Android TV screen mirroring

This page contains the user manual for alfacast application. This complete instruction is useful for people who want to learn how to use alfacast screen mirror app on Android TV OS. To use Android TV screen mirroring feature with alfacast app, you need one or more of the following devices: set-top box, PC (Personal Computer), SBC (Single-Board Computer) like Raspberry Pi, Orange Pi, Banana Pi, or other Android TV compatible device. Your device must have Google Android TV operating system installed.

Alfacast is a screen mirroring app with streaming and viewing features. For the best understanding of this user manual, whenever the Android TV screen mirroring feature is mentioned, it means alfacast app is used to mirror the screen on your Android TV device. You can find more detailed info about alfacast app on Home page. In this user manual we will show you how to use the application and tell you about its main functions.

Main app features

Our Android TV screen mirroring solution is available in two versions. There are two separate versions of alfacast application: regular (alfacast) and extended (alfacast x). Below is a list of the app’s main features:
• Audio and video stream splitter for simultaneous real time streaming of content to multiple devices (up to 8 channels).
• Streaming through all network interface types: Wi-Fi, Ethernet, Bluetooth.
• Screen streamer and viewer within local area network.
• Serverless single channel peer-to-peer streaming technology.
• Serverless multichannel peer-to-many streaming technology.
• Low latency playback. This feature is only available in the extended version of the app.
• Video streamer & viewer up to SD quality and 30 FPS in the regular app version.
• Video streamer & viewer up to 4K Ultra HD quality and 60 FPS in the extended app version.
• Automatic discovery of users on the local network.
• Secure connection with end-to-end AES-128 encryption technology in the regular app version.
• More secure connection with end-to-end AES-256 encryption technology in the extended app version.

The extended version of the application differs from the regular version by its more advanced functionality and capabilities. Everything described here applies to both versions of the application (regular and extended), unless the different behavior of the two versions is explicitly described. More detailed information about the differences between the two versions of the app will be provided later in this user guide.

System requirements

Please note, alfacast app has some requirements to use the Android TV screen mirroring feature:
• Google Android TV operating system with minimum version 6.0.
• Minimum RAM size: 1 GB. Recommended RAM size: 4 GB.
• Minimum CPU: 1.5 GHz quad-core. Recommended CPU: 2.5 GHz octa-core.
• Minimum display resolution 1280×720 pixels.
• Minimum 100 Mbps router. Recommended 1 Gbps 5 GHz Wi-Fi router.
• Supported CPU architectures: AMD64, I386, ARM64, ARMHF.
• Minimum 100 MB disk space.
• Support IPv4 networks only.
• The devices should be connected to the same network.
• The operating system must support the following video codecs: H.264, H.265, VP8, VP9 (hardware accelerated or software).

4K Ultra HD resolution and 60 FPS requirements

Please check the following points to ensure proper support for 4K Ultra HD Android TV screen mirroring on your devices:
• Extended version of application on streamer and viewer side.
• Display with 4K Ultra HD resolution and 60 Hz on streamer side.
• Hardware accelerated H.264, H.265, VP8, VP9 video codec with 4K Ultra HD support.
• The final video stream resolution and refresh rate depends from the maximum resolution and refresh rate of streamer’s display, current video codec configuration and network bandwidth.

The application supports

For a better understanding, we provide the following list of features that our application supports:
• Streaming audio and video from your screen.
• Playback audio and video on the side of the viewer.
• Screen streamer and viewer in one application.
• Audio and video splitter for simultaneously streaming screen content to multiple devices in real time.
• Secure connection with end-to-end encryption.
• Display current streaming information.
• Automatic users discovery in the local area network.
• Android TV screen mirroring with a local network connection only.

The application does not support

To avoid any misunderstandings, we provide the following list of what our application does not support:
• Alfacast is not DLNA™, UPnP™ media render or media server.
• Alfacast is not Apple AirPlay™ receiver or transmitter.
• Alfacast is not Google Chromecast™ receiver or transmitter.
• Alfacast is not Miracast™ receiver or transmitter.
Alfacast is an independent Android TV screen mirroring application based on proprietary streaming technology. As a result, the user has to install alfacast app on both sides: on the streamer and on the viewer devices.

Installing and uninstalling the app

As we mentioned earlier, our Android TV screen mirroring solution is available in two separate app versions. You can find current links to the application on our Downloads page.

Figure 1. Alfacast application icons for Android TV.
The regular (left) and extended (right) versions

Figure 1 shows two app icons. On the left is the icon for the regular version of the “alfacast” app. On the right is the icon for the extended version of the “alfacast x” app. We use our website to distribute app for Android TV OS. Please download the app package directly to your device or use a USB drive to install. After a successful download, you need to install the APK file on your device using any method: through a browser, a file manager, or using the adb command. If the setup app (browser, file manager or adb command) asks for permission to install the APK package, please grant this permission. The application is available in the standard Applications Menu on your Android TV device immediately after successful installation.

