Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
GStreamer(1)		    General Commands Manual		  GStreamer(1)

       gst-launch - build and run a GStreamer pipeline

       gst-launch [OPTION...] PIPELINE-DESCRIPTION

       gst-launch is a tool that builds	and runs basic GStreamer pipelines.

       In  simple form,	a PIPELINE-DESCRIPTION is a list of elements separated
       by exclamation marks (!). Properties may	be appended  to	 elements,  in
       the form	property=value.

       For  a  complete	 description of	possible PIPELINE-DESCRIPTIONS see the
       section pipeline	description below or consult the GStreamer  documenta-

       Please  note that gst-launch is primarily a debugging tool for develop-
       ers and users. You should not build applications	on top of it. For  ap-
       plications, use the gst_parse_launch() function of the GStreamer	API as
       an easy way to construct	pipelines from pipeline	descriptions.

       gst-launch accepts the following	options:

       --help  Print help synopsis and available FLAGS

       -v, --verbose
	       Output status information and property notifications

       -q, --quiet
	       Do not print any	progress information

       -m, --messages
	       Output messages posted on the pipeline's	bus

       -t, --tags
	       Output tags (also known as metadata)

       -e, --eos-on-shutdown
	       Force an	EOS event on  sources  before  shutting	 the  pipeline
	       down.  This is useful to	make sure muxers create	readable files
	       when a muxing pipeline is shut down forcefully via Control-C.

       -i, --index
	       Gather and print	index statistics. This is  mostly  useful  for
	       playback	or recording pipelines.

       -o FILE,	--output=FILE
	       Save  XML  representation  of pipeline to FILE and exit (DEPRE-
	       CATED, DO NOT USE)

       -f, --no-fault
	       Do not install a	fault handler

	       Do not install signal handlers for SIGUSR1 (play)  and  SIGUSR2

       -T, --trace
	       Print  memory allocation	traces.	The feature must be enabled at
	       compile time to work.

	      gst-launch also accepts the following options that are common to
	      all GStreamer applications:

	       Prints the version string of the	GStreamer core library.

	       Causes  GStreamer to abort if a warning message occurs. This is
	       equivalent to setting the environment variable G_DEBUG to  'fa-
	       tal_warnings'  (see the section environment variables below for
	       further information).

	       A comma separated list of category_name:level pairs to  specify
	       debugging  levels  for each category. Level is in the range 0-5
	       where 0 will show no messages, and 5 will  show	all  messages.
	       The wildcard * can be used to match category names.

	       Use --gst-debug-help to show category names

	       Example:	GST_CAT:5,GST_ELEMENT_*:3,oggdemux:5

	       Sets  the  threshold for	printing debugging messages.  A	higher
	       level will print	more messages.	The useful range is 0-5,  with
	       the default being 0.

	       GStreamer  normally  prints debugging messages so that the mes-
	       sages are color-coded when printed to a terminal	 that  handles
	       ANSI  escape  sequences.	 Using this option causes GStreamer to
	       print messages without color.  Setting  the  GST_DEBUG_NO_COLOR
	       environment variable will achieve the same thing.

	       Disables	debugging.

	       Prints  a  list of available debug categories and their default
	       debugging level.

	       GStreamer info flags to set Enable  printout  of	 errors	 while
	       loading GStreamer plugins

	       Add directories separated with ':' to the plugin	search path

	       Preload	plugins	 specified  in a comma-separated list. Another
	       way to specify plugins to preload is  to	 use  the  environment
	       variable	GST_PLUGIN_PATH

       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.



       Creates an element of type ELEMENTTYPE and sets the PROPERTIES.



       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.



       Specifies that a	bin of type BINTYPE is created and the	given  proper-
       ties  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 al-
       most never need this functionality, it is only really useful for	appli-
       cations using the gst_launch_parse() API	with 'bin'  as	bintype.  That
       way it is possible to build partial pipelines instead of	a full-fledged
       top-level pipeline.


       [[SRCELEMENT].[PAD1,...]]   !   [[SINKELEMENT].[PAD1,...]]    [[SRCELE-
       MENT].[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 are given, both sides
       must have the same number of pads specified and multiple	links are done
       in the given order.
       So  the simplest	link is	a simple exclamation mark, that	links the ele-
       ment to the left	of it to the element right of it.


       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.


       in lists	and ranges: [(TYPE)]VALUE

       Sets the	requested property in capabilities. The	name  is  an  alphanu-
       meric  value  and the type can have the following case-insensitive val-
       - i or int for integer values or	ranges
       - f or float for	float values or	ranges
       - 4 or fourcc for FOURCC	values
       - b, bool or boolean for	boolean	values
       - s, str	or string for strings
       - fraction for fractions	(framerate, pixel-aspect-ratio)
       - 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  in-
       sensitive)  yes,	no, true or false and may like strings be escaped with
       " or '.
       Ranges are in this format:  [ VALUE, VALUE ]
       Lists use this format:	   ( VALUE [, VALUE ...] )

       A pipeline can be controlled by signals.	SIGUSR2	will stop the 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 signals defined to go into the  ready  or	 pause
       (GST_STATE_READY	and GST_STATE_PAUSED) state explicitly.

