docs: tools: sync gst-launch page with man page

This still had the content from 0.10 time.

See https://gitlab.freedesktop.org/gstreamer/gst-docs/-/issues/108

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7859>
This commit is contained in:
Tim-Philipp Müller 2024-11-07 20:07:16 +00:00 committed by GStreamer Marge Bot
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@ -21,15 +21,18 @@ gst-launch-1.0 [OPTIONS] PIPELINE-DESCRIPTION
In its simplest form, a PIPELINE-DESCRIPTION is a list of elements separated In its simplest form, a PIPELINE-DESCRIPTION is a list of elements separated
by exclamation marks (!). Properties may be appended to elements in the by exclamation marks (!). Properties may be appended to elements in the
form `property=value`. form `property=value`. A "preset" can also be set using
the `@preset=<preset name>` syntax.
For a more complete description of possible PIPELINE-DESCRIPTIONS see the For a more complete description of possible PIPELINE-DESCRIPTIONS see the
section [Pipeline Description](#pipeline-description) below or consult the GStreamer documentation. section [Pipeline Description](#pipeline-description) below or consult the
GStreamer documentation.
Please note that `gst-launch-1.0` is primarily a debugging tool. You should 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 not build applications on top of it. For applications, write a little python
`gst_parse_launch()` function of the GStreamer API as an easy way to construct script or Rust application (or use whatever other programming language you
pipelines from pipeline descriptions. prefer) and use the `gst_parse_launch()` function of the GStreamer API as an
easy way to construct pipelines from pipeline descriptions.
## Options ## Options
@ -55,24 +58,118 @@ Output messages posted on the pipeline's bus
Output tags (also known as metadata) Output tags (also known as metadata)
**-o FILE, --output=FILE** **-e, --eos-on-shutdown**
Save XML representation of pipeline to FILE and exit 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 (especially in case of `mp4mux` and `qtmux`
where the created file will be unreadable if the file has not been finalised
properly).
**-f, --no\_fault** **-f, --no\_fault**
Do not install a fault handler Do not install a segfault handler
**-T, --trace** **--no-position**
Do not print the current position of pipeline.
If this option is unspecified, the position will be printed when stdout is a TTY.
To enable printing position when stdout is not a TTY,
use the "--force-position" option.
**--force-position**
Allow printing the current position of pipeline even if stdout is not a TTY.
This option has no effect if the "--no-position" option is specified.
Print memory allocation traces. The feature must be enabled at compile
time to work.
## GStreamer Options ## 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: 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=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 (this is the highest 'normal' debug level)
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:LOG,GST_ELEMENT_*:INFO,oggdemux:LOG`
**--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=1`
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-path=PATH**
Add directories separated with `:` (`;` on Windows) 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 ## Pipeline Description
A pipeline consists of *elements* and *links*. *Elements* can be put A pipeline consists of *elements* and *links*. *Elements* can be put
@ -97,6 +194,16 @@ 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 out about properties and allowed values of different elements. Enumeration
properties can be set by name, nick or value. properties can be set by name, nick or value.
### Element Presets
```
@preset=<preset name> ...
```
Sets the preset (basically a pre-made collection of property settings for a
specific element) on the element. you can use `gst-inspect-1.0` to
find out what presets are available for a specific element.
### Bins ### Bins
``` ```
@ -114,19 +221,27 @@ pipeline.
### Links ### Links
``` ```
[[SRCELEMENT\].[PAD1,...]] ! [[SINKELEMENT].[PAD1,...]] [[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. 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 using the `name` property. If the name is omitted, 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 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 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 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 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 pads specified and multiple links are done in the given order.
is a simple exclamation mark. This links the element to the left of it with the
element at its right.
The simplest link is a simple exclamation mark. This links the element to the
left of it with the element at its right.
