Row 1364 of ./ffmpeg-0.4.9-pre1/configure states: echo "http://www.3gpp.org/ftp/Specs/latest/Rel-5/26_series/26073-510.zip" but the file is no longer available at that path. I found a file with that name at: http://www.3gpp.org/ftp/Specs/2003-06/Rel-5/26_series/