I recently purchased one of these generic HDMI-USB Video Capture Cards from Amazon. The seller claims that it can output 1080p video, but in reality it has only been 720p. I've heard rumor that the chip managing the HDMI -> USB conversion (MS2109) is fully capable of outputting 1080p and simply needs to have it's firmware updated- however these capture devices are being mass-produced by Chinese manufacturers and I have yet to find a datasheet or any helpful documentation.
Has anyone tried hacking these devices as of yet or by chance have any information about the MS2109 chip? It'd be a pretty amazingly cheap 1080p capture device if the firmware could be updated to support higher resolutions.