Can Raspberry PI capture HDMI input

Question

Is it possible to capture HDMI input with an Raspberry PI board (or alternative)? My goal is to capture the HDMI data send from my TV and work with it from the Raspberry PI board.

Solution 1

Capturing HDMI is possible but it requires dedicated hardware called a digitiser or a video capture device. It will not work with a HDMI output. It will not work with a Raspberry Pi unless you add this hardware.

Having said that, the Pi does have an USB port and you can easily find an USB based HDMI to USB video capture dongle. (Google it)

Make sure that whatever device to buy can work with USB2 (power and bandwith issues!) and that there is driver support for it.

Following up on Keltari's note bout capturing in full resolution:

HDMI 1.0 defines up to 3.96 Gbit/s of video bandwidth (1080p/60 Hz or UXGA) and 8 channel LPCM/192 kHz/24-bit audio. ^{(Source: Wikipedia)}

Compare this with USB2's theoretical max bandwidth. which is 480mbit/sec.

Even with smart compression on your digitiser you are likely to run into problems unless you really lower resolution. And to make things worse the rPi model B+ (and I think also other Pi models) has only one USB port. On my B+ that single port (and its bandwidth) is fed to a chip which turns it into 4x USB and Ethernet. But the max thoughput is still limited. If you write to an external USB harddrive (likely since recordings are unlikely to fit on the SD card) then you have to share this bandwidth.

Solution 2

There is a new device announced called the PiCapture HD1 from Lintest Systems, but it is not yet available. The PiCapture SD1 which works with standard definition sources is available for preorder now.

Comments

[Keltari]

correct. also important to note that you wont be able to capture HDCP content at full resolution.

[Rob Angelier]

I'm aware of this HDCP limitation, but thanks for your reminder!

[Rob Angelier]

Just asking, do you know more devices like this (existing), maybe for other boards than Raspberry PI?

[mwl]

Sorry, but I don't.

[Rob Angelier]

Update: I just received an email from Lintest that this board will be availble on 31th december.

[Kirill2485]

If it requires a digitizer, how come analog USB-C to HDMI cables exist: store.hp.com/us/en/pdp/…

[ganesh]

USB-C is typical USB3 or even 3.1 gen2 (10Gbit/sec, not the 0.480Gbit/sec from USB2). That solves a lot of bandwidth issues. But the rPI's input still stays USB2, so no it will still not work with a rPI. Secondly, the page you linked to is not a cable. It is a adaptor (read: it has active electronics components, it does not just change the format of the plugs). Lastly, it seems to provide HDMI output. The question is about captureing HDMI input.

[August]

The hardware is now available, for both SD and HD: lintestsystems.com/products/picapture-hd1