tools: gst-launch: improve content and formatting

This commit is contained in:
Reynaldo H. Verdejo Pinochet 2017-10-18 22:20:55 -07:00
parent 764b8d0c70
commit 76a492c467

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@ -1,35 +1,35 @@
# gst-launch-1.0
> ![information] This is the Linux man page for
> ![information] This content comes mostly from the Linux man page for
> the `gst-launch-1.0` tool. As such, it is very Linux-centric
> regarding path specification and plugin names. Please be patient while
> it is rewritten to be more generic.
## Name
gst-launch-1.0 - build and run a GStreamer pipeline
`gst-launch-1.0` - build and run a GStreamer pipeline
## Synopsis
**gst-launch-1.0** *\[OPTION...\]* PIPELINE-DESCRIPTION
```
gst-launch-1.0 [OPTIONS] PIPELINE-DESCRIPTION
```
## Description
*gst-launch-1.0* is a tool that builds and runs
basic *GStreamer* pipelines.
`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*.
In its simplest 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.
For a more 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.
Please note that `gst-launch-1.0` is primarily a debugging tool. 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
@ -68,300 +68,411 @@ Do not install a fault handler
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
`gst-launch-1.0` also accepts the following options that are common to
all GStreamer applications:
## Pipeline Description
A pipeline consists *elements* and *links*. *Elements* can be put
into *bins* of different sorts. *Elements*, *links* and *bins* can be
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**
### Elements
ELEMENTTYPE *\[PROPERTY1 ...\]*
```
ELEMENTTYPE [PROPERTY1 ...]
```
Creates an element of type ELEMENTTYPE and sets the PROPERTIES.
Creates an element of type `ELEMENTTYPE` and sets its `PROPERTIES`.
**Properties**
### Element 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.
Sets the property to the specified value. You can use `gst-inspect-1.0` to find
out about properties and allowed values of different elements. Enumeration
properties can be set by name, nick or value.
**Bins**
### Bins
*\[BINTYPE.\]* ( *\[PROPERTY1 ...\]* PIPELINE-DESCRIPTION )
```
[BINTYPE.] ([PROPERTY1 ...] PIPELINE-DESCRIPTION)
```
Specifies that a bin of type BINTYPE is created and the given properties
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
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
using the `gst_parse_launch()` API with 'bin' as bintype. That way it is
possible to build partial pipelines instead of a full-fledged top-level
pipeline.
**Links**
### Links
*\[\[SRCELEMENT\].\[PAD1,...\]\]* ! *\[\[SINKELEMENT\].\[PAD1,...\]\]
\[\[SRCELEMENT\].\[PAD1,...\]\]* ! CAPS
! *\[\[SINKELEMENT\].\[PAD1,...\]\]*
```
[[SRCELEMENT\].[PAD1,...]] ! [[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.
Links the element with name SRCELEMENT to the element with name SINKELEMENT.
Names can be set on elements using 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 using that
pad. If no pad names are given all possibilities are tried and a compatible 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. The simplest link
is a simple exclamation mark. This links the element to the left of it with the
element at its right.
**Caps**
MIMETYPE *\[, PROPERTY\[, PROPERTY ...\]\]\] \[; CAPS\[; CAPS ...\]\]*
The following links the element with name SRCELEMENT to the element with name
SINKELEMENT, using the caps specified in CAPS as a filter:
```
[[SRCELEMENT].[PAD1,...]] ! CAPS ! [[SINKELEMENT].[PAD1,...]]
```
### 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
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**
### Caps Properties
NAME=*\[(TYPE)\]*VALUE in lists and ranges: *\[(TYPE)\]*VALUE
```
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 - **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 *\[, VALUE ...\]* )
(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.
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`) states explicitly.
## 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 "directsoundsink", "esdsink", "alsasink",
"osxaudiosink", or "artsdsink". Likewise, "xvimagesink" can be
substituted with "d3dvideosink", "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
videoconvert (for video) in front of the sink to make things work.
