Unable to use --no-display --turn-screen-off at the same time

[mukheshpugal]

• I have read the FAQ.
• I have searched in existing issues.

Environment

• OS: Ubuntu 18.04
• scrcpy version: 1.18
• installation method: linux-brew
• device model: ONEPLUS A6003
• Android version: 11

Describe the bug

I'm trying to stream the video to a v4l2 loopback device. Everything seems to work fine except when using the options --no-display --turn-screen-off at the same. There is no windowed display as expected, however the phone screen does not get turned off.

On using the options one at a time everything works as expected.

I've tried it with another device (PANASONIC ELUGA Turbo (Android 5.1)). Still the same issue persists.

[rom1v]

Indeed, the controller is not started if there is no display:

scrcpy/app/src/scrcpy.c

Lines 346 to 357 in ab12b6c

	if (options->display) {
	if (options->control) {
	if (!controller_init(&s->controller, s->server.control_socket)) {
	goto end;
	}
	controller_initialized = true;
	if (!controller_start(&s->controller)) {
	goto end;
	}
	controller_started = true;
	}

The reason was that initially controls could only be initiated by input events (captured by the window). This might be changed now.

[mukheshpugal]

Will I be able to run an adb command from another terminal to turn the screen off? That is without disturbing the v4l2 stream. If I can, please let me know of the command.

[rom1v]

Unfortunately, in the current state, no.

[mukheshpugal]

Alright. Looking forward for the fix! Thanks.

[rom1v]

Out of curiosity, what is the use case?

If your device screen is off and you pass --no-display, you can't control it at all?

[mukheshpugal]

Well, there's this game called Mortal Kombat mobile and in the game, you can recieve extra coins by logging in every hour and completing a few tasks. I want to automate it so that I can run it through the night. Obviously I don't want the phone display to be on all the time.

Since I'll be running the controlling program headlessly on an rpi, I don't want a window.

With the screen off, I am able to sent inputs using the adb shell input command independently.

[mukheshpugal]

I just realised that the backlight is still on on my non amoled device while using --turn-screen-off. Is this normal?

[rom1v]

Fixed on dev.

I just realised that the backlight is still on on my non amoled device while using --turn-screen-off. Is this normal?

Scrcpy just request the device to change the "power mode", how the action is done is device-dependent.

[mukheshpugal]

Great!