How to make a callout on Android: displaying the screen on a computer

Modern users are often faced with the need to broadcast images from a mobile device to a large monitor or computer screen. This process, which in the technical environment is often called “callout” or screencasting, allows you to demonstrate presentations, record game streams, or simply control your smartphone with a keyboard and mouse. Image output may be required both for entertainment and for professional debugging of applications by developers.

There are many methods for implementing this tasks, from built-in operating system functions to third-party utilities with advanced functionality. The choice of a specific method depends on your goals: do you need minimal latency for games or high picture quality for videos. In this article we will look in detail at how to make a callout on Android using various tools and data transfer protocols.

It is worth noting right away that the quality of the broadcast directly depends on the processor power of your device and the bandwidth of the communication channel. Wireless methods are convenient but can suffer from lag, while a wired connection provides stability. Let's move on to the practical part and look at the settings required to get started.

Preparing the device and enabling developer mode

Before you start setting up the broadcast, you need to activate the hidden capabilities of the system. By default, many advanced features, including USB debugging, are disabled. This is done for security purposes to prevent unauthorized access to device data.

First, you will need to go to the section Settings and find the item About phone. Here you need to Locate the string Build number (or MIUI version, Shell depending on the manufacturer). Click on this line quickly 7 times in a row. The system will ask for your password or pattern, after which a notification will appear that you have become a developer.

Now return to the main settings menu. A new item will appear in the System or Advanced section. Go into it and find the switch For developers. Go into it and find the switch USB debugging. Activate it. It is this parameter that allows the computer to send commands to the phone and receive a video stream.

⚠️ Attention: Never enable USB debugging when connected to public chargers stations at airports or shopping centers. This may lead to theft of personal data through vulnerabilities in the ADB protocol.

After enabling debugging, connect your smartphone to the computer with a cable. The device screen will ask you to allow debugging from this computer. Be sure to check the box Always allow from this computer and click OK. Without this confirmation, the software on the PC will not be able to establish a connection.

Using built-in wireless broadcast functions

Most modern Android smartphones have built-in support for the Miracast standard or similar protocols. This method allows you to make a callout wirelessly using a Wi-Fi network. The function may be called differently depending on the brand: Smart View for Samsung, Broadcast for Xiaomi or Projection for stock Android.

To launch process, lower the notification shade and find the corresponding icon. Click on it and the phone will start searching for available displays on your network. On a computer with Windows 10 or 11, you need to open the application Connection (Connect) so that the device becomes visible to the smartphone.

After selecting your PC in the list on the phone, the connection will begin to be established. The image will appear on the monitor almost instantly, but the delay may range from 100 to 300 milliseconds. This makes the method suitable for watching videos or presentations, but not for dynamic games.

• 📶 Advantages: no wires, easy connection, works on most TVs and PCs.
• 📉 Disadvantages: noticeable input lag, dependence on the quality of the Wi-Fi signal, increased battery consumption.
• ⚙️ Requirements: both devices must be on the same Wi-Fi network (preferably 5 GHz).

If you are using a TV instead of a monitor, the process is even simpler: just select the signal source Screen Mirroring on the TV remote control. The picture quality will automatically adjust to the capabilities of the receiver. In some cases, the resolution may be limited by the format 1280×720 to save traffic.

Professional debugging via Scrcpy and ADB

For users who require maximum performance and minimal latency, the best solution would be the utility Scrcpy. This is an open source application that broadcasts the device's screen via the ADB (Android Debug Bridge) protocol. It does not require installing additional applications on the phone itself and works incredibly fast.

To get started, you need to download the archive with the Scrcpy app from the official GitHub repository and unpack it to your computer. Also make sure that ADB drivers are installed on your PC. After connecting the phone via USB, run the file scrcpy.exe. A window with an image of the smartphone screen will open automatically.

adb devices
scrcpy --bit-rate 8M --max-size 1920

The above command allows you to set the bitrate and maximum resolution manually. By default, the app uses settings that are optimal for the balance between quality and processor load. You can control your phone with the mouse and keyboard, copy text via the clipboard, and even install APK files by dragging and dropping.

Parameter	Description	Recommended value
--bit-rate	Video bitrate (Mbit/s)	8M for high definition
--max-size	Maximum width/height	1920 for Full HD
--record	Record video to file	screen.mp4
--no-audio	Mute audio	false (enabled)

One of the main advantages of Scrcpy is support for audio transmission on Android 11 and higher. Previously, sound could only be obtained through third-party add-ons, but now it is transmitted natively. This makes the tool a universal solution for streamers and testers.

