How to render a self-written widget in Gtk

I've been writing a Gtk+ Widget which plays videos and, using libAV, I can load and read video files but I don't know how to get the frame data rendered as a widget. What do I do to render it? The frame data consists of an array of unsigned chars.

>>8 BUT I LIKED GOPHER!  *sniff*

- It's also a good practice to include the word "Long" in the subject header so the recipient knows the message will take time to read and respond to. Over 100 lines is considered "long".

Attention spans have dropped drastically in 16 years.

- If you include a signature keep it short.  Rule of thumb is no longer than 4 lines.

*cough* Warlording *cough*