S-video Port Question

[plupp]

I have conducted a few searches in the forum, and I have not come up with an answer to this question.

I understand that the pandora will have an s-video port.

My question is whether it will use the 7-pin s-video connector or the 4-pin s-video connector.

The 7-pin one, like in a laptop, can be used with a simple adapter which supplies a composite signal, but the 4-pin one only supports s-video.

If a 4-pin s-video port is used, does this not limit the usability of the device with for example a projector or a television set?

 

[Chip]

The Pandora will not have a physical S-video port built in to the case. Instead there will be a multi-purpose connector into which you can plug various adapter cables. I do not know whether the S-video adapter will be of the 4 pin or 7 pin variety, but we have been promised both S-video and composite out, so you're covered one way or the other.

 

[WizardStan]

it'll be the 4 pin.
The simple adapter can be used on the 7 pin because the extra pins actually are the extra output (whether it be composite or component).
The OMAP only outputs svideo, so the extra pins would be unused anyway.

 

[Squidge]

As chip says, the Pandora will support both S-Video and Composite, so a 7-pin SVideo connector would be pretty useless anyway.

EDIT: Actually, I don't think it does support composite.

 

[emil10001]

I thought that with a 7 pin svideo connector you can get an adapter to component connection. Which would not be useless.

http://en.wikipedia.org/wiki/S-Video#7_pin_mini-DIN

 

[Jaxartes]

I thought that with a 7 pin svideo connector you can get an adapter to component connection. Which would not be useless.

http://en.wikipedia.org/wiki/S-Video#7_pin_mini-DIN


So: "A/V -> S-video-7 pins -> component" vs the simpler "A/V -> component"?

 

[WizardStan]

I thought that with a 7 pin svideo connector you can get an adapter to component connection. Which would not be useless.

http://en.wikipedia.org/wiki/S-Video#7_pin_mini-DIN


Like I said, that's only if the port is already putting component line data out on the extra pins. The adapter just takes those extra lines.

 

[Tinnus]

And as everyone knows, Pandora's not outputting composite component, HDMI, DVI, RGB, VGA or anything like that

edit: fixed

 

[Squidge]

I thought that with a 7 pin svideo connector you can get an adapter to component connection. Which would not be useless.

With a 7 pin connector, you can get a wide variety of video output options (even VGA), but only if the device supports sending those signals down the connector. Also, those devices which do support such options typically don't allow a s-video plug to be directly connector to them - they require a converter lead (many graphics card do this).

And as everyone knows, Pandora's not outputting composite, HDMI, DVI, RGB, VGA or anything like that

Ah yes, true. I was thinking of a previous OMAP that supported composite. Not that composite is difficult to get from a S-Video signal anyway

 

[rokdcasbah]

So: "A/V -> S-video-7 pins -> component" vs the simpler "A/V -> component"?

Just to clarify: I don't think either of those are happening. The others have said composite is there but not component.

 

[emil10001]

All I was saying was that they weren't useless.

 

[Tinnus]

And as everyone knows, Pandora's not outputting composite, HDMI, DVI, RGB, VGA or anything like that

Ah yes, true. I was thinking of a previous OMAP that supported composite. Not that composite is difficult to get from a S-Video signal anyway
Sorry, I meant component instead of composite. IIRC someone (MWeston?) said the OMAP in the Pandora outputs both s-video and composite (signal is split inside the chip).

 

[Eolair]

And as everyone knows, Pandora's not outputting composite, HDMI, DVI, RGB, VGA or anything like that

Ah yes, true. I was thinking of a previous OMAP that supported composite. Not that composite is difficult to get from a S-Video signal anyway
Sorry, I meant component instead of composite. IIRC someone (MWeston?) said the OMAP in the Pandora outputs both s-video and composite (signal is split inside the chip).

From http://focus.ti.com/docs/prod/folders/print/omap3503.html:

Display subsystem
[..]
* 2 10-Bit Digital-to-Analog Converters (DACs) Supporting:
- Composite NTSC/PAL Video
- Luma/Chroma Separate Video (S-Video)

 

[Soulkiller]

Just to clarify.