The examples below assume that you have the correct plugins available.
In general, `osssink` can be substituted with another audio output
plugin such as `directsoundsink`, `esdsink`, `alsasink`, `osxaudiosink`, or
`artsdsink`. Likewise, `xvimagesink` can be substituted with `d3dvideosink`,
`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
`videoconvert` in front of the sink to make things work.
**Audio playback**
### Audio playback
`gst-launch-1.0 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
Play the mp3 music file "music.mp3" using a libmad-based plugin and output to
an OSS device:
`gst-launch-1.0 filesrc location=music.ogg ! oggdemux ! vorbisdec !
audioconvert ! audioresample ! osssink` Play an Ogg Vorbis format file
```
gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert !
audioresample ! osssink
```
`gst-launch-1.0 gnomevfssrc location=music.mp3 ! mad ! osssink
Play an Ogg Vorbis format file:
```
gst-launch-1.0 filesrc location=music.ogg ! oggdemux ! vorbisdec !
audioconvert ! audioresample ! osssink
```
Play an mp3 file using GNOME-VFS:
```
gst-launch-1.0 gnomevfssrc location=music.mp3 ! mad ! osssink
```
Play an HTTP stream using GNOME-VFS:
```
gst-launch-1.0 gnomevfssrc location=<http://domain.com/music.mp3> ! mad
! audioconvert ! audioresample ! osssink` Play an mp3 file or an http
stream using GNOME-VFS
! audioconvert ! audioresample ! osssink
```
`gst-launch-1.0 gnomevfssrc location=<smb://computer/music.mp3> ! mad !
audioconvert ! audioresample ! osssink` Use GNOME-VFS to play an mp3
file located on an SMB server
Use GNOME-VFS to play an mp3 file located on an SMB server:
**Format conversion**
```
gst-launch-1.0 gnomevfssrc location=<smb://computer/music.mp3> ! mad !
audioconvert ! audioresample ! osssink
```
`gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert !
vorbisenc ! oggmux ! filesink location=music.ogg` Convert an mp3 music
file to an Ogg Vorbis file
### Format conversion
`gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert !
flacenc ! filesink location=test.flac` Convert to the FLAC format
Convert an mp3 music file to an Ogg Vorbis file:
**Other**
```
gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert ! vorbisenc !
oggmux ! filesink location=music.ogg
```
`gst-launch-1.0 filesrc location=music.wav ! wavparse ! audioconvert !
audioresample ! osssink` Plays a .WAV file that contains raw audio data
(PCM).
Convert to the FLAC format:
`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 ! lame ! filesink
location=music.mp3` Convert a .WAV file containing raw audio data into
an Ogg Vorbis or mp3 file
```
gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert ! flacenc !
filesink location=test.flac`
```
`gst-launch-1.0 cdparanoiasrc mode=continuous ! audioconvert ! lame !
id3v2mux ! filesink location=cd.mp3` rips all tracks from compact disc
and convert them into a single mp3 file
### Other
`gst-launch-1.0 cdparanoiasrc track=5 ! audioconvert ! lame ! id3v2mux
! filesink location=track5.mp3` rips track 5 from the CD and converts
it into a single mp3 file
Play a .WAV file that contains raw audio data (PCM):
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
```
gst-launch-1.0 filesrc location=music.wav ! wavparse ! audioconvert !
audioresample ! osssink
```
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 ! lame !
filesink location=music.mp3
```
Rip all tracks from CD and convert them into a single mp3 file:
```
gst-launch-1.0 cdparanoiasrc mode=continuous ! audioconvert ! lame !
