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Cheap HDMI capture for Linux

blog.benjojo.co.uk

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Re: Cheap HDMI capture for Linux

#61

Post by jamesfmilne »

djsumdog wrote: post #53
gcb0 wrote: post #44

Earlier quoted context omitted.

there's a reason the Starts with "cheap". all solutions so far cost well over what most people paid for their computers or TVs. there was pro composite capture under 200 for a long time. and cobsumer ones for 30ish. and thats dealing with analog. hdmi without DRM should produce even cheapers devices, but yeah, everyone has to embrace DRM to name it hdmi

The UVC one mentioned looks to be in the ~$400 USD price range, which is a far cry from the $800 stuff the article author looked at, but it's still more expensive than the Was that $300~$400 worth the time needed to reverse engineer the cheaper solution? It's all about tradeoffs really. At least it's open source so other people can use it now without the time involved. Also if you need to read in from 5 ~ 10 cameras,…

If you want to save cash you can try your luck on AliExpress.

Here's a device that looks a lot like the Magewell USB 3 UVC HDMI grabber for $118 (with free shipping):

http://www.aliexpress.com/item/Free-Shipping-XI100D-UVC-USB3...

Re: Cheap HDMI capture for Linux

#62

Post by jamesfmilne »

gcb0 wrote: post #44
jamesfmilne wrote: post #7

You can also use devices that are USB Video Class (UVC) compliant, thus which don't require any drivers. libuvc can be used to capture from these devices: https://github.com/ktossell/libuvc You can get cheap off-brand UVC USB grabbers, or you can get higher quality gear, like the AJA U-TAP: https://www.aja.com/en/products/u-tap Admittedly though I haven't seen anything that comes close to £45 :-)

there's a reason the Starts with "cheap". all solutions so far cost well over what most people paid for their computers or TVs. there was pro composite capture under 200 for a long time. and cobsumer ones for 30ish. and thats dealing with analog. hdmi without DRM should produce even cheapers devices, but yeah, everyone has to embrace DRM to name it hdmi

It's not HDMI and DRM increasing the costs. HDMI is a far higher bandwidth signal than composite/SVideo, as is USB3. So you have to design a more complex chip and PCB.

These are slightly more niche products too, so you don't get the economy of scale you would with something like an ARM SoC.

Also these UVC grabber deal in uncompressed video, so they are more expensive but produce a far higher quality capture.

The £45 Cat5 grabber is performing some pretty heavy compression to fit the HD video signal down a 100 Mbit Ethernet connection.

Re: Cheap HDMI capture for Linux

#63

Post by blakeyrat »

kevingadd wrote: post #37
jamesfmilne wrote: post #7

You can also use devices that are USB Video Class (UVC) compliant, thus which don't require any drivers. libuvc can be used to capture from these devices: https://github.com/ktossell/libuvc You can get cheap off-brand UVC USB grabbers, or you can get higher quality gear, like the AJA U-TAP: https://www.aja.com/en/products/u-tap Admittedly though I haven't seen anything that comes close to £45 :-)

I've personally had a great experience with the Magewell USB3 HDMI capture device, which I believe is also UVC - requires no drivers on Windows/Mac and claims to be Linux compatible. Slightly cheaper than the u-tap. https://www.amazon.com/Magewell-HDMI-USB-Capture-Dongle/dp/B... Can do lossless capture with extremely low latency, which is pretty nice - it's good enough that I've been able to play console video games…

It's still about $150 more than just swallowing your pride and using Hauppauge's Windows drivers.

Re: Cheap HDMI capture for Linux

#64

Post by sigio »

jamesfmilne wrote: post #61
djsumdog wrote: post #53

Earlier quoted context omitted.

