What is this situation???

[topjx]

Undefined symbols for architecture armv7: "_kVTProfileLevel_H264_Baseline_AutoLevel", referenced from: webrtc::H264VideoToolboxEncoder::ConfigureCompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_kVTEncodeFrameOptionKey_ForceKeyFrame", referenced from: webrtc::H264VideoToolboxEncoder::Encode(webrtc::VideoFrame const&, webrtc::CodecSpecificInfo const, std::1::vector<webrtc::FrameType, std::1::allocator > const) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_kVTCompressionPropertyKey_RealTime", referenced from: webrtc::H264VideoToolboxEncoder::ConfigureCompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_kVTCompressionPropertyKey_ProfileLevel", referenced from: webrtc::H264VideoToolboxEncoder::ConfigureCompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_VTCompressionSessionGetPixelBufferPool", referenced from: webrtc::H264VideoToolboxEncoder::Encode(webrtc::VideoFrame const&, webrtc::CodecSpecificInfo const, std::1::vector<webrtc::FrameType, std::1::allocator > const) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_VTCompressionSessionInvalidate", referenced from: webrtc::H264VideoToolboxEncoder::DestroyCompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_kVTDecompressionPropertyKey_RealTime", referenced from: webrtc::H264VideoToolboxDecoder::ResetDecompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_decoder.o) "_VTCompressionSessionCreate", referenced from: webrtc::H264VideoToolboxEncoder::ResetCompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_VTCompressionSessionEncodeFrame", referenced from: webrtc::H264VideoToolboxEncoder::Encode(webrtc::VideoFrame const&, webrtc::CodecSpecificInfo const, std::1::vector<webrtc::FrameType, std::1::allocator > const) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_VTSessionSetProperty", referenced from: webrtc::H264VideoToolboxDecoder::ResetDecompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_decoder.o) internal::SetVTSessionProperty(void const, __CFString const, unsigned int) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) internal::SetVTSessionProperty(void const, __CFString const, bool) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) internal::SetVTSessionProperty(void const, __CFString const, __CFString const) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_kVTCompressionPropertyKey_AverageBitRate", referenced from: webrtc::H264VideoToolboxEncoder::SetBitrateBps(unsigned int) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) webrtc::H264VideoToolboxEncoder::ConfigureCompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_VTDecompressionSessionCreate", referenced from: webrtc::H264VideoToolboxDecoder::ResetDecompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_decoder.o) "_kVTCompressionPropertyKey_AllowFrameReordering", referenced from: webrtc::H264VideoToolboxEncoder::ConfigureCompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_encoder.o) "_VTDecompressionSessionDecodeFrame", referenced from: webrtc::H264VideoToolboxDecoder::Decode(webrtc::EncodedImage const&, bool, webrtc::RTPFragmentationHeader const, webrtc::CodecSpecificInfo const*, long long) in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_decoder.o) "_VTDecompressionSessionInvalidate", referenced from: webrtc::H264VideoToolboxDecoder::DestroyDecompressionSession() in SkyWay(webrtc_h264_video_toolbox.h264_video_toolbox_decoder.o) ld: symbol(s) not found for architecture armv7 clang: error: linker command failed with exit code 1 (use -v to see invocation)