Linking using the `:` operator attempts to link all possible pads between
the elements
The following links the element with name SRCELEMENT to the element with name The following links the element with name SRCELEMENT to the element with name
SINKELEMENT, using the caps specified in CAPS as a filter: SINKELEMENT, using the caps specified in CAPS as a filter:
@ -156,73 +271,66 @@ value and the type can have the following case-insensitive values:
- `i` or `int` for integer values or ranges; - `i` or `int` for integer values or ranges;
- `f` or `float` for float values or ranges; - `f` or `float` for float values or ranges;
- `4` or `fourcc` for FOURCC values;
- `b`, `bool`, or `boolean` for boolean values; - `b`, `bool`, or `boolean` for boolean values;
- `s`, `str`, or `string` for strings; - `s`, `str`, or `string` for strings;
- `fraction` for fractions (framerate, pixel-aspect-ratio); - `fraction` for fractions (framerate, pixel-aspect-ratio);
- `l` or `list` for lists. - `l` or `list` for lists.
If no type was given, the following order is If no type was given, the following order is tried: integer, float, boolean,
tried: integer, float, boolean, string. Integer values must be parsable by string. Integer values must be parsable by `strtol()`, floats by `strtod()`.
`strtol()`, floats by `strtod()`. FOURCC values may either be integers or Boolean values are (case insensitive) `yes`, `no`, `true` or `false`
strings. Boolean values are (case insensitive) `yes`, `no`, `true` or `false` and may like strings be escaped with `"` or `'`.
and may like strings be escaped with `"` or `'`. Ranges are in this format: `[
VALUE, VALUE]`; lists use this format: `(VALUE [, VALUE ...])`.
## Pipeline Control Ranges are in this format: `[VALUE, VALUE]`, e.g. `width=[16,1920]`
A pipeline can be controlled by signals. `SIGUSR2` will stop the pipeline Lists use this format: `{VALUE [, VALUE ...]}`, e.g. `width={1920,1280,640}`
(`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 ## Pipeline Examples
The examples below assume that you have the correct plugins available. The examples below assume that you have the correct plug-ins available.
In general, `osssink` can be substituted with another audio output In general, "pulsesink" can be substituted with another audio output
plugin such as `directsoundsink`, `esdsink`, `alsasink`, `osxaudiosink`, or plug-in such as "alsasink", "osxaudiosink", or "wasapisink"
`artsdsink`. Likewise, `xvimagesink` can be substituted with `d3dvideosink`,
`ximagesink`, `sdlvideosink`, `osxvideosink`, or `aasink`. Keep in mind though Likewise, `xvimagesink` can be substituted with `d3dvideosink`,
that different sinks might accept different formats and even the same sink might `ximagesink`, `sdlvideosink`, `osxvideosink`, or `aasink`.
accept different formats on different machines, so you might need to add
converter elements like `audioconvert` and `audioresample` for audio or Keep in mind though that different sinks might accept different formats and
`videoconvert` in front of the sink to make things work. 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 `videoconvertscale` in front of the sink to make things work.
### Audio playback ### Audio playback
Play the mp3 music file "music.mp3" using a libmad-based plugin and output to **Note:** For audio/video playback it's best to use the `playbin3` or
an OSS device: `uridecodebin3` elements, these are just example pipelines.
Play the mp3 music file "music.mp3" using a libmpg123-based plug-in and
output it to an audio device via PulseAudio (or PipeWire).