The UVC one mentioned looks to be in the ~$400 USD price range, which is a far cry from the $800 stuff the article author looked at, but it's still more expensive than the Was that $300~$400 worth the time needed to reverse engineer the cheaper solution? It's all about tradeoffs really. At least it's open source so other people can use it now without the time involved. Also if you need to read in from 5 ~ 10 cameras,…

If you want to save cash you can try your luck on AliExpress. Here's a device that looks a lot like the Magewell USB 3 UVC HDMI grabber for $118 (with free shipping): http://www.aliexpress.com/item/Free-Shipping-XI100D-UVC-USB3...

I just bought that device 2 weeks ago... and tried it, but so far haven't gotten any video out of it under Linux or Windows.

Re: Cheap HDMI capture for Linux

#65

Post by blakeyrat »

warmwaffles wrote: post #55
hacker42 wrote: post #17

Are the gamer HDMI capture devices expensive because they have a low latency? (Besides the verticality of the market.)

Any capture devices you know that are decent? I've been toying with getting one to do demos.

I have an Hauppauge HD PVR2 "Gaming Edition", which now costs about $135 and I can recommend. The only downside is there's a long "boot time" after you first tell it to record video (don't expect to just hit a hotkey and capture video 2 seconds later; give it more like 10-15.)

For what I'm using it for, latency doesn't matter much. I'd estimate it has about 1.5-2 seconds of latency, but I've never actually measured it.

Re: Cheap HDMI capture for Linux

#66

Post by KaiserPro »

kevingadd wrote: post #38
SoapSeller wrote: post #3

Cool hack, but the part about the cost of off-the-shelf solutions is wildly wrong - Blackmagic's HDMI capture solutions can be purchased for less than 145usd for pci-e and 200usd for usb3 and they have free drivers&sdk for linux.

The reason why Blackmagic hardware is cheaper is that it's rubbish. Bad hardware, bad firmware, bad drivers. Everyone I know that's ever owned Blackmagic (myself included) has had a bad time. It's not worth buying from them just to save a hundred dollars.

Yup. but not as bad a RED hardware.

I've personally seen 4 red rockets die. considering the price at the time, for what was basically a glorified jpeg2000 decoder, it was bollocks.

Re: Cheap HDMI capture for Linux

#67

Post by jamesfmilne »

sigio wrote: post #64
jamesfmilne wrote: post #61

Earlier quoted context omitted.

If you want to save cash you can try your luck on AliExpress. Here's a device that looks a lot like the Magewell USB 3 UVC HDMI grabber for $118 (with free shipping): http://www.aliexpress.com/item/Free-Shipping-XI100D-UVC-USB3...

I just bought that device 2 weeks ago... and tried it, but so far haven't gotten any video out of it under Linux or Windows.

They certainly seem a bit confused about what kind of USB 3 connector they are meant to put on their box!

Re: Cheap HDMI capture for Linux

#68

Post by jamesfmilne »

kevingadd wrote: post #38
SoapSeller wrote: post #3

Cool hack, but the part about the cost of off-the-shelf solutions is wildly wrong - Blackmagic's HDMI capture solutions can be purchased for less than 145usd for pci-e and 200usd for usb3 and they have free drivers&sdk for linux.

The reason why Blackmagic hardware is cheaper is that it's rubbish. Bad hardware, bad firmware, bad drivers. Everyone I know that's ever owned Blackmagic (myself included) has had a bad time. It's not worth buying from them just to save a hundred dollars.

Indeed, Blackmagic stuff is junk (although I am biased)

Re: Cheap HDMI capture for Linux

#69

Post by pjc50 »

rsync wrote: post #50

"These units are not perfect for quality, however they are not bad at all, Here is a screenshot taken on my laptop..." I am confused by this ... HDMI is a digital interconnect and deals in digital I/O ... in my mind, if you succeed in capturing that HDMI, the resulting stream should be identical ... why would there be a quality (or any other) difference ?

You nearly always want the capture device to compress because it's otherwise very hard to handle. 1080p/60/8 HDMI is 4.46Gbps; just about fits in a USB3 or PCIe3 data link, but exceeds most SSDs' write bandwidths.
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