TV(3)TV(3)NAMEtv - Hauppage TV device
SYNOPSIS
bind -b #V /dev
/dev/tv
/dev/tvctl
DESCRIPTION
The tv device serves two files giving access to a Hauppage television
card in NTSC mode (only).
The control device tvctl accepts the following commands to control tun‐
ing and image processing:
init Reset the device to the default settings.
window minx miny maxx maxy
Set the display window size (default: none).
colorkey rl rh gl gh bl bh
Set the key limits for chromakey display to the given `low' and
`high' values for each of red, green and blue (default: 15 63
255 15 15 63), and enable use of the colour key. The value 255
for a lower limit disables the limit.
capture minx miny maxx maxy
Set the capture window (default: none); see the description of
reading the tv file, below.
capbrightness n
Set the brightness of a captured frame to n, on a scale from 0
to 100 (default: 13).
capcontrast n
Set the contrast of a captured frame to n, on a scale from 0 to
100 (default: 57).
capsaturation n
Set the saturation of a captured frame to n, on a scale from 0
to 100 (default: 51).
caphue n
Set the hue of a captured frame to n, on a scale from 0 to 100
(default: 0).
capbw n
Capture colour (n=0) or monochrome (n=1); (default: 0).
brightness n
Set the image brightness to n, on a scale from 0 to 100
(default: 0)
contrast n
Set the image contrast to n, on a scale from 0 to 100 (default:
54)
saturation n
Set image saturation to n, on a scale from 0 to 100 (default:
54)
source n
Set the input source to n (default: video input 0).
svideo n
If n is non-zero, set the input capture format to S-Video.
format n
Set the input format to n (0, NTSC-M; 1, NTSC-443; 2, external
control). Default: 0.
channel c f
Sets the right frequency for HRC CATV channel c, with fine tun‐
ing by signed offset f (in MHz).
volume m[ n ]
Set the volume of left and right channels to m and n, on a scale
from 0 to 100 (default: 80). If only m is given, set both left
and right volumes to m.
bass n Set the bass to n, on a scale from 0 to 100 (default: 50).
treble n
Set the treble to n, on a scale from 0 to 100 (default: 50).
freeze n
If n is non-zero, freeze the current frame; if n is zero,
unfreeze the video.
The data file tv is read-only. Reading is valid only after a capture
window has been set (see capture above). Each read at file offset 0
causes the contents of the input video image within the previously-set
capture window to be captured. The frame data is successively returned
in this and subsequent reads until a short read signals that all frame
data has been transferred. The data is returned in Plan 9 picfile for‐
mat, with a two line textual header followed by an empty line, followed
by the image data in binary format. The header has the form:
TYPE=ccir601
WINDOW=minx miny maxx maxy
The WINDOW coordinates are those of the capture window. The image data
is organised as interleaved scan lines from top to bottom of the win‐
dow, with UY0 and VY1 values alternating, with two bytes per value,
stored high-order byte first, encoded according to the IEEE digital
component video standard.
SOURCE
/os/port/devtv.c
/os/pc/tv.h
SEE ALSOaudio(3)TV(3)
