Multimedia: GStreamer

Audio streaming

gstreamer pipeline to stream raw audio over network

gst-launch-1.0 -v filesrc location=/tmp/musicfile.mp3 ! mpegaudioparse ! mpg123audiodec ! audioconvert ! audioresample ! audio/x-raw, rate=16000, channels=1, format=S16LE ! audiomixer blocksize=320 ! udpsink host=192.168.1.10 port=10000

gst-launch-1.0 -v udpsrc port=10000 ! rawaudioparse use-sink-caps=false format=pcm pcm-format=s16le sample-rate=16000 num-channels=1 ! queue ! audioconvert ! audioresample ! autoaudiosink

v4l2loopback

Il software v4l2loopback consente di aprire “due volte” un dispositivo V4L2. Ciò può essere utile per consentire di effettuare snasphot (es. con v4l2grab) mentre è in corso la trasmissione del video da parte di un altro programma.

Installazione e creazione di un device virtuale con v4l2loopback

sudo apt-get install v4l2loopback-dkms
sudo modprobe v4l2loopback video_nr=10

Redirezione dell’output prodotto da un dispositivo reale (/dev/video0) in ingresso al dispositivo virtuale (/dev/video10)

Con ffmpeg

sudo apt-get install ffmpeg
ffmpeg -f video4linux2 -i /dev/video0 -vcodec copy -f v4l2 /dev/video10

Con gstreamer

sudo apt-get install gstreamer1.0-tools gstreamer1.0-plugins-good
gst-launch-1.0 v4l2src device=/dev/video0 ! v4l2sink device=/dev/video10

Script provati su Raspberry Pi 2 con Raspbian GNU/Linux 10 (buster)

uname -a Linux raspberrypi 4.19.97-v7+ #1294 SMP Thu Jan 30 13:15:58 GMT 2020 armv7l GNU/Linux

Script video-test.sh

#!/bin/sh
gst-launch-1.0 videotestsrc ! autovideosink

Script video-test-ball.sh

#!/bin/sh
gst-launch-1.0 videotestsrc pattern=ball ! autovideosink

Script video-cam-test.sh

#!/bin/sh
gst-launch-1.0 -v v4l2src device=/dev/video0 ! video/x-raw,width=640,height=480,framerate=30/1 ! videoconvert ! tee ! queue ! autovideosink

Script video-test-src.sh

#!/bin/sh
gst-launch-1.0 videotestsrc ! video/x-raw,width=320,height=240 ! videoconvert ! tee ! v4l2sink device=/dev/video1

Script video-cam-src.sh

#!/bin/sh
gst-launch-1.0 v4l2src device=/dev/video0 ! video/x-raw,width=320,height=240 ! videoconvert ! tee ! v4l2sink device=/dev/video1

Streaming with GStreamer

GStreamer-devel – Stream UDP + MPEG-TS to VLC time display
GStreamer in Docker = overlays not working
I need to stream a video from a server to a client, with a clock overlay. The server must be inside a Docker image. Here is the server command:

gst-launch-1.0 \
v4l2src device=/dev/video0 \
! videorate ! videoscale \
! clockoverlay shaded-background=true font-desc="Sans 38" \
! video/x-raw,format=I420,width=640,height=360,framerate=25/1 \
! jpegenc ! rtpjpegpay \
! udpsink host=localhost port=5000

And here is the client:

gst-launch-1.0 -v \
udpsrc port=5000 \
! application/x-rtp, encoding-name=JPEG, framerate=25/1 \
! rtpjpegdepay ! jpegdec ! videoconvert ! ximagesink

Solution: I just needed to install gstreamer1.0-x as well.

#!/bin/bash
clear
raspivid -n -t 0 -rot 270 -w 960 -h 720 -fps 30 -b 6000000 -o - | gst-launch-1.0 -e -vvvv fdsrc ! h264parse ! rtph264pay pt=96 config-interval=5 ! udpsink host=***YOUR_PC_IP*** port=5000

Windows Command Prompt

gst-launch-1.0 -e -v udpsrc port=5000 ! application/x-rtp, payload=96 ! rtpjitterbuffer ! rtph264depay ! avdec_h264 ! fpsdisplaysink sync=false text-overlay=false