$ make
cc -I./  -lm  apiexample.c   -o apiexample
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0xdb): undefined reference to `_avcodec_find_decoder'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x10d): undefined reference to `_avcodec_alloc_context'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x115): undefined reference to `_avcodec_alloc_frame'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x149): undefined reference to `_avcodec_open'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x22e): undefined reference to `_avcodec_decode_video'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x32e): undefined reference to `_avcodec_decode_video'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x3d2): undefined reference to `_avcodec_close'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x3dd): undefined reference to `_av_free'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x3e8): undefined reference to `_av_free'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x425): undefined reference to `_avcodec_init'
/cygdrive/c/TEMP/ccwvz8j6.o:apiexample.c:(.text+0x42a): undefined reference to `_avcodec_register_all'
collect2: ld returned 1 exit status
make: *** [apiexample] Error 1