``` ```
gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert ! gst-launch-1.0 filesrc location=music.mp3 ! mpegaudioparse ! mpg123audiodec ! audioconvert ! audioresample ! pulsesink
audioresample ! osssink
``` ```
Play an Ogg Vorbis format file: Play an Ogg Vorbis format file:
``` ```
gst-launch-1.0 filesrc location=music.ogg ! oggdemux ! vorbisdec ! gst-launch-1.0 filesrc location=music.ogg ! oggdemux ! vorbisdec ! audioconvert ! audioresample ! pulsesink
audioconvert ! audioresample ! osssink
``` ```
Play an mp3 file using GNOME-VFS: Play an mp3 file or an http stream using GIO:
``` ```
gst-launch-1.0 gnomevfssrc location=music.mp3 ! mad ! osssink gst-launch-1.0 giosrc location=music.mp3 ! mpegaudioparse ! mpg123audiodec ! audioconvert ! pulsesink
``` ```
Play an HTTP stream using GNOME-VFS:
``` ```
gst-launch-1.0 gnomevfssrc location=<http://domain.com/music.mp3> ! mad gst-launch-1.0 giosrc location=http://domain.com/music.mp3 ! mpegaudioparse ! mpg123audiodec ! audioconvert ! audioresample ! pulsesink
! audioconvert ! audioresample ! osssink
``` ```
Use GNOME-VFS to play an mp3 file located on an SMB server: Use GIO to play an mp3 file located on an SMB server:
``` ```
gst-launch-1.0 gnomevfssrc location=<smb://computer/music.mp3> ! mad ! gst-launch-1.0 giosrc location=smb://computer/music.mp3 ! mpegaudioparse ! mpg123audiodec ! audioconvert ! audioresample ! pulsesink
audioconvert ! audioresample ! osssink
``` ```
### Format conversion ### Format conversion
@ -230,15 +338,13 @@ audioconvert ! audioresample ! osssink
Convert an mp3 music file to an Ogg Vorbis file: Convert an mp3 music file to an Ogg Vorbis file:
``` ```
gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert ! vorbisenc ! gst-launch-1.0 filesrc location=music.mp3 ! mpegaudioparse ! mpg123audiodec ! audioconvert ! vorbisenc ! oggmux ! filesink location=music.ogg
oggmux ! filesink location=music.ogg
``` ```
Convert to the FLAC format: Convert to the FLAC format:
``` ```
gst-launch-1.0 filesrc location=music.mp3 ! mad ! audioconvert ! flacenc ! gst-launch-1.0 filesrc location=music.mp3 ! mpegaudioparse ! mpg123audiodec ! audioconvert ! flacenc ! filesink location=test.flac
filesink location=test.flac`
``` ```
### Other ### Other
@ -246,34 +352,29 @@ filesink location=test.flac`
Play a .WAV file that contains raw audio data (PCM): Play a .WAV file that contains raw audio data (PCM):
``` ```
gst-launch-1.0 filesrc location=music.wav ! wavparse ! audioconvert ! gst-launch-1.0 filesrc location=music.wav ! wavparse ! audioconvert ! audioresample ! pulsesink
audioresample ! osssink
``` ```
Convert a .WAV file containing raw audio data into an Ogg Vorbis or mp3 file: 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 ! gst-launch-1.0 filesrc location=music.wav ! wavparse ! audioconvert ! vorbisenc ! oggmux ! filesink location=music.ogg
vorbisenc ! oggmux ! filesink location=music.ogg
``` ```
``` ```
gst-launch-1.0 filesrc location=music.wav ! wavparse ! audioconvert ! lame ! gst-launch-1.0 filesrc location=music.wav ! wavparse ! audioconvert ! lamemp3enc ! xingmux ! id3v2mux ! filesink location=music.mp3
filesink location=music.mp3
``` ```
Rip all tracks from CD and convert them into a single mp3 file: Rip all tracks from CD and convert them into a single mp3 file:
``` ```
gst-launch-1.0 cdparanoiasrc mode=continuous ! audioconvert ! lame ! gst-launch-1.0 cdparanoiasrc mode=continuous ! audioconvert ! lamemp3enc ! mpegaudioparse ! xingmux ! id3v2mux ! filesink location=cd.mp3
id3v2mux ! filesink location=cd.mp3
``` ```
Rip track 5 from the CD and converts it into a single mp3 file: Rip track 5 from the CD and converts it into a single mp3 file:
``` ```
