Video

VideoView shows video frames your app decodes. guise links no codec, opens no socket and owns no clock — like the AI components it is transport agnostic: you decode (ffmpeg, a camera or screen-capture API, a WebRTC track), guise puts the newest picture on screen through gpui's GPU image path and fits it into its box.

It is a picture surface, not a player. Play, pause and seek belong to whatever is decoding; controls are ordinary components you put around the view.

use guise::prelude::*;

let video = cx.new(|cx| {
    VideoView::new(cx)
        .height(360.0)
        .fit(VideoFit::Contain)
        .radius(Size::Md)
});

#Getting frames in

A VideoFrame is one decoded picture. Build it from whichever layout your decoder produces; each constructor returns None if the buffer is the wrong size for the dimensions, so a decoder bug is a missing frame rather than a panic in the paint pass.

From the UI thread, push directly:

video.update(cx, |v, cx| v.push_frame(frame, cx));

From a decoder thread, ask the view for a VideoFeed — a cloneable, Send handle — and send into it:

let feed = video.update(cx, |v, cx| v.feed(cx));

std::thread::spawn(move || {
    for decoded in decoder {
        if let Some(frame) = VideoFrame::i420(decoded.w, decoded.h, &decoded.y, &decoded.u, &decoded.v) {
            feed.send(frame);
        }
    }
});

The feed is a one-slot mailbox: send replaces a frame the view hasn't picked up yet. For live video that is the right policy — a stale frame is worth nothing and queueing it only adds latency. The view polls it every 8 ms and stops when every clone of the feed is dropped. view.stats() reports shown and dropped, so you can see how far behind the UI ran.

#Fitting

Letterbox bars take .background(color), defaulting to the theme surface. fit_rect(src, dst, fit) is the pure arithmetic if you need the same mapping for an overlay.

#Builder and methods

Subscribe for VideoEvent::Resized { width, height }, emitted on the first frame and whenever the dimensions change — the moment to resize a container or re-run layout around the view:

cx.subscribe(&video, |_this, _v, event: &VideoEvent, _cx| {
    let VideoEvent::Resized { width, height } = event;
})
.detach();

#Notes

• Every frame is a new gpui image and gpui keeps an image's atlas slot until told to drop it. The view retires each replaced frame and drops it at the start of the next render, so a long stream does not fill the atlas.
• The gallery's VideoView section runs a generated colour-bar pattern through a VideoFeed from a plain thread at 30 fps — the same path a real decoder takes.
• macOS could avoid the CPU copy with gpui's surface() and a CVPixelBuffer; VideoView does not use it, to stay on the portable image path that gpui 0.2.2 offers on every platform.