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

FreeBSD Manual Pages


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

       gst-launch-1.0 -	build and run a	GStreamer pipeline

       gst-launch-1.0 [OPTION...] PIPELINE-DESCRIPTION

       gst-launch-1.0  is  a  tool  that builds	and runs basic GStreamer pipe-

       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-1.0 is primarily a debugging	tool  for  de-
       velopers	and users. You should not build	applications on	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.

       gst-launch-1.0 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-1.0  also accepts the following options that are com-
	      mon 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-in-
       spect-1.0(1) to find out	about properties and allowed values of differ-
       ent 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,...]]    [[SRCELE-
       MENT].[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.
       Linking using the : operator attempts to	link all possible pads between
       the elements


       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, "pulsesink" can be substituted with	another	 audio	output
       plug-in	such  as  "alsasink" or	"osxaudiosink" Likewise, "xvimagesink"
       can be substituted with "ximagesink", "glimagesink", or "osxvideosink".
       Keep in mind though that	different sinks	might accept different formats
       and even	the same sink might accept different formats on	different  ma-
       chines,	so  you	might need to add converter elements like audioconvert
       and audioresample (for audio) or	videoconvert (for video) in  front  of
       the sink	to make	things work.

       Audio playback

       Play the	mp3 music file "music.mp3" using a libmpg123-based plug-in and
       output to an Pulseaudio device
	       gst-launch-1.0 filesrc location=music.mp3  !  mpegaudioparse  !
       mpg123audiodec !	audioconvert ! audioresample ! pulsesink

       Play an Ogg Vorbis format file
	       gst-launch-1.0  filesrc location=music.ogg ! oggdemux ! vorbis-
       dec ! audioconvert ! audioresample ! pulsesink

       Play an mp3 file	or an http stream using	GIO
	       gst-launch-1.0 giosrc  location=music.mp3  !  mpegaudioparse  !
       mpg123audiodec !	audioconvert ! pulsesink
	       gst-launch-1.0  giosrc  location=  !
       mpegaudioparse !	mpg123audiodec ! audioconvert !	audioresample !	 puls-

       Use GIO to play an mp3 file located on an SMB server
	       gst-launch-1.0  giosrc location=smb://computer/music.mp3	! mpe-
       gaudioparse ! mpg123audiodec ! audioconvert ! audioresample ! pulsesink

       Format conversion

       Convert an mp3 music file to an Ogg Vorbis file
	       gst-launch-1.0 filesrc location=music.mp3  !  mpegaudioparse  !
       mpg123audiodec  !  audioconvert	!  vorbisenc ! oggmux !	filesink loca-

       Convert to the FLAC format
	       gst-launch-1.0 filesrc location=music.mp3  !  mpegaudioparse  !
       mpg123audiodec !	audioconvert ! flacenc ! filesink location=test.flac


       Plays a .WAV file that contains raw audio data (PCM).
	       gst-launch-1.0  filesrc	location=music.wav ! wavparse !	audio-
       convert ! audioresample ! pulsesink

       Convert a .WAV file containing raw audio	data into an Ogg Vorbis	or mp3
	       gst-launch-1.0  filesrc	location=music.wav ! wavparse !	audio-
       convert ! vorbisenc ! oggmux ! filesink location=music.ogg
	       gst-launch-1.0 filesrc location=music.wav ! wavparse  !	audio-
       convert ! lamemp3enc ! filesink location=music.mp3

       Rips  all  tracks  from compact disc and	convert	them into a single mp3
	       gst-launch-1.0 cdparanoiasrc mode=continuous !  audioconvert  !
       lamemp3enc ! mpegaudioparse ! id3v2mux !	filesink location=cd.mp3

       Rips track 5 from the CD	and converts it	into a single mp3 file
	       gst-launch-1.0	cdparanoiasrc	track=5	  !   audioconvert   !
       lamemp3enc ! mpegaudioparse ! id3v2mux !	filesink location=track5.mp3

       Using gst-inspect-1.0(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-1.0 cdda://5 !	 lamemp3enc  vbr=new  vbr-quality=6  !
       filesink	location=track5.mp3

       Records sound from your audio input and encodes it into an ogg file
	       gst-launch-1.0  pulsesrc	 ! audioconvert	! vorbisenc ! oggmux !
       filesink	location=input.ogg


