Use full path for #includes from another directory.

cmdutils.c

ffmpeg.c

ffplay.c

ffserver.c

libavcodec/ac3dec.c

libavcodec/ac3enc.c

libavcodec/ac3tab.h

libavcodec/alpha/dsputil_alpha.c

libavcodec/alpha/motion_est_alpha.c

libavcodec/alpha/mpegvideo_alpha.c

libavcodec/alpha/simple_idct_alpha.c

libavcodec/armv4l/dsputil_arm.c

libavcodec/armv4l/dsputil_iwmmxt.c

libavcodec/armv4l/mpegvideo_arm.c

libavcodec/armv4l/mpegvideo_armv5te.c

libavcodec/armv4l/mpegvideo_iwmmxt.c

libavcodec/bethsoftvideo.c

libavcodec/bfi.c

libavcodec/bfin/dsputil_bfin.c

libavcodec/bfin/mpegvideo_bfin.c