       The examples below assume that you have the correct plug-ins available.
       In general, "osssink" can be  substituted  with	another	 audio	output
       plug-in	such as	"esdsink", "alsasink", "osxaudiosink", or "artsdsink".
       Likewise,  "xvimagesink"	 can   be   substituted	  with	 "ximagesink",
       "sdlvideosink",	"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  au-
       dio)  or	 ffmpegcolorspace  (for	 video)	 in  front of the sink to make
       things work.

       Audio playback

	       gst-launch filesrc location=music.mp3 ! mad  !  audioconvert  !
       audioresample ! osssink
       Play  the  mp3  music file "music.mp3" using a libmad-based plug-in and
       output to an OSS	device

	       gst-launch filesrc location=music.ogg ! oggdemux	! vorbisdec  !
       audioconvert ! audioresample ! osssink
       Play an Ogg Vorbis format file

	       gst-launch gnomevfssrc location=music.mp3 ! mad ! osssink
	       gst-launch  gnomevfssrc	location= !
       mad ! audioconvert ! audioresample ! osssink
       Play an mp3 file	or an http stream using	GNOME-VFS

	       gst-launch gnomevfssrc location=smb://computer/music.mp3	!  mad
       ! audioconvert !	audioresample !	osssink
       Use GNOME-VFS to	play an	mp3 file located on an SMB server

       Format conversion

	       gst-launch  filesrc  location=music.mp3	! mad !	audioconvert !
       vorbisenc ! oggmux ! filesink location=music.ogg
       Convert an mp3 music file to an Ogg Vorbis file

	       gst-launch filesrc location=music.mp3 ! mad  !  audioconvert  !
       flacenc ! filesink location=test.flac
       Convert to the FLAC format


	       gst-launch filesrc location=music.wav ! wavparse	! audioconvert
       ! audioresample ! osssink
       Plays a .WAV file that contains raw audio data (PCM).

	       gst-launch filesrc location=music.wav ! wavparse	! audioconvert
       ! vorbisenc ! oggmux ! filesink location=music.ogg
	       gst-launch filesrc location=music.wav ! wavparse	! audioconvert
       ! lame !	filesink location=music.mp3
       Convert a .WAV file containing raw audio	data into an Ogg Vorbis	or mp3

	       gst-launch  cdparanoiasrc mode=continuous ! audioconvert	! lame
       ! id3v2mux ! filesink location=cd.mp3
       rips all	tracks from compact disc and convert them into	a  single  mp3

	       gst-launch  cdparanoiasrc  track=5  !  audioconvert  !  lame  !
       id3v2mux	! filesink location=track5.mp3
       rips track 5 from the CD	and converts it	into a single mp3 file

       Using gst-inspect(1), it	is possible  to	 discover  settings  like  the
       above  for cdparanoiasrc	that will tell it to rip the entire cd or only
       tracks of it.  Alternatively, you can use an  URI  and  gst-launch-0.10
       will  find  an element (such as cdparanoia) that	supports that protocol
       for you,	e.g.:
	      gst-launch cdda://5 ! lame vbr=new vbr-quality=6 ! filesink  lo-

	       gst-launch  osssrc  !  audioconvert  !  vorbisenc  !  oggmux  !
       filesink	location=input.ogg
       records sound from your audio input and encodes it into an ogg file


	       gst-launch filesrc location=JB_FF9_TheGravityOfLove.mpg !  dvd-
       demux ! mpeg2dec	! xvimagesink
       Display	only  the video	portion	of an MPEG-1 video file, outputting to
       an X display window

	       gst-launch filesrc location=/flflfj.vob ! dvddemux ! mpeg2dec !
       Display	the video portion of a .vob file (used on DVDs), outputting to
       an SDL window

	       gst-launch filesrc location=movie.mpg !	dvddemux  name=demuxer
       demuxer.	 !  queue  ! mpeg2dec !	sdlvideosink  demuxer. ! queue ! mad !
       audioconvert ! audioresample ! osssink
       Play both video and audio portions of an	MPEG movie

	       gst-launch filesrc location=movie.mpg ! mpegdemux  name=demuxer
       demuxer.	 !  queue  !  mpeg2dec ! ffmpegcolorspace ! sdlvideosink   de-
       muxer. !	queue !	mad ! audioconvert ! audioresample ! osssink
       Play an AVI movie with an external text subtitle	stream

       This example also shows how to refer to specific	pads by	name if	an el-
       ement (here: textoverlay) has multiple sink or source pads.

