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Title: HDMI to VGA converter
Post by: Brian Larson on April 24, 2013, 07:01:12 pm
I need to take an HDMI signal and convert (scale) it to VGA. Ive found plenty of cheap looking options geared towards home theater setups but I need something reliable and flexible. Ideally just a single channel scaler with an HDMI input and a VGA output. Does not need to pass HDCP.  Can anyone recommend something? Budget is about $300.
Title: Re: HDMI to VGA converter
Post by: Ryan C. Davis on April 24, 2013, 07:57:29 pm
I've been having good luck with Atlona and whenever I've had questions they've been easy to contact and easy to talk to.

http://www.atlona.com/Atlona-HDMI-to-VGA-Component-Stereo-Audio-Format-Converter.html

I like Intellix and Kramer as well but I don't think either of them have such an offering.
Title: Re: HDMI to VGA converter
Post by: Brad Weber on April 25, 2013, 12:43:25 pm
I need to take an HDMI signal and convert (scale) it to VGA. Ive found plenty of cheap looking options geared towards home theater setups but I need something reliable and flexible. Ideally just a single channel scaler with an HDMI input and a VGA output. Does not need to pass HDCP.  Can anyone recommend something? Budget is about $300.
Technically, such a device would likely be illegal unless it rejected or downconverted any HDCP encrypted content.  For example, http://www.altinex.com/index.php?q=VP500-100&sbc=1 (http://www.altinex.com/index.php?q=VP500-100&sbc=1)d normally directly converts the HDMI input to the VGA output but automatically downconverts the output if the input is HDCP encrypted.  The devices such as the HDFury that get around that do so by being described as intended to convert a physical VGA input into a physical HDMI input and not to be used as a signal conversion device (which is probably how most people use them).

As you noted, there are a number of non-HDCP compliant HDMI-to-VGA converters.  However, do you really need it to scale as well as convert?  And do you need a "VGA" or HD15 output or would RGB or component video also be acceptable?
Title: HDMI to VGA converter
Post by: Brian Larson on April 25, 2013, 12:51:57 pm
HDCP is not an issue since all of the content will be made in house. What I need to do is come out of a switcher (Blackmagic Atem) and feed four HDTVs about 300' away. HD-SDI would obviously be ideal but too expensive for this project. We've already got a ton of VGA cable and DAs in the shop so I'd like to utilize those. RGBHV on BNCs would also be acceptable but eventually it will be adapted to HD15.

I'm pretty sure it needs to scale but maybe I'm wrong?

I'll look into that Atlona product.
Title: Re: HDMI to VGA converter
Post by: Jonathan Kok on April 25, 2013, 01:15:37 pm
HDCP is not an issue since all of the content will be made in house. What I need to do is come out of a switcher (Blackmagic Atem) and feed four HDTVs about 300' away. HD-SDI would obviously be ideal but too expensive for this project. We've already got a ton of VGA cable and DAs in the shop so I'd like to utilize those. RGBHV on BNCs would also be acceptable but eventually it will be adapted to HD15.

I'm pretty sure it needs to scale but maybe I'm wrong?

I'll look into that Atlona product.
Since your Atem is HD-SDI out, why not go HD-SDI to analog instead?  May be a better long-term solution.  BlackMagic, Aja and Kramer have HD-SDI to Component adapters; Aja & Kramer have HD-SDI to VGA adapters.  Atlona probably has similar; not familiar with their products. Whatever you do, verify that the adapter box will output a resolution that your TV will support.
Title: Re: HDMI to VGA converter
Post by: Brian Larson on April 25, 2013, 08:03:26 pm
Since your Atem is HD-SDI out, why not go HD-SDI to analog instead?  May be a better long-term solution.  BlackMagic, Aja and Kramer have HD-SDI to Component adapters; Aja & Kramer have HD-SDI to VGA adapters.  Atlona probably has similar; not familiar with their products. Whatever you do, verify that the adapter box will output a resolution that your TV will support.

When I first looked it seemed like all of the HD-SDI converters would be too expensive. Taking another look now and it's not as bad as I had thought.

Would the AJA HD10C work?

http://www.aja.com/en/products/mini-converters/hd10c2/#overview

It says it will output component or RGBHV but I only see three BNCs on the cable which leads me to believe it's only component. I'll be totally honest, I don't really know what the difference is between component and RGBHV aside from component being geared more towards consumer and RGBHV more towards the professional market.

Assume the HD10C does work for VGA; if I'm outputting 1080p from the Atem and I connect the HD10C to it through HD-SDI and loop out of the HD10c to a high end production monitor with an HD-SDI input, will the output quality of the HD10C dictate the quality/format of everything on that HD/SDI line? i/e: If i have a 720p monitor connected the output of the HD10C will the entire HD-SDI line be converted to 720p? I think this is the reason why I need a scaler.

Title: Re: HDMI to VGA converter
Post by: Gareth Marsh on April 26, 2013, 06:16:45 am
When I first looked it seemed like all of the HD-SDI converters would be too expensive. Taking another look now and it's not as bad as I had thought.

