Missing dependancies

I ran go get -d, then go generate, both seemed to run fine, but running go install caused these errors

```
go install
# pkg-config --cflags -- gtk+-2.0 gstreamer-0.10 libxine libavdevice libavformat libavfilter libavcodec libswscale libavutil
Package gstreamer-0.10 was not found in the pkg-config search path.
Perhaps you should add the directory containing `gstreamer-0.10.pc'
to the PKG_CONFIG_PATH environment variable
No package 'gstreamer-0.10' found
Package libxine was not found in the pkg-config search path.
Perhaps you should add the directory containing `libxine.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libxine' found
Package libavdevice was not found in the pkg-config search path.
Perhaps you should add the directory containing `libavdevice.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libavdevice' found
Package libavfilter was not found in the pkg-config search path.
Perhaps you should add the directory containing `libavfilter.pc'
to the PKG_CONFIG_PATH environment variable
No package 'libavfilter' found
pkg-config: exit status 1
```

Reproduce the reported sequence with go get -d, go generate, and go install, then inspect how the project declares or documents its native pkg-config dependencies. The issue names missing gstreamer-0.10, libxine, and libav* packages but no files or tests; done should mean the installation requirements are clear and go install succeeds.

Written by the indexing model from the issue text.