--- title: "GStreamer" date: 2020-02-08T20:46:36-05:00 draft: false tags: [ "Audio-Video" ] --- GStreamer is a pipeline based multimedia framework that goes from capture, processing, to a sink such as a X window or UDP sink. To install on Ubuntu run, ```bash sudo apt install gstreamer1.0-tools ``` Pipelines are indicated via `!`. To capture your webcam feed and display it in a X window, run the following: ```bash gst-launch-1.0 v4l2src device=/dev/video0 ! videoconvert ! ximagesink ``` For the PiCar project I'm on, I need to send the video from the raspberry pi over the network as fast as possible. The next couple commands have options that reflect this. On the PiCar, I send h264 video over the network. You might need to install an additional package for h264 encoding to work. ```bash sudo apt install gstreamer1.0-plugins-ugly ``` To send h264 video over the network, ```bash gst-launch-1.0 \ v4l2src device=/dev/video0 ! \ videoconvert ! \ x264enc ! \ rtph264pay ! \ udpsink host=192.168.0.2 port=5000 ``` To send it as fast as you can, ```bash gst-launch-1.0 \ v4l2src device=/dev/video0 ! \ videoconvert ! \ x264enc interlaced=true tune=zerolatency speed-preset=ultrafast ! \ rtph264pay ! \ udpsink host=192.168.0.2 port=5000 ``` To send it as fast as possible under a given framerate (ex: 30) ```bash gst-launch-1.0 \ v4l2src device=/dev/video0 ! \ videoconvert ! \ videorate ! \ video/x-raw,framerate=30/1 ! \ x264enc interlaced=true tune=zerolatency speed-preset=ultrafast ! \ rtph264pay ! \ udpsink host=192.168.0.2 port=5000 ``` To receive it and display it on an X-window, ```bash gst-launch-1.0 \ udpsrc port=5000 ! \ application/x-rtp,payload=96 ! \ rtph264depay ! \ decodebin ! \ videoconvert n-threads=4 ! \ ximagesink ```