[003] LKV373A: a $40 HDMI capture solution?

The Lenkeng LKV373A is a $40 HDMI-over-IP network sender used for sending video over a network to a remove TV, but can it be used instead as a cheap video capture device?
Show Notes: opentechlab.org.uk/videos:003...
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[@computerjantje]

Thank you very much for this great informative video. I got so much more then I expected when clicking the link to this video about the LKV373A

[@edgeeffect]

Funny watching this... as soon as you mentioned ffmpeg had a problem with the zero-length packets my shouted-at-the-screen-suggestion was to bop something into iptables to block 'em..... but I'd have never thought of using wireshark to notice they were there in the first place. :/

[@OpenTechLab]

Updates since the release of the video: 1. John Kelly started a python setup tool (see show notes). 2. I found a playback method that gives 0.2s latency. 3. The chipset is probably low-cost chinese no-name brand, not custom for the product.

[@xroute1926]

how are you getting 0.2s latency? do you have the firmware versions? mine is always in the region of 1+s. thanks!

[@joelholdsworth]

Did you try the socat+mplayer trick from the show notes?

[@FractalTeapot]

Amazing stuff here! Please share more about finding number 2..

[@xroute1926]

yes i did, but the video kept bleeding

[@microcolonel]

When I saw that prompt on the Raspberry Pi I immediately thought "let's run cmatrix!", and my wish was immediately fulfilled.

[@danmanmgm]

The google drive repository is mine. I collect there all relevant files I gathered. I would also enjoy proper references to my work. But great video anyway.

[@OpenTechLab]

Sorry- I wasn't aware of this as I filmed the video. I can add a note to the show notes at least.

[@unifly8241]

Thanks for sharing this. Do you know what different date stamp means here: TX Server Version :4.0.0.0.20161116 Encoder Version :7.1.2.0.11.20161116 Can I use exactly the same firmware as shown in the video? So the versions are the same, except date stamp (20161116) is different. Is there a better firmware available at this date? I'm mainly interested in stability and unicast option.

[@unifly8241]

I can answer to my own question that firmware upgrade was successful. But I was not able to use default user and password so had to reset using command line: nc 9999 list factory_reset

[@methanoid]

Daniel, my box came with a newer FW not listed on your repo. Do you want it and if so how do I extract it? V4.0.0.0.20161116 and Encoder 7.1.2.0.11.20161116

[@methanoid]

@@unifly8241 you just downgraded to old firmware?!?! Its the date 20161116 16th November 2016

[@MichaelGraves3304]

The HDMI splitter doesn't strip away the HDCP/DRM. It merely allows you to satisfy the HDCP handshake using a monitor. Once the HDCP handshake has been validated, the sending device will start the stream, unaware that it's being split.

[@MichaelGraves3304]

Incidentally, I was just reminded that it doesn't have to be a monitor to satisfy HDCP. The fit-PC​ headless plug works well also.

[@chrisnewnham1431]

Can you elaborate what a " +fit-PC​ headless plug" is exactly? I've been using a HD Fury 2 to complete the handshake

[@christerjohanzzon]

It's a emulator hdmi plug that emulates a display connection, costs about 10 USD on Amazon, www.amazon.com/CompuLab-4K-Display-Emulator-fit-Headless/dp/B00JKFTYA8?SubscriptionId=AKIAILSHYYTFIVPWUY6Q&tag=duckduckgo-d-20&linkCode=xm2&camp=2025&creative=165953&creativeASIN=B00JKFTYA8

[@Takeo-iq2lh]

Wow, very great Video! I was looking for a good Capture Card that is not to expensive but offers good quality. This seems like a good option, even if there is work to do. Is there a big loss in quality or something? Also is there any way to get the video signal into OBS for recording and live streaming?

[@lostspace5811]

Do the 0 udp packets mess up OBS?

[@simrontp2790]

thx bos..

[@melvinch]

Would be nice if it can be flashed with NDI protocol.

[@omaoda4462]

will it be possible to only capture the video stream if somthing is moving/changing in the video? If so, how? Thx.

[@leadbetter1349]

Great video, thanks! I'm interested in how the Acer laptop is performing under Linux, looking for a decent portable open source machine myself. Any comments would be appreciated. Thanks again.