The application is removed in the usual manner for an Android TV device. Press and hold the Select button on your remote control, a pop-up menu will appear. After this, select the menu item Remove app or Uninstall app. The application will be removed. You can also use the adb command to uninstall the app.

As we can see, the installation and removal of the application is carried out in the standard way using APK files for a device based on the Android TV OS.

App permissions

The screen mirroring function combines two main features: screen capture and audio capture. Android TV OS requests permission to capture screen and record sound. Please provide all necessary permissions for the application to function properly.

The application also requests permissions in the following cases:
• On selecting a user avatar image from files or a photo library. Permissions to read data from your device’s disk.
• On installing a new version of the app. Permission to install applications.

Later in this user manual, we will examine in more detail all requests for access to the required permissions.

Launching the application

Please tap on the application icon from the Applications Menu and launch it. On launch the application, it will initialize and you will see the window shown in the following figure.

Figure 2. Application splash screen window

After some time, but no more than 90 seconds, the window will show the main controls. Main application window displays the streaming devices found on the local network in a special area, see the following figure.

Figure 3. Main application window

The Main application window contains the following controls:
1 – Display area of discovered network nodes. List of network nodes with streamer functionality.
2 – Current status of the application with activity indicator. The values for this field can be:
• “Initializing…” – the application is in the initialization state.
• “Please wait…” – need to wait for some time.
• “No connection” – there is no network connection on your Android TV device.
• “Discovery…” – the application is ready to work and is discovering all network nodes within the local network.
3 – Options button. Show and hide options menu.
4 – Network node icon with name – “Apple iPhone 17“.
5 – Network node icon with name – “Windows PC“.
6 – Letter logo for the application.
7 – Multichannel streamer mode indicator. This indicator always appears on network nodes with enabled multichannel streaming mode.

In this manual we will use the concept of a network node – this is a network host on which alfacast application is running. Alfacast is both a streaming and a viewing app. Accordingly, each network node may have either the streaming function, the viewing function, or both functions available. Android TV based network nodes support both streaming and viewing functions to provide Android TV screen mirroring functionality.

Navigation in the application is carried out in the standard way, as on any device based on the Android TV OS. Typically, any Android TV remote control has the following main buttons: D-pad (left, right, up, down), Select button in the center of the D-pad and Back button. The Back button on your remote control is used to exit the current window.

After starting, the application immediately tries to detect all network interfaces and start the network node discovery process on each network interface. If no network interfaces are detected, you will see the corresponding application status – “No connection“. In this case, you should provide at least one network interface to start the network node discovery process. Please connect to the Wi-Fi router or use wired connection between router and your Android TV device. If the network interface is present, the application will change its status to – “Discovery…“. The “Discovery…” status means that network discovery is currently in progress. The discovery process is typically quick and takes no more than 30 seconds.

To display the application’s Options menu, click the Options button. After clicking the Options button, the Options window will appear, see the following image.

Figure 4. Options window with menu

The Options menu contains the following controls:
1 – Option icon, option name and short description of the option.
2 – 4K Ultra HD switch button. This button is used to review with the extended version of the application.
3 – Live broadcast button. The button switches the streamer to multichannel streaming mode.
4 – Incoming connection button. The button opens a window with information about the incoming connection.
5 – Settings button. The button opens a window with the application settings.
6 – Instruction button. The button opens a window with instructions for the application.
7 – Update button. The button opens the application update window.
8 – About button. The button opens a window with information about the application.
9 – License key button. The button opens a window with license key information.
10 – Quit button. This button completely terminates the application.
11 – Cancel button. Click this button to close the current window.

Each window associated with application options or settings is accompanied by an icon, the name of the option, and a short description of the option.

The 4K Ultra HD switch button is a reminder that there is a more advanced, extended version of the app. This button is only available in the regular version of the app and is hidden in the extended version. Click this button to see options for switching to the extended version of the application.

The functionality of all buttons is discussed further, please see the following sections of this user manual. A description of how the Live broadcast button works can be found in the Multichannel streamer section of this manual.

Interacting with the Incoming connection button is described in the Incoming connection section. For more information on how the Instruction button and About button works, please refer to the App instruction and About sections. The Settings button is described in the App settings section.

For information on how to update the app and how the Update button works, see the App update section.

Click the License key button if you have one and want to activate it. All necessary steps for activating the license key are described in the App license key activation section.

The display area of discovered network nodes will reflect all detected network nodes with steaming function. In simple terms, these are streamers on your local network. To start the Android TV screen mirroring process, you need to select a network node from this area. Click on any network node to start the playback process.

The Multichannel streamer mode indicator is displayed if the network node has enabled multichannel streaming mode. The multichannel streaming mode is described further in this user manual.

In addition to the current application status, there is a mini application status. This mini status is displayed at the bottom right corner of the Main application window, see the picture below.

Figure 5. App mini status

The application’s mini status graphically explains what is currently happening, making it easier to understand the current status. Mini status is displayed in the following cases:
• The application is initializing.
• An operation is taking place that requires some time to wait.
• There is no network connection.

If you switch to another application or send the application to the background by pressing the Back button on remote control, the application will continue to work in the background: detecting network nodes and waiting for incoming connections. To fully terminate the app, tap the Quit button. This action will shut down all background services and close the app. Only the unused and uninitialized Main application window will remain in the list of recent apps.

Below we provide a description with the minimum set of steps to start streaming or viewing on your Android TV device.

Steps for screen streaming

To start streaming your display with Android TV screen mirroring feature, please follow the steps below on your streaming device:
• Download alfacast application on your devices.
• Connect your devices to the same network.
• Run alfacast application on your devices.
• Now you are ready to accept incoming connection.

Steps for screen viewing

To start viewing remote display with Android TV screen mirroring feature, please follow the steps below on your viewing device:
• Download alfacast application on your devices.
• Connect your devices to the same network.
• Run alfacast application on your devices.
• Wait end of the discovery process (approximately 15-30 seconds).
• Select the required streamer from the list and wait end of the connection process.
• Now you will view remote screen.

App notifications

The application will generate notifications while it is running. Android TV OS does not have native notification support; the app implements this function internally. In the following figure you can see an example of a notification from alfacast application on Android TV OS.

Figure 6. App notifications

The app will send notifications every time the user connects or disconnects, as well as informational, warning, error, and other messages. You cannot block Android TV screen mirroring notifications in the app settings because this option does not exist.

Screen streaming

All Android TV based network nodes already have the streamer option enabled. There is no need to enable streaming in the app separately – this option does not exist. The Android TV screen mirroring streamer feature is always enabled after launching the app.

To establish an incoming connection on the broadcasting device, follow the steps to start streaming and make it active (on top of other application windows). On the viewing device, follow the steps to start viewing.

Screen capture permission must be granted each time a new incoming connection is established. If you do not grant screen capture permission, the connection between the streaming device and the viewing device will be terminated. When establishing an incoming connection, the app will also request permission to record audio. You can deny permission to record audio if you do not want to grant the app access to the Android TV audio subsystem or simply do not want to transmit audio during the broadcast.

On initiating an incoming connection, the app will request permission to access your audio device firstly. You will see the following dialog box.

Figure 7. Start audio streaming dialog box

If you click the Don’t allow button, the audio capture will not be performed and the incoming connection initiation will still continue. Please click the While using the app button or Only this time button if you want the application to capture audio. The request for permission to access audio recording only occurs if you have enabled the Audio captureoption in the app settings (see the App settings section below) and your Android TV device has audio input sources: microphone, line-in audio port, etc.

Once you have chosen the audio capture option, the application will ask for permission to capture screen from your device.

If you are using Android TV 13 or earlier, when you establish an incoming connection, you will see the following dialog box.

Figure 8. Start video streaming dialog box on Android TV 13 and earlier

This dialog box presents two buttons to choose from. Click the Start now button when you are ready to begin broadcasting. If you change your mind or want to cancel the broadcast, click the Cancel button. Please remember that once the broadcast starts, the video image will be captured entirely from the screen of your device.

If you are using Android TV 14 or higher, when you establish an incoming connection, you will see the following dialog box with a list of available sources.

Figure 9. Source selection dialog box on Android TV 14 and higher

In this dialog box, you need to select the screen or app window that will be used by the application as a video capture source. A single app option from the list means that video image capture will be performed only from one application. Entire screen option means that the video image will be captured completely from the entire display of your device. Click the Start button when you are ready to begin broadcasting. If you change your mind or want to cancel the broadcast, click the Cancel button.

All incoming connections and disconnections are notified. There are two streaming modes: single channel (enabled by default) and multichannel mode (see below).

Screen viewing

To start viewing content from a remote screen, you have to select a network node in the Main application window. After selecting a network node please press Select button on your remote control, a Playback window will open, see below.

Figure 10. Playback window

At the connection stage, the Playback window contains the following elements:
1 – Network node name. Remote host alfaname or user name.
2 – Activity indicator.
3 – Current connection status. The values for this field can be:
• “Connecting…” – the process of connecting to a network node is in progress.
• “Buffering…” – the data buffering process is in progress.
• “Disconnecting…” – the process of disconnecting is in progress.
4 – Letter logo for the application.
5 – Network node avatar image.

We have shown above the appearance of the Playback window before the content playback process starts. All of the above elements are static and serve to display the current state of the connection. If the connection cannot be established within one minute, the playback window closes automatically. If the connection is successfully established, controls will become available in the Playback window, see below.

