Live Video Input

[David N]

is it possible to run a live video input into a piwall videowall? 

for instance a camera feed or vj software?

thanks!

[Patrick Weissinger]

Hi DSN,

my purpose of using a Piwall is to transmit my VJ-Software Output to several screens. Did you get further??

[Richard Taylor]

Hey Patrick, I'm looking to do the same, is it possible?

[Ludovic Chougny]

Hello ! Did your find how to do that... I want to stream Resolume ARENA on the Piwall !!!

[Ludovic Chougny]

Hello, I'm using FFmpeg with W10 now to try to do that, but I'm experiencing problems while streaming !

I'm not in front of my dev PC but on the W10 command prompt (admin mode) I lunch the streaming source with ffmpeg -re -video_size....gdigrab...desktop...vcodec...udp://239.0.1.23:1234 and on the slaves pwomxplayer -A udp://239.0.1.23:1234...buffersize...2000000B

This with a LAN switch and two RPI2B tiles and the result is always the same... one of the tile (always the same wich is the second one following the IP addresses and .pitile config) starts to have an offset wich grows and grows...

I've tried to change codec between avi, mpeg4 (moving quality cursor), mpegts, h264 (not working at all for me for now), framerate from 16 to 50, buffersize on the tiles... nothing really works fine and fix this problem !

Any suggestion in the community ?

Thanks

[Ted Marchant]

I don't suppose you ever got this working, did you? I'm having the same issue but with only one tile. 

[Ludovic Chougny]

Works fine for me now on 6 tiles RPI2B !

windows command is : ffmpeg -f gdigrab -framerate 20 -probesize 42M -i desktop -r 20 -filter:v "crop=1080:1280:220:0" -vcodec mpeg4 -b:v 4000k -q 4 -f avi -an udp://239.0.1.23:1234

tile command is : pwomxplayer -A udp://239.0.1.23:1234?buffer_size=2000000B

Streaming my second display via UDP with Resolume Arena !

I've choose 1080:1280 resolution because of my Piwall configuration, with this command I've got 300ms latency ! Quite enough to play live...

[Ted Marchant]

That's great, I'll give that a go. I guess the command would be the same if I was using a pi as the master? My current command looks like this - 

raspivid -t 0 -w 896 -h504 -p750,10,500,500 -fps 25 -b900000 -g 1 -fl -o - | ffmpeg -i pipe:0 -c:v copy -f avi udp://239.0.1.25:1234

Just for some background info, I'm using the master in conjunction with a HDMI to CSI card to get input to raspivid and then sending it out via ffmpeg

[Ludovic Chougny]

Video of my first live test using Resolume MIDI Controlled by Arturia Beatstep Pro

https://drive.google.com/file/d/1lGaSdBuyIL5qAG6o1536eduSAcbBg4JG/view?usp=sharing

[Ted Marchant]

Looks great! So i'm still having no joy with reducing the latency. Could it be that the Pi just cant process the information fast enough? 

[Thierry Mijsoot]

Super ça Ludovic ! ça déchire !

[Thierry Mijsoot]

For my part I have the same kind of problem and I suspect that it is the network that is not powerful enough. I used the master to make a router as well because I wanted to make a demo that was easily transportable and at a lower cost.
But I think I need to try with a router that is not the master.

Maybe your network isn't enough too.

Thierry

[Ted Marchant]

It was certainly a theory at one point but when I play a video from the master it syncs fine and I'm not dropping packets along the way. I think I can see the latency happen between starting the HDMI stream and starting the FFmpeg stream. I'm going to try and run the master code on a different SBC and see how that goes. I'll report back if I have any luck but I think its a lack of processing power from the Pi that's the problem here. 

[Brian Fox]

Its definitely possible.  But I've only been able to achieve it with touch designer streaming rtsp out to a master pi, that then listens and sends it to the rest of the pis.  For whatever reason I have to restart the stream like 4-6 times, then it'll be under 5-10ms live.  I have sent resolume thru ndi to touch to pi to piwall and its great.  You definitely need a pretty fast comp and to be hard wired directly to the pis.  

[Ludovic Chougny]

Lunching the stream on an Core i7 (dual core) ffmpeg takes ~10% of cpu activity, no real differences with HD or SD stream except latency.... I've tried ultra low latency settings with multiple codecs but the best result I've managed to get was 300ms in 1280x1024 in avi with 20fps... My LAN is 10/100 not a Giga, cables are CAT6, normally it can handle HD without major problems...? I think I'd found some clues for latency in the fact that we use an UDP pipe wich can be a problem for speed with streaming... It seems that RTP/RTSP/RTMP are really better for that... but I think it's not supported by omxplayer... Make sense for you ? I'm not really a boss with network settings...

Merci Thierry !

[Ludovic Chougny]

I have to restart the stream 2 times to get the 300ms...

What are your commands and setup with the NDI and the PIs ? I've started this project with Resolume 6 that haven't got the NDI if I remeber well, but now I'm using the 7th... That's really interesting ?

[Thierry Mijsoot]

Apparemment Omxplayer lit le RTSP, le problème est de savoir si PWOmxplayer le lit aussi ...

https://raspberry-projects.com/pi/software_utilities/media-players/omxplayer

[Thierry Mijsoot]

English is better!
Apparently Omxplayer reads the RTSP, the problem is whether PWOmxplayer reads it too ...

https://raspberry-projects.com/pi/software_utilities/media-players/omxplayer

[SchoolOnStage Muziek&educatie]

Nice one,

i,m trying to do the same with Pi Zero,s .Not working at the moment sadley

Op maandag 23 november 2020 om 10:06:46 UTC+1 schreef skaro...@gmail.com: