Advice needed on HD connections please

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Adrian.P
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Joined: Mar 8 2002

A colleague of mine has one on the new Sony GV-HD 700 HD Walkmans (Walkmen?) and the instruction manual says that HD is transferred from the camera to the 700 via I Link (firewire) , but is played back to the HD television via the HDMI cable.

I thought the transfer should be in both directions using HDMI for HD and Firewire for DV.

Is HDMI a bi directional connection, or a one way street?

Alan Roberts
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You can't connect a IEEE1394 (Firewire/iLink) cable to a tv set, they don't have the sockets or the decoders. But they do have HDMI; that's what HDMI was invented for, as a closed connection between source and destination. The protocol carries a degree of encryption to prevent recording; it replaced DVI as the means of getting HDTV from a decoder into the display, and, as such, needs only to be unidirectional.

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Adrian.P
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Joined: Mar 8 2002

Thanks Alan for the speedy reply.

Alan Roberts
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My pleasure.

However, I could be wrong, because HDMI is the preferred connection to BluRay as well, so it could be bi-directional. The problem is that the kit at both ends of the connection would need to know that. The only HDMI kit I have is in the new plasma tele, nothing else yet. But I think you should regard it as only uni-directional for all practical purposes, until and unless someone proves me wrong (it does happen :))

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

harlequin
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I have seen hdmi stated as bi-directional , BUT , many manufacturers may make ports omni-directional , like many scart connections are on player only devices :)

Gary MacKenzie

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Alan Roberts
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Yep, that's my point. The technology may well allow it, but the implementations mostly don't. I suspect that my new P42Z81 may well have bi-directional HDMI ports, but I've no way of testing that yet.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

Tony Neal
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Joined: Oct 27 2006

From experience I've noticed that HDMI is bi-directional to the extent that devices at either end can have a digital conversation.

When first plugged into my Toshiba HDTV via HDMI, my Sony laptop instantly knew what make of TV it was connected to and what maximum resolution it could support.

Similarly, my PS3 knows when the Tosh is switched to its HDMI input and refuses to fire up a disk until until the TV is monitoring it. The PS3 also seems to know that the Tosh is1080i capable and always puts it into 1920x1080 exact scan mode.

Alan Craven
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Joined: Jan 26 2001

I have both a Sony V1E and a GV-HD700E, both of which have HDMI jacks which are described in the manuals as "Out", and that appears to be what they are. They are described as offering the highest quality connection to a TV with a suitable HDMI input jack.

HDMI is not mentioned as a possible means of transfer of files between devices and there is a warning in the camera manual about possible damage caused by unsuitable HDMI connections.

Alan Roberts
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Quite so, any bus connection must involve a degree of bi-directional chat to establish itself. But it's the continuous flow of content that's important here, 1394 has it, but I'm njot sure in HDMI has, in the implementations we come across these days.

Get my test cards document, and cards for 625, 525, 720 and 1080. Thanks to Gavin Gration for hosting them.
Camera settings documents are held by Daniel Browning and at the EBU
My book, 'Circles of Confusion' is available here.
Also EBU Tech.3335 tells how to test cameras, and R.118 tells how to use the results.

RayL
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Joined: Mar 31 1999

With many connectors (jack plugs and sockets, for example) the distinction between 'male' and 'female' is obvious. With others (like XLR) it's the pins (or the lack of them) that defines which is which (and either 'chassis' or 'inline' has to be added to complete the description).

But what about the HDMI? Is that connector (to be found on both ends of the cable) male or female?

Ray Liffen

harlequin
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male .... it plugs into the ''female'' connector on the equipment

Gary MacKenzie

sepulce@hotmail.com ( an account only used for forum messages )

Thinkserver TS140 , 750ti Graphics card  & LG 27" uws led backlight , Edius 8

Humax Foxsat HD Pvr / Humax Fox T2 dvbt