This is a library to help application developers easily write applications where multiple devices connected to a network need to play back media in sync.
Use cases include multi-room audio playback, video walls, and any other situation where it is required that possibly heteregenous devices on a network need to playback the same audio/video stream.
There is a talk about this library at:
You can read more at:
-
An introduction to
gst-sync-server: https://arunraghavan.net/2016/11/gstreamer-and-synchronisation-made-easy/ -
Building a video wall: https://arunraghavan.net/2016/12/synchronised-playback-and-video-walls/
-
Measuring synchronisation: https://arunraghavan.net/2017/01/quantifying-synchronisation-oscilloscope-edition/
There is an example server and client in the examples directory. Once you've
built the project, just run examples/test-server --help and
examples/text-client --help to see how you can run these.
The example server expects a playlist file. The playlist file is a simple text line with each line containing a URI, a space, and the length of the media at that URI in nanoseconds (or -1 if it is unknown). An example might look like:
file://github.com/some/local/foo.mp4 123456789
http://myhttpserver/bar.mkv -1
udp://192.168.0.0.1:5004 -1
The config file that can be passed to a server is a serialised
GVariant. These
are programmatically created using
g_variant_print.
This example configuration was used to scale a video and play it across two displays, after cropping to adjust for bezels.
{
"client1": <{
"crop": <{
"right": 973
}>,
"offset": <{
"left": 449
}>,
"scale": <{
"width": 1280,
"height": 720
}>
}>,
"client2": <{
"crop": <{
"left": 973
}>,
"offset": <{
"right": 449
}>,
"scale": <{
"width": 1280,
"height": 720
}>
}>
}