[Buildroot] [PATCH 6/7] opencv: rework V4L/libv4l support

[Samuel Martin]

Starting with the 2.4.7 release, for V4L support, OpenCV does not
requires a libv4l dependency for its V4L support.

SO, it now provides 2 distincts knobs for this: WITH_V4L and a new
one: WITH_LIBV4L.

This patch takes advantage of this new knob and libv4l support is
now automatically enabled if only the libv4l package is enabled.

Signed-off-by: Samuel Martin <s.martin49 at gmail.com>
---
 package/opencv/Config.in | 11 ++++++-----
 package/opencv/opencv.mk | 10 +++++++---
 2 files changed, 13 insertions(+), 8 deletions(-)

diff --git a/package/opencv/Config.in b/package/opencv/Config.in
index bd466ca..a4342da 100644
--- a/package/opencv/Config.in
+++ b/package/opencv/Config.in
@@ -193,14 +193,15 @@ config BR2_PACKAGE_OPENCV_WITH_TIFF
 
 config BR2_PACKAGE_OPENCV_WITH_V4L
 	bool "v4l support"
-	depends on BR2_LARGEFILE
-	depends on BR2_TOOLCHAIN_HAS_THREADS
-	select BR2_PACKAGE_LIBV4L
 	help
 	  Enable Video 4 Linux support.
 
-comment "v4l support needs a toolchain w/ largefile, threads"
-	depends on !BR2_LARGEFILE || !BR2_TOOLCHAIN_HAS_THREADS
+	  If the package libv4l is enabled, its support is automatically enabled.
+
+if BR2_PACKAGE_OPENCV_WITH_V4L && !(BR2_LARGEFILE && BR2_TOOLCHAIN_HAS_THREADS)
+comment "libv4l support will be disabled."
+comment "libv4l support needs a toolchain w/ largefile, threads"
+endif
 
 comment "Install options"
 
diff --git a/package/opencv/opencv.mk b/package/opencv/opencv.mk
index c53d984..bbaba72 100644
--- a/package/opencv/opencv.mk
+++ b/package/opencv/opencv.mk
@@ -164,10 +164,14 @@ OPENCV_CONF_OPT += -DWITH_TIFF=OFF
 endif
 
 ifeq ($(BR2_PACKAGE_OPENCV_WITH_V4L),y)
-OPENCV_CONF_OPT += -DWITH_V4L=ON -DWITH_LIBV4L=ON
-OPENCV_DEPENDENCIES += libv4l
+OPENCV_CONF_OPT += \
+	-DWITH_V4L=ON \
+	-DWITH_LIBV4L=$(if $(BR2_PACKAGE_LIBV4L),ON,OFF)
+OPENCV_DEPENDENCIES += $(if $(BR2_PACKAGE_LIBV4L),libv4l)
 else
-OPENCV_CONF_OPT += -DWITH_V4L=OFF -DWITH_LIBV4L=OFF
+OPENCV_CONF_OPT += \
+	-DWITH_V4L=OFF \
+	-DWITH_LIBV4L=OFF
 endif
 
 # Installation hooks:
-- 
1.8.4.2