Video for Linux

1st place to understand basic structure of V4L2 interface is here. vivi driver is a sample source which could be used for either testing V4L2 based application or to start developing new driver. More information about vivi could be found here. Driver writer's guide is available here. Once all above links are covered, linux media interface could be looked here to go inside.

Although link is not for current scope, but it is good to have this link as a quick reference for lot of other interfaces.


Other references:
http://www.linuxtv.org/downloads/legacy/video4linux/v4l2dwgNew.html
Good sample to learn: v4l2 loopback-master

Check for
linux/videodev2.h
media/v4l2-ioctl.h
media/v4l2-common.h
http://www.kernel.org/doc/Documentation/video4linux/

Linux Windowing System

If your system doesn't have windowing system, probably you will be limited to console. You might be working from remote or you are an admin. But if end user is a consumer who is interested to see at-least a minimal GUI, you have to provide windowing system. X windowing system is one of the common windowing system used these days. X works on client server structure. Where server is installed in the system you are interested to interact and client could be anywhere, either local to the system or connected through network. A project developed with really a well thought.

If you have installed server in your system, it is up to the client how to mange the layout. Server just provides the service for windowing and how to put it in screen, this is clients responsibility and interest. Each window on screen is a client of X.


Refer:
http://linuxdevcenter.com/pub/a/linux/2005/08/25/whatisXwindow.html?page=1
http://xwinman.org/
http://en.wikipedia.org/wiki/X_Window_System