Alternatives

This page lists various alternatives to the HDMI2USB device and their pro/cons.

USB Based Capture Devices

Magewell XI100DUSB-HDMI

WARNING: This device has not been tested by Tim Videos team, all information is based on manufacturer specifications.

http://www.magewell.com/hardware/usb3-0-capture-dongle/xi100dusb-hdmi/xi100dusb-hdmi_features.html?lang=en

Evaluation

Pros

1080p@60Hz - Full frame rate capture
Appears as a UVC webcam, no driver should be needed
Price range is under $USD400

Cons

Not a pass-through device, needs a splitter in front of it.

Specifications

Video capture resolution: 1080p@60Hz
Interface Speed: Theoretical 5.0Gbit/s, Actual 3.2 Gbit/s
Input cable length: ???
Output cable length: N/A

Where to buy

???? -- http://www.oupree.com/OPR-XI100D-USB3.0-1080P-60FPS-HDMI-Capture-Dongle.html
€EUR285.00 (~$USD388.71) -- http://www.vd-shop.de/hdmi-video-capture-for-usb-imageprocessing-and-capture-19201200p60-p-561.html
$USD299.99 -- http://www.sabrepc.com/magewell-xi100dusb-hdmi-hd-hdmi-to-usb-3-0-video-capture-dongle.html (same supplier as the Amazon link)
$USD329.99 -- http://www.amazon.com/Magewell-XI100DUSB-HDMI-Video-Capture-Dongle/dp/B00I16VQOY/ref=sr_1_1?s=pc&ie=UTF8&qid=1392027895&sr=1-1

Blackmagic Design Intensity Shuttle

WARNING: This device has not been tested by Tim Videos team, all information is based on manufacturer specifications.

Specifications

Video capture resolution: 1080p@60Hz
Format: H.264
HDCP Support: ???
Interface Speed: Theoretical 5.0Gbit/s, Actual 3.2 Gbit/s
Input cable length: ???
Output cable length: N/A

Evaluation

Pros

1080p@60Hz - Full frame rate capture

Cons

Needs proprietary drivers, no Linux support.

Buy

$USD189.05 -- http://www.bhphotovideo.com/c/product/686585-REG/Blackmagic_Design_BINTSSHU_Intensity_Shuttle.html

StarTech USB2HDCAP (USB 2.0 HD PVR Gaming and Video Capture Device – 1080p HDMI / Component)

WARNING: This device has not been tested by Tim Videos team, all information is based on manufacturer specifications.

http://www.startech.com/AV/Converters/Audio/USB-2-HD-PVR-Gaming-and-Video-Capture-Device-1080p-HDMI-Component~USB2HDCAP

Evaluation

Might be supported by Linux (some shops like http://direkt.jacob-computer.de/startech.com-usb2.0-hd-pvr-gaming-and-video-capture-device-artnr-1889919.html (in german) and http://www.notebooksbilliger.de/startechcom+usb2hdcap+video+capture+board (also in german)) say so.
Might not be supported by Linux: http://www.gossamer-threads.com/lists/mythtv/users/575510?page=last
I have tested it (https://github.com/SteveBz) or at least collaborated with a demonstration. It is blindingly fast on Windows, but the Linux compatibility is overstated. It did have some old kernel code available, but the help desk denies it has any Linux compatibility at all. One distributer said they would work with a buyer to update the code, but that it would be a few months work. I would love to see it working and I'd collaborate with anyone who wanted to work with me on it.*

Pros

HDMI pass-through
Also supports component video for older pro hardware
USB powered - no external power supply needed

Cons

No support for HDCP encrypted sources

Specifications

Video capture resolution: 1080i/p. Framerate should be okay due to hardware MPEG-4/H264 encoding
USB 2.0 interface

Where to buy

Device in development by Auvidea ("Raspberry Pi HDMI in, 2nd Generation" (product numbers 36079 and 38082))

WARNING: This device has not been tested by Tim Videos team, all information is based on manufacturer specifications.

http://www.auvidea.com/index.php/theme-styles/2013-06-22-21-23-34/raspberry-pi-hdmi-in

Started as kickstarter campaign (https://www.kickstarter.com/projects/1419380698/connect-your-hd-camcorder-to-your-raspberry-pi) to interface HDMI video to the RaspberryPi board via its MIPI/CSI interface but was stopped due to technical reasons. Now the plan B is to use a hardware H264 encoder and interface it to the Pi via USB. A "standalone" version is also planned to use it as HDMI to USB converter with H264 encoding.

Evaluation

Pros

Will be supported by Linux
HDMI pass-through (not in all versions?)
USB powered - no external power supply needed

Cons

No support for HDCP encrypted sources
Not yet available and might be expensive then

Ethernet Capture Devices

Lenkeng HDMI over IP extender

WARNING: This device has not been tested by Tim Videos team, all information is based on manufacturer specifications.

http://www.lenkeng.biz/ProductDetails_HDMI+EXTENDER_61.html

There's a HDMI extender device, Lenkeng LKV373, which captures HDMI, and transcodes the video into MJPEG and outputs the stream over multicast UDP.

They're designed to run as a pair of sender + receiver, but someone has reverse engineered the wire protocol, and written some notes on reverse engineering the units:

http://danman.eu/blog/?p=110

Evaluation

Pros

Uses Ethernet rather than USB, meaning no capture PC needed at Podium
Cheap! Cheap! Cheap!

Cons

Uses broken IP implementation (size is wrong!)
No designed for this usage, internals could change any time.
Does 1080p at ~18fps

Specifications

Video capture resolution: ???
Format: MJPEG
HDCP Support: Yes
Speed: Ethernet 100Mbps
Input cable length: ≤5m (AWG26 HDMI1.3 standard cable)
Output cable length: ≤5m (AWG26 HDMI1.3 standard cable)

More info

In the comments there seems to be notes about a TTL serial interface which allows control of encoder parameters. It streams 1080p video at about 18fps -- more than adequate for capturing slides.

In a real-world setup, you would still use the receiver hardware, in order to output the video to a projector. As they output to ethernet, there would be no need to have the "projector laptop" as in a typical capture scenario, or that would be needed with HDMI2USB. With some gstreamer trickery, this could appear as a source.

I can see these on places like Aliexpress for about 80 USD in lots of 1 (of both sender + receiver). I haven't yet ordered one but it looks promising.

http://www.lenkeng.biz/ProductDetails_HDMI+EXTENDER_61.html