Figure 11. Playback window after successful connection

At the playback stage, the Playback window contains the following controls:
1 – Network node name and remote screen source name.
2 – Currently selected channel.
3 – Current video stream resolution.
4 – Current encryption method.
5 – Network node avatar image.
6 – Content from a remote screen. Playing video content is the main purpose of the Playback window.
7 – Current bitrate of the stream.
8 – Current connection time.
9 – Close button. The button terminates the outgoing connection.
10 – Aspect ratio button. The value of this button changes after each press in a circle. The values for this button can be:
• “Default” – do not change the video aspect ratio, use the same aspect ratio as on the remote screen.
• “Stretch” – the video aspect ratio will be the same as the aspect ratio of the Playback window.
• “16:9” – video aspect ratio 16:9.
• “16:10” – video aspect ratio 16:10.
• “21:9” – video aspect ratio 21:9.
• “1:1” – video aspect ratio 1:1.
• “2:1” – video aspect ratio 2:1.
• “4:3” – video aspect ratio 4:3.
• “5:4” – video aspect ratio 5:4.
• “3:2” – video aspect ratio 3:2.
11 – Scale button. The value of this button changes after each press in a circle. The values for this button can be:
• “No scale” – do not scale the video image.
• “Crop” – an automatic video image cropping mode. It crops the video image based on the window size and aspect ratio of the original video frame: horizontally or vertically.
• “Horizontal” – crops the video image horizontally.
• “Vertical” – crops the video image vertically.
• “100 %” – 100 percent of the original video image.
• “125 %” – 125 percent of the original video image.
• “150 %” – 150 percent of the original video image.
• “200 %” – 200 percent of the original video image.
• “250 %” – 250 percent of the original video image.
• “300 %” – 300 percent of the original video image.
• “400 %” – 400 percent of the original video image.
• “25 %” – 25 percent of the original video image.
• “50 %” – 50 percent of the original video image.
• “75 %” – 75 percent of the original video image.
12 – Picture button. Video image adjustment button. Clicking this button opens a window with elements for adjusting the video image.
13 – PiP mode button. To enter Picture-in-Picture mode.
14 – Get low latency button. This button is used to review with the extended version of the application.

To finish the current playback session, simply click the Close button, this will automatically disconnect you from the streamer. Pressing the Back button on your remote control will perform the same action.

The elements 1, 2, 3, 4, 7, 8 display all the necessary information about the stream. These are: source info, current video resolution, encryption method, current bitrate and connection time. This information is updated once per second.

To ensure a comfortable viewing experience when you use the Android TV screen mirroring feature, we provide the following additional controls in the Playback window.

The Picture button shows additional elements where you can adjust the video image by: brightness, contrast, saturation or hue. Not all video decoders and video renderers support this feature, and this feature is also unavailable on some video resolutions. If this feature is unavailable and you need it, try to change the video decoder in the app settings. Click on this button and the application will show additional elements as shown in the image below.

Figure 12. Picture adjustments elements

The Picture adjustments elements contain the following components:
1 – Buttons for setting the brightness of the video image and the current brightness value.
2 – Buttons for setting the contrast of the video image and the current contrast value.
3 – Buttons for setting the saturation of the video image and the current saturation value.
4 – Buttons for setting the hue of the video image and the current hue value.
5 – Reset button. Reset all video image settings to default values.

You can adjust the video image levels using the buttons. Video picture settings are saved and applied to subsequent playback sessions. To return video picture settings to default values, click the Reset button.

Click the Aspect ratio button to give the video image the shape you need. The Aspect ratio button changes the aspect ratio of the currently playing video frame. To understand how it works, try using it: click several times and you will see the effect on the displayed video image.

To scale the video frame image, use the Scale button. This button allows you to zoom in, zoom out or crop the video image. Similarly, to understand how it works, try using it: click several times and you will see the effect on the displayed video image. Sometimes this feature is limited and you can scale the image by 25, 50, 75 and 100 percent. In this case, the scaling percentage is calculated based on the size of the Playback window, not the size of the original video frame. This limitation is due to the fact that not all video decoders and video renderers support this feature, and it is also limited for some video resolutions. If this feature is limited and you need it, try to change the video decoder in the app settings.

The settings for these two values (scale and aspect ratio) are not stored and are set to default when starting a new video playback session.

The application supports the function of overlaying a video image on top of the graphical user interface: Picture-in-Picture mode. To enter Picture-in-Picture mode, press the PiP mode button. After this, the playback window will be reduced and allow you to view and interact with the user interface. To exit Picture-in-Picture mode, please use your Android TV remote control and tips on the screen. This feature is not available on all Android TV devices. The app automatically checks for this feature when starting a connection. If the feature is not supported, the app will not display the PiP mode button.

