Installing gst-python in macOS

Question

I installed GStreamer 1.22.10 on macOS (Sonoma) using the official binaries. I realized that gst-python is not automatically installed, so I cloned the GStreamer Gitlab repository and followed the related instructions in the gst-python subproject to install it.

I'm using Python (3.12) installed via homebrew, so I gave its pygi overrides directory to meson during setup:

meson setup builddir -Dpygi-overrides-dir=/opt/homebrew/lib/python3.12/site-packages/gi/overrides

Pygobject3 is also installed via brew in the path: /opt/homebrew/Cellar/pygobject3/3.46.0_1

Now when I do python -c "import gi; gi.require_version('Gst', '1.0');", I get an error that the namespace Gst is not available.

Traceback (most recent call last):
  File "<string>", line 1, in <module>
  File "/opt/homebrew/lib/python3.12/site-packages/gi/__init__.py", line 126, in require_version
    raise ValueError('Namespace %s not available' % namespace)
ValueError: Namespace Gst not available

Any help is appreciated.

Note: If GStreamer is installed using brew, gst-python is included but that is not my preferred approach because the brew version does not contain some of the packages I need, like webrtc.

Answer 1

I'm having the same problem.

To my understanding the gst-python is only an extension to the regular GStreamer Python bindings and adds some pythonic "syntactic sugar". So it is not really a requirement to create GStreamer applications in Python.

The error Namespace Gst not available means that it can't find the gobject-introspection information required to dynamically create the regular Python bindings for GStreamer in the first place.

This information is usually stored in *.typelib files (e.g. Gst-1.0.typelib).

Those files seem to be missing when installing the latest GStreamer for MacOS using the official binaries.

However when I install GStreamer through Homebrew they are installed properly:

$ find /opt/homebrew -name "Gst*.typelib"
/opt/homebrew/lib/girepository-1.0/GstVideo-1.0.typelib
/opt/homebrew/lib/girepository-1.0/GstRtsp-1.0.typelib
/opt/homebrew/lib/girepository-1.0/GstCodecs-1.0.typelib
/opt/homebrew/lib/girepository-1.0/GstAllocators-1.0.typelib
/opt/homebrew/lib/girepository-1.0/GstSdp-1.0.typelib
/opt/homebrew/lib/girepository-1.0/GstNet-1.0.typelib
/opt/homebrew/lib/girepository-1.0/Gst-1.0.typelib
...

and python -c "import gi; gi.require_version('Gst', '1.0');" works.

But sadly the Homebrew installation seems broken for me (MacOS 14.3.1, GStreamer 1.22.10).