gst-launch-1.0 cdparanoiasrc track=5 ! audioconvert ! lame ! id3v2mux gst-launch-1.0 cdparanoiasrc track=5 ! audioconvert ! lamemp3enc ! mpegaudioparse ! xingmux ! id3v2mux ! filesink location=track5.mp3
! filesink location=track5.mp3
``` ```
Using `gst-inspect-1.0`, it is possible to discover settings like Using `gst-inspect-1.0`, it is possible to discover settings like
@ -283,72 +384,58 @@ will find an element (such as cdparanoia) that supports that protocol
for you, e.g.: for you, e.g.:
``` ```
gst-launch-1.0 [cdda://5] ! lame vbr=new vbr-quality=6 ! gst-launch-1.0 cdda://5 ! lamemp3enc vbr=new vbr-quality=6 ! xingmux ! id3v2mux ! filesink location=track5.mp3
filesink location=track5.mp3
``` ```
Record sound from your audio input and encode it into an ogg file: Record sound from your audio input and encode it into an ogg file:
``` ```
gst-launch-1.0 osssrc ! audioconvert ! vorbisenc ! oggmux ! gst-launch-1.0 pulsesrc ! audioconvert ! vorbisenc ! oggmux ! filesink location=input.ogg
filesink location=input.ogg
```
Running a pipeline using a specific user-defined latency
(see gst_pipeline_set_latency()):
```
gst-launch-1.0 pipeline. \( latency=2000000000 videotestsrc ! jpegenc ! jpegdec ! fakevideosink \)
``` ```
### Video ### Video
Display only the video portion of an MPEG-1 video file, outputting to an X **Note:** For audio/video playback it's best to use the `playbin3` or
`uridecodebin3` elements, these are just example pipelines.
Display only the video portion of an MPEG-2 video file, outputting to an X
display window: display window:
``` ```
gst-launch-1.0 filesrc location=videofile.mpg ! dvddemux ! mpeg2dec ! gst-launch-1.0 filesrc location=JB_FF9_TheGravityOfLove.mpg ! mpegdemux ! mpegvideoparse ! mpeg2dec ! videoconvert ! xvimagesink
xvimagesink
``` ```
Display the video portion of a .vob file (used on DVDs), outputting to an SDL Display the video portion of a .vob file (used on DVDs), outputting to an SDL
window: window:
``` ```
gst-launch-1.0 filesrc location=flflfj.vob ! dvddemux ! mpeg2dec ! sdlvideosink gst-launch-1.0 filesrc location=flflfj.vob ! dvddemux ! mpegvideoparse ! mpeg2dec ! videoconvert ! sdlvideosink
``` ```
Play both video and audio portions of an MPEG movie: Play both video and audio portions of an MPEG movie:
``` ```
gst-launch-1.0 filesrc location=movie.mpg ! dvddemux name=demuxer gst-launch-1.0 filesrc location=movie.mpg ! dvddemux name=demuxer \
demuxer. ! queue ! mpeg2dec ! sdlvideosink \
demuxer. ! queue ! mad ! audioconvert ! audioresample ! osssink demuxer. ! queue ! mpegvideoparse ! mpeg2dec ! videoconvert ! sdlvideosink \
demuxer. ! queue ! mpegaudioparse ! mpg123audiodec ! audioconvert ! audioresample ! pulsesink
``` ```
Play an AVI movie with an external text subtitle stream: Play an AVI movie with an external text subtitle stream:
```
gst-launch-1.0 filesrc location=movie.mpg ! mpegdemux name=demuxer
demuxer. ! queue ! mpeg2dec ! videoconvert ! sdlvideosink
demuxer. ! queue ! mad ! audioconvert ! audioresample ! osssink
```
This example shows how to refer to specific pads by name if an This example shows how to refer to specific pads by name if an
element (here: textoverlay) has multiple sink or source pads: element (here: textoverlay) has multiple sink or source pads:
``` ```
gst-launch-1.0 textoverlay name=overlay ! videoconvert ! videoscale ! gst-launch-1.0 textoverlay name=overlay ! videoconvert ! videoscale ! autovideosink \
autovideosink filesrc location=movie.avi ! decodebin3 ! videoconvert ! overlay.video_sink \
filesrc location=movie.avi ! decodebin2 ! videoconvert ! overlay.video_sink
filesrc location=movie.srt ! subparse ! overlay.text_sink filesrc location=movie.srt ! subparse ! overlay.text_sink
``` ```
Play an AVI movie with an external text subtitle stream using playbin: Play an AVI movie with an external text subtitle stream using playbin:
