Add native screen recording with themed top-bar controls

portal/src/recorder.rs

@@ -0,0 +1,488 @@
+use futures_util::StreamExt;
+use gstreamer::{self as gst, prelude::*};
+use std::{
+    collections::HashMap,
+    fs::{File, OpenOptions},
+    io::{Read, Write},
+    os::{fd::AsRawFd, unix::fs::OpenOptionsExt},
+    path::{Path, PathBuf},
+    sync::{
+        Arc,
+        atomic::{AtomicBool, Ordering},
+    },
+    time::{Duration, Instant},
+};
+use tokio::sync::watch;
+use zbus::{
+    Connection, Proxy,
+    zvariant::{OwnedFd, OwnedObjectPath, OwnedValue, Value},
+};
+
+type Options = HashMap<String, OwnedValue>;
+const DESKTOP: &str = "org.freedesktop.portal.Desktop";
+const DESKTOP_PATH: &str = "/org/freedesktop/portal/desktop";
+
+pub fn event(state: &str, message: Option<&str>, path: Option<&Path>) {
+    let value = serde_json::json!({"state": state, "message": message, "path": path});
+    let mut stdout = std::io::stdout().lock();
+    let _ = writeln!(stdout, "{value}");
+    let _ = stdout.flush();
+}
+fn option_string(value: String) -> OwnedValue {
+    OwnedValue::try_from(Value::from(value)).unwrap()
+}
+async fn request<B: serde::Serialize + zbus::zvariant::DynamicType>(
+    connection: &Connection,
+    method: &str,
+    token: &str,
+    body: &B,
+    stop: &mut watch::Receiver<bool>,
+) -> Result<Option<Options>, String> {
+    let sender = connection
+        .unique_name()
+        .ok_or("No D-Bus identity")?
+        .as_str()[1..]
+        .replace('.', "_");
+    let path = format!("{DESKTOP_PATH}/request/{sender}/{token}");
+    let request = Proxy::new(
+        connection,
+        DESKTOP,
+        path.as_str(),
+        "org.freedesktop.portal.Request",
+    )
+    .await
+    .map_err(|e| e.to_string())?;
+    let mut responses = request
+        .receive_signal("Response")
+        .await
+        .map_err(|e| e.to_string())?;
+    let portal = Proxy::new(
+        connection,
+        DESKTOP,
+        DESKTOP_PATH,
+        "org.freedesktop.portal.ScreenCast",
+    )
+    .await
+    .map_err(|e| e.to_string())?;
+    let returned: OwnedObjectPath = portal
+        .call(method, body)
+        .await
+        .map_err(|e| format!("Screen recording portal unavailable: {e}"))?;
+    if returned.as_str() != path {
+        return Err("Unexpected portal request handle".into());
+    }
+    if *stop.borrow() {
+        let _: Result<(), _> = request.call("Close", &()).await;
+        return Ok(None);
+    }
+    tokio::select! {
+        _ = stop.changed() => {
+            let _: Result<(), _> = request.call("Close", &()).await;
+            Ok(None)
+        }
+        signal = tokio::time::timeout(Duration::from_secs(125), responses.next()) => {
+            let signal = signal.map_err(|_| "Display selection timed out")?.ok_or("Portal disconnected")?;
+            let (code, options): (u32, Options) = signal.body().deserialize().map_err(|e| e.to_string())?;
+            match code { 0 => Ok(Some(options)), 1 => Ok(None), _ => Err("Screen recording request failed".into()) }
+        }
+    }
+}
+
+pub async fn run() -> Result<(), String> {
+    gst::init().map_err(|e| e.to_string())?;
+    for factory in [
+        "pipewiresrc",
+        "queue",
+        "videoconvert",
+        "vp8enc",
+        "webmmux",
+        "fdsink",
+    ] {
+        if gst::ElementFactory::find(factory).is_none() {
+            return Err(format!(
+                "Recording needs the GStreamer {factory} plugin. See the recording installation guide."
+            ));
+        }
+    }
+    let output = output_directory()?;
+    let (stop_send, mut stop) = watch::channel(false);
+    std::thread::spawn(move || {
+        let _ = std::io::stdin().read(&mut [0u8]);
+        let _ = stop_send.send(true);
+    });
+    let connection = Connection::session().await.map_err(|e| e.to_string())?;
+    let token = |step| format!("ferese_record_{}_{step}", std::process::id());
+    let Some(created) = request(
+        &connection,
+        "CreateSession",
+        &token(0),
+        &(HashMap::from([
+            ("handle_token", option_string(token(0))),
+            ("session_handle_token", option_string(token(0))),
+        ]),),
+        &mut stop,
+    )
+    .await?
