Add adaptive virtual display that adjusts to window size. by TinuraD · Pull Request #6705 · Genymobile/scrcpy

TinuraD · 2026-03-04T21:11:55Z

I noticed some developers have made GUI or companion apps using scrcpy, so being able to open apps in resizable windows would be cool. SO I’ve just added an adaptive virtual display option.

Instead of using --new-display, you can now also use --adaptive-new-display too, which provides an adaptive virtual display that resizes according to your current window.
It also includes --adaptive-scale, which allows you to change the scale (default is 1). [Eg: 0.5, 2.0]
This basically changes the virtual display's resolution and calculates an adaptive DPI based on your current PC screen resolution.
All existing functions remain untouched, so --new-display still works as before.
I attached two video clips to show how it works.
But i didn't update documentations.

adaptivevd.mp4

adaptiveapp.mp4

TinuraD · 2026-03-04T21:21:50Z

P.S. I noticed that someone implemented the same feature in [#6351]. Since it hasn't been merged yet, I decided to reopen my PR too. I hope one of these will be added to scrcpy soon.

LHLaurini

Thank you for your PR!

I left you some comments. I personally find your implementation cleaner than the other one, although that one works a bit better at the moment.

Your implementation makes the video look a bit blurry, probably because the server does some rounding to the dimensions.

LHLaurini · 2026-03-07T20:31:31Z

server/src/main/java/com/genymobile/scrcpy/video/NewDisplayCapture.java

+            } catch (Exception e) {
+                Ln.w("Virtual display resize failed, fallback to recreate", e);
+                displaySizeMonitor.stopAndRelease();
+                virtualDisplay.release();
+                virtualDisplay = null;
+            }


The whole point of resize is to "to allow applications using virtual displays to adapt to changing conditions without having to tear down and recreate the display" (from the docs). Is this really necessary?

IMO unless this happens in some devices, you should just show a warning and keep going

Removed and added the warning.

LHLaurini · 2026-03-07T20:39:05Z

app/src/screen.c

+    if (size.width == 0 || size.height == 0) {
+        return;
+    }
+    if (size.width < 64 || size.height < 64) {
+        return;
+    }


Redundant...

LHLaurini · 2026-03-07T20:42:41Z

app/src/screen.c

@@ -811,6 +934,7 @@ sc_screen_handle_event(struct sc_screen *screen, const SDL_Event *event) {
            return true;
        }
        case SC_EVENT_NEW_FRAME: {
+            sc_screen_maybe_send_vd_resize(screen);


You probably only need one sc_screen_maybe_send_vd_resize here. I'd keep the one in SC_EVENT_NEW_FRAME.

Changed. Kept the one you did recommend.

LHLaurini · 2026-03-07T20:45:28Z

app/src/cli.c

+    {
+        .longopt_id = OPT_ADAPTIVE_NEW_DISPLAY,
+        .longopt = "adaptive-new-display",
+        .argdesc = "[<width>x<height>][/<dpi>]",


This dpi value is almost immediately ignored in favor of the one from adaptive-scale

Since scaling can basically handle dpi I thought it wasn’t needed. But it makes sense to add a known dpi value. So I fixed it.

LHLaurini · 2026-03-07T20:47:45Z

app/src/screen.c


+static uint16_t
+get_window_dpi(const struct sc_screen *screen) {
+    if (screen->adaptive_new_display) {


Maybe you meant to check vd_scale here? This is always true.

LHLaurini · 2026-03-07T20:50:55Z

app/src/screen.c

+    }
+    screen->vd_resize_size = size;
+    screen->vd_resize_pending = true;
+    screen->vd_resize_deadline_ms = SDL_GetTicks() + 250;


Use a constant for this value

LHLaurini · 2026-03-07T20:57:45Z

app/src/screen.c

-    struct sc_size window_size =
-        get_initial_optimal_size(screen->content_size, screen->req.width,
-                                                       screen->req.height);
+    struct sc_size window_size;
+    if (screen->adaptive_new_display
+            && !screen->req.width && !screen->req.height) {
+        struct sc_size bounds;
+        if (get_preferred_display_bounds(&bounds)) {
+            window_size = get_optimal_size(bounds, screen->content_size, true);
+        } else {
+            window_size = get_initial_optimal_size(screen->content_size,
+                                                   screen->req.width,
+                                                   screen->req.height);
+        }
+    } else {
+        window_size = get_initial_optimal_size(screen->content_size,
+                                               screen->req.width,
+                                               screen->req.height);
+    }


Could you explain the goal of this change?

Basically, the resizing function isn’t tied to the initial startup, as it’s mostly based on normal new-display behavior. This allows the virtual display to have adaptive window size on initial launch following px to dpi conversion or using custom arguments.

LHLaurini · 2026-03-07T21:03:32Z

app/src/screen.c

+    if (screen->new_display) {
+        // For new-display, keep the window size controlled by the user.
+        // Do not auto-resize the window to the content size to avoid
+        // feedback loops with virtual display resizing.
+        screen->content_size = new_content_size;
+        return;
+    }
+


Is this really a problem? Unless I'm mistaken, shouldn't the check in lines 108-110 avoid that?

This is to avoid issues when Android's rotation causes the virtual display to resize. Some Android apps, like video players, change the rotation while the app is in use, such as when opening a video. Even though the window appears the same, it still makes a very small size change as i noticed which can create loops.

LHLaurini · 2026-03-07T21:07:35Z

server/src/main/java/com/genymobile/scrcpy/control/Controller.java

+        if (pendingRelaunchOnResize && lastStartedAppPackage != null) {
+            pendingRelaunchOnResize = false;
+            Ln.i("Relaunching app \"" + lastStartedAppPackage + "\" on resized display " + virtualDisplayId + "...");
+            Device.startApp(lastStartedAppPackage, virtualDisplayId, lastStartedAppForceStop);
+        }


You shouldn't relaunch the app if you were able to resize the display successfully, as that causes some apps to restart (particularly PWAs)

Changed to not restart

…plication | dpi value arg added | Avoid relaunching on successful resizes

TinuraD · 2026-03-08T19:46:12Z

Hey, thanks for reviewing the PR. I’ve checked your comments and updated the required files.

Added adaptive virtual display that adjusts to window size

52709d6

TinuraD changed the title ~~Added adaptive virtual display that adjusts to window size.~~ Add adaptive virtual display that adjusts to window size. Mar 4, 2026

TinuraD closed this Mar 4, 2026

TinuraD reopened this Mar 5, 2026

LHLaurini suggested changes Mar 7, 2026

View reviewed changes

Removed recreate fallback | removed sc_screen_maybe_send_vd_resize du…

1f17564

…plication | dpi value arg added | Avoid relaunching on successful resizes

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TinuraD commented Mar 8, 2026

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