User Commands gst-launch(1)
NAME
gst-launch - build and run a GStreamer pipeline
SYNOPSIS
gst-launch [--exclude=type,type2,...] [--no-fault] [--
messages] [-output=file] [--tags] [--trace] [--verbose] [--
version] [gst-std-options] pipeline-description
DESCRIPTION
gst-launch builds and runs basic GStreamer pipelines.
In simple form, a pipeline-description is a list of elements
separated by exclamation marks (!). Properties can be appended to elements, in the form property=value.For a complete description of possible values for pipeline-
description, see the section Pipeline Description below or consult the GStreamer documentation.Please note that gst-launch is primarily a debugging tool
for developers and users. You should not build applicationson top of it. For applications, use the gst_parse_launch()
function of the GStreamer API as an easy way to construct pipelines from pipeline descriptions. OPTIONSThe following options are supported by gst-launch:
-X, --exclude=type1,type2,... Do not output status infor-
mation of specified type.-m, --messages Output messages posted on
the pipeline's bus.-f, --no-fault Do not install a fault
handler.-o, -output-=file Save XML representation of
pipeline to file, then exit.-t, --tags Output tags, also known as
metadata.SunOS 5.11 Last change: 12 Nov 2007 1
User Commands gst-launch(1)
-T, --trace Print memory allocation
trace, if enabled at compile time.-v, --verbose Output status information
and property notifications.--version Print GStreamer version
number.gst-std-options Standard options available
for use with most GStreamerapplications. See gst-std-
options(5) for more informa-
tion.EXTENDED DESCRIPTION
Pipeline Description A pipeline consists elements and links. elements can be put into bins of different sorts. elements, links and bins can be specified in a pipeline description in any order. Elements elementtype [property1 ...]Creates an element of type elementtype and sets the proper-
ties. Properties property=value ...Sets the property to the specified value. You can use gst-
inspect(1) to find out about properties and allowed values of different elements. Enumeration properties can be set by name, nick or value. Bins[bintype.] ( [property1 ...] pipeline-description )
Specifies that a bin of type bintype is created and the given properties are set. Every element between the braces is put into the bin. Please note the dot that has to be used after the bintype. You will almost never need thisSunOS 5.11 Last change: 12 Nov 2007 2
User Commands gst-launch(1)
functionality, it is only really useful for applicationsusing the gst_launch_parse() API with 'bin' as bintype. That
way it is possible to build partial pipelines instead of afull-fledged top-level pipeline.
Links [[srcelement].[pad1,...]] ! [[sinkelement].[pad1,...]] [[srcelement].[pad1,...]] ! caps ! [[sinkelement].[pad1,...]] Links the element with name srcelement to the element with name sinkelement, using the caps specified in caps as a filter. Names can be set on elements with the name property. If the name is omitted, the element that was specified directly in front of or after the link is used. This works across bins. If a padname is given, the link is done with these pads. If no pad names are given all possibilities are tried and a matching pad is used. If multiple padnames aregiven, both sides must have the same number of pads speci-
fied and multiple links are done in the given order. So the simplest link is a simple exclamation mark, that links the element to the left of it to the element right of it. Caps mimetype [, property[, property ...]]] [; caps[; caps ...]] Creates a capability with the given mimetype and optionally with given properties. The mimetype can be escaped using " or '. If you want to chain caps, you can add more caps in the same format afterwards. Properties name[:type]=value in lists and ranges: [type=]value Sets the requested property in capabilities. The name is an alphanumeric value and the type can have the followingcase-insensitive values:
+o i or int for integer values or ranges +o f or float for float values or ranges +o 4 or fourcc for FOURCC values +o b, bool, or boolean for boolean values +o s, str, or string for strings +o l or list for lists If no type was given, the following order is tried: integer, float, boolean, string. Integer values must be parsable by strtol(), floats by strtod(). FOURCC values may either be integers or strings. Boolean values are (case insensitive) yes, no, true or false and may like strings be escaped with " or '.SunOS 5.11 Last change: 12 Nov 2007 3
User Commands gst-launch(1)
Ranges are in this format: [ property, property ] Lists use this format: ( property [, property ...] ) Pipeline Control A pipeline can be controlled by signals. SIGUSR2 will stopthe pipeline (GST_STATE_NULL); SIGUSR1 will put it back to
play (GST_STATE_PLAYING). By default, the pipeline will
start in the playing state. There are currently no signalsdefined to go into the ready or pause (GST_STATE_READY and
GST_STATE_PAUSED) state explicitly.
