gst-launch-0.10

GStreamer(1)                                                      GStreamer(1)



NAME
       gst-launch - build and run a GStreamer pipeline

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

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‐
       tion.

       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
       applications,  use the gst_parse_launch() function of the GStreamer API
       as an easy way to construct pipelines from pipeline descriptions.

OPTIONS
       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)

       -o FILE, --output=FILE
               Save XML representation of pipeline to FILE and exit

       -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.



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

       --gst-version
               Prints the version string of the GStreamer core library.

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

       --gst-debug=STRING
               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


       --gst-debug-level=LEVEL
               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.

       --gst-debug-no-color
               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.

       --gst-debug-disable
               Disables debugging.

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

       --gst-plugin-spew
               GStreamer  info  flags  to  set Enable printout of errors while
               loading GStreamer plugins

       --gst-plugin-path=PATH
               Add directories separated with ':' to the plugin search path

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


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 PROPERTIES.

       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 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
       almost never need this functionality, it  is  only  really  useful  for
       applications  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.

       Links

       [[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.

       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 alphanu‐
       meric value and the type can have the following  case-insensitive  val‐
       ues:
       - 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
       insensitive) 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 ...] )


PIPELINE CONTROL
       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 explicitely.


PIPELINE EXAMPLES
       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
       audio) 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=http://domain.com/music.mp3  !
       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

       Other

               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
       file

               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
       file

               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
       location=track5.mp3

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

       Video

               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 !
       sdlvideosink
       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
       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
       element (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  location=movie.srt  !
       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‐
       uri=file:///path/to/movie.srt

       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=192.168.1.1 port=5000 sync=false
       Use this command on the receiver

               gst-launch  udpsrc  port=5000   !   application/x-rtp,   clock-
       rate=90000,payload=96  !  rtph263pdepay  queue-delay=0  !  ffdec_h263 !
       xvimagesink
       This command would be run on the transmitter

       Diagnostic

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

               gst-launch  audiotestsrc  !  audioconvert  !  audioresample   !
       osssink
       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
       elements 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-
       int,rate=[32000,64000],width=[16,32],depth={16,24,32},signed=(bool‐
       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.



ENVIRONMENT VARIABLES
       GST_DEBUG
              Comma-separated  list  of  debug  categories  and  levels,  e.g.
              GST_DEBUG=totem:4,typefind:5

       GST_DEBUG_NO_COLOR
              When this environment variable is set, coloured debug output  is
              disabled.

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

       GST_REGISTRY
              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
              details).

       GST_REGISTRY_UPDATE
              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.

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

       GST_PLUGIN_SYSTEM_PATH
              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

       OIL_CPU_FLAGS
              Useful liboil environment  variable.  Set  OIL_CPU_FLAGS=0  when
              valgrind  or other debugging tools trip over liboil's CPU detec‐
              tion (quite a few important GStreamer plugins like videotestsrc,
              audioconvert or audioresample use liboil).

       G_DEBUG
              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.

FILES
       ~/.gstreamer-0.10/registry-*.xml
               The  xml  plugin  database; can be deleted at any time, will be
               re-created automatically when it does not exist yet or  plugins
               change.

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

AUTHOR
       The GStreamer team at http://gstreamer.freedesktop.org/



                                   May 2007                       GStreamer(1)