gstreamer/tools/gst-launch.1.in

.TH "GStreamer" "1" "April 2003"
.SH "NAME"
gst\-launch \- build and run a GStreamer pipeline
.SH "SYNOPSIS"
\fBgst\-launch\fR \fI[OPTION...]\fR PIPELINE\-DESCRIPTION
.SH "DESCRIPTION"
.LP 
\fIgst\-launch\fP is a tool that builds and runs basic
\fIGStreamer\fP 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 \fIproperty=value\fR.

For a complete description of possible PIPELINE-DESCRIPTIONS see above under
\fIpipeline description\fR or the GStreamer documentation.

.
.SH "OPTIONS"
.l
\fIgst\-launch\fP accepts the following options:
.TP 8
.B  \-\-help
Print help synopsis and available FLAGS
.TP 8
.B  \-v, \-\-verbose
Output status information
.TP 8
.B  \-XTYPE, \-\-exclude=TYPE, 
Do not output status information of TYPE
.TP 8
.B  \-oFILE, \-\-output=FILE
Save XML representation of pipeline to FILE and exit
.TP 8
.B  \-f, \-\-no_fault
Do not install a fault handler
.TP 8
.B  \-t, \-\-trace
Print memory allocation traces. The feature must be enabled at compile time to
work.
.TP 8
.B  \-i, \-\-iterations=N
Stop processing after N iterations.

.
.SH "GSTREAMER OPTIONS"
.l
\fIgst\-launch\fP also accepts the following options that are common
to all GStreamer applications:
.TP 8
.B  \-\-gst\-version
Prints the version string of the \fIGStreamer\fP core library.
.TP 8
.B  \-\-gst\-fatal\-warnings
Causes \fIGStreamer\fP to abort if a warning message occurs.
.TP 8
.B  \-\-gst\-debug=STRING
A colon seperated 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
.TP 8
.B  \-\-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.
.TP 8
.B  \-\-gst\-debug\-no\-color
\fIGStreamer\fP 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 \fIGStreamer\fP
to print messages without color.
.TP 8
.B  \-\-gst\-disable\-debug
Disables debugging.
.TP 8
.B  \-\-gst\-debug\-help
Prints a list of available debug categories and their default debugging level.
.TP 8
.B  \-\-gst\-disable\-cpu\-opt
\fIGStreamer\fP normally automatically detects the capabilities of the
current CPU and selects the optimal implementation for some functions.
Using this flag disables detection, which is useful for debugging.
.TP 8
.B  \-\-gst\-plugin\-spew
\fIGStreamer\fP info flags to set
Enable printout of errors while loading \fIGStreamer\fP plugins
.TP 8
.B  \-\-gst\-plugin\-path=PATH
Add directories separated with ':' to the plugin search path
.TP 8
.B  \-\-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
.TP 8
.B  \-\-gst\-scheduler=SCHEDULER
Use SCHEDULER as the default scheduler
.TP 8
.B  \-\-gst\-registry=REGISTRY
Use the file REGISTRY as registry instead of the default

.SH "PIPELINE DESCRIPTION"

A pipeline consists \fIelements\fR and \fIlinks\fR. \fIElements\fR can be put 
into \fIbins\fR of different sorts. \fIElements\fR, \fIlinks\fR and \fIbins\fR
can be specified in a pipeline description in any order.

.B Elements

ELEMENTTYPE \fI[PROPERTY1 ...]\fR

Creates an element of type ELEMENTTYPE and sets the PROPERTIES.

.B Properties

PROPERTY=VALUE ...

Sets the property to the specified value. You can use \fBgst\-inspect\fR(1) to
find out about properties and allowed values of different elements.
.br
Enumeration properties can be set by name, nick or value.

.B Bins

\fI[BINTYPE.]\fR ( \fI[PROPERTY1 ...]\fR PIPELINE-DESCRIPTION )
.br
{ \fI[PROPERTY1 ...]\fR 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. Using curly braces
(second line) is a short cut for using the first line and "thread" as the 
BINTYPE.
.br
Please note the dot that has to be used after the BINTYPE.

