Raspberry Pi WebRTC IP Camera

This is an experimental buildroot external tree to produce a webcam firmware for Raspberry Pi Zero 2 W. The firmware is designed for maximal reliability and has no admin GUI, configuration is done by SSH access or by editing files on the sd card.

The resulting SD card image only contains one FAT partition with the root image included in the kernel, running as initramfs. The FAT partition is mounted read only to /boot so there are no SD card writes during operation.

Features

The firmware currently provides a low latency WebRTC live stream to web browsers by accessing https://raspipcam.local/.

The video stream is captured and encoded using video4linux by gstreamer, which forwards a h264 RTP stream to Janus.

Video settings are optimized for a Raspberry Pi Camera v2, for different versions and capture/resolution settings, the gstreamer pipeline has to be modified.

To persist a modified gstreamer pipeline, create an environment file gstreamer.txt on the SD card and put the pipeline in the GSTREAMER_PIPELINE variable:

GSTREAMER_PIPELINE=v4l2src \
	extra-controls="controls,video_bitrate_mode=1,video_bitrate=4000000,h264_i_frame_period=60,repeat_sequence_header=1" \
	! video/x-h264,format=I420,width=1640,height=922,framerate=30/1 \
	! rtph264pay ! udpsink host=127.0.0.1 port=5004

This can also be used to configure streaming to external (rtmp/rtp) servers instead or additionally to the WebRTC browser output.

Building

git clone https://github.com/buildroot/buildroot.git
git clone https://github.com/markuslindenberg/raspipcam.git
make O=$PWD/build BR2_EXTERNAL=$PWD/raspipcam -C $PWD/buildroot raspipcam_raspberrypizero2w_defconfig
cd build
make

Installing

Create SD card from image in output/images/sdcard.img.

Updating

mount -o remount,rw /boot
Use output/images/zImage to replace the kernel7.img file on the SD card (mounted as /boot/) and reboot.

SSH access

Keys only. Put an authorized_keys file for root on the SD card FAT partition (/boot/authorized_keys), reboot.

Network

The image supports (USB) ethernet adapters and Wifi. It uses RA and DHCP for autoconfiguation and announces as mDNS host raspipcam.local. Additionally to IPv6, legacy IP is also supported.

Enabling Wifi

edit /boot/config.txt and remove the line dtoverlay=disable-wifi, reboot
Use iwctl (interactively) to scan&connect, then copy the /var/lib/iwd folder to /boot/ (FAT partition) to persist.

iwctl station wlan0 scan
iwctl station wlan0 get-networks
iwctl connect "some network"

FAQ

Can I build this for other Raspberry Pi boards?

Currently this only includes a working build configuration for a Zero 2 W but other boards can easily be added.

Can it support other streaming formats?

Most possibly yes, by including more gstreamer plugins into the build and adaping the gstreamer pipeline.

markuslindenberg / raspipcam