gistfile1.md

• Home page
• Original documetation from source code
• http://wiki.oz9aec.net/index.php/Gstreamer_cheat_sheet
• http://www.cin.ufpe.br/~cinlug/wiki/index.php/Introducing_GStreamer
• http://www.jonobacon.org/2006/12/27/using-gnonlin-with-gstreamer-and-python/
• https://felipec.wordpress.com/2008/01/19/gstreamer-hello-world/
• http://notes.brooks.nu/2011/01/gstreamer-video-crossfade-example/
• http://www.oz9aec.net/index.php/gstreamer/366-gstinputselector-to-switch-between-different-cameras
• Picture compositing
• https://github.com/fthiery/gst-gengui
• https://github.com/guijemont/GstStabilizer
• http://www.oz9aec.net/index.php/gstreamer/345-a-weekend-with-gstreamer
• https://github.com/umlaeute/v4l2loopback/wiki/Gstreamer
• http://cgit.freedesktop.org/gstreamer/gst-python/tree/examples/switch.py
• Queue after tee
• Some tricks to get "easy" stuffs out of GStreamer.
• GNonlin example
• http://luisbg.blogalia.com/historias/61887
• http://www.jonobacon.org/2006/08/28/getting-started-with-gstreamer-with-python/
• http://pygstdocs.berlios.de/
• http://gstreamer.freedesktop.org/data/doc/gstreamer/head/manual/html/section-dynamic-pipelines.html
• http://wiki.pitivi.org/wiki/PyGST_Tutorial/Combining_Audio_and_Video

First of all, a video came with two main types of data: audio and video. Since space is important, is important to compress data but since quality is important also, during the years has been developed a lot of codecs (this name came from their functions: coder and encoder). For a technical video overview look at the Xiph videos.

$ gst-launch -v -e  filesrc location="/home/gipi/Video/Nature by Numbers.mp4"  ! \
    qtdemux name=avi ! faad  ! pulsesink

And remember is not only about multimedia: http://www.cita.utoronto.ca/~kcannon/gstlalworkshop/intro_and_setup.html

PIPELINES

Play with guessing

$ gst-launch -v playbin uri="file:///home/gipi/Video/Nature by Numbers.mp4"

Play an image

$ gst-launch -v multifilesrc location=~/Image/debswirl-1280x1024.png caps="image/png, framerate=1/1" ! \
    pngdec ! ffmpegcolorspace ! ximagesink

Autodetect streams and play it

$ gst-launch-1.0 -v --gst-debug=4 filesrc location=//streaming.mp4 ! \
    decodebin name=demux \
    demux. ! queue ! autovideosink \
    demux. ! queue ! autoaudiosink

Show your webcam composite with a test pattern

gst-launch -e v4l2src ! \
    queue ! \
    ffmpegcolorspace ! \
    videoscale ! \
    video/x-raw-yuv, framerate=10/1, width=320, height=240 ! \
    videomixer name=mix ! \
    ffmpegcolorspace ! \
    xvimagesink \
    videotestsrc ! video/x-raw-yuv, framerate=10/1, width=640, height=360 ! mix.

Show an overlay over the video

gst-launch-1.0 videotestsrc ! timeoverlay font-desc=60px ! xvimagesink

Resize the output

gst-launch-1.0 -v filesrc location=assange-ecuador.mp4 ! decodebin ! \
    videoscale ! \
    video/x-raw,width=\(int\)320,height=\(int\)200 ! \
    autovideosink filter-caps=video/x-raw

Create a video stream from an image

gst-launch-1.0 filesrc location=image001.jpg ! jpegdec ! imagefreeze ! autovideosink

Remote resource via HTTP

gst-launch-1.0 souphttpsrc location=http://foo.com/miao.mp3 ! autoaudiosink

Attach to a mountpoint of icecast

gst-launch -v filesrc location=audio/04\ -\ Blu\ di\ metilene.ogg ! \
    decodebin ! \
    audioconvert ! \
    vorbisenc  !  \
    oggmux ! \
    shout2send ip=localhost port=8000 mount=/lov

Icecast, you know

$ gst-launch v4l2src ! \
    queue ! \
    ffmpegcolorspace ! \
    videoscale ! \
    video/x-raw-yuv,width=320,height=240 ! \
    tee name=tscreen ! \
    queue ! \
    autovideosink \
    tscreen. ! \
    queue ! \
    videorate ! \
    video/x-raw-yuv,framerate=25/2 ! \
    queue ! \
    theoraenc quality=16 ! \
    queue ! \
    oggmux name=mux \
    alsasrc ! \
    queue ! \
    audioconvert ! \
    vorbisenc quality=0.2 ! \
    queue ! \
    queue ! \
    mux. \
    mux. ! \
    queue ! \
    tee name=tfile ! \
    queue ! \
    filesink location=stream.ogg tfile. ! \
    queue ! \
    shout2send ip=192.168.0.5 port=8000 mount=test.ogv password=sourcepassword

From an IP camera that serves JPEG images (multipartdemux is useless)

$ gst-launch souphttpsrc location=http://192.168.1.5:8080/videofeed ! \
    multipartdemux ! \
    jpegdec ! \
    xvimagesink

A simple test with audio

$ gst-launch -v audiotestsrc  wave=ticks ! audioconvert !  pulsesink

Send audio to a given pulse device

gst-launch -v filesrc location="yet-another-amazing-song.mp3" ! \
 decodebin ! \
 audioconvert ! \
 pulsesink device=nullsinkname

(the device can be a null sink created with pactl load-module module-null-sink sink_name=nullsinkname)

Screencast

$ gst-launch-1.0 ximagesrc ! \
    videoconvert ! \
    queue ! \
    vp8enc  ! mux. \
   pulsesrc ! audio/x-raw ! \
    queue ! \
    audioconvert ! \
    vorbisenc ! \
   mux. webmmux name=mux ! filesink location=screencast.webm

Build from source

Using scripts/create-uninstalled-setup.sh is possible to create a checkout of the sources needed in ~/gst; in that directory a script gst-head is created: this is useful in order to configure all the environment variables correctly and make the build success.