This directory contains files used in gecko builds from libav (http://libav.org). The current files are from v11.3 of the library. All source files match their path from the library's source archive. Currently, we only use the fft portion of the library, and only on x86 based platforms. If this changes, configuration files will most likely need to be updated. Configuration files were initially generated by running configure on the libav project, then dividing the config.h files into multiple files to reduce repeated entries. config_common.h contains package and architecture configuration information, and are used on all platforms. Platform specific config files (config_win.h/asm, config_unix.h/asm, etc) contain platform specific header information. .asm files should match their .h counterparts. If new architectures or projects are added, we will need to update defines to the config_common files. Platform headers should only need to be changed if we upgrade libav versions and require new headers to be found.