AVPlayerItem.externalMetaData in Objective C with tvOS build Target

Question

I’m implementing a feature for a tvOS app and it keeps crashing with unrecognized selector.

The app has a VideoPlayerBase class in objc and both iOS's VideoPlayerController.swift and tvOS's VideoPlayerController.swift are inherited from the base class. I need to set AVPlayerItem.externalMetaData once the video is loaded up. However, when I try to call AVPlayerItem.externalMetaData, it crashes.

If I set break point in BasePlayerController.m and do po player.currectItem.externalMetaData in console, I'll get this error

error: property 'externalMetadata' not found on object of type 'AVPlayerItem *'

error: 1 errors parsing expression

And then it will crash with this line

self.playerController.player.currentItem?.externalMetadata = episode.metadataItems

The call stack:

2016-10-28 09:51:33.808 App[14081:103783] -[AVPlayerItem setExternalMetadata:]: unrecognized selector sent to instance 0x608000214e10
2016-10-28 09:51:33.827 App[14081:103783] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[AVPlayerItem setExternalMetadata:]: unrecognized selector sent to instance 0x608000214e10'
*** First throw call stack:
(
    0   CoreFoundation                      0x0000000109b00b1b __exceptionPreprocess + 171
    1   libobjc.A.dylib                     0x000000010920421e objc_exception_throw + 48
    2   CoreFoundation                      0x0000000109b702d4 -[NSObject(NSObject) doesNotRecognizeSelector:] + 132
    3   CoreFoundation                      0x0000000109a863e5 forwarding + 1013
    4   CoreFoundation                      0x0000000109a85f68 _CF_forwarding_prep_0 + 120
    5   ***App                              0x0000000105baebd0 TFC6AMCApp21VideoPlayerController21playerDidStartPlayingfT_T + 848
    6   ***App                              0x0000000105baec72 TToFC6AMCApp21VideoPlayerController21playerDidStartPlayingfT_T + 34
    7   ***App                              0x0000000105b33e38 -[PlayerController play] + 216
    8   ***App                              0x0000000105b364e8 __42-[PlayerController playerReadyForPlayback]_block_invoke + 952
    9   libdispatch.dylib                   0x000000010a5c1980 _dispatch_call_block_and_release + 12
    10  libdispatch.dylib                   0x000000010a5eb0cd _dispatch_client_callout + 8
    11  libdispatch.dylib                   0x000000010a5cb8d6 _dispatch_main_queue_callback_4CF + 406
    12  CoreFoundation                      0x0000000109ac4cc9 CFRUNLOOP_IS_SERVICING_THE_MAIN_DISPATCH_QUEUE + 9
    13  CoreFoundation                      0x0000000109a8a75d __CFRunLoopRun + 2205
    14  CoreFoundation                      0x0000000109a89c64 CFRunLoopRunSpecific + 420
    15  GraphicsServices                    0x000000010d12da6f GSEventRunModal + 161
    16  UIKit                               0x00000001067eb612 UIApplicationMain + 159
    17  ***App                              0x0000000105b91562 main + 114
    18  libdyld.dylib                       0x000000010a637749 start + 1
)
libc++abi.dylib: terminating with uncaught exception of type NSException
(lldb)

However, if I set a break point before or on the line self.playerController.player.currentItem?.externalMetadata = episode.metadataItems and do a po in console po self.playerController.player.currentItem?.externalMetadata. I’ll get this

(lldb) po self.playerController.player.currentItem?.externalMetadata
▿ Optional<Array<AVMetadataItem>>
  - Some : 0 elements

Continuing from this line won’t crash anything!!!!!!!

I'm aware that externalMetadata property is a tvOS only property and I have AVFoundation, AVKit both import in my objc file and swift file.

I spent whole day yesterday and didn't get this solved :(

score 0 · Answer 1 · answered Jan 19 '17 at 16:16

You need to wrap lines, that contain property externalMetadata of AVPlayerItem like this:

#if TARGET_OS_TV
    self.playerController.player.currentItem?.externalMetadata = episode.metadataItems
#endif

or choose only tvOS target in Target Membership section of appropriate class

AVPlayerItem.externalMetaData in Objective C with tvOS build Target

1 Answers1