1 .TH "GStreamer" "1" "May 2007"
3 gst\-launch \- build and run a GStreamer pipeline
5 \fBgst\-launch\fR \fI[OPTION...]\fR PIPELINE\-DESCRIPTION
8 \fIgst\-launch\fP is a tool that builds and runs basic
9 \fIGStreamer\fP pipelines.
11 In simple form, a PIPELINE\-DESCRIPTION is a list of
12 elements separated by exclamation marks (!). Properties may be appended to
13 elements, in the form \fIproperty=value\fR.
15 For a complete description of possible PIPELINE-DESCRIPTIONS see the section
16 \fIpipeline description\fR below or consult the GStreamer documentation.
18 Please note that \fIgst\-launch\fP is primarily a debugging tool for
19 developers and users. You should not build applications on top of it. For
20 applications, use the gst_parse_launch() function of the GStreamer API as an
21 easy way to construct pipelines from pipeline descriptions.
25 \fIgst\-launch\fP accepts the following options:
28 Print help synopsis and available FLAGS
31 Output status information and property notifications
34 Do not print any progress information
37 Output messages posted on the pipeline's bus
40 Output tags (also known as metadata)
42 .B \-e, \-\-eos\-on\-shutdown
43 Force an EOS event on sources before shutting the pipeline down. This is
44 useful to make sure muxers create readable files when a muxing pipeline is
45 shut down forcefully via Control-C.
48 Gather and print index statistics. This is mostly useful for playback or
51 .B \-o FILE, \-\-output=FILE
52 Save XML representation of pipeline to FILE and exit (DEPRECATED, DO NOT USE)
55 Do not install a fault handler
58 Print memory allocation traces. The feature must be enabled at compile time to
63 .SH "GSTREAMER OPTIONS"
65 \fIgst\-launch\fP also accepts the following options that are common
66 to all GStreamer applications:
69 Prints the version string of the \fIGStreamer\fP core library.
71 .B \-\-gst\-fatal\-warnings
72 Causes \fIGStreamer\fP to abort if a warning message occurs. This is equivalent
73 to setting the environment variable G_DEBUG to 'fatal_warnings' (see the
74 section \fIenvironment variables\fR below for further information).
76 .B \-\-gst\-debug=STRING
77 A comma separated list of category_name:level pairs to specify debugging levels
78 for each category. Level is in the range 0-5 where 0 will show no messages, and
79 5 will show all messages. The wildcard * can be used to match category names.
81 Use \-\-gst\-debug\-help to show category names
84 GST_CAT:5,GST_ELEMENT_*:3,oggdemux:5
87 .B \-\-gst\-debug\-level=LEVEL
88 Sets the threshold for printing debugging messages. A higher level
89 will print more messages. The useful range is 0-5, with the default
92 .B \-\-gst\-debug\-no\-color
93 \fIGStreamer\fP normally prints debugging messages so that the
94 messages are color-coded when printed to a terminal that handles
95 ANSI escape sequences. Using this option causes \fIGStreamer\fP
96 to print messages without color. Setting the \fBGST_DEBUG_NO_COLOR\fR
97 environment variable will achieve the same thing.
99 .B \-\-gst\-debug\-disable
102 .B \-\-gst\-debug\-help
103 Prints a list of available debug categories and their default debugging level.
105 .B \-\-gst\-plugin\-spew
106 \fIGStreamer\fP info flags to set
107 Enable printout of errors while loading \fIGStreamer\fP plugins
109 .B \-\-gst\-plugin\-path=PATH
110 Add directories separated with ':' to the plugin search path
112 .B \-\-gst\-plugin\-load=PLUGINS
113 Preload plugins specified in a comma-separated list. Another way to specify
114 plugins to preload is to use the environment variable GST_PLUGIN_PATH
116 .SH "PIPELINE DESCRIPTION"
118 A pipeline consists \fIelements\fR and \fIlinks\fR. \fIElements\fR can be put
119 into \fIbins\fR of different sorts. \fIElements\fR, \fIlinks\fR and \fIbins\fR
120 can be specified in a pipeline description in any order.