``` ```
gst-launch-1.0 playbin uri=<file:///path/to/movie.avi> gst-launch-1.0 playbin3 uri=<file:///path/to/movie.avi> suburi=<file:///path/to/movie.srt>
suburi=<file:///path/to/movie.srt>
``` ```
### Network streaming ### Network streaming
@ -358,18 +445,13 @@ Stream video using RTP and network elements
This command would be run on the transmitter: This command would be run on the transmitter:
``` ```
gst-launch-1.0 v4l2src ! gst-launch-1.0 v4l2src ! queue ! videoconvert ! x264enc tune=zerolatency key-int-max=15 ! video/x-h264,profile=main ! rtph264pay pt=96 config-interval=-1 ! udpsink host=192.168.1.1 port=5000
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: Use this command on the receiver:
``` ```
gst-launch-1.0 udpsrc port=5000 ! application/x-rtp, gst-launch-1.0 udpsrc port=5000 ! application/x-rtp,clock-rate=90000,payload=96 ! rtpjitterbuffer ! rtph264depay ! h264parse ! avdec_h264 ! videoconvert ! xvimagesink
clock-rate=90000,payload=96 ! rtph263pdepay queue-delay=0 ! ffdec_h263
! xvimagesink
``` ```
### Diagnostic ### Diagnostic
@ -377,7 +459,7 @@ clock-rate=90000,payload=96 ! rtph263pdepay queue-delay=0 ! ffdec_h263
Generate a null stream and ignore it (and print out details): Generate a null stream and ignore it (and print out details):
``` ```
gst-launch-1.0 -v fakesrc num-buffers=16 ! fakesink gst-launch-1.0 -v fakesrc num-buffers=16 ! fakesink silent=false
``` ```
Generate a pure sine tone to test the audio output: Generate a pure sine tone to test the audio output:
@ -392,31 +474,46 @@ Generate a familiar test pattern to test the video output:
gst-launch-1.0 videotestsrc ! ximagesink gst-launch-1.0 videotestsrc ! ximagesink
``` ```
```
gst-launch-1.0 videotestsrc ! xvimagesink
```
### Automatic linking ### Automatic linking
You can use the "decodebin" element to automatically select the right You can use the "decodebin3" element to automatically select the right
elements to get a working pipeline. elements to get a working pipeline.
Play any supported audio format: Play any supported audio format:
``` ```
gst-launch-1.0 filesrc location=musicfile ! decodebin ! audioconvert ! gst-launch-1.0 filesrc location=musicfile ! decodebin3 ! audioconvert ! audioresample ! pulsesink
audioresample ! osssink
``` ```
Play any supported video format with video and audio output. Threads are used Play any supported video format with video and audio output. Threads are used
automatically: automatically:
``` ```
gst-launch-1.0 filesrc location=videofile ! decodebin name=decoder gst-launch-1.0 filesrc location=videofile ! decodebin name=decoder decoder. ! queue ! audioconvert ! audioresample ! pulsesink decoder. ! videoconvert ! xvimagesink
decoder. ! queue ! audioconvert ! audioresample ! osssink ```
decoder. ! videoconvert ! xvimagesink
You can also support different inputs by using an URI and uridecodebin3, e.g.:
```
gst-launch-1.0 uridecodebin3 uri=file:///path/to/video.mp4 name=decoder decoder. ! queue ! audioconvert ! audioresample ! pulsesink decoder. ! videoconvert ! xvimagesink
```
```
gst-launch-1.0 uridecodebin3 uri=https://gstreamer.freedesktop.org/data/media/sintel_trailer-480p.webm name=decoder decoder. ! queue ! audioconvert ! audioresample ! pulsesink decoder. ! videoconvert ! xvimagesink
``` ```
To make the above even easier, you can use the playbin element: To make the above even easier, you can use the playbin element:
``` ```
gst-launch-1.0 playbin uri=<file:///home/joe/foo.avi> gst-launch-1.0 playbin3 uri=file:///home/joe/foo.avi
```
```
gst-launch-1.0 playbin3 uri=https://gstreamer.freedesktop.org/data/media/sintel_trailer-480p.webm
``` ```
### Filtered connections ### Filtered connections
@ -426,18 +523,20 @@ These examples show you how to use filtered caps.
