ColorBars (int "width", int "height", string "pixel_type")
The ColorBarsfilter produces a video clip containing SMPTE color bars scaled to any image size. The clip produced is 640x480, RGB32 [16,235], 29.97 fps, 1 hour long.
A test tone is also generated. Test tone is a 440Hz sine at 48KHz, 16 bit, stereo. The tone pulses in the RIGHT speaker, being turned on and off once every second.
In v2.56, pixel_type = "YUY2" or "YV12" is added (default "RGB32"). Note, this is almost equivalent to
ColorBars().ConvertToYUY2(matrix="PC.601") # don't scale the luma range
When directly generating YUV format data the color transitions are arranged to occur on a chroma aligned boundary.
The lower part of ColorBars is called the pluge. From left to right it consists of: -I, white, +Q, black, -4/0/+4 IRE levels and black. The -4/0/4 IRE levels can be used to set the brightness correctly. The -4 IRE and 0 IRE should have the same brightness, and the +4 IRE should be a little brighter than -4/0 IRE. The -I/+Q levels are not really interesting, since they are not used anymore for NTSC (analog TV), but they were used to set the chrominance correctly. More information about the colorbars and the pluge can be found here.
Changelog:
| v2.56 | added pixel_type="YUY2", "YV12" |
$Date: 2008/03/25 21:50:24 $