[@lty1993]

Lots of switches comes with IGMP Snooping capability nowadays which can prevent this device spamming your network.

[@user-eu4wh3vt7f]

Thanks for the detailed analysis! Will the LKV373A-4.0 control center tool work?

[@PinoDelloIacono]

Thanks for the intersting video. I just ordered a sender but unfortunately I had to order one from China so it will not arrive so soon. I just hope my model wont be capped somehow (removing http commands or restrict web options etc).

[@fwmultimedia]

Did you receive it? Works?

[@pushingtechnologytothelimi7519]

Great video. I have all kinds of HDMI extenders from the one you have shown on this video to KVM USB HDMI extenders. I found it interesting you can pull the ip address from the transmitter and watch it on your computer. I never knew you could do that. I have setup a small business network in my home to run all the extenders on their VLANs so I can run all of them at once without any conflicts. I would like to do two things with my extenders. 1 put QOS on them and 2nd I would like to transmit them through my Ubiquity litebeam m5 point to point wi-fi system. They do connect through the point to point but just black video shows up on the receiver Is there some default ip address they use in all of them? If I knew I could do different things with them over my network with my router. Thank you for doing a good job presenting the information. There are only a few presenters on KZbin that make their videos simple to understand.

[@AMPTechGrade]

I pulled the trigger and ordered it from Amazon, not the same brand but close, looks the same. I want to be able to stream TV away from home and most HDMI capture cards are expensive so I want to be able to pick it up in VLC and rebroadcast it from there to my other TV across the internet "password protected of course". Now that slingbox is being phased out in the US, I need to find another way of watching TV away from home.

[@GuideusTv]

Has anyone worked with the new lkv373 v4.0?

[@lostintheelectricalaisle5318]

Not sure if it has been mentioned, and you may already know this, but you often don't even need to open the case to see inside, so long as a device is FCC certified. Look up the FCCID at fccid.io and check for an "Internal Photos" PDF listed on the page. Sometimes the pictures are not very clear, but often it is more than enough to identify the ICs inside. Has saved me so much time in the past, especially when devices have shielding over the ICs, because in the photos the shielding is almost always removed. That is a great thing as you often don't have to risk damaging your (often new) devices when heating the shield to remove it.

[@methanoid]

If I switch this to Unicast it will stop it spamming my network and making it crawl but will I be able to view the content easily on my Nvidia Shield TV box with VLC or some simple app?

[@V1P3RSlab]

did you tested gstreamer?

[@DavidRosengarden]

Hi - do you know if you can put multiple LKA373A transmitters on the same network to capture several video sources and bring those separate sources (with multiple UDP URLs) into one machine (running several instances of VLC if I wanted to stream the source out via the NDI plugin I would imagine)? Thank you!

[@everest3334]

sure, just make sure that each unit has a seperate port assigned so as not to clash, and OC remember the 1Gigabit/s limit of your given ethernet card so as not to try and cram to much data on a given cable. if for instance you want to make a simple tiny and quick self contained GUI for the 21:41 cgi above you can use the generic rebol scripts see kzbin.info/www/bejne/pnrQeqZtgN2Xm9U "Nick Antonaccio :Published on Apr 13, 2017 There are 90+ app examples in this demonstration: CRUD and business apps, puzzles and games, network apps, web site apps, sound, 2D and 3D graphics, parse, image manipulation, user interface, server, email, validation, language and help tools, etc. No other practical development tool is less bloated or more productive than Rebol...."

[@rynax009]

For capturing video via VLC on PC , I shall only need to have a HDMI Splitter , one end to the TV, one end to this TX box, and I shall dont need to buy a RX box of this device?

[@NMHC1978]

which file do i use for thye firmware upgrade and which one for the encoder upgrade

[@user-we1kj7cr9u]

Hi Friend ! Tell me pleace Is it possible to flash this device to transfer an RTSP stream of 12 megabits?

[@muttlyirl]

Just found this video. It's great thanks but I was wondering have you tried using over a network powerline? Does it work? I don't mind about a longer delay more so that I'm just interested to see if it will work.

