Errors occuring for unchanged code that previously functioned fine

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I have previously (a few months ago) managed to build my program with no problems, however I tried doing so today, with all code unchanged, and I presented with these errors. Is anyone able to tell me what I would need to do to fix this?

10:25:05: Starting: "/usr/bin/make" 
g++  -o OMR main.o OMR.o svm.o score.o moc_OMR.o   -L/usr/local/lib -lopencv_core -lopencv_imgcodecs -lopencv_highgui -lopencv_imgproc -lopencv_ml -lopencv_objdetect -lQt5Widgets -lQt5Gui -lQt5Core -lGL -lpthread 
/usr/bin/ld: warning: libImath-2_2.so.12, needed by /usr/local/lib/libopencv_imgcodecs.so, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libIlmImf-2_2.so.22, needed by /usr/local/lib/libopencv_imgcodecs.so, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libIex-2_2.so.12, needed by /usr/local/lib/libopencv_imgcodecs.so, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libHalf.so.12, needed by /usr/local/lib/libopencv_imgcodecs.so, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libIlmThread-2_2.so.12, needed by /usr/local/lib/libopencv_imgcodecs.so, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libavcodec.so.57, needed by /usr/local/lib/libopencv_videoio.so.3.3, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libavformat.so.57, needed by /usr/local/lib/libopencv_videoio.so.3.3, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libavutil.so.55, needed by /usr/local/lib/libopencv_videoio.so.3.3, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libswscale.so.4, needed by /usr/local/lib/libopencv_videoio.so.3.3, not found (try using -rpath or -rpath-link)
/usr/bin/ld: warning: libavresample.so.3, needed by /usr/local/lib/libopencv_videoio.so.3.3, not found (try using -rpath or -rpath-link)
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `av_write_frame@LIBAVFORMAT_57'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `avcodec_flush_buffers@LIBAVCODEC_57'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `avformat_free_context@LIBAVFORMAT_57'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `av_reduce@LIBAVUTIL_55'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `av_rescale_q@LIBAVUTIL_55'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `av_write_trailer@LIBAVFORMAT_57'
/usr/bin/ld: /usr/local/lib/libopencv_imgcodecs.so: undefined reference to `Imf_2_2::ChannelList::insert(char const*, Imf_2_2::Channel const&)'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `av_free@LIBAVUTIL_55'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `avcodec_encode_video2@LIBAVCODEC_57'
/usr/bin/ld: /usr/local/lib/libopencv_imgcodecs.so: undefined reference to `Imf_2_2::hasChromaticities(Imf_2_2::Header const&)'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `avcodec_decode_video2@LIBAVCODEC_57'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `avcodec_get_context_defaults3@LIBAVCODEC_57'
/usr/bin/ld: /usr/local/lib/libopencv_videoio.so.3.3: undefined reference to `av_log_set_level ...