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frequency of composite video signal ? Answered

i try to configure a tv / video card on my computer to display input from composite video (yellow plug) input when i choose any of the inputs i still have to set the frequency (above). it should be some fixed standard frequency. what is it for pal b/g ?

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killerjackalope
killerjackalope

12 years ago

For PAL it should be 50hz and 60hz for NTSC, try both though, it depends on where you live... American is 60hz and UK is 50hz if that helps any, not sure elsewhere...

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Reply 12 years ago

thanks. i figured out. it displays what i need on composite-1 and ignores the frequency setting (i just left it at 1 mhz) now i have another problem with color system the composite signal (comind from digital cable tv decoder box) is pal - its the standard here and its what the tv detects when set to auto (the tv displays colors properly) i tried every possible color setting and they all kinda dont work properly image 1 (proper image but grayscale) : pal-nc and sometimes pal-m (pal-m is intermittent between images 1 and 5) image 2 (momentary snapshot) and 3 (onscreen - the frames are moving all the time) : all other pal's image 4 (momentary snapshot) and 5 (onscreen - the top of the screen is the proper bottom of the video in grayscale and below is constant green. the border between them does not move) : all ntsc's and sometimes pal-m image 2 and 3 but with each frame colored in one of r/g/b colors : all secam's why is there no color ? card is conexant bt878 and runs with linux

tv-1.pngtv-2.pngtv-3.pngtv-4.pngtv-5.png
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killerjackalope
killerjackalope

Reply 12 years ago

In that encoding box is there anything? Also take the time to test all the frequencies in case it's something weird about that. Check the output on something else aswell, if it displays fine check the settings on the output device. Also check the software output, it could be a problem with conversion rather than signal.

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Reply 12 years ago

this box converts encrypted digital stuff from cable tv to analog composite video i tried 1 mhz and 2 mhz and it is absolutely the same. i think the frequency setting is only for the tuner and ignored with composite the tv (standard analog tv) detects the signal as pal and displays video and colors correctly how do i test the software ?

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killerjackalope
killerjackalope

Reply 12 years ago

Test the software with another known source of video signal, to make sure it's not just a little problem with communications...

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Big Bwana
Big Bwana

Reply 12 years ago

who's drivers are you using ??

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Reply 12 years ago

linux v4l2 and xvideo