124 ELEMENTTYPE \fI[PROPERTY1 ...]\fR
126 Creates an element of type ELEMENTTYPE and sets the PROPERTIES.
132 Sets the property to the specified value. You can use \fBgst\-inspect\fR(1) to
133 find out about properties and allowed values of different elements.
135 Enumeration properties can be set by name, nick or value.
139 \fI[BINTYPE.]\fR ( \fI[PROPERTY1 ...]\fR PIPELINE-DESCRIPTION )
142 Specifies that a bin of type BINTYPE is created and the given properties are
143 set. Every element between the braces is put into the bin. Please note the dot
144 that has to be used after the BINTYPE. You will almost never need this
145 functionality, it is only really useful for applications using the
146 gst_launch_parse() API with 'bin' as bintype. That way it is possible to build
147 partial pipelines instead of a full-fledged top-level pipeline.
151 \fI[[SRCELEMENT].[PAD1,...]]\fR ! \fI[[SINKELEMENT].[PAD1,...]]\fR
152 \fI[[SRCELEMENT].[PAD1,...]]\fR ! CAPS ! \fI[[SINKELEMENT].[PAD1,...]]\fR
154 Links the element with name SRCELEMENT to the element with name SINKELEMENT,
155 using the caps specified in CAPS as a filter.
156 Names can be set on elements with the name property. If the name is omitted, the
157 element that was specified directly in front of or after the link is used. This
158 works across bins. If a padname is given, the link is done with these pads. If
159 no pad names are given all possibilities are tried and a matching pad is used.
160 If multiple padnames are given, both sides must have the same number of pads
161 specified and multiple links are done in the given order.
163 So the simplest link is a simple exclamation mark, that links the element to
164 the left of it to the element right of it.
169 MIMETYPE \fI[, PROPERTY[, PROPERTY ...]]]\fR \fI[; CAPS[; CAPS ...]]\fR
171 Creates a capability with the given mimetype and optionally with given
172 properties. The mimetype can be escaped using " or '.
173 If you want to chain caps, you can add more caps in the same format afterwards.
177 NAME=\fI[(TYPE)]\fRVALUE
179 in lists and ranges: \fI[(TYPE)]\fRVALUE
181 Sets the requested property in capabilities. The name is an alphanumeric value
182 and the type can have the following case-insensitive values:
184 - \fBi\fR or \fBint\fR for integer values or ranges
186 - \fBf\fR or \fBfloat\fR for float values or ranges
188 - \fB4\fR or \fBfourcc\fR for FOURCC values
190 - \fBb\fR, \fBbool\fR or \fBboolean\fR for boolean values
192 - \fBs\fR, \fBstr\fR or \fBstring\fR for strings
194 - \fBfraction\fR for fractions (framerate, pixel-aspect-ratio)
196 - \fBl\fR or \fBlist\fR for lists
198 If no type was given, the following order is tried: integer, float, boolean,
201 Integer values must be parsable by \fBstrtol()\fP, floats by \fBstrtod()\fP. FOURCC values may
202 either be integers or strings. Boolean values are (case insensitive) \fIyes\fR,
203 \fIno\fR, \fItrue\fR or \fIfalse\fR and may like strings be escaped with " or '.
205 Ranges are in this format: [ VALUE, VALUE ]
207 Lists use this format: ( VALUE \fI[, VALUE ...]\fR )
209 .SH "PIPELINE EXAMPLES"
211 The examples below assume that you have the correct plug-ins available.
212 In general, "osssink" can be substituted with another audio output
213 plug-in such as "esdsink", "alsasink", "osxaudiosink", or "artsdsink".
214 Likewise, "xvimagesink" can be substituted with "ximagesink", "sdlvideosink",
215 "osxvideosink", or "aasink". Keep in mind though that different sinks might
216 accept different formats and even the same sink might accept different formats
217 on different machines, so you might need to add converter elements like
218 audioconvert and audioresample (for audio) or ffmpegcolorspace (for video)
219 in front of the sink to make things work.
