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[Jeff Breen]

Hello,

I have a customer who recently upgraded the lab on campus to a "Digital" (hybrid analog/digital in reality) AV system centered around an AMX DVX-3150HD.  They would like to route one HDMI output to a capture card for recording.  Sources for recording are HD PTZ cameras, a desktop PC Displayport out and an HDMI connection for a laptop.  The laptop would often be a MacBook Pro.

I'm concerned about HDCP issues, particularly from the computers.  Since the typical use will be recording the cameras and the computers (to observe how people interact with software and websites), in theory nothing is copyright protected.  So what are the chances there will be a problem?  Will this capture card be viewed differently by the sources than a monitor or repeater?  In other words, COULD a computer's HDMI output refuse to send ANYTHING, copy protected or not, because the destination is a recorder?

Would I be better off with an HD-SDI capture card or VTR and scaling/converting the 2 computer's digital outputs to HD-SDI, stripping them of HDCP?  Or is that technically not legal to do so?

Sorry if this post lacks clarity.  Now back to my comfortable audio pursuits...

PS - since I really don't know enough about HDCP, can someone recommend a place to learn?  I'm going to look through support pages on Extron/Crestron/AMX web pages to see what I can learn.  Wish there were a video equivalent of Syn-Aud-Con.

[Brad Weber]

The laptop would often be a MacBook Pro.

Some Apple products will enable HDCP simply by being connected to a HDCP compatible input regardless of whether the content calls for it.  Unless you need the computer to be able to play back HDCP protected content you might want to see if you can turn off HDCP for that input.  In fact recording protected content seems to open up a number of potential issues and unless you really need to support playback of protected content you might be able to disable HDCP in general.

Will this capture card be viewed differently by the sources than a monitor or repeater?  In other words, COULD a computer's HDMI output refuse to send ANYTHING, copy protected or not, because the destination is a recorder?

In your case the AMX is handling the EDID and HDCP management and it could refuse to send any protected content to that output.
 
Perhaps another way to look at this is that if content is HDCP protected then the intent may be for it to not be digitally recorded so you may need to look at whether you are trying to address an unintended effect of the HDCP or to potentially subvert the intent of any copy protection.

Would I be better off with an HD-SDI capture card or VTR and scaling/converting the 2 computer's digital outputs to HD-SDI, stripping them of HDCP?  Or is that technically not legal to do so?

The HDMI-to-HD-SDI devices are typically HDCP compliant in that they will
not accept HDCP protected content and may tell the source to not send them HDCP protected content.  When I have talked with Blackmagic, Grass Valley, Aja and others about their converters they have all said that their products will not support being used as HDCP strippers as that would be effectively bypassing the copy protection.

PS - since I really don't know enough about HDCP, can someone recommend a place to learn?  I'm going to look through support pages on Extron/Crestron/AMX web pages to see what I can learn.  Wish there were a video equivalent of Syn-Aud-Con.

All three of those manufacturers as well as others such as Kramer Electronics have both online and classroom offerings on digital video.  While some of them tend to focus on their products, all of the related classes, workshops, etc. I've attended from those parties have included at least some general content.

[Jeff Breen]

Thanks, Brad, for your reply.

Perhaps another way to look at this is that if content is HDCP protected then the intent may be for it to not be digitally recorded so you may need to look at whether you are trying to address an unintended effect of the HDCP or to potentially subvert the intent of any copy protection.

The intent is to have the ability to record what is being done on these computers.  One day it may be to record student presentations for later review and critique, another day it may be to observe how different people interact with software or websites.  None of this should be HDCP protected content, and if they do want to try and record copy-written content then it should be throttled.

The big scary thing to me is "recording HDMI sources".  I'm afraid that because the DVX is HDCP capable, as well as all the downstream displays and the Black Magic capture card, that even if the content is not calling for HDCP that it will STILL somehow get shut down.

Perhaps I can disable HDCP on that input of the DVX.  I'm spending my weekend learning how AMX manages HDCP and EDID with these units.  I was thinking that all the devices down stream factor into the equation (HDCP can not be disabled on the recorder) but if the input of the DVX is considered as sink then perhaps that is not the case.

[Brad Weber]

Perhaps I can disable HDCP on that input of the DVX.  I'm spending my weekend learning how AMX manages HDCP and EDID with these units.  I was thinking that all the devices down stream factor into the equation (HDCP can not be disabled on the recorder) but if the input of the DVX is considered as sink then perhaps that is not the case.

While the default is HDCP compliance enabled you apparently can disable HDCP for each input.  In the DVX setup software go to the "Video" tab and then the "Video In" tab under that and there is a HDCP Setting checkbox.  Crestron apparently recently added a similar functionality to their DM products and both are supposedly in response to Macs and other devices that enable HDCP based on being connected to HDCP compliant devices rather than based on a content flag.  A potential downside to disabling the HDCP occurs where the related source devices will only provide a limited resolution output unless the HDCP handshake is completed.
 
Since all outputs on the DVX can be individually scaled you can independently set each output to pass the video with no scaling, to scale based on the EDID of the connected destination device or to scale to a manually selected setting.  If the EDID is based on the connected device you can then also select whether the EDID is automatically updated or not if the device EDID changes. On the inputs you can select to have the DVX automatically set the resolution or you can manually select a resolution.  EDID for the automatic selection can be selected to be mirrored from the connected display or set to use one of several internal EDID files (All, Full Screen only or Wide Screen only).  If you set the inputs to be automatically configured based on one of the internal EDID files and the outputs to automatically scale based on the destination device EDID you theoretically eliminate most potential EDID issues.

[ProSoundWeb Community]