[@Haris1977]

MartinCPhoto it should work

[@NMHC1978]

How did you get the udp ip adress, if i use the one you mention here it does not work

[@cruddylime]

Ddos the Mrs with this thing? just by plugging it in right? Subbed.

[@mikeselectricstuff]

Why would it be using IP (or UDP) rather than raw ethernet packets? I suspect some of these may not even be ethernet - just some arbitary protocol over cat5

[@OpenTechLab]

It does have a mode for that for passthrough (24:18). But without owning the receiver, I can't demonstrate this mode in action. We know it uses an ethernet PHY, so it must use the standard physical signaling. Does it use packets? or some closed-circuit mode? I would like to know. I think it might use IP so that the stream will play nice with a standard LAN, especially when casting to multiple receivers, and it's pretty easy for them to encapsulate the data with an IP header. And thank goodness it does, because it would be much more annoying to stream from if it used something weird.

[@CoolerQ]

Some of these devices are sold with an HDMI OUT port on the transmitter. I'm guessing the loopthrough option is just to enable or disable the HDMI output port. It probably has nothing to do with the network protocol.

[@DavidRosengarden]

21:13 can you change the port the unicast is sending to? I have multiple of these devices that I want to stream into the same PC (to use as difference scenes in OBS). Also, this command you're sending - can I do this from a Windows PC (if so, how)? Thanks!

[@ArianKordi]

I plugged a 9V 1A power supply into mine (the original is 5V 1A), and now it's broken. Whoops. The green LAN LED is on, but the activity LED never lights up. All I know is that the flash chips are fine because I checked them, but other than that, it's probably unrepairable. Just something to keep in mind.

[@fwmultimedia]

You mean It's possible connect hdmi camera to PC direct? like a cheap video capture device? Just plug hdmi, LKV373a and into pc by Ethernet rj45 port? If is possible that's a great advance, usually a elgato or many other capture device are up to $100. Really appreciate, great video.

[@user-ir2fu4cx6p]

why youtube were buried this channel on the ground ,

[@Mastacheata]

Is this RTP Multicast thing actually what the HDbitT protocol is or does this device implement multiple protocols with one being the RTP stuff and one being HDbitT/HDMI-in-IP? The HDbitT.org website claims multicast (IGMP) capability and refers to 4kx2k 60Hz HDMI2.0 and HDCP2.2 in it's version 2.0. Has anyone found out more about this?

[@GordonBennetttt]

I am really curious about the 1.6 second latency that you experienced for this LKV373v3 compared to the 400ms latency that Danman experienced. The visible configuration in your video seems to show that you still had a 1 second cache configured although you were saying that you had set it to 0. If you still had the 1 second cache configured then that would explain your 1.6s vs 400ms difference in latency but if you did have the cache set to 0 seconds then I wonder what caused your additional latency compared to Danman. Can you achieve a 400ms latency? The reason for my question is because I'd really like to know what sort of latency I can reasonably expect; 400ms is totally acceptable for my needs but 1.6s is not unfortunately. The 100ms latency for the LKV373v2 is very appealing but the problem with the v2 versus the v3 is that while v3 is directly compatible with VLC the v2 doesn't seem to be; with the v2 it seems that you need to pipe the packets through a Python script to massage the packets to get them into a form that VLC will accept. I'd prefer not to have to perform that additional manipulation... although the 100ms latency IS very appealing. ...edited... I just saw the lower latency (200ms) viewing technique ("socat UDP-RECV:5004 - | mplayer -fs -"). Very interesting. So how much of the latency was actually caused by your VLC? Was your VLC latency really 400ms to 500ms with a 1 second cache or was your VLC latency actually 1.6 seconds? The reason for all my questions about latency is because I'd like to use this primarily with a cheap Android or MS Windows tablet rather than my Linux PC so VLC is the easiest option that works on both platforms. Thanks for your insight!

[@OpenTechLab]

I never tried receiving the stream on a tablet. I'm not sure what (OSS?) apps are available apart from VLC. As you say the socat+mplayer trick proves that the transmitter+network is quite low latency, so then all that is needed is a client that can decode and display without excess buffering. The downside of this is that cutting the client buffering right down, reduces tolerance for network jitter caused by congestion - especially if you're going over WiFi. So I'm not sure what the answer is here. I would be interested if you find a way.

