**ges-launch-1.0** creates a multimedia [timeline](https://phabricator.freedesktop.org/w/gstreamer/gst-editing-services/ges-timeline/) and plays it back, or renders it to the specified format.
It can load a timeline from an existing project, or create one from the specified commands.
Updating an existing project can be done through thanks to the [GstValidate](http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-validate/html/) [scenarios](http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gst-validate/html/scenarios.html) using the `--set-scenario` argument, if ges-launch-1.0 has been compiled with GstValidate.
Assuming "media" is an audio video sample longer than 6 seconds, this will play a black frame and silence for 4 seconds, then the sample from its 4th second to its sixth second, resulting in a 6-seconds long playback.
Assume media1 and media2 both contain audio and video and last for 10 seconds.
This will first add media1 in a new layer of "priority" 1, thus implicitly creating a layer of "priority" 0, the start of the clip will be 0 as no clip had been added in that layer before.
It will then add media2 in the layer of "priority" 0 which was created previously, the start of this new clip will also be 0 as no clip has been added in this layer before.
Both clips will thus overlap on two layers for 10 seconds.
The "alpha" property of the second clip will finally be set to a value of 0.9.
All this will result in a 10 seconds playback, where media2 is barely visible through media1, which is nearly opaque. If alpha was set to 0.5, both clips would be equally visible, and if it was set to 0.0, media1 would be invisible and media2 completely opaque.
#### Mandatory arguments
__path|uri:__
```
Specifies the location of the sample to make a clip from.
```
#### Options
__inpoint[i]=<inpoint>:__
```
Sets the inpoint of the clip, that is the
position in the original sample at which the clip will start outputting
data.
It is an error to have an inpoint superior to the actual duration of the original sample.
0 by default.
```
__duration[i]=<duration>:__
```
Sets the duration of the clip, that is the
duration of the media the clip will output.
It is an error to have inpoint + duration be superior to the duration of the
original sample.
The default is the duration of the original sample - the inpoint of the clip.
```
__start[s]=<start>:__
```
Sets the start of the clip, that is its position in
the timeline.
If not specified, it will be set to the duration of the layer the clip is added on,
as the expected default behaviour is to queue clips one after another.
```
__layer[l]=<layer>:__
```
Sets the layer of the clip. The video stream in
overlapping clips on different layers will be blended together according
to their alpha property, starting with the clip on the last layer. An
example is shown in the EXAMPLES section.
If not specified, it will be set to the last layer a clip has been added on, or
a first layer if no clip has been added yet.
```
#### Properties
##### Video properties
These have no effects if there is no video stream in the sample.
__alpha:__
```
This is the amount of transparency of the clip, ranging from 0.0
to 1.0 Clips overlapping on different layers will be composited
together, unless --disable-mixing has been specified, in the order of
the layers.
```
__posx:__
```
This is the x position (offset) of the clip in pixels, relatively
to the output frame of the timeline.
```
__posy:__
```
This is the y position (offset) of the clip in pixels, relatively
to the output frame of the timeline.
```
__width:__
```
This is the width in pixels that the clip will occupy in the
final output frame.
```
__height:__
```
This is the height in pixels that the clip will occupy in the final output frame.
```
##### Audio properties
__volume:__
```
This is the volume that will be set on the audio part of the
clip, ranging from 0.0 to 10.0, with 1.0 being the default.
```
__mute:__
```
Set to true to mute the audio of the clip. Default is false.
```
### +effect
#### Mandatory arguments
__bin-description:__
```
Specifies the description of a GStreamer a bin, in the gst-launch format.
```
#### Options
Properties can be set on the effect either directly in the bin-description, or separately through the set-<property-name> command, which will lookup any readable property in any of the children of the bin, and set the provided value on it.