The Raspberry Pi has two ports to get a picture from it. There is a HDMI port which is able to transport a 1080p image to a monitor or a beamer and there is a composite port for the good old TVs. The problem with the HDMI port is HDMI itself – HDMI does not allow any conversion into another signal format. The con for the composite is its bad signal and the low resolution.
Currently I have no monitor which supports HDMI and there is no adapter from HDMI to something else. Therefor I have used an old TV grabber card as a workaround and attached the Pi using the composite port to the composite in of the TV card.
To get the output from the Pi on linux I use mplayer. It allows me to grab the signal from the TV card and display it at a window using the following command:
mplayer tv:// -tv driver=v4l2:device=/dev/video0:input=1:normid=3:fps=29 -nosound
Using a 3 meter cable placed between a whole bunch of other cables, the resulting image is somewhat bad. The white text on a console is displayed in rainbow colors and I can see some flickering and some scan lines all the time.