GST cookbook
In addition to being a powerful multimedia infrastructure for applications Gstreamer is also a useful tool for general manipulations of multimedia data. By invoking gst-launch from the command-line with a custom pipeline many useful processing steps are possible.
Gstreamer also usually has good support for Xiph-related formats.
Unfortunately, it can be rather difficult to figure out an appropriate pipeline without a starting point.
Here are some useful examples:
Encode a .wav to Vorbis:
- gst-launch filesrc location="INPUT.wav" ! wavparse ! audioconvert ! vorbisenc ! oggmux ! filesink location="OUTPUT.ogg"
Dump a Theora video to PNGs:
- gst-launch filesrc location="INPUT.ogv" ! oggdemux ! theoradec ! ffmpegcolorspace ! pngenc snapshot=false ! multifilesink location="OUTPUT%04d.png"
Transmux a MKV (containing vorbis and theora) to Ogg:
- gst-launch filesrc location="INPUT.mkv" ! matroskademux name=d ! video/x-theora ! queue ! theoraparse ! oggmux name=mux ! filesink location="OUTPUT.ogv" d. ! audio/x-vorbis ! queue ! vorbisparse ! queue ! mux.
Encode a y4m to lossless Dirac in Ogg:
- gst-launch filesrc location="INPUT.y4m" ! decodebin ! schroenc force-profile=vc2_main rate-control=lossless ! oggmux ! filesink location="OUTPUT.ogv"
Pull from a windows media stream, transcode to Ogg/Thera+Vorbis and send to a icecast server:
(requires purchasing fluendo plugins for decoding the encumbered codecs)
- gst-launch uridecodebin uri=mms://SOURCE.SERVER.COM/path name=d ! queue max-size-time=100000000 ! ffmpegcolorspace ! theoraenc bitrate=800 ! oggmux name=mux ! shout2send ip=YOURICECAST.SERVER.COM port=8000 password=YOURPASSWORD mount=/OUTPUTFILENAME.ogv d. ! queue max-size-time=100000000 ! audioconvert ! vorbisenc ! mux.
Capture video from a webcam, encode to an Ogg Theora file, decode and display on screen, write to a file whose name is the current date+time, and stream to an IceCast server
- gst-launch-0.10 --eos-on-shutdown v4l2src ! 'video/x-raw-yuv, width=640, height=480' ! videorate ! 'video/x-raw-yuv, framerate=15/1' ! queue max-size-bytes=100000000 max-size-time=0 ! theoraenc bitrate=150 ! oggmux ! tee name=ogged ! queue max-size-bytes=100000000 max-size-time=0 ! oggdemux ! theoradec ! xvimagesink sync=false force-aspect-ratio=true ogged. ! queue max-size-bytes=100000000 max-size-time=0 ! filesink location=`date +%F_%T`.ogv ogged. ! queue max-size-bytes=100000000 max-size-time=0 ! shout2send ip=YOURICECAST.SERVER.COM port=8000 password=YOURPASSWORD mount=/OUTPUTFILENAME.ogv streamname=YOURSTREAMNAME description=YOURDESCRIPTION genre=YOURGENRE url=YOURSTREAMURL ogged.