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 videotestsrc ! gst-launch-1.0 videotestsrc ! 'video/x-raw,format=YUY2;video/x-raw,format=YV12' ! xvimagesink
'video/x-raw-yuv,format=(fourcc)YUY2;video/x-raw-yuv,format=(fourcc)YV12' ```
! xvimagesink
or
```
gst-launch-1.0 v4l2src ! image/jpeg ! queue ! decodebin3 ! videoconvert ! autovideosink
``` ```
Record audio and write it to a .wav file. Force usage of signed 16 to 32 bit 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: samples and a sample rate between 32kHz and 64KHz:
``` ```
gst-launch-1.0 osssrc ! gst-launch-1.0 pulsesrc ! 'audio/x-raw,rate=[32000,64000],format={S16LE,S24LE,S32LE}' ! wavenc ! filesink location=recording.wav
'audio/x-raw-int,rate=[32000,64000],width=[16,32],depth={16,24,32},signed=(boolean)true'
! wavenc ! filesink location=recording.wav
``` ```
## Environment Variables ## Environment Variables
@ -448,16 +547,31 @@ gst-launch-1.0 osssrc !
GST_DEBUG=totem:4,typefind:5 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`). 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 `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 output is disabled. This might come handy when saving the debug output to a
file. file.
`GST_DEBUG_DUMP_DOT_DIR`: When set to a filesystem path, store dot `GST_DEBUG_DUMP_DOT_DIR`: When set to a filesystem path, store 'dot' files of
files of pipeline graphs there. 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 or use the pipeline_snapshot
tracer from the GStreamer Rust plugins.
`GST_REGISTRY`: Path of the plugin registry file. The default is `GST_REGISTRY`: Path of the plugin registry file. The default is
`~/.gstreamer-1.0/registry-CPU.xml` where CPU is the machine/cpu type `~/.cache/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. GStreamer was compiled for, e.g. 'x86_64', 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 `GST_REGISTRY_UPDATE`: Set to "no" to force GStreamer to assume that no plugins
@ -473,10 +587,15 @@ plugins. These take precedence over the system plugins.
default. If not set, this defaults to the system-installed path, and the plugins default. If not set, this defaults to the system-installed path, and the plugins
installed in the user's home directory installed in the user's home directory
`OIL_CPU_FLAGS`: Useful liboil environment variable. Set `OIL_CPU_FLAGS=0` when `GST_DEBUG_FILE`: Set this variable to a file path to redirect all GStreamer
valgrind or other debugging tools trip over liboil's CPU detection. Quite a few debug messages to this file. If left unset, debug messages will be output
important GStreamer plugins like `videotestsrc`, `audioconvert` and to the standard error output.
`audioresample` use liboil.
`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`: This is a useful GLib environment variable. Set `G_DEBUG`: This is a useful GLib environment variable. Set
`G_DEBUG=fatal_warnings` to make GStreamer programs abort when a critical `G_DEBUG=fatal_warnings` to make GStreamer programs abort when a critical