You should download the Full library archive, available as ZIP, TAR.GZ, and as installation package for windows (.MSI), unfortunatly this is an huge file, you may save bandwidth downloading single sub-archives.. which one depends on what your are going to do..

Easy, with a text pad open one of these components (or all):

• ./source/inputs/vetDirectXInput.h
• ./source/inputs/vetDirectXInput2.h
• ./source/inputs/vetVideo4Linux.h

and their own test files:

• ./tests/test_vetDirectXInput.cpp
• ./tests/test_vetDirectXInput2.cpp
• ./tests/test_vetVideo4Linux.cpp

but you are probably more interested in these simple "applications":

• ./tests/app_vetDirectXLamePlayer.cpp
• ./tests/app_vetVideo4LinuxPlayer.cpp

check them out, code is often commented and quite simple, you may take a look to tests' project files for building your own (or just edit them):

• ./tests/mvc/
• ./tests/bcb/
• ./tests/Makefile

for more information check ./USE.

Yes, but there are some many open source players...
Anyway, related components are located in ./source/codecs/ folder, read headers and their tests (similar filename), your should take a look to:

• ./tests/app_vetLinuxMOVPlayer.cpp
• ./tests/app_vetLinuxMOVPlayerGTK.cpp
• ./tests/app_vetLinuxMPEGPlayer.cpp
• ./tests/app_vetLinuxMPEGPlayerGTK.cpp
• ./tests/app_vetLinuxXVIDPlayer.cpp

Sure! You help is welcome, first check ToDo list, then contact us.