ffmpeg: add user-defined configure parameters

Closes #401

Signed-off-by: Luca Ceresoli <luca@lucaceresoli.net>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

CHANGES

@@ -7,7 +7,7 @@
 
 	New GTK-based configurator, usable using 'make gconfig'.
 
-	New packages: cgilua, copas, coxpcall, luafilesystem,
+	New packages: cgilua, copas, coxpcall, ffmpeg, luafilesystem,
 	luasocket, rings, wsapi, xavante
 
 	Updated/fixed packages: busybox, cdrkit, file, gawk,
@@ -19,6 +19,7 @@
 
 	Issues resolved (http://bugs.uclibc.org):
 
+	#401:  new package: ffmpeg
 	#1753: lmbench: convert to generic package infrastructure
 	#1771: Fakeroot and the target/generic/device_table.txt create bad...
 	#1807: LZMA 4.32.7, Required header file(s) are missing

package/multimedia/ffmpeg/Config.in

@@ -135,4 +135,11 @@ config BR2_PACKAGE_FFMPEG_OUTDEVS
 	bool "Enable output devices"
 	default y
 
+config BR2_PACKAGE_FFMPEG_EXTRACONF
+	string "Additional parameters for ./configure"
+	default ""
+	help
+	 Extra parameters that will be appended to FFmpeg's
+	 ./configure commandline.
+
 endif

package/multimedia/ffmpeg/ffmpeg.mk

@@ -114,6 +114,8 @@ else
 FFMPEG_CONF_OPT += --disable-zlib
 endif
 
+FFMPEG_CONF_OPT += $(call qstrip,$(BR2_PACKAGE_FFMPEG_EXTRACONF))
+
 # Override FFMPEG_CONFIGURE_CMDS: FFmpeg does not support --target and others
 define FFMPEG_CONFIGURE_CMDS
 	(cd $(FFMPEG_SRCDIR) && rm -rf config.cache && \