.B Links

\fI[[SRCELEMENT].[PAD1,...]]\fR ! \fI[[SINKELEMENT].[PAD1,...]]\fR
\fI[[SRCELEMENT].[PAD1,...]]\fR ! CAPS ! \fI[[SINKELEMENT].[PAD1,...]]\fR

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.
.br
So the simplest link is a simple exclamation mark, that links the element to
the left of it to the element right of it.
.br
Note that when specifying either pads or element names you have to include the
dot or your syntax will be misinterpreted. This is a change to the old syntax
used up to version 0.6 that allowed omitting the dot when only specifying a
padname.

.B Caps

MIMETYPE \fI[, PROPERTY[, PROPERTY ...]]]\fR \fI[; CAPS[; CAPS ...]]\fR

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.

.B Properties

NAME\fI[:TYPE]\fR=VALUE
.br
in lists and ranges: [TYPE=]VALUE

Sets the requested property in capabilites. The name is an alphanumeric value
and the type can have the following case-insensitive values:
.br
- \fBi\fR or \fBint\fR for integer values or ranges
.br
- \fBf\fR or \fBfloat\fR for float values or ranges
.br
- \fB4\fR or \fBfourcc\fR for FOURCC values
.br
- \fBb\fR, \fBbool\fR or \fBboolean\fR for boolean values
.br
- \fBs\fR, \fBstr\fR or \fBstring\fR for strings
.br
- \fBl\fR or \fBlist\fR for lists
.br
If no type was given, the following order is tried: integer, float, boolean, 
string.
.br
Integer values must be parsable by \fBstrtol()\fP, floats by \fBstrtod()\fP. FOURCC values may
either be integers or strings. Boolean values are (case insensitive) \fIyes\fR, 
\fIno\fR, \fItrue\fR or \fIfalse\fR and may like strings be escaped with " or '.
.br
Ranges are in this format:  [ PROPERTY, PROPERTY ]
.br
Lists use this format:      ( PROPERTY \fI[, PROPERTY ...]\fR )

.SH "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.
.br
There are currently no signals defined to go into the ready or pause
(GST_STATE_READY and GST_STATE_PAUSED) state explicitely.

.SH "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", or "artsdsink".  Likewise,
"xvideosink" can be substituted with "sdlvideosink" or "aasink".

.B Audio playback

.B
        gst\-launch filesrc location=music.mp3 ! mad ! osssink
.br
Play the mp3 music file "music.mp3" using a libmad-based plug-in and
output to an OSS device

.B
        gst\-launch filesrc location=music.ogg ! oggdemux ! vorbisdec ! audioconvert ! osssink
.br
Play an Ogg Vorbis format file

.B
        gst\-launch gnomevfssrc location=music.mp3 ! mad ! osssink
.br
.B
        gst\-launch gnomevfssrc location=http://domain.com/music.mp3 ! mad ! osssink
.br
Play an mp3 file or an http stream using GNOME\-VFS

.B
        gst\-launch gnomevfssrc location=smb://computer/music.mp3 ! mad ! osssink
.br
Use GNOME\-VFS to play an mp3 file located on an SMB server

.B Format conversion

.B
        gst\-launch filesrc location=music.mp3 ! mad ! vorbisenc ! filesink location=music.ogg
.br
Convert an mp3 music file to an Ogg Vorbis file

.B
        gst\-launch filesrc location=music.mp3 ! mad ! flacenc ! filesink location=test.flac
.br
Convert to the FLAC format

.B Other

.B
        gst\-launch filesrc location=music.wav ! wavparse ! osssink
.br
Plays a .WAV file

.B
        gst\-launch filesrc location=music.wav ! wavparse ! vorbisenc ! filesink location=music.ogg
.br
.B
        gst\-launch filesrc location=music.wav ! wavparse ! mpegaudio ! filesink location=music.mp3
.br
Convert a .WAV file into Ogg Vorbis (or mp3) file

Alternatively, if you have lame installed (and have the lame plug-in),
you can substitute lame for mpegaudio in the previous example.  It gives
better results than mpegaudio.

