HDMI connectivity

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euanandrews

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#15949 17-Sep-2007 21:53

I'm still looking around for a way to connect my laptop to my tv via HDMI.

I see many laptops now coming out with HDMI built in...

Surely there must be a cardbus/pcmcia or external usb device available that offers HDMI connectivity?

Anybody seen/recommend anything?

sbiddle

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#86960 18-Sep-2007 06:44

Why exactly do you want HDMI to connect a PC to a TV? Unless you require HDMI for HDCP support there are no significant gains in doing so.

Most LCD's and Plasma's these days do a good job with VGA and will give you 1:1 pixel mapping using the VGA input. Start trying to plug your PC in via HDMI and you'll start pulling your hair out dealing with the overscan issue and lack of 1:1 pixel mapping.

Plugging a PC in with a HDMI -> HDMI cable should be childs play but unfortunately TV and PC GFX card manufacturers can't seem to sit down and actually make this work easily..:-(

Regs

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#86972 18-Sep-2007 09:17

sbiddle: Why exactly do you want HDMI to connect a PC to a TV? Unless you require HDMI for HDCP support there are no significant gains in doing so.

Most LCD's and Plasma's these days do a good job with VGA and will give you 1:1 pixel mapping using the VGA input. Start trying to plug your PC in via HDMI and you'll start pulling your hair out dealing with the overscan issue and lack of 1:1 pixel mapping.

I use DVI-D connection between my PC and my 42" plasma and I get 1:1 pixel mapping (resolution 848x480) and a better looking picture than with VGA. The signal doesnt need to do a digital-analog-digital conversion this way.

I'm not sure if the same setup can be reproduced with HDCP compliant signals but if the TV supports non-HDCP HDMI input then I can imagine that the above method could produce similar results to what I have.

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euanandrews

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#87008 18-Sep-2007 12:36

sbiddle: Why exactly do you want HDMI to connect a PC to a TV? Unless you require HDMI for HDCP support there are no significant gains in doing so.

Convenience

The rest of what you have said is beyond my current level of understanding...

I want 1 cable that does video and sound...simple.

I am currently using a high quality VGA cable and the pitcure is excellent, but the sound does not come from the tv but my laptop, that I want to change...

And I refuse to use the crappy audio out on the laptop as I have in the past, it does not properly seperate the channels etc...

geekiegeek

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#87009 18-Sep-2007 12:43

Might be easier to just get a USB audio device. I use one on my HTPC as I ran out of PCI slots, feeds optical to my reciever and also has coax and RCA (red, White).

Mine is Xitel, but creative and a nuber of others make them also.

euanandrews

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#87037 18-Sep-2007 16:32

geekiegeek: Might be easier to just get a USB audio device. I use one on my HTPC as I ran out of PCI slots, feeds optical to my reciever and also has coax and RCA (red, White).

Mine is Xitel, but creative and a nuber of others make them also.

Yeah, I'm just being fussy wanting to achieve this with just one cable, but as that is what HDMI is, I cant see why not...

When I finally get around to building my HTPC, this will all be sorted then anyway, but in the mean time...

Looking around at Creative and Xitel, I dont see very helpfull products, or overly complex for what I want...

I would of thought one could go about it one of two ways...

1) A cable that has usb on one end and component connections/outputs on the other
2) a decoding/processing box that does THX/DTS processing etc, connects to the laptop via usb and the box itself has the component connections/outputs

sbiddle

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#87048 18-Sep-2007 17:17

TheBartender:
sbiddle: Why exactly do you want HDMI to connect a PC to a TV? Unless you require HDMI for HDCP support there are no significant gains in doing so.

Convenience

The rest of what you have said is beyond my current level of understanding...

I want 1 cable that does video and sound...simple.

I am currently using a high quality VGA cable and the pitcure is excellent, but the sound does not come from the tv but my laptop, that I want to change...

And I refuse to use the crappy audio out on the laptop as I have in the past, it does not properly seperate the channels etc...

The ultimate goal when displaying PC content on a screen is to have 1:1 pixel mapping. In a nutshell this means that every pixel generated by the video card will display use one pixel on the plasma/lcd tv. VGA inputs on virtually all TV's will give this resulting in a perfect quality picture. If you don't have 1:1 pixel mapping you'll get blurred text and picture as each pixel won't quite map properly. 1:1 pixel mapping over HDMI will work with some TV's and won't with others, as Regs has mentioned above he has it on his TV but I can't get it on my 50" Pioneer Plasma. This is primarily caused by the TV scaling the input to fit the native resolution of the screen.

