Introduction to KreaTV GFX

This documentation describes the KreaTV graphics and input handling mechanisms. Basically, these two features are handled in two different components that can be used by applications, or rather graphics rendering libraries used by applications.

This document is written primarily for people that are going to integrate such rendering libraries on top of KreaTV.

Introduction

The graphics and input handling is divided into two different libraries, the graphics library called KreaTvGfx and the input library called KreaTvInput.

KreaTvGfx is a low-level graphics interface that allows the user to allocate and display pixmaps (graphics memory), perform hardware accelerated graphics operations (blitting) and setup video layers.

KreaTvInput is the library used to get events when keys are pressed and released.

Rationale

Graphics has traditionally been done using the X Window System which is not an optimal solution for high-performance graphics. This is the main reason to introduce a new graphics solution which:

• Provides direct access to graphics memory through the use of pixmaps.
• Provides hardware accelerated blit operations, e.g. fill, copy and blend operations.

There are other commercial and open-source graphics libraries that provide similar functionality to KreaTvGfx and KreaTvInput but KreaTvGfx is different in some aspects.

• It is designed with video in mind, i.e. it allows setting up video layers to show one or several video streams. It also makes sure that changes to video layers are synchronized with graphics changes to avoid flickering artifacts on the screen.
• It is possible to show different content on different outputs, e.g. HD video and a graphical user interface on HD outputs (e.g. HDMI), and SD video and only subtitle graphics on SD outputs (e.g. SCART).