I see A LOT of people don't know the difference between video signals and OFTEN get composite and component confused. Just because they both start with a C doesn't mean their the same :rolleyes:

Composite

[Yellow cable contains video data, Red cable for right channel audio and White for left channel audio]

Component

[Green cable is green channel along with SYNC signals sometimes/luma signal, Red cable has red channel/ chroma signal, Blue cable has blue channel/chroma signal, and Red and white are the same as the composite audio cables]

Theirs a BIG difference between the two. Composite is the older standard and is based on a luminance signal (black and white) with an interlaced color burst right before the luminance signal for that line is received (after an H-Sync)

Component is a more modern video signal that was developed because of composites poor bandwidth. It's different from composite in that instead of having a luminance signal that's interlaced with a color burst, it splits the video data into 3 different channels. Different standards are used with component cables. One standard that is also used in VGA connectors is RGB. It splits the video data into Red Green and Blue Channels. By mixing these colors together you get the final desired color in the video (Think of mixing colors in a painters pallet to get another color). Theirs different kinds of sub RGB standards that deal with how sync signals are used but mostly on component cables you will see a sync on green model. But because the bandwidth of RGB was still very demanding it was overtaken by another standard

The second, and more popular standard for component cables is YPbPr which consists of a Luminance signal on one channel much like composite is, except now instead of an interlaced color signal, its spread across 2 separate channels as Chroma data and is put together when it arrives at the receiver. YPbPr is superior to RGB in that it doesn't transmit redundant data like RGB does, thus lowering the bandwidth requirement.

Because Component has more bandwidth than Composite, it is able to achieve higher resolutions. This could mean all the way up to 1080p sometimes (1920×1080) while the best composite can achieve is 480p (640x480).

I hope this has enlightened some of you, now PLEASE don't mix them up!

 

[Squidge]

All I was saying was that they weren't useless.

In the topic of the thread (Pandora video output), they are useless

Sorry, I meant component instead of composite. IIRC someone (MWeston?) said the OMAP in the Pandora outputs both s-video and composite (signal is split inside the chip).

Argh! I remembered that the dev board didn't support composite, and since it supported other omaps, then it must have been the older ones which did composite.

Damn you for getting me confused

 

[WizardStan]

[Green cable is green channel along with SYNC signals sometimes/luma signal, Red cable has red channel/ chroma signal, Blue cable has blue channel/chroma signal, and Red and white are the same as the composite audio cables]

Just to clarify your clarification, the green cable doesn't contain any colour information. It's purely luma/sync (Y). Luma is the a weighted sum of Red, Green, and Blue.
The red line is actually Y-R (ie, the weighted sum of Blue and Green) and blue line is actually Y-B (ie, weighted sum of Red and Green). Some very simple analogue math is used to get the seperate colours out. The luma line is high bandwidth, giving you crystal clear grey scale images. The Y-R and Y-B lines are lower bandwidth colour to overlay the luma signal.
As far as getting component, I've actually designed and am working on building a cheap circuit to take svideo and output component. It won't increase the quality any, the signal will still be 480i, but at least it'll be more compatible with newer systems. Don't know if I'll actually finish it though.

 

[Soulkiller]

I was aware of that. I said green,red,blue channel for the RGB standard. as you can see after that I included "/luma" for the YPbPr standard along with "/chroma" after the red and blue descriptions.

 

[danboid]

Yeah but can we output to compo?

/dev/compo , where all colours are mixed with brown

 

[WizardStan]

I was aware of that. I said green,red,blue channel for the RGB standard. as you can see after that I included "/luma" for the YPbPr standard along with "/chroma" after the red and blue descriptions.

Yes, yes you did. I somehow missed that entire paragraph. My brain sucks sometimes. Sorry.

 

[Choklad_boll]

Does anyone know if Pandora will be shipped with a cable with S-video output?