog(@"couldn't add facing video input");             }         }     } }  - (void)addstillimageoutput  {   [self setstillimageoutput:[[[avcapturestillimageoutput alloc] init] autorelease]];   nsdictionary *outputsettings = [[nsdictionary alloc] initwithobjectsandkeys:avvideocodecjpeg,avvideocodeckey,nil];   [[self stillimageoutput] setoutputsettings:outputsettings];    avcaptureconnection *videoconnection = nil;   (avcaptureconnection *connection in [[self stillimageoutput] connections]) {     (avcaptureinputport *port in [connection inputports]) {       if ([[port mediatype] isequal:avmediatypevideo] ) {         videoconnection = connection;         break;       }     }     if (videoconnection) {        break;      }   }    [[self capturesession] addoutput:[self stillimageoutput]]; }  - (void)capturestillimage {       avcaptureconnection *videoconnection = nil;     (avcaptureconnection *connection in [[self stillimageoutput] connections]) {         (avcaptureinputport *port in [connection inputports]) {             if ([[port mediatype] isequal:avmediatypevideo]) {                 videoconnection = connection;                 break;             }         }         if (videoconnection) {        break;      }     }      nslog(@"about request capture from: %@", [self stillimageoutput]);     [[self stillimageoutput] capturestillimageasynchronouslyfromconnection:videoconnection                                                         completionhandler:^(cmsamplebufferref imagesamplebuffer, nserror *error) {                                                           cfdictionaryref exifattachments = cmgetattachment(imagesamplebuffer, kcgimagepropertyexifdictionary, null);                                                          if (exifattachments) {                                                            nslog(@"attachements: %@", exifattachments);                                                          } else {                                                             nslog(@"no attachments");                                                          }                                                          nsdata *imagedata = [avcapturestillimageoutput jpegstillimagensdatarepresentation:imagesamplebuffer];                                                              uiimage *image = [[uiimage alloc] initwithdata:imagedata];                                                          [self setstillimage:image];                                                          [image release];                                                          [[nsnotificationcenter defaultcenter] postnotificationname:kimagecapturedsuccessfully object:nil];                                                        }]; }  - (void)dealloc {      [[self capturesession] stoprunning];      [previewlayer release], previewlayer = nil;     [capturesession release], capturesession = nil;   [stillimageoutput release], stillimageoutput = nil;   [stillimage release], stillimage = nil;      [super dealloc]; }  -(void)togglecamera:(bool)front {     nsarray *devices = [avcapturedevice devices];     avcapturedevice *frontcamera;     avcapturedevice *backcamera;      (avcapturedevice *device in devices) {          nslog(@"device name: %@", [device localizedname]);          if ([device hasmediatype:avmediatypevideo]) {              if ([device position] == avcapturedevicepositionback) {                 nslog(@"device position : back");                 backcamera = device;             }             else {                 nslog(@"device position : front");                 frontcamera = device;             }         }     }     [[self capturesession] beginconfiguration];     nserror *error = nil;     avcapturedeviceinput *frontfacingcameradeviceinput = [avcapturedeviceinput deviceinputwithdevice:frontcamera error:&error];     avcapturedeviceinput *backfacingcameradeviceinput = [avcapturedeviceinput deviceinputwithdevice:backcamera error:&error];     if (front)     {         [[self capturesession] removeinput:backfacingcameradeviceinput];         if (!error) {             if ([[self capturesession] canaddinput:frontfacingcameradeviceinput]) {                 [[self capturesession] addinput:frontfacingcameradeviceinput];             } else {                 nslog(@"couldn't add front facing video input");             }             [[self capturesession] addinput:frontfacingcameradeviceinput];         }     } else     {         [[self capturesession] removeinput:frontfacingcameradeviceinput];         if (!error) {             if ([[self capturesession] canaddinput:backfacingcameradeviceinput]) {                 [[self capturesession] addinput:backfacingcameradeviceinput];             } else {                 nslog(@"couldn't add facing video input");             }             [[self capturesession] addinput:backfacingcameradeviceinput];         }     }      [[self capturesession] commitconfiguration]; } 