224 gst\-launch filesrc location=music.mp3 ! mad ! audioconvert ! audioresample ! osssink
226 Play the mp3 music file "music.mp3" using a libmad-based plug-in and
227 output to an OSS device
230 gst\-launch filesrc location=music.ogg ! oggdemux ! vorbisdec ! audioconvert ! audioresample ! osssink
232 Play an Ogg Vorbis format file
235 gst\-launch gnomevfssrc location=music.mp3 ! mad ! osssink
238 gst\-launch gnomevfssrc location=http://domain.com/music.mp3 ! mad ! audioconvert ! audioresample ! osssink
240 Play an mp3 file or an http stream using GNOME\-VFS
243 gst\-launch gnomevfssrc location=smb://computer/music.mp3 ! mad ! audioconvert ! audioresample ! osssink
245 Use GNOME\-VFS to play an mp3 file located on an SMB server
250 gst\-launch filesrc location=music.mp3 ! mad ! audioconvert ! vorbisenc ! oggmux ! filesink location=music.ogg
252 Convert an mp3 music file to an Ogg Vorbis file
255 gst\-launch filesrc location=music.mp3 ! mad ! audioconvert ! flacenc ! filesink location=test.flac
257 Convert to the FLAC format
262 gst\-launch filesrc location=music.wav ! wavparse ! audioconvert ! audioresample ! osssink
264 Plays a .WAV file that contains raw audio data (PCM).
267 gst\-launch filesrc location=music.wav ! wavparse ! audioconvert ! vorbisenc ! oggmux ! filesink location=music.ogg
270 gst\-launch filesrc location=music.wav ! wavparse ! audioconvert ! lame ! filesink location=music.mp3
272 Convert a .WAV file containing raw audio data into an Ogg Vorbis or mp3 file
275 gst\-launch cdparanoiasrc mode=continuous ! audioconvert ! lame ! id3v2mux ! filesink location=cd.mp3
277 rips all tracks from compact disc and convert them into a single mp3 file
280 gst\-launch cdparanoiasrc track=5 ! audioconvert ! lame ! id3v2mux ! filesink location=track5.mp3
282 rips track 5 from the CD and converts it into a single mp3 file
284 Using \fBgst\-inspect\fR(1), it is possible to discover settings like the above
285 for cdparanoiasrc that will tell it to rip the entire cd or only tracks of it.
286 Alternatively, you can use an URI and gst-launch will find an element (such as
287 cdparanoia) that supports that protocol for you, e.g.:
289 gst\-launch cdda://5 ! lame vbr=new vbr-quality=6 ! filesink location=track5.mp3
292 gst\-launch osssrc ! audioconvert ! vorbisenc ! oggmux ! filesink location=input.ogg
294 records sound from your audio input and encodes it into an ogg file
299 gst\-launch filesrc location=JB_FF9_TheGravityOfLove.mpg ! dvddemux ! mpeg2dec ! xvimagesink
301 Display only the video portion of an MPEG-1 video file, outputting to
305 gst\-launch filesrc location=/flflfj.vob ! dvddemux ! mpeg2dec ! sdlvideosink
307 Display the video portion of a .vob file (used on DVDs), outputting to
311 gst\-launch filesrc location=movie.mpg ! dvddemux name=demuxer demuxer. ! queue ! mpeg2dec ! sdlvideosink demuxer. ! queue ! mad ! audioconvert ! audioresample ! osssink
313 Play both video and audio portions of an MPEG movie
316 gst\-launch filesrc location=movie.mpg ! mpegdemux name=demuxer demuxer. ! queue ! mpeg2dec ! ffmpegcolorspace ! sdlvideosink demuxer. ! queue ! mad ! audioconvert ! audioresample ! osssink
318 Play an AVI movie with an external text subtitle stream
320 This example also shows how to refer to specific pads by name if an element
321 (here: textoverlay) has multiple sink or source pads.
324 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
327 Play an AVI movie with an external text subtitle stream using playbin2
330 gst\-launch playbin2 uri=file:///path/to/movie.avi suburi=file:///path/to/movie.srt
334 Stream video using RTP and network elements.
337 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=192.168.1.1 port=5000 sync=false
339 This command would be run on the transmitter
342 gst\-launch udpsrc port=5000 ! application/x-rtp, clock-rate=90000,payload=96 ! rtph263pdepay queue-delay=0 ! ffdec_h263 ! xvimagesink
344 Use this command on the receiver
349 gst\-launch -v fakesrc num-buffers=16 ! fakesink
351 Generate a null stream and ignore it (and print out details).
354 gst\-launch audiotestsrc ! audioconvert ! audioresample ! osssink
356 Generate a pure sine tone to test the audio output
359 gst\-launch videotestsrc ! xvimagesink
362 gst\-launch videotestsrc ! ximagesink
364 Generate a familiar test pattern to test the video output
368 You can use the decodebin element to automatically select the right elements
369 to get a working pipeline.
