srvfb - Stream framebuffer content over HTTP
This repository contains a small webserver that can serve the contents of a
linux framebuffer device as video over HTTP. The video is encoded as a series
of PNGs, which are served in a
multipart/x-mixed-replace stream. The primary
use case is to stream a reMarkable screen to a computer and share
it from there via video-conferencing or capturing it. For that reason, there is
also a proxy-mode, which streams the frames as raw, uncompressed data from the
remarkable and can then do the png-encoding on a more powerful machine.
Whithout that, the framerate is one or two frames per second, which might not
be acceptable (it might be, though).
This should be considered a tech demo in the current state. The code is not particularly clean, it's not in any way secured, probably not very efficient and it's taylored specifically to the reMarkable (e.g. it can only stream 16-bit grayscale images). Feel free to use it and report any bugs you find, but I don't make any promises in regards to support or stability and any issues not directly related to my usecase will likely be closed.
You can see a short video demonstrating this in this tweet
Installation and usage
go get -d -u github.com/Merovius/srvfb GOARCH=arm GOOS=linux go build github.com/Merovius/srvfb scp srvfb email@example.com: ssh firstname.lastname@example.org ./srvfb -device /dev/fb0 -listen :1234
If you then open
http://10.11.99.1:1234/ in your browser (only Chrome is
tested) you should see the stream from your reMarkable. To use proxy-mode, run
(in a separate terminal)
go build github.com/Merovius/srvfb ./srvfb -listen localhost:1234 -proxy 10.11.99.1:1234
http://localhost:1234/ in your browser.
Once you can see the reMarkable screen in your browser (via proxy or not), clicking on the image should rotate it by 90°.
This repository also contains systemd unit files to run
(using socket activation). For security reasons, it only listens on the USB
network, though. To use it, run
cd $(go env GOPATH)/src/github.com/Merovius/srvfb GOARCH=arm GOOS=linux go build github.com/Merovius/srvfb scp srvfb email@example.com:/usr/bin scp contrib/srvfb.service contrib/srvfb.socket firstname.lastname@example.org:/etc/systemd/system ssh email@example.com systemctl enable --now srvfb.socket
Apart where otherwise noted, this code is published under the Apache License, Version 2.0:
Copyright 2018 Axel Wagner Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.