in viewcontroller , have

@property (retain) capturesessionmanager *capturemanager; @property (nonatomic,readwrite) bool isfrontcameraselected;      - (void)viewdidload {     self.isfrontcameraselected = no;      [self setcapturemanager:[[[capturesessionmanager alloc] init] autorelease]];      [[self capturemanager] addvideoinputfrontcamera:self.isfrontcameraselected]; // set yes front camera, no camera      [[self capturemanager] addstillimageoutput];      [[self capturemanager] addvideopreviewlayer];     cgrect layerrect = [[[self innerview] layer] bounds];     [[[self capturemanager] previewlayer] setbounds:layerrect];     [[[self capturemanager] previewlayer] setposition:cgpointmake(cgrectgetmidx(layerrect),cgrectgetmidy(layerrect))];     [[[self innerview] layer] addsublayer:[[self capturemanager] previewlayer]];      uiimageview *overlayimageview = [[uiimageview alloc] initwithimage:[uiimage imagenamed:@"overlaygraphic.png"]];     [overlayimageview setframe:cgrectmake(30, 60, 260, 260)];     [[self innerview] addsubview:overlayimageview];     [overlayimageview release];      uibutton *overlaybutton3 = [uibutton buttonwithtype:uibuttontypecustom];     [overlaybutton3 setimage:[uiimage imagenamed:@"camera.png"] forstate:uicontrolstatenormal];     [overlaybutton3 setframe:cgrectmake(130, 330, 60, 30)];     [overlaybutton3 addtarget:self action:@selector(innerscanbuttonpressed) forcontrolevents:uicontroleventtouchupinside];     [[self innerview] addsubview:overlaybutton3];      uibutton *cameraselection = [uibutton buttonwithtype:uibuttontypecustom];     [cameraselection setimage:[uiimage imagenamed:@"camera.png"] forstate:uicontrolstatenormal];     [cameraselection setframe:cgrectmake(260, 30, 60, 30)];     [cameraselection addtarget:self action:@selector(cameraselectiontapped:) forcontrolevents:uicontroleventtouchupinside];     [[self innerview] addsubview:cameraselection];    [[nsnotificationcenter defaultcenter] addobserver:self selector:@selector(saveimagetophotoalbum) name:kimagecapturedsuccessfully object:nil];      [[capturemanager capturesession] startrunning]; }  - (void)innerscanbuttonpressed {      [[self scanninglabel] sethidden:no];     [[self capturemanager] capturestillimage];  }  -(void)cameraselectiontapped:(id)sender {     [[self capturemanager] togglecamera:self.isfrontcameraselected]; } 

when click on togglecamera button , crashes below error

couldn't add facing video input *** terminating app due uncaught exception 'nsinvalidargumentexception', reason: '*** multiple audio/video avcaptureinputs not supported.' *** first throw call stack: (0x38f2f2a3 0x3725997f 0x39aff977 0x39aff091 0xe943d 0xe7875 0x3a4de0a5 0x3a4de057 0x3a4de035 0x3a4dd8eb 0x3a4ddde1 0x3a4065f1 0x3a3f3801 0x3a3f311b 0x37cad5a3 0x37cad1d3 0x38f04173 0x38f04117 0x38f02f99 0x38e75ebd 0x38e75d49 0x37cac2eb 0x3a4472f9 0xdf1ab 0x36324b20) 

i want add toggle feature user can use front / camera click photo.

any kind of highly appreciated. in advance.

you're trying add same device input twice in code:

if (!error) {         if ([[self capturesession] canaddinput:frontfacingcameradeviceinput]) {             [[self capturesession] addinput:frontfacingcameradeviceinput];         } else {             nslog(@"couldn't add front facing video input");         }         [[self capturesession] addinput:frontfacingcameradeviceinput];     } 

take out second call addinput on both front , logic.