+    else {
+        event("cancelled", None, None);
+        return Ok(());
+    };
+    let handle = created
+        .get("session_handle")
+        .ok_or("Portal returned no session")?;
+    // The public portal historically returns this path as a D-Bus string.
+    let handle = OwnedObjectPath::try_from(
+        String::try_from(handle.try_clone().map_err(|e| e.to_string())?)
+            .map_err(|e| e.to_string())?,
+    )
+    .map_err(|e| e.to_string())?;
+    let session = Proxy::new(
+        &connection,
+        DESKTOP,
+        handle.as_str(),
+        "org.freedesktop.portal.Session",
+    )
+    .await
+    .map_err(|e| e.to_string())?;
+    let result = record_session(&connection, &session, &handle, &token, &output, &mut stop).await;
+    let _: Result<(), _> = session.call("Close", &()).await;
+    match result {
+        Ok(Some(path)) => event("saved", None, Some(&path)),
+        Ok(None) => event("cancelled", None, None),
+        Err(e) => return Err(e),
+    }
+    Ok(())
+}
+async fn record_session(
+    connection: &Connection,
+    session: &Proxy<'_>,
+    handle: &OwnedObjectPath,
+    token: &impl Fn(u8) -> String,
+    output: &Path,
+    stop: &mut watch::Receiver<bool>,
+) -> Result<Option<PathBuf>, String> {
+    let mut closed = session
+        .receive_signal("Closed")
+        .await
+        .map_err(|e| e.to_string())?;
+    if request(
+        connection,
+        "SelectSources",
+        &token(1),
+        &(
+            handle,
+            HashMap::from([
+                ("handle_token", option_string(token(1))),
+                ("types", 1u32.into()),
+                ("multiple", false.into()),
+                ("cursor_mode", 2u32.into()),
+            ]),
+        ),
+        stop,
+    )
+    .await?
+    .is_none()
+    {
+        return Ok(None);
+    }
+    event("selecting", None, None);
+    let Some(started) = request(
+        connection,
+        "Start",
+        &token(2),
+        &(
+            handle,
+            "",
+            HashMap::from([("handle_token", option_string(token(2)))]),
+        ),
+        stop,
+    )
+    .await?
+    else {
+        return Ok(None);
+    };
+    let streams: Vec<(u32, Options)> = started
+        .get("streams")
+        .ok_or("Portal returned no video stream")?
+        .try_clone()
+        .map_err(|e| e.to_string())?
+        .try_into()
+        .map_err(|e: zbus::zvariant::Error| e.to_string())?;
+    if streams.len() != 1 {
+        return Err("Recording requires exactly one display".into());
+    }
+    let portal = Proxy::new(
+        connection,
+        DESKTOP,
+        DESKTOP_PATH,
+        "org.freedesktop.portal.ScreenCast",
+    )
+    .await
+    .map_err(|e| e.to_string())?;
+    let remote: OwnedFd = portal
+        .call("OpenPipeWireRemote", &(handle, Options::new()))
+        .await
+        .map_err(|e| e.to_string())?;
+    if *stop.borrow() {
+        return Ok(None);
+    }
+    let stop_capture = Arc::new(AtomicBool::new(*stop.borrow()));
+    let worker_stop = stop_capture.clone();
+    let node = streams[0].0;
+    let output = output.to_owned();
+    let mut worker = tokio::task::spawn_blocking(move || {
+        let source = gst::ElementFactory::make("pipewiresrc")
+            .property("fd", remote.as_raw_fd())
+            .property("path", node.to_string())
+            .property("do-timestamp", true)
+            // Keep queued frames valid when the portal revokes PipeWire buffers.
