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Benson's Avatar
Posts: 4,930 | Thanked: 2,272 times | Joined on Oct 2007
#21
Originally Posted by james415 View Post
A composite (yellow RCA cable) video signal is composed of three signals, intensity, horizontal and vertical retrace. Horizontal signals are 5microsecond low-pulls and the vertical similar but about 450microseconds. The data in in the intensity signal, a wave between 0.5 and 2.0 volts transmitted between the retrace signals. The total bandwidth required is about 3.0MHz.

For those that are not engineers, an basic video signal is not that different from an audio signal. If someone wrote a program to output sound through the headphones at the specific signal to represent an video image, the TV would be able to interpret it without a problem.
That's fine, except for Nyquist's theorem, which basically states that to construct a 3 MHz signal, you need at least a 6 MHz sample rate. (The audio chip in the N8x0 has a maximum sample rate of 48 kHz.)

Other devices use RF electronics to generate video signals; without that circuitry, you can't do it.
 
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#22
This is a needless restriction by nokia. The n95 which has similar specs can output component video via its headphone jack. Nokia is blatantly taking advantage of the community. This is why developers hate maemo. FSM forbid they do the same to QT? Look what they did to symbian. With symbian, you dont even own your phone. Viva la GPL V3

End fscking rant
 
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Posts: 2,535 | Thanked: 6,681 times | Joined on Mar 2008 @ UK
#23
Yes, Nokia obviously had all the ability to do it, but just couldn't be arsed.

There's no other possible explanation! They just hate us free-software-using red (text) commies and want to make our lives miserable.

Ari Jaaksi sits in his ivory tower, with Quim Gil at his feet, laughing maniacally every time there's a moan here about a missing feature. It's true, my wife's brother's best friend works there as a cleaner.
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#24
I don't know if this has been ask...what is the highest quality that can be output with N900 using TVOUT?? I am not getting clear picture with my HDTV. Is this normal with composite cable? Or is there some kind of adapter u can get to display better quality?
 
Posts: 1,258 | Thanked: 672 times | Joined on Mar 2009
#25
it's sdtv quality on composite. the 800x480 resolution is approx sdtv res.
 
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