Devlog

Over the past few years, we've been slowly working on improving the platform-specific plugins for Windows, macOS, iOS, and Android, and making them work as well as the equivalent plugins on Linux. In this episode, we will look at audio device switching in the source and sink elements on macOS and Windows.

On Linux, if you're using the PulseAudio elements (both with the PulseAudio daemon and PipeWire), you get perfect device switching: quick, seamless, easy, and reliable. Simply set the device property whenever you want and you're off to the races. If the device gets unplugged, the pipeline will continue, and you will get notified of the unplug via the GST_MESSAGE_DEVICE_REMOVED bus message from GstDeviceMonitor so you can change the device.

As of a few weeks ago, the Windows Audio plugin wasapi2 implements the same behaviour. All you have to do is set the device property to whatever device you want (fetched using the GstDeviceMonitor API), at any time.

A merge request is open for adding the same feature to the macOS audio plugin, and is expected to be merged soon.

For graceful error handling, such as accidental device unplug or other unexpected errors, there's a new continue-on-error property. Setting that will cause the source to output silence after unplug, whereas the sink will simply discard the buffers. An element warning will be emitted to notify the app (alongside the GST_MESSAGE_DEVICE_REMOVED bus message if there was a hardware unplug), and the app can switch the device by setting the device property.

Thanks to Seungha and Piotr for working on this!

With GStreamer 1.26, a new D3D12 backend GstD3D12 public library was introduced in gst-plugins-bad.

Now, with the new gstreamer-d3d12 rust crate, Rust can finally access the Windows-native GPU feature written in GStreamer in a safe and idiomatic way.

What You Get with GStreamer D3D12 Support in Rust

• Pass D3D12 textures created by your Rust application directly into GStreamer pipelines without data copying
• Likewise, GStreamer-generated GPU resources (such as frames decoded by D3D12 decoders) can be accessed directly in your Rust app
• GstD3D12 base GStreamer element can be written in Rust

Beyond Pipelines: General D3D12 Utility Layer

GstD3D12 is not limited to multimedia pipelines. It also acts as a convenient D3D12 runtime utility, providing:

• GPU resource pooling such as command allocator and descriptor heap, to reduce overhead and improve reuse
• Abstractions for creating and recycling GPU textures with consistent lifetime tracking
• Command queue and fence management helpers, greatly simplifying GPU/CPU sync
• A foundation for building custom GPU workflows in Rust, with or without the full GStreamer pipeline