Is there any cheap way to capture a HDMI video stream on Linux? - Page 1
Forum section: electronics / projects

author: cdev
author_rank: Super Contributor
timestamp: October 27, 2017, 08:57:22 pm
content: For example, a camera with HDMI out.Without spending a huge amount of money. Preferably under $100?EDIT:Found this..There is a gold mine of info here..https://github.com/timvideos/HDMI2USB/wiki/Seems the Cypress FX2 can possibly be used for HDMI 2 USB.. wonder if any of the commonly available FX2 dev boards might be usable there?https://hdmi2usb.tv/tofe/

author: NiHaoMike
author_rank: Super Contributor
timestamp: October 27, 2017, 10:39:30 pm
content: Does it have to be lossless? If not, here are two solutions I have seen:https://hackaday.com/2016/06/09/hdmi-extender-reverse-engineered/https://hackaday.com/2016/01/06/android-set-top-box-lets-you-stream-and-record-via-hdmi-input/

author: cdev
author_rank: Super Contributor
timestamp: October 27, 2017, 10:49:27 pm
content: Thank you, this looks promising.Lossless/not lossless.. I don't really know much about what HDMI is, that sounds a bit like the difference between analog and digital video? (except perhaps their positions are reversed?)

author: pardo-bsso
author_rank: Frequent Contributor
timestamp: October 27, 2017, 11:47:49 pm
content: What do you want to do with the video? Do you need audio too?Resolution?Blackmagic's Intensity and Decklink have hdmi input. I've used a simple pci-e decklink with gstreamer in the past without much hassle to capture hdmi and sdi.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: October 27, 2017, 11:55:08 pm
content: I know some people like to record the output of games consoles - see what hardware is available for that application

author: cdev
author_rank: Super Contributor
timestamp: October 28, 2017, 12:43:27 am
content: There is a gold mine of info here..https://github.com/timvideos/HDMI2USB/wiki/Moved some info to the top of this post..

author: cdev
author_rank: Super Contributor
timestamp: October 28, 2017, 01:10:52 am
content: A PCI-e card would work well if it had Linux drivers and wasn't too expensive..Audio would be nice.. It is a major PITA to synchronize audio externally but I'm sure it can be done..Would need something like those boards they use in movies.. "Lights, Camera, Action!" *Snap*Quote from: pardo-bsso on October 27, 2017, 11:47:49 pmI have a USB2 device that accepts composite video - and it actually does a decent job digitizing it on a lightly loaded machine.. it was around $15 Its a easycap and it uses an stc60 chip, I think.. (from memory so I likely have that wrong) It has composite video and S-video inputs as well as a stereo audio input which isnt so good, its noisy.Its meant for digitizing old video tapes.. for that it works fine..Its resolution is around 640x480, and its an honest 640x480..I think it came with the exact same yellow CD pictured in your video.. but its video looks better, even though its analog.But HDMI is what I need, the camera I want to use supports HDMI.

author: Monkeh
author_rank: Super Contributor
timestamp: October 28, 2017, 01:40:56 am
content: How about a ~$40 extender which craps out a video and audio stream over the network?https://blog.danman.eu/new-version-of-lenkeng-hdmi-over-ip-extender-lkv373a/

author: cdev
author_rank: Super Contributor
timestamp: October 28, 2017, 02:36:13 am
content: Quote from: Monkeh on October 28, 2017, 01:40:56 amI just read about that.. that looks promising..Thank you!

author: amyk
author_rank: Super Contributor
timestamp: October 28, 2017, 04:14:43 am
content: Quote from: wilfred on October 28, 2017, 01:01:00 amTechnically, it could capture a 1080p signal... but also downsamples and rescales it. I'm not surprised, given the existing proliferation of ultra-cheap analog capture hardware, that the manufacturers would come up with a version containing an HDMI input by adding an equally cheap HDMI-composite converter IC. These products aren't purely scams, they find uses in applications where e.g. one part of a system has been upgraded from composite to one which has only an HDMI output, but the other part it connects to doesn't need the higher resolution or frame rate.In the same way you can find really cheap "1080p HDMI LCD projectors" which certainly will accept HDMI 1080p, but then downscale it to display on something like a 320x240 LCD...

author: cdev
author_rank: Super Contributor
timestamp: October 28, 2017, 02:19:06 pm
content: The network sender device described in one of the posts looks like it can do what I am looking for, with the caveat that it seems to want to be on its own little subnet so I will need to set that up.But its affordable, looks fairly well-built, and it offers a chance to learn some new stuff.

author: cdev
author_rank: Super Contributor
timestamp: October 28, 2017, 02:28:51 pm
content: A bunch of things. I want to be able to capture the output of an HDMI-capable camera.. Lots of cameras can send their output to an HDMI monitor. Its much faster and often much much better than USB.It would be nice to be able to use that for both videography and tethered still image capture.Quote from: pardo-bsso on October 27, 2017, 11:47:49 pm

author: Monkeh
author_rank: Super Contributor
timestamp: October 28, 2017, 04:13:14 pm
content: Just beware the latency.

author: cdev
author_rank: Super Contributor
timestamp: October 28, 2017, 07:33:12 pm
content: Yes, the latency does seem to be a lot. Where do you think its coming from?

author: Monkeh
author_rank: Super Contributor
timestamp: October 28, 2017, 07:34:35 pm
content: Quote from: cdev on October 28, 2017, 07:33:12 pmRealtime compression is hard, especially when you want to keep bitrate down.

author: Monkeh
author_rank: Super Contributor
timestamp: October 28, 2017, 07:57:15 pm
content: You pretty much can do this for $35.

author: cdev
author_rank: Super Contributor
timestamp: October 28, 2017, 08:01:28 pm
content: This is a good overviewhttps://opentechlab.org.uk/videos:003:notes