Add libv4l2 to the pkg-config in order not to fail linking ffmpeg to nvmpi.so on the environments that doesn't support linking shared libs "like a chain"

[kazuki0824]

On Ubuntu the linker refers to rpath location by default. But when other environments like openembedded+bitbake or something like this, it is not. Adding libv4l2 to the Requires in pkg-config is essential since the program is slightly dependent on v4l2 function and lacking it can cause an issue on linking.

[kazuki0824]

@jocover is it checked?

[xia-chu]

when i merged this pr, cmake and ffmpeg configure cannot find libv4l2

[kazuki0824]

@xia-chu Thank you for filing it. Can you find libv4l2's pkg-config file manually? I bet pkg-config isn't configured properly.
Please check for 3 locations, under

• ${BITBAKE_SYSROOT}/usr/lib/pkgconfig
• ${BITBAKE_SYSROOT}/usr/lib/aarch64-linux-gnu/pkgconfig
• ${BITBAKE_SYSROOT}/usr/local/lib/pkgconfig

Next, please try a recently committed new one.

[xia-chu]

@xia-chu Thank you for filing it. Can you find libv4l2's pkg-config file manually? I bet pkg-config isn't configured properly. Please check for 3 locations, under

* ${BITBAKE_SYSROOT}/usr/lib/pkgconfig

* ${BITBAKE_SYSROOT}/usr/lib/aarch64-linux-gnu/pkgconfig

* ${BITBAKE_SYSROOT}/usr/local/lib/pkgconfig

Next, please try a recently committed new one.

No, pkg-config can not find libv4l2 manually. libv4l2 is located in /usr/lib/aarch64-linux-gnu/tegra , if set the environment variable of PKG_CONFIG_PATH, we should be able to find libv4l2