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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.

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

       -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 0-9
	       where 0 will show no messages, and 9 will  show	all  messages.
	       The  wildcard * can be used to match category names.  Note that
	       the order of categories and levels is important,	 wildcards  at
	       the  end	 may  override levels set earlier. The log levels are:
	       1=ERROR,	2=WARNING, 3=FIXME, 4=INFO, 5=DEBUG,  6=LOG,  7=TRACE,
	       9=MEMDUMP. Since	GStreamer 1.2 one can also use the debug level
	       names, e.g. --gst-debug=*sink:LOG. A full  description  of  the
	       various debug levels can	be found in the	GStreamer core library
	       API documentation, in the "Running GStreamer Applications" sec-

	       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 0-9,  with
	       the default being 0. Level 6 (LOG level)	will show all informa-
	       tion that is usually required for  debugging  purposes.	Higher
	       levels  are  only  useful in very specific cases. See above for
	       the full	list of	levels.

	       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.

	       GStreamer normally prints debugging messages so that  the  mes-
	       sages  are  color-coded when printed to a terminal that handles
	       ANSI escape sequences (on *nix),	or uses	 W32  console  API  to
	       color  the messages printed into	a console (on W32). Using this
	       option causes GStreamer to print	messages without color	('off'
	       or  'disable'),	print  messages	 with  default colors ('on' or
	       'auto'),	or print messages using	ANSI escape sequences for col-
	       oring  ('unix').	 Setting  the GST_DEBUG_COLOR_MODE 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.


       MEDIATYPE [, PROPERTY[, PROPERTY	...]]] [; CAPS[; CAPS ...]]

       Creates	a  capability  with  the  given	media type and optionally with
       given properties. The media type	can be escaped using " or '.   If  you
       want  to	 chain	caps,  you can add more	caps in	the same format	after-


       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
       - 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 ...] }

       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 videoconvert (for video)	in front of the	sink  to  make	things

       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-1.0
       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 ! videoconvert ! sdlvideosink   demuxer.  !
       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 ! videoconvert ! videoscale
       !   autovideosink    filesrc location=movie.avi ! decodebin ! videocon-
       vert ! overlay.video_sink   filesrc	!  subparse  !

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

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

       Network streaming

       Stream video using RTP and network elements.

	       gst-launch   v4l2src   !	  video/x-raw,width=128,height=96,for-
       mat=UYVY	! videoconvert ! ffenc_h263 ! video/x-h263 ! rtph263ppay pt=96
       ! udpsink host= port=5000
       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.  !
       videoconvert ! 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,format=YUY2;video/x-
       raw,format=YV12'	! xvimagesink
       Show a test image and use the YUY2 or YV12 video	format for this.

	       gst-launch   osssrc   !	  'audio/x-raw,rate=[32000,64000],for-
       mat={S16LE,S24LE,S32LE}'	! 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.
	      GST_DEBUG=totem:4,typefind:5).  '*'  is allowed as a wildcard as
	      part of debug category names (e.g. GST_DEBUG=*sink:6,*audio*:6).
	      Since 1.2.0 it is	also possible to specify the log level by name
	      (1=ERROR,	2=WARN,	 3=FIXME,  4=INFO,  5=DEBUG,  6=LOG,  7=TRACE,
	      9=MEMDUMP) (e.g. GST_DEBUG=*audio*:LOG)

	      When  this environment variable is set, coloured debug output is

	      When set to a filesystem path, store  'dot'  files  of  pipeline
	      graphs  there.   These can then later be converted into an image
	      using the	'dot' utility from the graphviz	 set  of  tools,  like
	      this: dot	-Tsvg -o foo.svg (png or jpg are also possible
	      as output	format). There is also a utility called	 'xdot'	 which
	      allows  you to view the .dot file	directly without converting it

	      Path   of	   the	  plugin    registry	file.	 Default    is
	      ~/.cache/gstreamer-1.0/registry-CPU.bin  where  CPU  is  the ma-
	      chine/cpu	type GStreamer was compiled for, e.g. 'i486',  'i686',

	      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

	      Set this variable	to a file path to redirect all GStreamer debug
	      messages to this file. If	left unset,  debug  messages  with  be
	      output unto the standard error.

	      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 plugin cache; can be	deleted	at any time, will  be  re-cre-
	       ated  automatically  when  it  does  not	 exist	yet or plugins
	       change. Based on	XDG_CACHE_DIR, so may be in a different	 loca-
	       tion than the one suggested.

       gst-inspect-1.0(1), gst-launch-1.0(1),

       The GStreamer team at

				   May 2007			  GStreamer(1)


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