miracast

A Miracast (Wi-Fi Display) source in Rust: mirror a screen to a TV, projector or display adapter over Wi-Fi Direct.

• WFD information elements (ie): build the elements a source announces, read a sink's RTSP port and role from its elements.
• RTSP negotiation (source, rtsp, params, modes): the source side of messages M1 to M8 and the M16 keep-alive, capability exchange, video mode selection against the sink's CEA/VESA tables and H.264 levels, AAC or LPCM audio, IDR requests, source- and sink-initiated teardown.
• Wi-Fi Direct groups (p2p, feature networkmanager): find the sink, form a group through NetworkManager announcing the source's elements, learn the addresses. The group is bound to the D-Bus connection that asked for it.
• Media (media, feature gstreamer): capture a PipeWire node (what the ScreenCast portal grants) or a test pattern, encode H.264 with the best encoder present (VA-API, NVENC, V4L2, OpenH264, x264), add AAC or LPCM audio, and send MPEG-TS over RTP.
• WFD LPCM muxing (ts): an MPEG-TS muxer that writes LPCM the way WFD sinks such as Microsoft's Wireless Display Adapter expect (stream_type 0x83 in private_stream_1 with the WFD LPCM headers), which general-purpose muxers do not.
• A strict test sink (sink): negotiates as a TV would, checks each message, receives the RTP stream and reads the transport stream, to test a source end to end without hardware.

Example

use std::net::TcpListener;
use std::time::{Duration, Instant};
use miracast::media::{AudioInput, GstMediaConfig, GstMediaFactory, VideoInput};
use miracast::source::accept_sink;
use miracast::{Source, SourceEvent, SourceOptions};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let listener = TcpListener::bind(("0.0.0.0", miracast::ie::DEFAULT_RTSP_PORT))?;
    // ... form the Wi-Fi Direct group with `miracast::p2p::connect` ...
    let stream = accept_sink(&listener, Instant::now() + Duration::from_secs(30), &|_| true, &|| false)?
        .expect("the sink connected");
    let mut media = GstMediaFactory::new(GstMediaConfig::new(
        VideoInput::TestPattern,
        AudioInput::DefaultMonitor,
        8_000,
    ))?;
    Source::new(stream, SourceOptions::default())?.run(&mut media, &mut |event| {
        if let SourceEvent::Playing(plan) = event {
            println!("streaming {} to {}", plan.mode.name(), plan.sink_rtp);
        }
    })?;
    Ok(())
}

Features

Feature	What it adds	Needs
networkmanager	p2p: Wi-Fi Direct groups	NetworkManager, a tokio runtime
gstreamer	media: capture, encoding, MPEG-TS/RTP	GStreamer 1.20+ and its plugins

The protocol modules have no dependencies.

At run time the media path needs GStreamer's base and good plugins, mpegtsmux and rtpmp2tpay (bad), pipewiresrc for screen capture, an H.264 encoder and, for AAC, an AAC encoder (fdkaacenc, avenc_aac or voaacenc).

Testing

cargo test --all-features (or t test, see t.toml) runs the protocol tests, group formation against a simulated NetworkManager, and the media tests, which encode a live test pattern and send it to the test sink. The media tests need the GStreamer plugins above with an H.264 and an AAC encoder, and fail without them. The screen-capture test also needs pipewire, wireplumber and pw-dump; it is skipped without them unless MIRACAST_REQUIRE_SCREEN_CAPTURE=1 is set.

Status

Used by Tilo's screen projection. Not yet published to crates.io. Not covered: HDCP, UIBC (input back from the sink), R2 features such as direct streaming, and acting as a sink.

This is an independent implementation of the Wi-Fi Display specification; it contains no code from other Miracast implementations.

License

Licensed under either of Apache License, Version 2.0 or MIT license at your option. Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in this crate by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.