GStreamer RaspberryPi Streaming

Prerequisites:

• GStreamer installed
• Raspberry Pi Cam Setup

Install rpicamsrc

rpicamsrc is officially part of gstreamer 1.18. However, at the time of this writing, the latest supported gstreamer on Raspberry Pi OS is 1.14.

We can build and install rpicamsrc from source.

Firstly, install build dependencies:

sudo apt-get install autoconf automake libtool pkg-config \
libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev \
libraspberrypi-dev

Now, clone and install the library from source:

git clone https://github.com/thaytan/gst-rpicamsrc
cd gst-rpicamsrc
./autogen.sh --prefix=/usr --libdir=/usr/lib/arm-linux-gnueabihf/
make
sudo make install

Create a stream on the Pi

I like using rpicamsrc because it gives me really great control over the camera.

gst-launch-1.0 rpicamsrc \
sensor-mode=4 keyframe-interval=1 preview-opacity=50 ! \
h264parse ! \
rtph264pay config-interval=1 pt=96 ! \
gdppay ! \
tcpserversink host=0.0.0.0 port=5000

• sensor-mode=4 gives the best viewing angle
• keyframe-interval=1 sends each frame as a keyframe
  • This prevents streamed frames from going grey due to the H264 encoding
• preview-opacity=50 means you can still use your RPi display
  • especially useful when using CLI mode
• See gstreamer rpicamsrc docs for more properties

An alternative to rpicamsrc is v412src; but, often frames get dropped doing this because of the H264 encoding.

gst-launch-1.0 v4l2src device=/dev/video0 ! \
video/x-h264,width=640,height=480,framerate=30/1 ! \
h264parse ! \
rtph264pay config-interval=1 pt=96 ! \
gdppay ! \
tcpserversink host=0.0.0.0 port=5000

Watch the stream using gstreamer

gst-launch-1.0 -v tcpclientsrc host=192.168.50.202 port=5000 ! \
gdpdepay ! rtph264depay ! avdec_h264 ! videoconvert ! \
autovideosink sync=false

sync=false means we always get the latest frame. This helps keep the latency as low as possible.