The Get low latency button is only available in the regular version of the app and is hidden in the extended version. Click this button to see options for switching to the extended version of the application.

If the streamer is in single channel mode, the main channel is selected for connection. If the streamer is in multichannel mode, you will be prompted to select a channel at the connection establishment stage, see the next window.

Figure 13. Channels list window

The Channels list window contains the following controls:
1 – List of channels to select.
9 – Cancel button. Click this button to close the current window.

First, select the channel you need in the list. Then click by selected item. After this, the connection with your streamer begins in the same way as described earlier. If you want to cancel the connection, simply press Back button on your remote control or press Cancel button.

Multichannel streamer

Android TV screen mirroring can be single channel or multichannel. To start broadcasting in multichannel mode, please press Live broadcast button in the Options menu. The multichannel streaming feature allows you to broadcast content from your Android TV device to multiple devices simultaneously in real time. This function splits audio and video signals and transmits content from the device screen to multiple devices. The type of viewing device does not matter and it can be: a Mac, a Windows PC or Linux PC, an iPhone, an Apple TV, an Android device, etc. The app will open Live broadcast window.

Figure 14. Live broadcast window

The Live broadcast window contains the following controls:
1 – HD multichannel streamer button is a reminder that there is a more advanced, extended version of the app. This button is only available in the regular version of the app and is hidden in the extended version. Click this button to see options for switching to the extended version of the application.
2 – Single channel streamer button. Click this button to change the streamer’s broadcast mode.
3 – Multichannel streamer button. Click this button to change the streamer’s broadcast mode.
4 – Cancel button. Click this button to close the current window.

The Single channel streamer button switches the streamer’s broadcast mode to single channel mode. The Multichannel streamer button switches the streamer’s broadcast mode to multichannel mode. The Cancel button closes the Live broadcast window. Select the required broadcast mode by clicking on the corresponding button. When you select the multichannel broadcast mode, the application will ask for permission to access the audio device and to access the screen capture. We have already described the necessary steps for granting permissions earlier. Grant all necessary permissions to the application and broadcasting in multichannel mode will begin.

Each time you select a new streaming mode, the app updates its description on the left side.

Incoming connection

The application supports displaying information about the current incoming connection. To display information about the current incoming connection, please connect to your Android TV device from another device. You can use any device as a viewing device, such as an iPhone or Android smartphone, TV, Mac, Windows PC or Linux PC. After that click the Incoming connection button in the Options menu to open the Incoming connection window.

Figure 15. Incoming connection window in single channel mode

The Incoming connection window in single channel mode contains the following elements:
1 – Incoming connection icon, title and subtitle. Title displays the name of the remote network node. Subtitle displays incoming connection information:
• Display resolution of the connected network node.
• The encryption method used for this channel.
• Current bitrate on the channel.
• Channel connection time.
• Channel name.
2 – Disconnect button.
3 – Cancel button. Click this button to close the current window.

Title and subtitle elements are static and simply display current broadcast information. The information in these fields is updated once per second. Time in hours, minutes and seconds. You can stop the Android TV screen mirroring feature and finish the incoming connection on your device using the Disconnect button.

The Incoming connection window operates in two modes. The current window mode depends on the streamer’s current state: single channel or multichannel streaming. In multichannel streaming mode, Incoming connection window shows general information about the streamer, see the following figure.

Figure 16. Incoming connection window in total info mode

The Incoming connection window in total info mode contains the following controls:
1 – Incoming connection icon, title and subtitle. Title displays current multichannel streamer mode. Subtitle displays total streaming information for all channels:
• Encoder resolution field. Current video encoder resolution.
• Encryption method field. The values for this field can be: “AES-128” – encryption using the AES-128 method; “AES-128/AES-256” – encryption using the AES-128 and AES-256 methods, for support regular and extended app versions.
• The full bitrate of broadcast stream. Total bitrate for all channels.
• Full broadcast time in multichannel mode. 
• The number of network nodes currently connected to the multichannel streamer.
2 – Disconnect all button. The button to disconnect all connected network nodes.
3 – Display mode selection button. Click this button to display full statistics for all channels.
4 – Channels list.
5 – Cancel button. Click this button to close the current window.

Title and subtitle elements are static and simply display current broadcast information. The information in these fields is updated once per second. Time is displayed in hours, minutes and seconds.

The regular application version has a video resolution limitation for multichannel streaming mode up to SD (768×432) quality. The extended version of the application can broadcast video up to HD (1280×720) quality in multichannel streaming mode.

To disconnect all connected network nodes from all channels, press Disconnect all button.

