Provided by: gstreamer1.0-tools_1.14.5-0ubuntu1~18.04.2_amd64 bug

NAME

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

SYNOPSIS

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

DESCRIPTION

       gst-launch-1.0 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 documentation.

       Please  note  that  gst-launch-1.0 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.

OPTIONS

       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.

       GSTREAMER OPTIONS
              gst-launch-1.0 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 0-9 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" section.

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

       --gst-debug-no-color
               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.

       --gst-debug-color-mode
               GStreamer normally prints debugging messages so that the messages 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   coloring  ('unix').  Setting  the  GST_DEBUG_COLOR_MODE
               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-1.0(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 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.

       Links

       [[SRCELEMENT].[PAD1,...]] ! [[SINKELEMENT].[PAD1,...]]  [[SRCELEMENT].[PAD1,...]] ! CAPS !
       [[SINKELEMENT].[PAD1,...]]     [[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.
       Linking using the : operator attempts to link all possible pads between the elements

       Caps

       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 afterwards.

       Properties

       NAME=[(TYPE)]VALUE
       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
       - 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 EXAMPLES

       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
       machines,  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 ! vorbisdec ! 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=http://domain.com/music.mp3  !  mpegaudioparse  !
       mpg123audiodec ! audioconvert ! audioresample ! pulsesink

       Use GIO to play an mp3 file located on an SMB server
               gst-launch-1.0   giosrc   location=smb://computer/music.mp3   !  mpegaudioparse  !
       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 location=music.ogg

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

       Other

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

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

       Rips all tracks from compact disc and convert them into a single mp3 file
               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

       Video

       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=demuxer   demuxer.  !
       queue  !  mpegvideoparse  !  mpeg2dec  ! sdlvideosink  demuxer. ! queue ! mpegaudioparse !
       mpg123audiodec ! audioconvert ! audioresample ! pulsesink

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

       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-1.0   textoverlay   name=overlay   !   videoconvert   !   videoscale  !
       autovideosink   filesrc location=movie.avi ! decodebin ! videoconvert ! overlay.video_sink
       filesrc location=movie.srt ! subparse ! 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
       suburi=file:///path/to/movie.srt

       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,format=UYVY    !
       videoconvert  !  ffenc_h263  ! video/x-h263 ! rtph263ppay pt=96 ! udpsink host=192.168.1.1
       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

       Diagnostic

       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 ! pulsesink

       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 elements to get a
       working pipeline.

       Play any supported audio format
               gst-launch-1.0  filesrc  location=musicfile   !   decodebin   !   audioconvert   !
       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 playbin element:
               gst-launch-1.0 filesrc location=videofile  !  decodebin  name=decoder  decoder.  !
       queue ! audioconvert ! audioresample ! pulsesink   decoder. !  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,format=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],format={S16LE,S24LE,S32LE}'   !    wavenc    !    filesink
       location=recording.wav

ENVIRONMENT VARIABLES

       GST_DEBUG
              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)

       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.  These
              can then later be converted into an image using the 'dot' utility from the graphviz
              set of tools, like this: dot foo.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 first.
              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.

       GST_REGISTRY
              Path       of       the       plugin       registry      file.      Default      is
              ~/.cache/gstreamer-1.0/registry-CPU.bin 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

       GST_DEBUG_FILE
              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.

       ORC_CODE
              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).

       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

       ~/.cache/gstreamer-1.0/registry-*.bin
               The  plugin  cache;  can  be deleted at any time, will be re-created automatically
               when it does not exist yet or plugins change. Based on XDG_CACHE_DIR, so may be in
               a different location than the one suggested.

SEE ALSO

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

AUTHOR

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

                                             May 2007                                GStreamer(1)