libavutil.pc missing some dependencies

[Mr-Dave]

Summary of the bug:
Some dependent libraries are missing in the package config

How to reproduce:
Build ffmpeg with the following script

cd /home/user/ffmpeg_sources
wget http://ffmpeg.org/releases/ffmpeg-3.2.2.tar.bz2
tar xjvf ffmpeg-3.2.2.tar.bz2
cd ffmpeg-3.2.2

PATH="/home/user/ffmpeg_32/bin:$PATH" PKG_CONFIG_PATH="/home/user/ffmpeg_32/lib/pkgconfig" ./configure \
  --prefix="/home/user/ffmpeg_32" \
  --pkg-config-flags="--static" \
  --extra-cflags="-I/home/user/ffmpeg_32/include" \
  --extra-ldflags="-L/home/user/ffmpeg_32/lib" \
  --bindir="/home/user/ffmpeg_32/bin" \
  --enable-gpl \
  --enable-libass \
  --enable-libfdk-aac \
  --enable-libfreetype \
  --enable-libmp3lame \
  --enable-libopus \
  --enable-libtheora \
  --enable-libvorbis \
  --enable-libvpx \
  --enable-libx264 \
  --enable-libx265 \
  --enable-nonfree
PATH="/home/user/ffmpeg_32/bin:$PATH" make
make install

This results in the following line in libavutil.pc

Libs: -L${libdir}  -lavutil -lm

When linking programs that use ffmpeg, libavutil fails with

/home/user/ffmpeg_32/lib/libavutil.a(hwcontext_vaapi.o): In function `vaapi_device_free':
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:829: undefined reference to `XCloseDisplay'
/home/user/ffmpeg_32/lib/libavutil.a(hwcontext_vaapi.o): In function `vaapi_device_create':
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:859: undefined reference to `XOpenDisplay'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:864: undefined reference to `vaGetDisplay'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:871: undefined reference to `XDisplayName'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:861: undefined reference to `XDisplayName'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:885: undefined reference to `vaGetDisplayDRM'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:859: undefined reference to `XOpenDisplay'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:861: undefined reference to `XDisplayName'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vaapi.c:866: undefined reference to `XDisplayName'
/home/user/ffmpeg_32/lib/libavutil.a(hwcontext_vdpau.o): In function `vdpau_device_create':
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vdpau.c:432: undefined reference to `XOpenDisplay'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vdpau.c:438: undefined reference to `XDisplayString'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vdpau.c:440: undefined reference to `XDefaultScreen'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vdpau.c:440: undefined reference to `vdp_device_create_x11'
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vdpau.c:434: undefined reference to `XDisplayName'
/home/user/ffmpeg_32/lib/libavutil.a(hwcontext_vdpau.o): In function `vdpau_device_free':
/home/user/ffmpeg_sources/ffmpeg-3.2.2/libavutil/hwcontext_vdpau.c:411: undefined reference to `XCloseDisplay'
collect2: error: ld returned 1 exit status

To work around the issue, revise libavutil.pc to have the following line:

Libs: -L${libdir}  -lavutil -lm -lX11 -lvdpau -lva-drm -lva-x11 -lva

This issue appears to have been introduced in version 3.1

[jkqxz]

This was fixed on master some time ago.