optional_depends flac                              \
                 '--with-flac'                     \
                 '--without-flac'                  \
                 'for FLAC audio decoding'         &&
optional_depends speex                             \
                 '--with-speex'                    \
                 '--without-speex'                 \
                 'for audio compression'           &&
optional_depends libmad                            \
                 '--with-libmad'                   \
                 '--without-libmad'                \
                 'for MPEG audio decoding'         &&
optional_depends libsamplerate                     \
                 '--with-libsamplerate'            \
                 '--without-libsamplerate'         \
                 'for sample rate converting'      &&
optional_depends JACK-DRIVER                       \
                 '--with-jack'                     \
                 '--without-jack'                  \
                 'for Jack audio connection kit'   &&
optional_depends polypaudio                        \
                 '--with-polypaudio'               \
                 '--without-polypaudio'            \
                 'for polypaudio sound server'     &&
optional_depends LIBAVCODEC                        \
                 '--with-ffmpeg'                   \
                 '--without-ffmpeg'                \
                 'for audio/video broadcasting'    &&
optional_depends alsa-lib                          \
                 '--with-alsa'                     \
                 '--without-alsa'                  \
                 'for ALSA sound support'          &&
optional_depends libogg                            \
                 '--with-vorbis'                   \
                 '--without-vorbis'                \
                 'for OGG Vorbis support'