Overscan also causes a problem - PC's are a fixed resolution and only go to the edge of your screen whereas TV broadcasts are overscanned and actually extend past the edge of your TV screen. Using HDMI inputs will probably mean your PC picture will extend at least 5% outside the dimensions of the screen which means you may need to use a utility such as powerstrip to create a custom resolution and timing to get around this issue.

HDMI connectivity should be straight forward and be as simple as plugging a VGA cable in but unfortunately it's still some way from being a plug and play solution. This is something the industry is fully aware of however so hopefully we'll see things change for the better.

euanandrews

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#87053 18-Sep-2007 17:30

Cheers sbiddle, that was a great easy to understand reply for a simpleton like me...

I think I will leave it for now on that advice, but I will keep a look out for anything simular that catches my attention...

Just outa curosity, these lappys that have HDMI ports built in, how have they got around these issues, or have they not?

Such as this beast:

HP HDX9002

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Canterbury

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#87150 19-Sep-2007 11:22

I had similar issue - connecting laptop and home pc to sony 60" tv. My tv has a priopritory vga connector as well as 2 hdmi connectors. The vga cable only supports to 1376*768 so i bought a dvi to hdmi cable off trademe. Now i can connect to the TV as primary or secondary screen at full 1920*1080. As for the sound - theres no way i was going to watch blu-ray movies at full 1080p glory and have the sound come out of crappy 19watt speakers attached to TV. I therefore connect sound from sound card of either PC or PS3 to Amp as only the very latest Amps have HDMI support.
- As a side note - i'm fairly sure usb doesn't have the capacity to support true hdmi bandwith.
in short
Video :PC - TV= DVI-HDMI

Sound:PC - Amp= Analog (creative X-Fi sound card)
Video :PS3 - TV = HDMI-HDMI
Sound:PS3 - Amp= Digital Optical cable

chiefie

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#87152 19-Sep-2007 11:32

The least you could try (if you have laptop capable of ExpressCard/34) then try this option. Belkin High Speed Docking Station, using ExpressCard/34 to connect your LAN, VGA/DVI, Optical Digital output, 6-channels 3.5mm audio-out.

As mentioned by Canterbury, there is no such USB device that capable of doing what you want to HDMI, the best is USB-VGA for secondary monitor setup, even at its best, it doesn't carry sound either.

You'd have to look at newer laptops with HDMI which carry both video and audio to HDMI-TV, or PC with video card that can do HDMI (at the moment, Asus seems to be the only one that does HDMI with digital audio routed to GPU and through HDMI).

Or put up with what you have now, then later you can enjoy much better set up with money can buy to do what you want.

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lchiu7

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#87192 19-Sep-2007 17:13

The ultimate goal when displaying PC content on a screen is to have 1:1 pixel mapping. In a nutshell this means that every pixel generated by the video card will display use one pixel on the plasma/lcd tv. VGA inputs on virtually all TV's will give this resulting in a perfect quality picture. If you don't have 1:1 pixel mapping you'll get blurred text and picture as each pixel won't quite map properly. 1:1 pixel mapping over HDMI will work with some TV's and won't with others, as Regs has mentioned above he has it on his TV but I can't get it on my 50" Pioneer Plasma. This is primarily caused by the TV scaling the input to fit the native resolution of the screen.

Overscan also causes a problem - PC's are a fixed resolution and only go to the edge of your screen whereas TV broadcasts are overscanned and actually extend past the edge of your TV screen. Using HDMI inputs will probably mean your PC picture will extend at least 5% outside the dimensions of the screen which means you may need to use a utility such as powerstrip to create a custom resolution and timing to get around this issue.

HDMI connectivity should be straight forward and be as simple as plugging a VGA cable in but unfortunately it's still some way from being a plug and play solution. This is something the industry is fully aware of however so hopefully we'll see things change for the better.

Bang on. My RPTV only supports 1024x768 via VGA but the native resolution is 1376x768

And when using VGA the picture is windowed on the screen which is pretty annoying.

So I have to use DVI to HDMI and send a 1280x720 signal to the set. Then use the Nvidia drivers to compensate for overscan, After all that I can't really get 1:1 pixel mapping but for me it's not so much of a big deal. I only used the TV primarily for viewing content on my HTPC (using gbpvr and WinDVD) and with video as opposed to text in Windows, the lack of pixel mapping is hardly noticeable

But it's hardly plug and play!

Larry

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