The regular version of the application always uses the AES-128 encryption method. Accordingly, in the regular version of the application, in multichannel broadcast mode, the encryption field will also be AES-128. The extended version of the application uses two encryption methods: AES-128 and AES-256. The extended version of the app supports AES-128 encryption for compatibility with the regular version of the app. Accordingly, in the extended version of the application, in multichannel broadcast mode, the encryption field will be AES-128/AES-256.

To display information on a specific channel, please select the channel using the Channels list. After selecting a specific channel from the Channels list, the application will display the following menu.

Figure 17. Channel menu

The Channel menu contains the following controls:
1 – Incoming connection icon, title and subtitle. Title displays current multichannel streamer mode. Subtitle displays total streaming information for all channels. We have already described the information in these fields.
2 – Channel button.
3 – Channel statistic button.
4 – Disconnect button.

If you click the Channel statistic button, information on a specific channel will be displayed in the Incoming connection window. To disconnect a client from a channel, click the Disconnect button. In the following figure we show the Incoming connection window in specific channel info mode.

Figure 18. Incoming connection window in specific channel info mode

The Incoming connection window in specific channel info mode contains the following elements:
1 – Incoming connection icon, title and subtitle. Title displays the name of the remote network node. Subtitle displays incoming connection information. We have already described the information in these fields.
2 – Disconnect all button. The button to disconnect all connected network nodes.
3 – Display mode selection button. Click this button to display full statistics for all channels.
4 – Channels list.
5 – Cancel button. Click this button to close the current window.

The appearance of the Incoming connection window in the specific channel mode is the same as in the single channel connection mode. The only difference from single channel mode is the menu in the right sidebar. If you click Display mode selection button, the Incoming connection window will display full statistics for all channels, we have already described this mode above.

App instruction

There is a built-in instruction in the app. It is a short guide to understanding how to use the app. This instruction describes how to use Android TV screen mirroring feature, including the basic steps to start streaming and viewing content from a remote screen. To display the Instruction window, press Instruction button in the Options menu or press on icon with “No streamers” label.

Figure 19. Instruction window

Please read the instruction before using the application. This instruction will cover some of the issues on using the Android TV screen mirroring feature and how to fix them.

App settings

Today it is difficult to imagine the Android TV screen mirroring function without settings. To fine-tune the application to your needs, use the Settings window. Click the Settings button in the Options menu to open the window. The Settings window includes various options: general application settings, streamer application settings and viewer application settings.

Figure 20. Settings window

The Settings window contains the following elements:
1 – Settings icon, setting name and short description of the setting.
2 – Avatar picture option. This option allows you to choose an avatar picture for your Android TV device.
3 – Alfaname option. This option is used to select the name of your network node.
4 – Audio capture option. This option enables or disables audio capture in the application.
5 – Video resolution option. This option provides list of supported resolutions for video display.
6 – Bitrate policy option. This option provides list of network bitrate policies.
7 – Playback method option. This option sets the delay time during playback.
8 – Video decoder option. List of video decoders for user selection.
9 – Cancel button. Click this button to close the current window.

The Settings window is simple to navigate: select the desired option, and the app will display a separate window for that option. Then, select the desired value of the option from the list and press the Select button on your remote control. If you do not want to save the currently selected option value, simply press the Back button on your remote control or press Cancel button. The icon on the left side of each window serves as a tooltip for the current setting. Next to the icon is the name of the option and a short description or the required actions.

An avatar image is an icon of your network node. This icon is displayed on the viewing device in the Main application window (the area of detected devices). In fact, this icon symbolizes your network node or Android TV device, it is used to better perceive the different network nodes by the user. Click on the Avatar picture option, and the app will display the following Avatar selection window.

Figure 21. Avatar selection window

The Avatar selection window contains the following elements:
1 – Avatar picture button.
2 – Default avatar button.
3 – Cancel button. Click this button to close the current window.

Click the Avatar picture button to select an image from your photo library or files on your device. The app will show the standard image selection dialog. Please grant all necessary permissions for the app to access your files on your Android TV device. Supported image formats for avatar selection: BMP, JPEG, and PNG. Click the Default avatar button option to reset the avatar picture to the default image. Once you select it, your new avatar image is automatically applied and sent to all devices running the alfacast app within your local network.

Alfaname is the name of your network node. This field looks like a nickname. This field has certain character requirements. Click this field to edit it and review the requirements.

Figure 22. Alfaname window

The Alfaname window contains the following elements:
1 – Current alfaname value.
2 – Description indicating the length and character limits used for alfaname. Please read it.
3 – Ok button.
4 – Reset button.
5 – Cancel button. Click this button to close the current window.

Click on the Current alfaname value to modify it, the application will display the keyboard for entering text. Enter text using your device’s keyboard and click the Ok button to apply the changes. Click the Reset button if you want to reset alfaname to its default value. Click the Cancel button to close the current window and leave the alfaname value unchanged.

Using the Audio capture option, you can enable or disable audio capture. Click on the Audio capture option to display the following Audio capture window.

