MPlayer

Here are some commands to achieve simple playback in MPlayer from a variety of inputs. Here is the lspci output for the card used for testing:

0000:02:09.0 Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 02)
0000:02:09.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 02)

MPlayer will display the available inputs from the currently select video input device in it's output when it is invoked:

Playing tv://.
TV detected! ;-)
Selected driver: v4l2
 name: Video 4 Linux 2 input
 author: Martin Olschewski <olschewski@zpr.uni-koeln.de>
 comment: first try, more to come ;-)
Selected device: BT878 video (Askey CPH05X/06X (
 Tuner cap:
 Tuner rxs: MONO
 Capabilites:  video capture  video overlay  VBI capture device  tuner  read/write  streaming
 supported norms: 0 = PAL; 1 = NTSC; 2 = SECAM; 3 = PAL-Nc; 4 = PAL-M; 5 = PAL-N; 6 = NTSC-JP; 7 = PAL-60;
 inputs: 0 = Television; 1 = Composite1; 2 = S-Video;
 Current input: 1
 Current format: YUV420
v4l2: current audio mode is : MONO

This command will output to the default framebuffer the video signal that is connected to the RCA input on the TV card:

mplayer -tv driver=v4l2:input=1 tv://