Switching for video

Rob Spence

Rob Spence

Senior
Jan 11, 2011
897
4
18
Boston Metro North West
www.lynxaudioservices.com
I find myself needing to connect several video sources (one at a time) to a projector.
In the past, one source was HDMI, which I adapted to the DVI input, and a PC which had a 15 pin D connector to the other input. Now I have 2 or possibly 3 HDMI sources to deal with.

I see on eBay a number of possibilities from a simple 3 way switch to 4x2 matrix switches. One even had audio outputs which in my application could save me running separate audio from each source.

Of course, given my lack of knowledge in this area, the cheap prices I see make me wary though I don't want to spend large on this one shot event.

So, advice and suggestions?

One source is a satellite receiver 120' away via a powered HDMI cable, and another is a MacBook pro with a HDMI dongal (unless they use an older one with DVI out).


Sent from my iPad HD
 
Re: Switching for video

Rob, there is a thread about HDMI distribution amps over in the PSW AV forum that might provide more info for you. One of the devilish details seems to involve HD copy protection and the required "handshake" between devices that is part of that CP scheme.
 
Re: Switching for video

For doing something on the cheap I'd highly recommend monoprice.com (Audio & Video Converters / Switches - Monoprice.com)

However like Tim said there's the issue of HDCP, meaning that even if you can get the signal to the projector it may not display it. The MacBook probably will be fine but I wouldn't count on that satellite receiver working.

For a bit more money look at Kramer's VP series of switchers, specifically one with a component input on it. If you go that route you still get HD but without all the encryption bullshit. Sadly that's probably more money then you want to spend though.
 
Re: Switching for video

One of the factors may be how 'cleanly' you want or expect it to switch. A simple HDMI switch may have to reestablish the HDMI 'handshake' every time you switch sources, which may also result in the projector having to resync to a different resolution or scan/refresh rate and all that can take several seconds (or longer) during which you get no image. More advanced seamless switchers with EDID management may allow much quicker and cleaner switches with a fixed resolution and scan/refresh rate output to the projector but you will pay a price for that added functionality.

The satellite receiver and MacBook may also introduce HDCP considerations. With a single output to a single display device that may not be as complex but there may still be considerations in how the switcher passes through or other handles HDCP.

One of the biggest 'gotchas' with HDCP is that the standards require enabling it when called for by the content but do no prohibit enabling it at other times. Thus if it is considered easier or better for a device to enable HDCP whenever connected to a HDCP compliant input or even at all times rather than only when the content flags it that is acceptable within the standards, although with sometimes unexpected consequences. In this case a switcher that is HDCP compliant feeding a projector that is not might trigger HDCP for the satellite receiver or Mac and then not allow the projector to display that signal.
 
Peter Etheredge said:
For doing something on the cheap I'd highly recommend monoprice.com (Audio & Video Converters / Switches - Monoprice.com)

However like Tim said there's the issue of HDCP, meaning that even if you can get the signal to the projector it may not display it. The MacBook probably will be fine but I wouldn't count on that satellite receiver working.

For a bit more money look at Kramer's VP series of switchers, specifically one with a component input on it. If you go that route you still get HD but without all the encryption bullshit. Sadly that's probably more money then you want to spend though.
Click to expand...

I used the satellite receiver last year with a 120' amplified HDMI cable through a DVI-D adapter to the projector with no problems (other than finding out I needed the cable three days before the event).

I will check out mono price.


Sent from my iPad HD
 
So, the saga continues.

The latest hitch is that when switch away from the MacBook to the TV feed, the display adapter on the MacBook disappears. Then, when I switch back to the MacBook, it has to rediscover the adapter and shows the rediscover on the projector. Sigh...

Any suggestions? I know I am over my head here and learning as I go but I am all they got for this.

Time is running out.


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Re: Switching for video

What switcher did you end up with? I've only ever seen my Macs do that when they stop seeing anything at the other end of the cable. The dongle is only an adaptor, it doesn't pretend to be destination equipment (display, switcher, projector, etc.)
 
Re: Switching for video

Rob Spence said:
So, the saga continues.

The latest hitch is that when switch away from the MacBook to the TV feed, the display adapter on the MacBook disappears. Then, when I switch back to the MacBook, it has to rediscover the adapter and shows the rediscover on the projector. Sigh...

Any suggestions? I know I am over my head here and learning as I go but I am all they got for this.

Time is running out.


Sent from my iPad HD
Click to expand...

You need a real switcher if doing this quasi-seamlessly matters to you. Kramer VP-4XX series have keepalives that will prevent your Mac from losing the screen, and I believe they support HDCP (please verify though). They are not truly seamless though - the projector will drop one or more frames when switching inputs. The VP-7XX series adds seamless switching - the switcher has a framebuffer that covers the glitch between inputs. Price of entry for a 7XX series is ~$1000, depending on how many and what kind of inputs you need.

I haven't found a cheaper way to do this well.
 
TJ Cornish said:
You need a real switcher if doing this quasi-seamlessly matters to you. Kramer VP-4XX series have keepalives that will prevent your Mac from losing the screen, and I believe they support HDCP (please verify though). They are not truly seamless though - the projector will drop one or more frames when switching inputs. The VP-7XX series adds seamless switching - the switcher has a framebuffer that covers the glitch between inputs. Price of entry for a 7XX series is ~$1000, depending on how many and what kind of inputs you need.

I haven't found a cheaper way to do this well.
Click to expand...