372 gst\-launch filesrc location=musicfile ! decodebin ! audioconvert ! audioresample ! osssink
374 Play any supported audio format
377 gst\-launch filesrc location=videofile ! decodebin name=decoder decoder. ! queue ! audioconvert ! audioresample ! osssink decoder. ! ffmpegcolorspace ! xvimagesink
379 Play any supported video format with video and audio output. Threads are used
380 automatically. To make this even easier, you can use the playbin element:
383 gst\-launch playbin uri=file:///home/joe/foo.avi
387 .B Filtered connections
389 These examples show you how to use filtered caps.
392 gst\-launch videotestsrc ! 'video/x-raw-yuv,format=(fourcc)YUY2;video/x-raw-yuv,format=(fourcc)YV12' ! xvimagesink
394 Show a test image and use the YUY2 or YV12 video format for this.
397 gst\-launch osssrc ! 'audio/x-raw-int,rate=[32000,64000],width=[16,32],depth={16,24,32},signed=(boolean)true' ! wavenc ! filesink location=recording.wav
399 record audio and write it to a .wav file. Force usage of signed 16 to 32 bit
400 samples and a sample rate between 32kHz and 64KHz.
403 .SH "ENVIRONMENT VARIABLES"
406 Comma-separated list of debug categories and levels, e.g.
407 GST_DEBUG=totem:4,typefind:5
409 \fBGST_DEBUG_NO_COLOR\fR
410 When this environment variable is set, coloured debug output is disabled.
412 \fBGST_DEBUG_DUMP_DOT_DIR\fR
413 When set to a filesystem path, store dot files of pipeline graphs there.
416 Path of the plugin registry file. Default is
417 ~/.gstreamer-GST_MAJORMINOR/registry-CPU.xml where CPU is the machine/cpu type
418 GStreamer was compiled for, e.g. 'i486', 'i686', 'x86-64', 'ppc', etc. (check
419 the output of "uname -i" and "uname -m" for details).
421 \fBGST_REGISTRY_UPDATE\fR
422 Set to "no" to force GStreamer to assume that no plugins have changed,
423 been added or been removed. This will make GStreamer skip the initial check
424 whether a rebuild of the registry cache is required or not. This may be useful
425 in embedded environments where the installed plugins never change. Do not
426 use this option in any other setup.
428 \fBGST_PLUGIN_PATH\fR
429 Specifies a list of directories to scan for additional plugins.
430 These take precedence over the system plugins.
432 \fBGST_PLUGIN_SYSTEM_PATH\fR
433 Specifies a list of plugins that are always loaded by default. If not set,
434 this defaults to the system-installed path, and the plugins installed in the
435 user's home directory
438 Useful Orc environment variable. Set ORC_CODE=debug to enable debuggers
439 such as gdb to create useful backtraces from Orc-generated code. Set
440 ORC_CODE=backup or ORC_CODE=emulate if you suspect Orc's SIMD code
441 generator is producing incorrect code. (Quite a few important
442 GStreamer plugins like videotestsrc, audioconvert or audioresample use Orc).
445 Useful GLib environment variable. Set G_DEBUG=fatal_warnings to make
446 GStreamer programs abort when a critical warning such as an assertion failure
447 occurs. This is useful if you want to find out which part of the code caused
448 that warning to be triggered and under what circumstances. Simply set G_DEBUG
449 as mentioned above and run the program in gdb (or let it core dump). Then get
450 a stack trace in the usual way.
454 ~/.gstreamer-GST_MAJORMINOR/registry-*.xml
455 The xml plugin database; can be deleted at any time, will be re-created
456 automatically when it does not exist yet or plugins change.
459 .BR gst\-feedback (1),
460 .BR gst\-inspect (1),
461 .BR gst\-typefind (1)
463 The GStreamer team at http://gstreamer.freedesktop.org/