Andy Walls schrieb: > On Tue, 2010-07-06 at 13:27 +0200, Frank Schaefer wrote: > >> Hi, >> >> there are two video controls in the Bttv-driver called "whitecrush >> upper" and "whitecrush lower". >> But what does "whitecrush" mean ? Is it the same as "white noise" ? >> The german KDE translators are currently trying to translate these >> strings... >> > > "White Crush" is Conexant's term for adapting to nonstandard or varying > Sync to White level voltage differences of the incoming video signal. > It's basically an adaptive AGC to prevent "blooming" of the video signal > due to very high Luminance levels. > > The public BT878A datasheet has terse descriptions of what the registers > settings do: they are basically upper and lower thresholds to determine > when to adapt the automatic gain control. > > The public CX25840 datasheet gives a better written description of white > crush in section 3.4.9: > > http://dl.ivtvdriver.org/datasheets/video/cx25840.pdf > > I'm actually surprised the bttv driver has those presented as user > controls at all. > > Regards, > Andy > Thank you Andy, that really helps a lot ! Regards, Frank -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
