Instead of trying to deal with this in the core SDL library, there are several text drawing libraries designed for use with SDL on the SDL libraries page . Common tecniques include using bitmap fonts, truetype fonts, and custom images for text. There are several GUI libraries available from the SDL libraries page . There is also a demo on the SDL demos page of using GTk natively with SDL, which works really well for graphics output. Many of them have documentation on how to get the toolkits to work with other applications.
Pitch refers to the number of bytes in a row of pixels.
This can differ from the width in pixels times the number of bytes per pixel, because of various alignment restrictions. In particular, this is the case for the X11 target which always presents you with a software framebuffer. Your video memory will always be reported to be zero if no acceleration is available. Note that this has nothing to do with 3D acceleration, just 2D hardware acceleration support in the underlying operating system graphics interface.