Scrcpy secret hotkeys

Press Ctrl+G to capture the mouse cursor inside the emulation window. Use Ctrl+arrows to change the volume, and double-click on the black area to minimize the notification panel.

Third-party applications for gamers and bloggers

If standard tools and console utilities seem too complicated, specialized applications with a graphical interface come to the rescue. apps like Vysor, AirDroid or ApowerMirror offer a convenient interface for setting up callouts. They often have paid versions with advanced features, such as 4K recording or watermark removal.

Installation of such applications usually occurs in two stages: the client on the computer and the companion application on the smartphone. After launch, the app itself will check for access rights and offer to enable debugging if it is disabled. The interface is intuitive: one button to start broadcasting.

However, it is worth considering that free versions of such apps often have limitations. For example, the resolution can be reduced to 480p, and the picture quality is degraded due to strong compression. For professional activities this may be critical, but for everyday tasks it is quite sufficient.

⚠️ Attention: When using cloud versions of applications (as in AirDroid), your video stream can pass through third-party servers. For confidential information, use only local network (LAN) mode.

Some applications allow you to create virtual joysticks on the screen to control games. This turns the PC into a gaming powerhouse where the phone acts as a console. The function is especially popular among fans of PUBG Mobile and Call of Duty Mobile.

Hardware solutions: capture cards and HDMI

The most reliable way to make a callout, independent of the software and load on the phone's processor, is to use hardware adapters. If your device supports video output via the USB-C port (technology MHL or DisplayPort Alt Mode), you can connect it directly to a monitor or capture card.

For this you will need an adapter USB-C to HDMI. By connecting it to your phone and monitor, you get screen mirroring with zero latency. This is ideal for watching high-definition movies or demonstrating heavy applications. The picture will be clear, without compression artifacts.

If you want to record the screen or output it to OBS Studio on a computer, the signal from the adapter is sent to a capture card (for example, Elgato or cheap Chinese analogues on a UVC chip). The computer sees the phone as a regular webcam, which allows you to overlay graphics and stream.

It is important to check the specifications of your smartphone before purchasing an adapter. Budget models often have a USB 2.0 port, which does not support video signal transmission, even if the physical connector is type C. In this case, software methods remain the only option.

Solving common problems and errors

When setting up callouts, users often encounter typical problems. The most common one is that the computer does not see the device, despite the cable being connected. This is usually solved by replacing the USB port on the motherboard (use the ports on the back of the system unit) or installing universal Google USB Drivers.

Another problem is a black screen when sound is running in Scrcpy. This may be due to DRM (Digital Rights Management) protection. Apps like Netflix or banking clients block screen recording and broadcasting for security purposes. In these windows you will see only a black field.

If the broadcast is slow or breaks up into squares, try lowering the resolution in the app settings or switching to a wired connection. The wireless channel may be overloaded by neighboring networks. Also make sure that the power saving mode is not enabled on the phone, which limits the operation of the processor.

• 🔌 "Device unauthorized" error: reconnect the cable and confirm the RSA key fingerprint on the phone screen.
• 🎨 Color distortion: check the color settings in the graphics driver of the PC video card.
• 🔊 No sound on Android 10 and below: use a third-party module SNDcpy or upgrade to Android 11+.

Sometimes a simple restart of the ADB service helps. To do this, in the command line you need to enter the command adb kill-server, and then adb start-server. This resets stuck connections and allows the system to re-detect the device.

Why doesn't wireless debugging work on Android 11?

For wireless debugging to work on new versions of Android, you must first connect your phone via cable once to pair. After this, the “Wireless Debugging” option will appear in the developer menu, where you need to click “Pair by code.” Without a primary cable connection, the function is not activated.

Is it possible to output sound to a PC when using Miracast?

Yes, the Miracast standard supports audio transmission. However, in Windows sound settings, you need to make sure that your smartphone or "Wireless Display" is selected as the default playback device. Sometimes Wi-Fi adapter drivers do not support audio streaming, then the sound will remain on the phone.

Is it safe to leave USB debugging enabled all the time?

Always-on debugging reduces the security of the device. If the phone is lost or stolen, an attacker with physical access to the computer can gain full rights to the file system. It is recommended to enable the function only for the duration of the work session.

What delay is considered normal for games?

For a comfortable game, the delay (input lag) should not exceed 50-70 ms. Wireless methods usually result in 150-300ms, which makes shooters unplayable. Wired methods (Scrcpy, HDMI) provide a latency of about 30-40 ms, which is quite acceptable for most genres.

Does screen bubble work if the phone screen is off?

In most cases, the phone screen must be on for the image to be transmitted. However, some specialized utilities and “kiosk mode” functions allow you to broadcast content when the device’s display is off, saving battery power.