build fails on osx.

cd src ; make ../caption-inspector
clang -c -Wpedantic -Wno-deprecated-declarations -I ../include source/mcc_file.c -o ../obj/mcc_file.o
In file included from source/mcc_file.c:29:
In file included from ../include/captions_file.h:23:
In file included from ../include/pipeline_utils.h:23:
../include/context.h:117:5: error: unknown type name 'AVCodecContext'
AVCodecContext* decoderContext;
===============================

any ideas??