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

       Please note that gst-launch is primarily a debugging tool for developers
       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 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 (DEPRECATED,
               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
               'fatal_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 messages
               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

       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 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 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.


       [[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 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 element
       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 alphanumeric
       value and the type can have the following case-insensitive values:
       - 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 ...] )

       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 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= ! 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 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,
              gst-launch cdda://5 ! lame vbr=new vbr-quality=6 ! filesink

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


               gst-launch filesrc location=JB_FF9_TheGravityOfLove.mpg !
       dvddemux ! 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   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 !
       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

       Network streaming

       Stream video using RTP and network elements.

               gst-launch v4l2src ! video/x-raw-
       yuv,width=128,height=96,format='(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 ! 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 ! audioconvert
       ! 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 playbin

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

               gst-launch osssrc ! 'audio/x-raw-
       ! 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

              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-
              generated 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,
              audioconvert 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)