id3v2mux ! filesink location=cd.mp3
```
Rip track 5 from the CD and converts it into a single mp3 file:
```
gst-launch-1.0 cdparanoiasrc track=5 ! audioconvert ! lame ! id3v2mux
! filesink location=track5.mp3
```
Using `gst-inspect-1.0`, 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 \[cdda://5\] ! lame vbr=new
vbr-quality=6 ! filesink location=track5.mp3`
for you, e.g.: 
`gst-launch-1.0 osssrc ! audioconvert ! vorbisenc ! oggmux ! filesink
location=input.ogg` records sound from your audio input and encodes it
into an ogg file
```
gst-launch-1.0 [cdda://5] ! lame vbr=new vbr-quality=6 !
filesink location=track5.mp3
```
**Video**
Record sound from your audio input and encode it into an ogg file:
`gst-launch-1.0 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-1.0 osssrc ! audioconvert ! vorbisenc ! oggmux !
filesink location=input.ogg
```
`gst-launch-1.0 filesrc location=/flflfj.vob ! dvddemux ! mpeg2dec !
sdlvideosink` Display the video portion of a .vob file (used on DVDs),
outputting to an SDL window
### Video
`gst-launch-1.0 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
Display only the video portion of an MPEG-1 video file, outputting to an X
display window:
`gst-launch-1.0 filesrc location=movie.mpg ! mpegdemux name=demuxer
demuxer. ! queue ! mpeg2dec ! videoconvert ! sdlvideosink demuxer. !
queue ! mad ! audioconvert ! audioresample ! osssink` Play an AVI movie
with an external text subtitle stream
```
gst-launch-1.0 filesrc location=videofile.mpg ! dvddemux ! mpeg2dec !
xvimagesink
```
This example also shows how to refer to specific pads by name if an
element (here: textoverlay) has multiple sink or source pads.
Display the video portion of a .vob file (used on DVDs), outputting to an SDL
window:
`gst-launch-1.0 textoverlay name=overlay ! videoconvert !
videoscale ! autovideosink filesrc location=movie.avi ! decodebin2 !
videoconvert ! overlay.video\_sink filesrc location=movie.srt !
subparse ! overlay.text\_sink`
```
gst-launch-1.0 filesrc location=flflfj.vob ! dvddemux ! mpeg2dec ! sdlvideosink
```
Play an AVI movie with an external text subtitle stream using playbin
Play both video and audio portions of an MPEG movie:
`gst-launch-1.0 playbin uri=<file:///path/to/movie.avi>
suburi=<file:///path/to/movie.srt>`
```
gst-launch-1.0 filesrc location=movie.mpg ! dvddemux name=demuxer
demuxer. ! queue ! mpeg2dec ! sdlvideosink
demuxer. ! queue ! mad ! audioconvert ! audioresample ! osssink
```
**Network streaming**
Play an AVI movie with an external text subtitle stream:
Stream video using RTP and network elements.
```
gst-launch-1.0 filesrc location=movie.mpg ! mpegdemux name=demuxer
demuxer. ! queue ! mpeg2dec ! videoconvert ! sdlvideosink
demuxer. ! queue ! mad ! audioconvert ! audioresample ! osssink
```
`gst-launch-1.0 v4l2src !
This example 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 ! decodebin2 ! 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-yuv,width=128,height=96,format='(fourcc)'UYVY !
videoconvert ! ffenc\_h263 ! video/x-h263 ! rtph263ppay pt=96 !
udpsink host=192.168.1.1 port=5000 sync=false` Use this command on the
receiver
videoconvert ! ffenc_h263 ! video/x-h263 ! rtph263ppay pt=96 !
udpsink host=192.168.1.1 port=5000 sync=false
```
`gst-launch-1.0 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
Use this command on the receiver:
**Diagnostic**
```
gst-launch-1.0 udpsrc port=5000 ! application/x-rtp,
clock-rate=90000,payload=96 ! rtph263pdepay queue-delay=0 ! ffdec_h263
! xvimagesink
```
`gst-launch-1.0 -v fakesrc num-buffers=16 ! fakesink` Generate a null
stream and ignore it (and print out details).