       Display only the	video portion of an MPEG-1 video file,	outputting  to
       an X display window
	       gst-launch-1.0  filesrc	location=JB_FF9_TheGravityOfLove.mpg !
       dvddemux	! mpegvideoparse ! mpeg2dec ! xvimagesink

       Display the video portion of a .vob file	(used on DVDs),	outputting  to
       an SDL window
	       gst-launch-1.0	filesrc	  location=/flflfj.vob	!  dvddemux  !
       mpegvideoparse !	mpeg2dec ! sdlvideosink

       Play both video and audio portions of an	MPEG movie
	       gst-launch-1.0 filesrc location=movie.mpg !  dvddemux  name=de-
       muxer  demuxer. ! queue ! mpegvideoparse	! mpeg2dec ! sdlvideosink  de-
       muxer. !	queue !	mpegaudioparse ! mpg123audiodec	! audioconvert	!  au-
       dioresample ! pulsesink

       Play an AVI movie with an external text subtitle	stream
	       gst-launch-1.0  filesrc location=movie.mpg ! mpegdemux name=de-
       muxer demuxer. !	queue !	mpegvideoparse !  mpeg2dec  !  videoconvert  !
       sdlvideosink   demuxer. ! queue ! mpegaudioparse	! mpg123audiodec ! au-
       dioconvert ! audioresample ! pulsesink

       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-1.0	textoverlay   name=overlay  !  videoconvert  !
       videoscale !  autovideosink   filesrc location=movie.avi	! decodebin  !
       videoconvert  !	overlay.video_sink   filesrc	! sub-
       parse ! overlay.text_sink

       Play an AVI movie with an external text subtitle	stream using playbin
	       gst-launch-1.0	playbin	  uri=file:///path/to/movie.avi	  sub-

       Network streaming

       Stream video using RTP and network elements.

       This command would be run on the	transmitter
	       gst-launch-1.0  v4l2src	! video/x-raw,width=128,height=96,for-
       mat=UYVY	! videoconvert ! ffenc_h263 ! video/x-h263 ! rtph263ppay pt=96
       ! udpsink host= port=5000

       Use this	command	on the receiver
	       gst-launch-1.0	 udpsrc	   port=5000	!   application/x-rtp,
       clock-rate=90000,payload=96 ! rtph263pdepay queue-delay=0 !  ffdec_h263
       ! xvimagesink


       Generate	a null stream and ignore it (and print out details).
	       gst-launch-1.0 -v fakesrc num-buffers=16	! fakesink

       Generate	a pure sine tone to test the audio output
	       gst-launch-1.0  audiotestsrc  !	audioconvert ! audioresample !

       Generate	a familiar test	pattern	to test	the video output
	       gst-launch-1.0 videotestsrc ! xvimagesink
	       gst-launch-1.0 videotestsrc ! ximagesink

       Automatic linking

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

       Play any	supported audio	format
	       gst-launch-1.0  filesrc location=musicfile ! decodebin !	audio-
       convert ! audioresample ! pulsesink

       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-1.0 filesrc location=videofile ! decodebin  name=de-
       coder decoder. !	queue !	audioconvert ! audioresample ! pulsesink   de-
       coder. !	 videoconvert !	xvimagesink
	       gst-launch-1.0 playbin uri=file:///home/joe/foo.avi

       Filtered	connections

       These examples show you how to use filtered caps.

       Show a test image and use the YUY2 or YV12 video	format for this.
	       gst-launch-1.0	   videotestsrc	     !	     'video/x-raw,for-
       mat=YUY2;video/x-raw,format=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.
	       gst-launch-1.0 pulsesrc !  'audio/x-raw,rate=[32000,64000],for-
       mat={S16LE,S24LE,S32LE}'	! wavenc ! filesink location=recording.wav

	      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
	      When the pipeline	changes	state through NULL to PLAYING and back
	      to NULL, a dot file is generated on each state change. To	 write
	      a	snapshot of the	pipeline state,	send a SIGHUP to the process.

	      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',
	      'x86-64',	'ppc', etc. (check the output of "uname	-i" and	"uname
	      -m" for details).

	      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)


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

home | help