Options for external Video input


I’m new here and trying to set up a video link with better quality and range than the cheap analog tx on my photo/video copter. I got a (very) basic setup up and running and now I’m looking into the video stuff. Yes, I read the wiki. Everything, multiple times :wink:

Basically I want to get my Canon EOS M3 camera with HDMI output hooked up to the Airpi (3A+). The Audvidea B101 seems to be picky in terms of HDMI input format and I’d like to be flexible on this side (GoPro compatibility also would be nice, via AV to HDMI board).
So my idea for now is to go the HDMI-to-USB way. Unfortunately I can’t find something not too expensive and heavy with h.264 encoder.
Could something like this cheap capture stick work with gstreamer and software h.264 encoder? https://www.amazon.de/dp/B08BHNS9XZ/
Or is my impression of the auvidea card wrong and it just supports everything “up to” 1080p30?
Or somebody has a hint to a small and not too expensive HDMI->h.264->USB card, available in Europe/Germany?

Ah, and thanks for this great project!

Still looking around for a solution… Currently I’m trying with the capture stick from above. Stick works fine with gstreamer on a Ubuntu PC and my OpenHD setup works fine with gstreamer and the video testsource.

The airpi (including gstreamer) boots up fine without any errors with
USBCamera="gst-launch-1.0 v4l2src device=/dev/video0 ! videoconvert ! videorate ! video/x-raw,width=640,height=480,framerate=30/1 ! omxh264enc control-rate=1 target-bitrate=600000 interval-intraframes=1 periodicty-idr=1 ! h264parse config-interval=3 ! rtph264pay ! udpsink host= port=5600
But unfortunately no image on the ground. Any hints here? Currently I’m on OpenHD 2.0.0rc1.2

As far as I read, gstreamer and omxh264enc should make use of the Pi’s hardware encoding capabilities, but still I’m not really sure about this… https://raspberrypi.stackexchange.com/questions/3936/what-speed-can-i-expect-from-the-hardware-h264-encoding

Pi 3B+

Pi 3A+

I don’t know about hdmi-usb but you should check the hdmi-csi route.
Also auvidea seems awfully overpriced.
There are nice hdmi-csi converters out there for 20 - 30 €

The problem there will be due to the USB connection on the pi, it’s just not capable of handling 640x480 raw video. You can try 320x240 that may work at least, but probably not at 30fps.

Anything connected by USB is generally going to need to have its own h264 encoder hardware in order for it to work well with OpenHD.

If you’re definitely going to be using an HDMI camera, you could get one of the fairly cheap HDMI-CSI boards from AliExpress.

720p60 should work with those, however the pi doesn’t have enough bandwidth on the CSI connection for 1080p60, at least the pi3b/4b models don’t (the compute module can do it but it requires some driver changes we haven’t made yet).

Thanks for the hints. Okay, I was aware of the Pi’s USB bottleneck, but somehow had the hope that at least 604x480 would work.
I “have” to go the HDMI way as i already have the mirrorless canon and would like to use it for great photos.
But if the HDMI-CSI adapters are the recommended way, I’ll try one of these. 720p30 should be enough for having a better image on the tablet than the cheap analog transmission delivers now… At least in 1-2 months, when the aliexpress shipment arrives here :wink: