Based on libav commits by Luca Barbato and Yogender Gupta:
https://git.libav.org/?p=libav.git;a=commit;h=352741b5ead1543d775ccf6040f33023e4491186
https://git.libav.org/?p=libav.git;a=commit;h=e02e2515b24bfc37ede6ca1744696230be55e50b