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Posts: 124 | Thanked: 52 times | Joined on May 2010 @ Sweden
#1
does anyone know what maximum display resolution the n900 supports through tv-out?

i remember the nokia N95 and N93. they supported 320x240 on the phone display. but on the tv-out it was pumped to 640x480 during video/picture playback.

maybe the n900 theoretically support 1024x768 or 800x600 with tv out?

what do u people think?

ps. of course there will be some distortions/noise with such a low standard video cable but it would still be a nice addition :-)
 
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#2
I think the resolution of the output is either 720x576 (PAL) and 720x480 (NTSC), or the phones resolution of 840x480. Hard to say.
But the technology used is outdated (analog), so it does look noisy at times.

The TV output is the only thing i hate about the N900. Why couldn't it have gotten a HDMI-Mini? It doesn't make sense, since you don't need to convert files...
 
Posts: 1,427 | Thanked: 2,074 times | Joined on Aug 2009 @ Sydney
#3
Yeah. 720p AVCHD video recording and playback support with HDMI out would have been awesome.... =(
 
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#4
I dont know exactly what the resolution is, but it is much lower than the internal screen's one.
It is correct to play games, but weak to read text.
Getting at least the same resolution as the internal screen would be great.
 
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#5
Originally Posted by phpman View Post
I dont know exactly what the resolution is, but it is much lower than the internal screen's one.
It is correct to play games, but weak to read text.
Getting at least the same resolution as the internal screen would be great.
You will never - with normal analog TV signals - get to that.
There are simply not 800 columns displayed on any TV standard, by most sensible measures.

For example - NTSC - yes - it has around 480 displayable rows, but the maximum luminance frequency is 4.5MHz - which divided by the line rate is 285.

http://www.maxim-ic.com/app-notes/index.mvp/id/734 - the active picture is 52/64ths of the line, so 52/64 * 285 = 231 complete cycles.

This means the image can go from black to white 231 times, or you might call this 462 pixels.

In practice, no normal reciever will quite do this, as the sound would begin to bleed through as high frequency artifacts, the real limit will be somewhat lower - perhaps around 420 pixels.

The colour bandwidth is considerably lower - if you want to display a red/green crosshatch, then this is around a resolution of 150 pixels.

The horizontal numbers for PAL are similar.
 

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Posts: 70 | Thanked: 408 times | Joined on Sep 2009 @ Fife, Scotland.
#6
Originally Posted by SpeedEvil View Post
You will never - with normal analog TV signals - get to that.
There are simply not 800 columns displayed on any TV standard, by most sensible measures.
The separate question of what might be the theoretical resolution of the tv-out - hooked up to a non-standard monitor is also an interesting one.

The relevant part of the schematic is on the left of page 2.
The tv out pin of the SoC is connected to a 3u3H inductor, and a 47pF cap to the Vfb pin.
This then goes to an analog switch at the top of page 8 - and straight to the output of the socket (through an ESD filter).


The DAC itself IIRC has a stupid maximum clock - 40MHz.
I would need to chec what the inductor/cap mean.

(however - you couldn't connect a _standard_ monitor of any description here, and get 1024*768).
At best it would be mono. Even if it's possible at all.

Another theroretically possible option would be USB-host with a USB video card - this is very much under development - nobodies gotten USB working properly yet.
 

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Posts: 179 | Thanked: 115 times | Joined on Apr 2010 @ Victoria BC Canada
#7
Originally Posted by Jack6428 View Post
The TV output is the only thing i hate about the N900. Why couldn't it have gotten a HDMI-Mini? It doesn't make sense, since you don't need to convert files...
Ironically, the composite out is one of the things I like most about this device.
Like anyone, I would like higher resolutions and digital output, but the simplicity and incredible connectivity, world wide, is one of the reasons I chose the n900 for my ultimate world travel companion. I can't imagine a more compact answer for video/picture viewing, anywhere I travel.
It's a knockout punch for me!
 
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Posts: 1,091 | Thanked: 322 times | Joined on Feb 2010 @ ~
#8
Originally Posted by Grok View Post
Ironically, the composite out is one of the things I like most about this device.
Like anyone, I would like higher resolutions and digital output, but the simplicity and incredible connectivity, world wide, is one of the reasons I chose the n900 for my ultimate world travel companion. I can't imagine a more compact answer for video/picture viewing, anywhere I travel.
It's a knockout punch for me!
I agree, I don't travel(I'm studying right now), but being able to use the N900 with all TV's that are manufactured from, lets say 1995 and forward is great. You might have to get a composite -> scart adapter though since older TV's might only have a scart connector.
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Posts: 635 | Thanked: 277 times | Joined on Sep 2009 @ Black Mesa Research Facility
#9
Originally Posted by Grok View Post
Ironically, the composite out is one of the things I like most about this device.
Like anyone, I would like higher resolutions and digital output, but the simplicity and incredible connectivity, world wide, is one of the reasons I chose the n900 for my ultimate world travel companion. I can't imagine a more compact answer for video/picture viewing, anywhere I travel.
It's a knockout punch for me!
While I do agree with this fact, still... a digital output (doesn't have to be HDMI) would benefit more from the capabilities of this device.
 
Posts: 124 | Thanked: 52 times | Joined on May 2010 @ Sweden
#10
awesome replies everyone. especially SpeedEvil's

ok it seems rather pointless to add higher resolutions to tvout then unless someone gets the usb host working.

i know some graphiccards can output analog s-video with acceptable quality in 800x600 and even half-usable 1024x768... but i can now see that regular composite video apparantly doesnt cut it.
 
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