	       gst-launch   textoverlay	  name=overlay	!  ffmpegcolorspace  !
       videoscale ! autovideosink   filesrc location=movie.avi ! decodebin2  !
       ffmpegcolorspace	 !  overlay.video_sink	  filesrc !
       subparse	! overlay.text_sink

       Play an AVI movie with an external text subtitle	stream using playbin2

	       gst-launch    playbin2	 uri=file:///path/to/movie.avi	  sub-

       Network streaming

       Stream video using RTP and network elements.

	       gst-launch  v4l2src  ! video/x-raw-yuv,width=128,height=96,for-
       mat='(fourcc)'UYVY ! ffmpegcolorspace !	ffenc_h263  !  video/x-h263  !
       rtph263ppay pt=96 ! udpsink host= port=5000 sync=false
       This command would be run on the	transmitter

	       gst-launch   udpsrc   port=5000	 !  application/x-rtp,	clock-
       rate=90000,payload=96 !	rtph263pdepay  queue-delay=0  !	 ffdec_h263  !
       Use this	command	on the receiver


	       gst-launch -v fakesrc num-buffers=16 ! fakesink
       Generate	a null stream and ignore it (and print out details).

	       gst-launch  audiotestsrc	 !  audioconvert ! audioresample ! os-
       Generate	a pure sine tone to test the audio output

	       gst-launch videotestsrc ! xvimagesink
	       gst-launch videotestsrc ! ximagesink
       Generate	a familiar test	pattern	to test	the video output

       Automatic linking

       You can use the decodebin element to automatically select the right el-
       ements to get a working pipeline.

	       gst-launch  filesrc  location=musicfile ! decodebin ! audiocon-
       vert ! audioresample ! osssink
       Play any	supported audio	format

	       gst-launch filesrc location=videofile ! decodebin  name=decoder
       decoder.	 ! queue ! audioconvert	! audioresample	! osssink   decoder. !
       ffmpegcolorspace	! xvimagesink
       Play any	supported video	format with video and  audio  output.  Threads
       are used	automatically. To make this even easier, you can use the play-
       bin element:

	       gst-launch playbin uri=file:///home/joe/foo.avi

       Filtered	connections

       These examples show you how to use filtered caps.

	       gst-launch      videotestsrc	 !	 'video/x-raw-yuv,for-
       mat=(fourcc)YUY2;video/x-raw-yuv,format=(fourcc)YV12' ! xvimagesink
       Show a test image and use the YUY2 or YV12 video	format for this.

	       gst-launch	    osssrc	     !		 'audio/x-raw-
       ean)true' ! wavenc ! filesink location=recording.wav
       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.

	      Comma-separated  list  of	 debug	categories  and	 levels,  e.g.

	      When  this environment variable is set, coloured debug output is

	      When set to a filesystem	path,  store  dot  files  of  pipeline
	      graphs there.

	      Path    of    the	   plugin    registry	 file.	  Default   is
	      ~/.gstreamer-0.10/registry-CPU.xml where CPU is the  machine/cpu
	      type  GStreamer was compiled for,	e.g. 'i486', 'i686', 'x86-64',
	      'ppc', etc. (check the output of "uname -i" and "uname  -m"  for

	      Set  to  "no"  to	force GStreamer	to assume that no plugins have
	      changed, been added or been removed. This	 will  make  GStreamer
	      skip  the	 initial check whether a rebuild of the	registry cache
	      is required or not. This may be useful in	embedded  environments
	      where the	installed plugins never	change.	Do not use this	option
	      in any other setup.

	      Specifies	a list of directories to scan for additional  plugins.
	      These take precedence over the system plugins.

	      Specifies	 a  list of plugins that are always loaded by default.
	      If not set, this defaults	to the system-installed	path, and  the
	      plugins installed	in the user's home directory

	      Useful  Orc  environment	variable. Set ORC_CODE=debug to	enable
	      debuggers	such as	gdb to create useful backtraces	from  Orc-gen-
	      erated  code.   Set  ORC_CODE=backup  or ORC_CODE=emulate	if you
	      suspect Orc's SIMD code generator	is producing  incorrect	 code.
	      (Quite  a	few important GStreamer	plugins	like videotestsrc, au-
	      dioconvert or audioresample use Orc).

	      Useful GLib environment variable.	Set G_DEBUG=fatal_warnings  to
	      make GStreamer programs abort when a critical warning such as an
	      assertion	failure	occurs.	This is	useful if you want to find out
	      which  part  of the code caused that warning to be triggered and
	      under what circumstances.	Simply set G_DEBUG as mentioned	 above
	      and  run	the  program  in gdb (or let it	core dump). Then get a
	      stack trace in the usual way.

	       The xml plugin database;	can be deleted at any  time,  will  be
	       re-created  automatically when it does not exist	yet or plugins

       gst-feedback(1),	gst-inspect(1),	gst-typefind(1)

       The GStreamer team at

				   May 2007			  GStreamer(1)


Want to link to this manual page? Use this URL:

home | help