there are many encode failed error

[notedit]

DEBUG2: 0030: 73 08 eb 9f s...
2014-05-13 17:01:54.092 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.101 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.112 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.116 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.123 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.144 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.146 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.152 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.172 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.173 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.230 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.260 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.290 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.294 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.296 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.298 testVideoPicker[983:6007] *************** Failed to encode given sample buffer
2014-05-13 17:01:54.367 testVideoPicker[983:6007] Failed to append sample buffer: Error Domain=AVFoundationErrorDomain Code=-11800 "The operation could not be completed" UserInfo=0x173471e0 {NSLocalizedDescription=The operation could not be completed, NSUnderlyingError=0x17226c00 "The operation couldn’t be completed. (OSStatus error -12763.)", NSLocalizedFailureReason=An unknown er