I don't believe for a second chroma subsampling is performed by a dedicated ROM chip. It's all software, run by the image processor. Though likely more complicated than simple variable swap, and may need rewriting a lot of the function to achieve it, whether out to the codec, or over HDMI.
4:2:2 is only 1 and 1/3rd times more information to process (though it may not necessarily have greater processor load, depending on where and how things are done, and may only need 1.33x more bus bandwidth than 4:2:0, not a problem over HDMI), than 4:2:0. But the image processor is certainly fast enough to handle that much more load, especially considering, 30p is 1.25x more in everything, than 23.976p.
Now that the HyperDeck Shuttle 2 is out, it looks like B&H has reduced the price on the original to $250 while supplies last. Although this first model's firmware is not upgradeable to Avid DNxHD, it can still serve as a cheap HDMI-to-SDI converter.
Although this first model's firmware is not upgradeable to Avid DNxHD
Are you sure about this?
Yes, the first HyperDeck Shuttle is not able to be upgraded to DNxHD, from what I read elsewhere. BMD had to make changes to the drive internally to accommodate DNxHD writing ability, as well as changes to the firmware. I believe it is only the Shuttle that has this problem, as the HyperDeck Studio IS able to be firmware upgraded to write DNxHD.
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