Figure 23. Audio capture window

The Audio capture window contains the following elements:
1 – On button. Turn on audio capture.
2 – Off button. Turn off audio capture.
3 – Cancel button. Click this button to close the current window.

Select the option you need by clicking on the corresponding button. If you disable audio capture, the app will only capture the device’s screen without audio support. Please note: screen capture cannot be disabled.

App supports audio capture only from default audio device: from the microphone or external USB audio device. There is not legal software way to capture system sound on Android TV device for third party apps, this is Google Android TV limitation. If you need to capture system audio on Android TV, this is possible using the method described later in this user manual: see System audio capture section.

It is also possible to select the required video resolution of the encoder using the Video resolution option. Click on the Video resolution option to display the following Video resolution window.

Figure 24. Video resolution window

The Video resolution window contains the following elements:
1 – Automatic best option.
2 – List of downscaled video display resolutions.
3 – Cancel button. Click this button to close the current window.

This list includes video resolutions up to the maximum physical resolution of the display. If you select Automatic best option, the application will automatically determine the best resolution from all available ones. In fact, the exact resolution of the frame buffer (this buffer is used for image capture) cannot be determined in advance, so the resolutions in the list are presented as names: Maximum resolution, Super resolution, High resolution, Medium resolution, Classic resolution, Low resolution. The regular version of the application limits this value to the minimum resolution with 30 Hz frequency. The extended version of the application supports resolution up to 4k Ultra HD (3840×2160) with a frequency of 60 Hz.

Another useful feature is bitrate policy. Click on the Bitrate policy option to display the following Bitrate policy window.

Figure 25. Bitrate policy window

The Bitrate policy window contains the following elements:
1 – Adaptive bitrate policy.
2 – Constant bitrate policy.
3 – Cancel button. Click this button to close the current window.

The bitrate policy can be adaptive or constant. Adaptive bitrate policy – adjusts the bitrate to network conditions. With the Adaptive bitrate policy enabled, the bitrate will change dynamically depending on the maximum network bandwidth.Constant bitrate policy – a consistent, high bitrate throughout the entire broadcast. Constant bitrate policy is useful when you are confident in your network’s bandwidth and always want excellent video quality. This option has an effect only for single channel broadcasting mode and does not affect multichannel mode. The multichannel streamer always operates with an Adaptive bitrate policy. The regular version of the application always uses the Adaptive bitrate policy.

The Playback method option can be used to reduce or increase the delay time between the streaming device and the viewer. Click on the Playback method option to display the following Playback method window.

Figure 26. Playback method window

The Playback method window contains the following elements:
1 – No buffer delay. Minimum latency without buffering.
2 – List of playback delay values.
3 – Cancel button. Click this button to close the current window.

The delay time is adjustable from 0 (No buffer) to 3000 milliseconds (3 seconds). This is an approximate delay time. We recommend using a 500 milliseconds buffer. The No buffer option provides minimal delay between the broadcasting and viewing devices, but synchronization problems and other audio and video artifacts may appear. In the regular version of the application, this option is always set to 3000 milliseconds.

The Video decoder option displays the video decoders supported by the application and the Android TV OS. Click on theVideo decoder option to display the following Video decoder window.

Figure 27. Video decoder window

The Playback method window contains the following elements:
1 – Automatic best option.
2 – List of video decoders.
3 – Cancel button. Click this button to close the current window.

You can select any video decoder from the list and evaluate the image quality and bitrate of the stream. If you select a video decoder that is supported by your Android TV device, but there is no similar video encoder on the streamer side, the application on the streamer side will automatically select the video encoder. In any case, the application automatically selects a video encoder on the streamer’s side. The regular version of the application limits this value to SD quality (768×768) with a frequency of 30 Hz. The extended version of the application allows viewing content up to 4k Ultra HD (3840×2160) quality with a frequency of 60 Hz.

System audio capture

As we mentioned earlier, there is no legal software way to capture system audio for third-party apps on Android TV devices. There is one way to do this: make or purchase a loop device to capture sound through a microphone: Audio Loopback Dongle (https://source.android.com/docs/core/audio/latency/loopback). The basic idea is this: you route the audio from your playback device to your capture device (the audio from your headphones to your microphone). For these purposes, you can use an external USB sound card (loop from audio speakers to line-in port). The main goal is to loop the playback device into the recording device. Our application already supports capturing sound from a microphone or an external USB sound card.

App update

The app supports automatic update checking. It periodically checks for new app version and notifies the user. Please update the application regularly as soon as possible. This will reduce software errors and make the Android TV screen mirroring function more optimal in terms of performance and OS resources. You can also check for app updates manually by clicking the Update button in the Options menu. After clicking the button, the application will open the Update window shown in the following figure.

