Fix setup without pkg-config
Fix setup without pkg-config

mikeboers/PyAV,mcpv/PyAV,PyAV-Org/PyAV,xxr3376/PyAV,mikeboers/PyAV,PyAV-Org/PyAV,pupil-labs/PyAV,markreidvfx/PyAV,mcpv/PyAV,xxr3376/PyAV,xxr3376/PyAV,pupil-labs/PyAV,markreidvfx/PyAV,markreidvfx/PyAV,mcpv/PyAV,pupil-labs/PyAV,pupil-labs/PyAV