.B
        gst\-launch cdparanoia ! mpegaudio ! filesink location=cd.mp3
.br
Rip all tracks from compact disc and convert them into a single mp3 file

Using \fBgst\-inspect\fR(1), it is possible to discover settings for cdparanoia
that will tell it to rip individual tracks.

.B
        gst\-launch osssrc ! vorbisenc ! filesink location=input.ogg
.br
Record sound from your audio input and encode it into an ogg file

.B Video

.B
        gst\-launch filesrc location=JB_FF9_TheGravityOfLove.mpg ! mpegdemux ! mpeg2dec ! xvideosink
.br
Display only the video portion of an MPEG-1 video file, outputting to
an X display window

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

.B
        gst\-launch filesrc location=movie.mpg ! mpegdemux name=demuxer ! mpeg2dec ! sdlvideosink demuxer. ! mad ! osssink
.br
Play both video and audio portions of an MPEG movie

.B
        gst\-launch filesrc location=movie.mpg ! mpegdemux name=demuxer ! { queue ! mpeg2dec ! sdlvideosink } { demuxer. ! queue ! mad ! osssink }
.br
Use threaded output to improve synchronization and smoothness. Threads require
queues for buffering on thread boundaries

.B
        gst\-launch filesrc location=movie.avi ! avidemux name=demuxer ! { queue ! ffdecall ! sdlvideosink } { demuxer. ! queue ! mad ! osssink }
.br
Play an AVI movie

.B Network streaming

An MPEG\-1 system stream can be streamed via RTP from one machine to
another. 

.B
        gst\-launch rtprecv media_type=mpeg1_sys ! mpegdemux name=demuxer ! { queue ! mpeg2dec ! xvideosink } { demuxer. ! queue ! mad ! osssink }
.br
Use this command on the receiver

.B
        gst\-launch filesrc location=mpeg1system.mpeg ! mpegparse ! rtpsend ip=IPorHostname
.br
This command would be run on the transmitter

.B Diagnostic

.B
        gst\-launch fakesrc ! fakesink
.br
Generate a null stream and ignore it

.B
        gst\-launch sinesrc ! osssink
.br
Generate a pure tone to test the audio output

.B
        gst\-launch videotestsrc ! xvideosink
.br
Generate a familiar test pattern to test the video output

.B Automatic linking

You can use the spider element to automatically select the right elements to get
a working pipeline.

.B
        gst\-launch filesrc location=musicfile ! spider ! osssink
.br
Play any supported audio format

.B
        gst\-launch filesrc location=videofile ! spider name=spider ! osssink spider. ! xvideosink
.br
.B
        gst\-launch filesrc location=videofile ! spider name=spider ! { queue ! osssink } { spider. ! queue ! xvideosink }
.br
Play any supported video format with video and audio output. The second pipeline
uses threaded output.

.B Filtered connections

These examples show you how to use filtered caps.

.B
        gst\-launch videotestsrc ! video/raw, format:fourcc=YUY2; video/raw, format:fourcc=YV12 ! xvideosink
.br
Show a test image and use the YUY2 or YV12 video format for this.

.B
        gst\-launch osssrc ! "audio/raw", format=int, width=[16, 32], depth=(16, 24, 32), signed=TRUE ! osssink
.br
Playback currently recorded audio. Force usage of signed 16 to 32 bit samples.




.
.SH "SEE ALSO"
.BR gst\-complete (1),
.BR gst\-register (1),
.BR gst\-inspect (1)
.SH "AUTHOR"
The GStreamer team at http://gstreamer.net/