Would the AJA HD10C work?

http://www.aja.com/en/products/mini-converters/hd10c2/#overview

It says it will output component or RGBHV but I only see three BNCs on the cable which leads me to believe it's only component. I'll be totally honest, I don't really know what the difference is between component and RGBHV aside from component being geared more towards consumer and RGBHV more towards the professional market.

Assume the HD10C does work for VGA; if I'm outputting 1080p from the Atem and I connect the HD10C to it through HD-SDI and loop out of the HD10c to a high end production monitor with an HD-SDI input, will the output quality of the HD10C dictate the quality/format of everything on that HD/SDI line? i/e: If i have a 720p monitor connected the output of the HD10C will the entire HD-SDI line be converted to 720p? I think this is the reason why I need a scaler.

I think it is worth noting that you will struggle to get a 1080 signal to run down a VGA line for any considerable length - so unless you were converting from HD-SDI to VGA at each TV I wouldn't go down that route. Most of those little converters just convert the signal format and not the resolution at all.

If you ran everything at 720p then you will have more success as far as length is concerned. As far as your HD-SDI output question, as the ATEM isn't a scaler of any kind you have to have your inputs and switcher set to exactly the same frame rate and resolution, and that is what your output will also become. Most HD-SDI monitors will accept all varieties of HD-SDI and will not change the signal format at any point in the chain.

If it were me, here are the routes I would take, in order of preference (but not cost!):

- HDMI over fiber directly from ATEM to TVs through a DA (no conversions in line and least/no frame delay)

- HD-SDI through DA and to each TV then converted to HDMI at each TV (Keeping digital signal chain and high res but some conversion happening)

- HD-SDI to HD component through a converter like the AJA and then run over 5 core bnc to each TV. (Should be ok over that distance)


If you were to have to use VGA then a proper scaler of some kind would be the best option. You would need to down scale to get a reliable signal over that distance IMO. Something like the Barco Imagepro is the best for these issues, but is serious $$$. Any scaler/switcher with an HD-SDI input would also work, of course. This would likely give you another 1 or 2 frames of delay but that may not be a concern in this setup.

There is a possibility that you could have some colourspace issues depending on your input and output signal formats and your display devices. Any setup like this would need thorough testing of the entire system.


HTH

Gareth
Title: Re: HDMI to VGA converter
Post by: Brad Weber on April 26, 2013, 01:38:33 pm
HDCP is not an issue since all of the content will be made in house.
That means the content may not flag it, but it does not prevent the sources device from enabling it.  It should not be a factor for the ATEM since it does not support HDCP but with some limited number of computers and Blu-Ray players simply being connected to a HDCP compliant input may cause the source device to enable HDCP.

What I need to do is come out of a switcher (Blackmagic Atem) and feed four HDTVs about 300' away. HD-SDI would obviously be ideal but too expensive for this project. We've already got a ton of VGA cable and DAs in the shop so I'd like to utilize those. RGBHV on BNCs would also be acceptable but eventually it will be adapted to HD15.
As Gareth noted, even with a DA 300' is a long run for HD resolution signals over VGA/RGBHV cable.

When I first looked it seemed like all of the HD-SDI converters would be too expensive. Taking another look now and it's not as bad as I had thought.

Would the AJA HD10C work?

http://www.aja.com/en/products/mini-converters/hd10c2/#overview

It says it will output component or RGBHV but I only see three BNCs on the cable which leads me to believe it's only component. I'll be totally honest, I don't really know what the difference is between component and RGBHV aside from component being geared more towards consumer and RGBHV more towards the professional market.

Assume the HD10C does work for VGA; if I'm outputting 1080p from the Atem and I connect the HD10C to it through HD-SDI and loop out of the HD10c to a high end production monitor with an HD-SDI input, will the output quality of the HD10C dictate the quality/format of everything on that HD/SDI line? i/e: If i have a 720p monitor connected the output of the HD10C will the entire HD-SDI line be converted to 720p? I think this is the reason why I need a scaler.
I'm pretty sure it needs to scale but maybe I'm wrong?
I don't believe the ATEM supports 1080p, only 720p50/59.94 or 1080i50/59.94 for HD.  You select one of those and all of the ATEM inputs and outputs are set for that (the HDMI inputs will also accept the closest standard computer equivalent).

On the HD10C2, I have not seen a 13W3 connector since the Sun Microsystems and Silicon Graphics days but the three large pins are RGB/PbYPr while two of the smaller pins are the H and V signals and another two are ground connections.  So you can get RGBHV on an HD15, or essentially 'VGA', with the provided adapter. 

However, the HD10C2 apparently does not support 720p50 and that seems to leave 720p59.94 and 1080i50/59.94 as the HD options that both the ATEM and HD10C2 support.  As long as your displays accept the one of those options that you select for their VGA input then they will internally scale it to their native resolution.
Title: Re: HDMI to VGA converter
Post by: James Feenstra on May 05, 2013, 06:54:03 pm
I'll be totally honest, I don't really know what the difference is between component and RGBHV aside from component being geared more towards consumer and RGBHV more towards the professional market.
component is chroma/red/blue, rgbhv is red/blue/green/horizontal sync/verticle sync

Other than what the individual lines carry signal wise, there isn't a distinct advantage to any of them