+            .property("always-copy", true)
+            .build()
+            .map_err(|e| e.to_string())?;
+        let result = encode(source, &output, worker_stop);
+        drop(remote);
+        result
+    });
+    let result = tokio::select! {
+        result = &mut worker => result,
+        _ = stop.changed() => { stop_capture.store(true, Ordering::Relaxed); worker.await },
+        _ = closed.next() => { stop_capture.store(true, Ordering::Relaxed); worker.await },
+    };
+    result.map_err(|e| e.to_string())?.map(Some)
+}
+
+fn output_directory() -> Result<PathBuf, String> {
+    let args: Vec<_> = std::env::args_os().skip(1).collect();
+    match args.as_slice() {
+        [] => dirs::video_dir()
+            .or_else(|| dirs::home_dir().map(|p| p.join("Videos")))
+            .map(|p| p.join("Ferese"))
+            .ok_or("Cannot find your Videos folder".into()),
+        [flag, path] if flag == "--output-dir" => Ok(PathBuf::from(path)),
+        _ => Err("Usage: ferese-record [--output-dir DIRECTORY]".into()),
+    }
+}
+fn recording_file(directory: &Path) -> Result<(File, PathBuf, PathBuf), String> {
+    std::fs::create_dir_all(directory)
+        .map_err(|e| format!("Cannot create recording folder: {e}"))?;
+    let name = format!(
+        "Recording-{}-{}",
+        jiff::Zoned::now().strftime("%Y-%m-%d_%H-%M-%S"),
+        std::process::id()
+    );
+    for suffix in 0..100 {
+        let final_path = directory.join(format!("{name}-{suffix}.webm"));
+        let partial = final_path.with_extension("webm.part");
+        if final_path.exists() {
+            continue;
+        }
+        match OpenOptions::new()
+            .write(true)
+            .create_new(true)
+            .mode(0o600)
+            .open(&partial)
+        {
+            Ok(file) => return Ok((file, partial, final_path)),
+            Err(e) if e.kind() == std::io::ErrorKind::AlreadyExists => continue,
+            Err(e) => return Err(format!("Cannot save recording: {e}")),
+        }
+    }
+    Err("Cannot choose a unique recording filename".into())
+}
+
+fn encode(source: gst::Element, output: &Path, stop: Arc<AtomicBool>) -> Result<PathBuf, String> {
+    let (file, partial, destination) = recording_file(output)?;
+    let pipeline = gst::Pipeline::new();
+    let result = (|| {
+        let queue = gst::ElementFactory::make("queue")
+            .property("max-size-buffers", 4u32)
+            .property("max-size-bytes", 0u32)
+            .property("max-size-time", 0u64)
+            .property_from_str("leaky", "downstream")
+            .build()
+            .map_err(|e| e.to_string())?;
+        let convert = gst::ElementFactory::make("videoconvert")
+            .build()
+            .map_err(|e| e.to_string())?;
+        let encoder = gst::ElementFactory::make("vp8enc")
+            .property("deadline", 1i64)
+            .property("cpu-used", 8i32)
+            .property("threads", 4i32)
+            .property("target-bitrate", 8_000_000i32)
+            .property("keyframe-max-dist", 60i32)
+            .build()
+            .map_err(|e| e.to_string())?;
+        let mux = gst::ElementFactory::make("webmmux")
+            .build()
+            .map_err(|e| e.to_string())?;
+        let sink = gst::ElementFactory::make("fdsink")
+            .property("fd", file.as_raw_fd())
+            .property("sync", false)
+            .build()
+            .map_err(|e| e.to_string())?;
+        pipeline
+            .add_many([&source, &queue, &convert, &encoder, &mux, &sink])
+            .map_err(|e| e.to_string())?;
+        gst::Element::link_many([&source, &queue, &convert, &encoder, &mux, &sink])
+            .map_err(|e| e.to_string())?;
+        let announced = Arc::new(AtomicBool::new(false));
+        let notice = announced.clone();
+        source
+            .static_pad("src")
+            .ok_or("Capture has no video output")?
+            .add_probe(gst::PadProbeType::BUFFER, move |_, info| {
+                if info.buffer().is_some_and(|b| b.size() > 0)
+                    && !notice.swap(true, Ordering::Relaxed)
+                {
+                    event("recording", None, None);
+                }
+                gst::PadProbeReturn::Ok
+            });
+        pipeline
+            .set_state(gst::State::Playing)
+            .map_err(|e| e.to_string())?;
+        let bus = pipeline.bus().ok_or("Encoder has no message bus")?;
+        let mut finishing = None;
+        let started = Instant::now();
+        let mut failure = None;
+        loop {
+            if stop.load(Ordering::Relaxed) && finishing.is_none() {
+                event("saving", None, None);
+                finishing = Some(Instant::now());
+                // Inject after the capture source: it may already have disappeared
+                // when the portal closes on lock or monitor removal.
+                if !queue
+                    .static_pad("sink")
+                    .ok_or("Encoder queue has no input")?
+                    .send_event(gst::event::Eos::new())
+                {
+                    // The source may already have sent EOS. Let the bus confirm
+                    // finalization; a duplicate EOS can legitimately be rejected.