EXAMPLES
The examples below assume that you have the correct plugins available. In general, "sunaudiosink" can be substituted with another audio output plugin such as "esdsink","alsasink", "osxaudiosink", or "artsdsink". Likewise, "xvi-
magesink" can be substituted with "ximagesink", "sdlvideo-
sink", "osxvideosink", or "aasink". Keep in mind though that different sinks might accept different formats and even the same sink might accept different formats on different machines, so you might need to add converter elements like audioconvert and audioresample (for audio) or ffmpegcolorspace (for video) in front of the sink to make things work. Example 1: Audio Playback Play the WAV music file "music.wav":example% gst-launch filesrc location=music.wav ! wavparse ! sunaudiosink
Play the mp3 music file "music.mp3":example% gst-launch filesrc location=music.mp3 ! flump3dec ! sunaudiosink
Play the Ogg Vorbis file "music.ogg":example% gst-launch filesrc location=music.ogg ! oggdemux ! vorbisdec ! audioconvert ! sunaudiosink
Play an mp3 file or an http stream using GNOME-VFS:
example% gst-launch gnomevfssrc location=music.mp3 ! flump3dec ! sunaudiosink
example% gst-launch gnomevfssrc location=http://domain.com/music.mp3 ! flump3dec ! sunaudiosink
Use GNOME-VFS to play an mp3 file located on an SMB server:
example% gst-launch gnomevfssrc location=smb://computer/music.mp3 ! flump3dec ! sunaudiosink
Example 2: Video PlaybackSunOS 5.11 Last change: 12 Nov 2007 4
User Commands gst-launch(1)
Play an Ogg video file:example% gst-launch filesrc location=video.ogg ! oggdemux ! theoradec ! ffmpegcolorspace ! xvimagesink
Example 3: Format Conversion Convert an mp3 music file to the Ogg Vorbis format:example% gst-launch filesrc location=music.mp3 ! flump3dec ! audioconvert ! vorbisenc ! oggmux ! filesink location=music.ogg
Convert an mp3 music file to the FLAC format:example% gst-launch filesrc location=music.mp3 ! flump3dec ! audioconvert ! flacenc ! filesink location=test.flac
Convert a .WAV file to the Ogg Vorbis format:example% gst-launch filesrc location=music.wav ! wavparse ! audioconvert ! vorbisenc ! oggmux ! filesink location=music.ogg
Example 4: Recording Audio Record sound from your audio input and encode it into an Ogg file:example% gst-launch sunaudiosrc ! audioconvert ! vorbisenc ! oggmux ! filesink location=music.ogg
Example 5: Compact Disk (CDDA) Play track number 3 from compact disc:example% gst-launch cddasrc track=3 ! sunaudiosink
Play track number 5 from compact disc:example% gst-launch cdda://5 ! sunaudiosink
Example 6: Diagnostic Generate a null stream and ignore it:example% gst-launch fakesrc ! fakesink
Generate a pure tone to test the audio output:example% gst-launch audiotestsrc ! sunaudiosink
Generate a familiar test pattern to test the video output:example% gst-launch videotestsrc ! xvimagesink
Generate a familiar test pattern to test the video output:SunOS 5.11 Last change: 12 Nov 2007 5
User Commands gst-launch(1)
example% gst-launch videotestsrc ! ximagesink
Example 7: Automatic Linking You can use the decodebin element to automatically select the right elements to get a working pipeline. Play any supported audio format:example% gst-launch filesrc location=musicfile ! decodebin ! sunaudiosink
Play any supported video format with video and audio output. Threads are used automatically.example% gst-launch filesrc location=videofile ! decodebin name=decoder decoder. ! queue ! audioconvert ! audioresample ! osssink decoder. ! ffmpegcolorspace ! xvimagesink
To make this even easier, you can use the playbin element:example% gst-launch playbin uri=file:///home/joe/foo.avi
Example 8: Filtered Connections These examples show how to use filtered capabilities. Show a test image and use the YUY2 or YV12 video format for this:example% gst-launch videotestsrc ! video/x-raw-yuv,format=urcc)YUY2;video/x-raw-yuv,format=urcc)YV12 ! xvimagesink
Record audio and write it to a .wav file. Force usage of signed 16 to 32 bit samples and a sample rate between 32kHz and 64KHz:example% gst-launch sunaudiosrc ! 'audio/x-raw-int,rate=[32000,64000],width=[16,32],depth={16,24,32},signed=(boolean)true' ! wavenc ! filesink location=recording.wav
FILES The following files are used by this application:/usr/bin/gst-launch
Executable to build and run a GStreamer pipeline./usr/lib/gstreamer-0.10/
GStreamer system plugin directory.~/gstreamer-0.10/plugins
SunOS 5.11 Last change: 12 Nov 2007 6
User Commands gst-launch(1)
GStreamer user-specific plugin directory.
~/gstreamer-0.10/registry-*.xml
GStreamer plugin registry for user.ATTRIBUTES
See attributes(5) for descriptions of the following attri-
butes:____________________________________________________________
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
|_____________________________|_____________________________|
| Availability | library/audio/gstreamer ||_____________________________|_____________________________|
| Interface stability | Volatile ||_____________________________|_____________________________|
SEE ALSO
gst-feedback(1), gst-inspect(1), gst-typefind(1), gst-
xmlinspect(1), gst-xmllaunch(1), gstreamer-properties(1),
libgstreamer-0.10(3), attributes(5), gst-std-options(5)
NOTES Original man page written by the GStreamer team at http://www.gstreamer.net/. Updated by Brian Cameron, Sun Microsystems Inc., 2004, 2006, 2007.SunOS 5.11 Last change: 12 Nov 2007 7