### Diagnostic
`gst-launch-1.0 audiotestsrc ! audioconvert ! audioresample ! osssink`
Generate a pure sine tone to test the audio output
Generate a null stream and ignore it (and print out details):
`gst-launch-1.0 videotestsrc ! xvimagesink gst-launch-1.0 videotestsrc
! ximagesink` Generate a familiar test pattern to test the video output
```
gst-launch-1.0 -v fakesrc num-buffers=16 ! fakesink
```
**Automatic linking**
Generate a pure sine tone to test the audio output:
```
gst-launch-1.0 audiotestsrc ! audioconvert ! audioresample ! osssink
```
Generate a familiar test pattern to test the video output:
```
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.
`gst-launch-1.0 filesrc location=musicfile ! decodebin ! audioconvert !
audioresample ! osssink` Play any supported audio format
Play any supported audio format:
`gst-launch-1.0 filesrc location=videofile ! decodebin name=decoder
decoder. ! queue ! audioconvert ! audioresample ! osssink decoder. !
videoconvert ! 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 element:
```
gst-launch-1.0 filesrc location=musicfile ! decodebin ! audioconvert !
audioresample ! osssink
```
`gst-launch-1.0 playbin uri=<file:///home/joe/foo.avi>`
Play any supported video format with video and audio output. Threads are used
automatically:
**Filtered connections**
```
gst-launch-1.0 filesrc location=videofile ! decodebin name=decoder
decoder. ! queue ! audioconvert ! audioresample ! osssink
decoder. ! videoconvert ! xvimagesink
```
To make the above even easier, you can use the playbin element:
```
gst-launch-1.0 playbin uri=<file:///home/joe/foo.avi>
```
### Filtered connections
These examples show you how to use filtered caps.
`gst-launch-1.0 videotestsrc !
'video/x-raw-yuv,format=(fourcc)YUY2;video/x-raw-yuv,format=(fourcc)YV12'
! xvimagesink` Show a test image and use the YUY2 or YV12 video format
for this.
Show a test image and use the YUY2 or YV12 video format for this:
`gst-launch-1.0 osssrc !
'audio/x-raw-int,rate=\[32000,64000\],width=\[16,32\],depth={16,24,32},signed=(boolean)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.
```
gst-launch-1.0 videotestsrc !
'video/x-raw-yuv,format=(fourcc)YUY2;video/x-raw-yuv,format=(fourcc)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 osssrc !
'audio/x-raw-int,rate=[32000,64000],width=[16,32],depth={16,24,32},signed=(boolean)true'
! 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
`GST_DEBUG`: Comma-separated list of debug categories and levels, e.g:
`GST\_DEBUG\_NO\_COLOR`: When this environment variable is set,
coloured debug output is disabled.
```
GST_DEBUG=totem:4,typefind:5
```
`GST\_DEBUG\_DUMP\_DOT\_DIR`: When set to a filesystem path, store dot
`GST_DEBUG_NO_COLOR`: When this environment variable is set, coloured debug
output is disabled. This might come handy when saving the debug output to a
file.
`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-1.0/registry-CPU.xml where CPU is the machine/cpu type
`GST_REGISTRY`: Path of the plugin registry file. The default is
`~/.gstreamer-1.0/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).
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_REGISTRY_UPDATE`: Set to "no" to force GStreamer to assume that no plugins
have changed, have been added or have been removed. This will make GStreamer
skip the initial check to determine 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_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_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 detection (quite a few important GStreamer plugins like
videotestsrc, audioconvert or audioresample use liboil).
`OIL_CPU_FLAGS`: Useful liboil environment variable. Set `OIL_CPU_FLAGS=0` when
valgrind or other debugging tools trip over liboil's CPU detection. Quite a few
important GStreamer plugins like `videotestsrc`, `audioconvert` and
`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
`G_DEBUG`: This is a 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 under
gdb (or let it core dump). Then get a stack trace in the usual way.
[information]: images/icons/emoticons/information.png