A Kramer VP-4xx seems like what I need ( or rent a 7xx).
Anyone in the northeast got one to loan or rent?


Sent from my iPad HD
 
The saga continues...

I believe I now have a workable solution for this weeks event though there are aspects I don't understand. I am hoping some of you video gurus can educate me.

I have reverted to a simple mechanical HDMI switch. Between each of the sources I have a Gefen HDMI or DVI Detective which records the EDID of the projector and keeps the source happy when disconnected from the projector. So, now all there is is a little resync of the projector when switching inputs. I can live with this.

My puzzle for now is that some combinations of DVI cables to HDMI and also an electronic switch/scaler from Monoprice (3x1 HDMI Converter Switch -MC301) end up with an image that looks kinda pink ( like the green is missing ?).

I guess I could understand that perhaps the HDMI signal source could be a little weak after the Gefen box since the source is over an amplified 120' cable. I didnt expect the 10' DVI cable through the scaler and a 6' HDMI to a DVI adapter at the projector to o it too.

Can someone explain to a sound guy what is likely going on and are there any low cost solutions you can suggest?

I expect that if I had a thousand dollar or more budget there are likely lots of Kramer class products that could help.

At this time I am already spent out of my budget for this gig and need to get it behind me but my quest for understanding is not yet satisfied.

Thank you


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Re: Switching for video

Rob, pretty much the same approach as audio, keep trying to narrow it down and see if you can isolate it to particular components or cables. And with HDMI connectors it could be as simple as a poorly seated connector.

I will also note that although theoretically the video portion of HDMI and DVI-D/I are identical and I have usually been able to adapt directly between them without any problem, I have encountered some devices that don't always work properly with that. When I encountered a problem with a specific HDMI input device one of the first questions that manufacturer asked was whether we were sending it actual HDMI or DVI via an adapter cable, turns out they had apparently found that their product did not work reliably with a number of DVI-to-HDMI adapters. And although apparently a known 'feature', that was not noted in any of the product literature or documentation. To their credit, the manufacturer agreed to take the units back, unfortunately the Contractor was not a direct dealer and had purchased them through a distributor who would not take them back.
 
Re: Switching for video

Rob Spence said:
The saga continues...
My puzzle for now is that some combinations of DVI cables to HDMI and also an electronic switch/scaler from Monoprice (3x1 HDMI Converter Switch -MC301) end up with an image that looks kinda pink ( like the green is missing ?).
Click to expand...

I've had that too using a monoprice 4X4 HDMI matrix switcher. Except it was really pink almost purple and there was no other color on the screen -like B&W TV except only pink instead of white.

I had to power everything down (physically disconnect power as Sat boxes, TV's and monoprice switch never actually turn "off" 100%) to get it all to return top normal. After a few switchings it would re-occur. I ended up putting an EDID manager box (Audio Authority 1322d) on every source. still doesn't work as smoothly as analog used to.

Lately I try to do as much "switching" in software using Keynote or Q-Lab and then connecting to the projectors with VGA (sad but true)
Component video works good too as you can get HD resolutions and older blu-ray and sat boxes have it also -this of course will only work as long as they don't start restricting the output resolutions on analog connections.

All of my clients don't notice any analog picture-quality issues but are very happy with instant switching and no handshake issues. It helps with good cableing and keeping mind of native resolutions.
 
Craig Hauber said:
I've had that too using a monoprice 4X4 HDMI matrix switcher. Except it was really pink almost purple and there was no other color on the screen -like B&W TV except only pink instead of white.

I had to power everything down (physically disconnect power as Sat boxes, TV's and monoprice switch never actually turn "off" 100%) to get it all to return top normal. After a few switchings it would re-occur. I ended up putting an EDID manager box (Audio Authority 1322d) on every source. still doesn't work as smoothly as analog used to.

Lately I try to do as much "switching" in software using Keynote or Q-Lab and then connecting to the projectors with VGA (sad but true)
Component video works good too as you can get HD resolutions and older blu-ray and sat boxes have it also -this of course will only work as long as they don't start restricting the output resolutions on analog connections.

All of my clients don't notice any analog picture-quality issues but are very happy with instant switching and no handshake issues. It helps with good cableing and keeping mind of native resolutions.
Click to expand...

I sure would like to know what it is that causes that pink. You described it well.


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Re: Switching for video

Rob,

If you have the ability to choose the color space, you might want to make sure your working in RGB and not YUV. Switching that on our Analog Way PLS300 gives the output (or input) a pink tone.
 
Jordan Wolf said:
Rob,

If you have the ability to choose the color space, you might want to make sure your working in RGB and not YUV. Switching that on our Analog Way PLS300 gives the output (or input) a pink tone.
Click to expand...

If all my inputs and outputs are HDMI or DVI, how do I choose color space?

I really am a neo on video just leaning as my feet burn :)


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Re: Switching for video

Rob Spence said:
If all my inputs and outputs are HDMI or DVI, how do I choose color space?

I really am a neo on video just leaning as my feet burn :)


Sent from my iPad HD
Click to expand...

Hi Rob,

Here is the manual http://www.analogway.com/files/uplo...enue-presentation-switchers-usermanual(2).pdf

Try the following
Menu> Input> DVI 1/2..... At this point make sure it's set to DVI with RGB.
Then do
Menu> Output> DVI Type...... At this point make sure it's set to RGB full.

Hope this helps
 
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