[@mattbrooks4484]

Anybody tried connected the Ethernet out of the reviver directly into their PC? Maybe this can be cheap option to use camera with HDMI out as webcam..

[@slap_my_hand]

KZbin says that you have 7 new videos for some reason. the front page is probably broken again.

[@paulk9532]

I'm not 100% sure the iptables command is working. It doesn't produce an error, but when I use `iptables -L` it doesn't show up. In fact, there's not even a PREROUTING chain that shows, just empty INPUT, OUTPUT, and FORWARD chains. What's a good way to verify this?

[@nikize]

Go in to your network switch options and enable IGMP snooping, that way the multicast traffic will be filtred and only reach devices that actually want to listen to it. Unicast would be that you connect to the device itself, so instead of it force sending, you will instead fetch it. I would suggest running nmap against it.

[@Marzyart]

Hi...I have started a drawing channel and am facing problems. I use my phone to record long videos and I want to record them directly to an external USB. Because my phone doesnt have enough storage space left. Would you please tell me what to do? I have tried many Apps but they stop recording after half an hour

[@OpenTechLab]

+Marzy Art Hard to say. Depends on your phone. Could you put a larger SD card in it? 9r does it only have built in storage? If your channel is growing, it might be worth trying to get a better camera

[@Marzyart]

OpenTechLab I am a beginner..I film with my phone. Its galaxy note 4. Any advices?

[@mikeselectricstuff]

I have a smaller version of these sold as a simple HDMI over cat5 extender- one chip in each box ( numbers lasered off), suspect this one may not be ethernet

[@briz0l1t]

This thing looks awesome. Can it handle 1080p60 video and in bigger bitrates like 100mbps?

[@ArianKordi]

It doesn't encode 1080p60, just 720p60 or 1080p30. The max bitrate is 32735kbps, which has excellent quality video. The REAL problem is with the audio codec it chooses to use, MPEG-2 audio layer _2_. It sounds like it's a lower sample rate than it actually is, but this isn't a big deal if you use the line in on your PC to capture from the device. Sadly, none of this can be hacked, since this device uses a completely custom architecture, bootloader, FreeRTOS port, even its own compression algorithm so you can't see or edit the code on it. Sigh.

[@briz0l1t]

@@ArianKordi Thank you! Camera that i want to connect to it can do only 60frames in 1080p hdmi output. Do you think this thingy would be able to downscale this into 720p60?

[@methanoid]

Your website is down? So cannot read show notes and see where the repo is.... :-(

[@OpenTechLab]

Fixed it now - thanks for the heads up!

[@kardelfotografia]

Did you tried capture using OBS?

[@OpenTechLab]

+Kardel Foto Filme I did try that, and it didn't work well. OBS currently doesn't seem to have good support for RTP sources. I wonder if there's a way of proxying it somehow.

[@kardelfotografia]

Did you tried another webcast software on Mac? Thank you very much!

[@OpenTechLab]

I'm not a Mac user, so I wouldn't know. My favorite method so far is the socat method described in the show-notes. It's low latency, and it worked well when I recored video [004]. I really wish OBS had better support for network-based sources. If someone wants to hack on this problem, I'm sure it would help a lot of people. It might be worth talking to the OBS folks to find out if anyone is working on this already.

[@SportStream2015]

how to buy this device i will need to stream sports event with dlsr camera

[@quentinrogers3868]

Can you explain how you will stream the event using this device?

[@SportStream2015]

Quentin Rogers hdmi to this and add unicast adress to vlc and push to wirecast

[@brotheralec8998]

From what I saw you didnt use a receiver...if so could you just plug the ethernet cable straight into an ethernet port on the receving computer?

[@paulklapperich7520]

Yes.

[@brojoe787]

So yea..."v4.0" will not work. =(

[@GilbertoBeda]

Utility for Lenkeng / ESYNiC HDMI extender devices to grab and encode Udp H.264 stream github.com/Red5goahead/Lenkeng-Hdmi-Extender-Encoder