Undefined symbols for architecture x86_64:
  "_av_fast_realloc", referenced from:
      _ff_thread_release_buffer in libavcodec.a(pthread_frame.o)
  "_av_fifo_alloc_array", referenced from:
      _ff_frame_thread_encoder_init in libavcodec.a(frame_thread_encoder.o)
  "_av_fifo_freep", referenced from:
      _ff_frame_thread_encoder_free in libavcodec.a(frame_thread_encoder.o)
  "_av_frame_copy", referenced from:
      _ff_reget_buffer in libavcodec.a(utils.o)
  "_av_image_check_sar", referenced from:
      _ff_set_sar in libavcodec.a(utils.o)
      _ff_init_buffer_info in libavcodec.a(utils.o)
      _avcodec_open2 in libavcodec.a(utils.o)
  "_av_opt_copy", referenced from:
      _avcodec_copy_context in libavcodec.a(options.o)