In the early days compatibility between HDMI components was/is a major issue...
Basically because few brands would spend the significant $ expense and time allowance required for HDMI/HDCP certification. Also the certification was less crucial for an HDMI source or HDMI sync product as many are simply a plug & play type as no HDMI repeater was required.. The biggest challenge are the AVRs which have to take the incoming
HDMI/HDCP encoded stream, extract it, decode it and the re-encode it then export out to the HD display in exactly the same timing as the input stream..
1 way a brand could check their product for HDMI/HDCP was to attend 1 of the HDMI plug-fests.. @ the plug-fests a brand could check an engineering sample with other brands, not perfect but a great inexpensive way to check for compatibility between HDMI products. Here is an overview of how & what is tested @ a plug-fest....
HDMI Plugfest types of Testing
The plugfest offers three types of testing:
Testing 1:1 with Test Equipment against the HDMI and HDCP specification
Testing will use the test equipment from Quantum Data and can cover:
- CEC
- HDMI (except for the Physical Layer). This includes associated items such as EDID.
- HDCP
"Mini-System" Testing
Testing in a system made up of products from different manufacturers eg a TV, STB, DVD and Home Theatre amplifier, using predetermined Test Scenarios.
Availability of diagnostic logging from Quantum Data.
Inter-manfacturer plugfesting
- Scheduled testing of products 1:1 with other manufacturers. The format of this part is open for the individual manufacturers to define within the scheduled timeslot.
- Availability of diagnostic logging from Quantum Data.
Unfortunately today many HDMI products go through minimal HDMI/HDCP testing and thats why it is still a continuous problem today. Being in the AV install sell/install biz for many years, we steer clear of brands that have the well-noted HDMI issues.
Just my $0.02...