Wednesday, October 05, 2016

HDMI, HDCP and SDi out from Bluray players

It's been a few years since the master HDCP key escaped into the wild and so it seems that particular content protection system is fundamentally wounded (if not dead!) but reputable manufacturers still respect the HDCP flag (even if no encryption is present) and the MPAA are still issuing device keys to manufacturers and volume keys to content producers.
So - I have been installing some Oppo Bluray players (nice, high end machines) and they support HDCP rather too aggressively; on a non-compliant display you don't even get the boot screen or any menus! So - an SDi converter is out of the question. 
The usual trick is to use one of these cheap'n'cheerful HDMI splitters which present a device key to terminate the signal but then send it to two outputs having done the decryption. 

Works perfectly with Backmagic HDMI->SDi converters with the exception of the audio; the Blackmagic knows nothings about DTS+ or DolbyDigital (or any of their variants) - it only understands the basic PCM stereo part of the bitstream and so that's what you get in the SDi stream.

However - in the case of these Oppo 103D players they have decoders on board and present the de-compressed audio out of the back as good old analogue feeds;

In these rooms I've fed them to the analogue inputs of the Tektronix WVR8200 test set and hence by selecting a different audio input you can toggle the TC Electronix ClarityX controller between 7.1 from the Avid and surround sound from the Oppo.


Unknown said...

Two HDMI > SDI converter manufacturers, will if asked nicely and a suitable form signed, disable the HDCP checks on their portable converters. Not sure it's appropriate to name them online but both reputable companies in the broadcast and AV markets respectively.

rhollan said...

What does that mean? You don't disable HDCP checks: you either negotiate a shared secret key or you get no video.

Phil Crawley said...

Yes, you're right - but the HDMI distribution amplifier is both a sink (on it's input) and a source (on it's outputs) and so it has a device-key and along with the volume-key decodes the incoming HDMI to clear but doesn't re-apply the key to it's outputs (which it really should).
The MPAA should blacklist it's device-key (and would have done ten years ago!) but these small Chinese manufacturers seem to fly under the radar; either that or they've just used the universal key-pair that has been floating around for years online.
HDCP was a solid idea but as ever having a back-door "universal key" was it's downfall.

Phil Crawley said...

Sorry Rene - just re-read and your comment applies to the first comment, not the post!