+                    failure.get_or_insert_with(|| "Encoder could not finish the recording".into());
+                }
+            }
+            if finishing.is_some_and(|t: Instant| t.elapsed() > Duration::from_secs(10)) {
+                return Err(failure.unwrap_or("Finishing the recording timed out".into()));
+            }
+            if !announced.load(Ordering::Relaxed) && started.elapsed() > Duration::from_secs(15) {
+                return Err("No video frames arrived from the selected display".into());
+            }
+            let Some(message) = bus.timed_pop(gst::ClockTime::from_mseconds(50)) else {
+                continue;
+            };
+            match message.view() {
+                gst::MessageView::Eos(_) => {
+                    if !announced.load(Ordering::Relaxed) {
+                        return Err("Recording ended before receiving video".into());
+                    }
+                    return Ok(());
+                }
+                gst::MessageView::Error(error) => {
+                    failure = Some(format!("Recording interrupted: {}", error.error()));
+                    stop.store(true, Ordering::Relaxed);
+                }
+                _ => (),
+            }
+        }
+    })();
+    let _ = pipeline.set_state(gst::State::Null);
+    result.map_err(|e| format!("{e}. Incomplete file: {}", partial.display()))?;
+    file.sync_all()
+        .map_err(|e| format!("Cannot finish saving {}: {e}", partial.display()))?;
+    std::fs::rename(&partial, &destination)
+        .map_err(|e| format!("Cannot finish saving {}: {e}", partial.display()))?;
+    Ok(destination)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    #[test]
+    fn filenames_do_not_overwrite_existing_recordings() {
+        let directory = tempfile::tempdir().unwrap();
+        let (_, first, _) = recording_file(directory.path()).unwrap();
+        let (_, second, _) = recording_file(directory.path()).unwrap();
+        assert_ne!(first, second);
+        use std::os::unix::fs::PermissionsExt;
+        assert_eq!(
+            std::fs::metadata(first).unwrap().permissions().mode() & 0o777,
+            0o600
+        );
+    }
+    #[test]
+    #[ignore = "requires an explicitly provided temporary PipeWire test node"]
+    fn encoder_finishes_pipewire_stream() {
+        gst::init().unwrap();
+        let node = std::env::var("FERESE_TEST_RECORD_NODE").expect("temporary test node required");
+        let directory = tempfile::tempdir().unwrap();
+        let source = gst::ElementFactory::make("pipewiresrc")
+            .property("path", node)
+            .property("do-timestamp", true)
+            // Keep queued frames valid when the portal revokes PipeWire buffers.
+            .property("always-copy", true)
+            .build()
+            .unwrap();
+        let stop = Arc::new(AtomicBool::new(false));
+        let request_stop = stop.clone();
+        let stopper = std::thread::spawn(move || {
+            std::thread::sleep(Duration::from_secs(3));
+            request_stop.store(true, Ordering::Relaxed);
+        });
+        let result = encode(source, directory.path(), stop);
+        stopper.join().unwrap();
+        assert_video_decodes(&result.unwrap());
+    }
+
+    #[test]
+    #[ignore = "requires GStreamer video plugins"]
+    fn encoder_finishes_a_real_webm() {
+        gst::init().unwrap();
+        let directory = tempfile::tempdir().unwrap();
+        let source = gst::ElementFactory::make("videotestsrc")
+            .property("num-buffers", 90i32)
+            .property("is-live", true)
+            .build()
+            .unwrap();
+        let stop = Arc::new(AtomicBool::new(false));
+        let request_stop = stop.clone();
+        let stopper = std::thread::spawn(move || {
+            std::thread::sleep(Duration::from_millis(350));
+            request_stop.store(true, Ordering::Relaxed);
+        });
+        let path = encode(source, directory.path(), stop).unwrap();
+        stopper.join().unwrap();
+        let data = std::fs::read(&path).unwrap();
+        assert_eq!(&data[..4], &[0x1a, 0x45, 0xdf, 0xa3]);
+        assert!(data.len() > 1000);
+        assert_video_decodes(&path);
+    }
+
+    fn assert_video_decodes(path: &Path) {
+        let decoder = gst::parse::launch("filesrc name=input ! matroskademux ! vp8dec ! fakesink")
+            .unwrap()
+            .downcast::<gst::Pipeline>()
+            .unwrap();
+        decoder
+            .by_name("input")
+            .unwrap()
+            .set_property("location", path.to_str().unwrap());
+        decoder.set_state(gst::State::Playing).unwrap();
+        let message = decoder.bus().unwrap().timed_pop_filtered(
+            gst::ClockTime::from_seconds(10),
+            &[gst::MessageType::Eos, gst::MessageType::Error],
+        );
+        let duration = decoder.query_duration::<gst::ClockTime>();
+        decoder.set_state(gst::State::Null).unwrap();
+        assert!(
+            duration.is_some_and(|d| d > gst::ClockTime::from_mseconds(100)),
+            "Invalid saved duration: {duration:?}"
+        );
+        assert!(
+            matches!(
+                message.as_ref().map(|m| m.view()),
+                Some(gst::MessageView::Eos(_))
+            ),
+            "Saved video did not decode: {message:?}"
+        );
+    }
+}