Figure 28. Update window. Checking for updates

The Update window contains the following elements:
1 – Update icon, title and subtitle. Title and subtitle display useful information about the update.
2 – Action button. Multifunctional button, its purpose changes during the update process. It can take the following names: Cancel button, Download button, Update button – depending on the current update status.

Please wait some time to establish a connection with the update server. You can interrupt the checking at any time by clicking the Cancel button. If the current version is updated, the application will notify you about it.

Figure 29. Update window. The current app version is actual

Click the Cancel button to close the Update window. If a new version of the application is detected, the Update window will notify you as follows.

Figure 30. Update window. There is new app version

Click the Download button if you want to download the update or press Back button on your remote control if you do not want to download and install the new app version. If you click the Back button, the Update window will close. If you click the Download button, the application will ask for permission to install.

Figure 31. App requests install permissions

Please grant the app install access otherwise you will not be able to update the app. Move the slider as shown in the figure below and press the Back button on your remote control. After that, click on the Download button again, the update file will begin downloading from the server.

Figure 32. Update window. Downloading update

Please wait until the update file is downloaded completely. If you want cancel the download please click the Cancel button. The Update window displays the progress of the update file download. After the update file has fully downloaded, the application will ask you again if you want to install the new app version.

If you agree to run the application update, click the Update button, otherwise click the Back button on your remote control. If you clicked Back button, the Update window will close. If you clicked the Update button, the Android TV OS will provide additional setup dialog box.

Figure 33. Android TV OS install app update dialog box

Please click the Install button to begin installing the update. If you decide to cancel the app update, click the Cancel button. Once the update starts, the application will be closed and the Android TV OS will update the application. After the application has been successfully updated, you will need to reopen it yourself.

About

Information about the program can be found in the About window. To display the About window, press About buttonin the Options menu. We provide the following information about our Android TV screen mirroring app: version, information about our project and website address. We also provide information about the open source libraries used, authors, and the text of the open source licenses.

Figure 34. About window

Please read the program information if you are interested in details about our software.

App license key activation

To take full benefits of the extended version of the app, you must have an activation key. After installing the extended version, you will be able to enjoy a trial period. During this trial, you will be able to evaluate all the app’s features. You can purchase an activation key on our website. After purchasing, please enter the key into the app. To begin activation, click the License key button in the Options menu. You will see the window shown in the following figure.

Figure 35. License window

The License window contains the following controls:
1 – Activation icon, title and subtitle. Title and subtitle display useful information about the activation.
2 – Action button. Multifunctional button, its purpose changes during the update process. It can take the following names: Activate button, Ok button, Cancel button – depending on the current activation status.
3 – License key button. Please provide a valid license key in the following format: xxxx-xxxx-xxxx-xxxx-xxxx(lowercase).
4 – Visit the store button. Click this button to open a web browser to the store page on our website.
5 – Cancel button. Click this button to close the current window.

After successfully purchasing a license key on the website, it must be activated. Click on the License key button to open the License key dialog box.

Figure 36. License key dialog box

The License key window contains the following controls:
1 – License key entry field.
2 – Description about license key. Please read it.
3 – Ok button.
4 – Reset button.
5 – Cancel button. Click this button to close the current window.

Click on the License key entry field. Enter your license key using the keyboard. Then click the Ok button. The License key window will close. Click the Reset button if you want to reset license key text value. Click the Cancel button to close the current window without applying the license key. If you entered the correct license key, the License key buttonsubtitle in the License window will be filled with your key. Next, click on the Activate button. At the beginning of the activation process, the application will create the following dialog box with information about the activation.

Figure 37. License key activation info

Please read the information provided in the dialog box to the end. If you agree to the terms, click the Yes button to begin the license key activation process. If you do not agree with the terms of license key activation, click the No button to finish and exit from the activation process. During the activation process, the License window will display the following elements, see the figure below.

Figure 38. License window during activation process

The license key activation process takes some time, please wait until it is complete. Typically, it takes no more than 30 seconds. If you want to cancel the activation process, click the Cancel button. If the key activation process failed, carefully review the error message. If you can fix the activation error, then fix it yourself; if not, then contact the developer. After successful activation of the license key, the application will inform you about it, see the next window.

Figure 39. License window after successful activation

At this point, the license key activation process is complete. Click Ok button to exit the License window and start using the full version of the application.

Conclusion

We have fully described and reviewed alfacast application. Overall, the application is intuitive and easy to use. Alfacast app for Android TV screen mirroring offers a wide range of features and functionality. There is a real-time streaming function. There is audio and video playback function. The connection is encrypted and secure. Each network node can broadcast its desktop content to multiple devices simultaneously. The extended version of the application has high quality video streaming feature up to 4K Ultra HD, it has low latency playback, more secure connection and other benefits. If you want to learn more about the application, you can watch the video on our YouTube channel.