Movie folder: In the Mac App Store versions of JustStream subtitles and external audio tracks may not be loaded automatically because the app has restricted access to the file system. Choose the root folder where most of your video files are saved. It helps JustStream get access to all files of this folder and automatically load external subtitle files and audio tracks (if any) during playback.

Note: This option is available in the Mac App Store versions only.

Autoload subtitles: Choose which subtitle files JustStream will load:

  • all with movie name;

  • same name as movie;

  • all in directory.

Autoload external audio tracks: Choose which external audio tracks JustStream will load:

  • all with movie name;

  • same name as movie;

  • all in directory.

Resume playing from where playback was stopped: When enabled, your media files will start playing from the point they were stopped last time.

Send anonymous usage statistics to Electronic Team, Inc.: Help improve JustStream by sending the information about the app usage to Electronic Team, Inc. (no personal information is collected).

Automatically check for updates: Allow JustStream to check for updates automatically.


Audio: Displays whether system audio will be captured during screen mirroring.

Capture options

Capture cursor: Specifies whether the mouse cursor appears in the captured output.

Capture mouse clicks: Specifies whether the mouse clicks appear highlighted in the captured output (a circle is drawn around the mouse for the duration of the click).

Scale picture to fit the TV screen: Most Mac primary displays have a width-to-height ratio equal to 1.6, while most TVs have a 16:9 aspect ratio (~1.78). Such mismatch leaves black borders when casting your display as it is. This option allows you to adapt the Mac screen to 16:9.

Resolution: Choose the output quality:

  • Auto;
  • Match screen resolution;
  • Full HD (1080p);
  • HD (720p).

Note: Restart mirroring to apply changes.


Transcoding and delivery settings

If the video/audio format is illegible, JustStream will convert it into a proper format by using its transcoding feature on the fly.

Audio transcoding needs very low to moderate CPU usage on a Mac running JustStream. Video transcoding (including subtitles) requires high to extreme CPU usage.

The settings below let you change the video quality and bitrate during transcoding (converting) media.


Choose the maximum resolution from the drop-down list to get the best quality for your video file.

Note: When converting a video, JustStream will never increase the original resolution of a file.

Tip: If you experience buffering, try lowering the video quality. If the quality is too poor (and you’ve got a high-end computer) try raising the bitrate.


Change the video bitrate. A higher bitrate will make the image quality higher in the video output. A too high or too low bitrate can cause poor image quality or buffering.

If your bandwidth is limited, reduce both the resolution and the bitrate accordingly.

Note: Full HD 1080p and 4K streams need significantly more encoding processing power and bandwidth. Use these resolutions only when you are sure that you have enough resources to successfully encode and send videos with no quality loss. Higher resolutions and bitrates without sufficient encoding resources or bandwidth can cause poor image quality and interrupted or corrupted viewing.


Set the buffer length in seconds. The minimum value is 90 seconds and the maximum is 1200 seconds.

This setting allows you to optimize the streaming experience.

Buffering accumulates media segments for serving to make streaming smooth and without interruptions. The larger the buffer length you set, the more time your playback will need to start.


  1. Increase the buffering time if you have a slow network connection or your Mac can’t do a video transcoding in real-time and streaming pauses frequently while playing.
  2. If you don’t have playback problems, try to reduce the value. The playback will begin sooner after clicking “Start Streaming”. You can try to change different values to optimize your playback.

Hardware-accelerated encoding: when enabled, a hardware-accelerated encoder will be used to convert video to H.264, which uses GPU to encode fast and improve performance. This reduces CPU usage during playback.

Downmix audio to stereo: This option allows streaming video with multi-channel audio to devices that do not support it.

Tip: Enable this option if there is no sound while streaming video.

Native playback

This option lets you enable/disable the native playback of your files.

JustStream app can play your files natively if they meet the device's native player capabilities. It means that the files should:

  • be stored in a compatible file container;
  • be encoded in a compatible bitrate;
  • be encoded with compatible codecs;
  • have a compatible resolution.

Consult your device's documentation to ensure that it meets these requirements.

When a media item is played natively, the file is sent directly to the device without being changed. Native playback requires almost no CPU usage on a Mac running JustStream.

Tip: It’s better to keep this option enabled because it improves the quality of the video image and reduces CPU usage.

Note: In case you disable the native playback, every media file will be transcoded. This can be useful if there are problems with video playback on particular devices.


Chromecast Font: applies the font of subtitles when streaming them to Chromecast devices.

Note: Chromecast devices have a limited set of fonts for subtitles.

Size: change the size of subtitles.

Color: change the font, border, and background color of subtitles.

Note: these settings are applied only when the "Burn subtitles into video" option in the Subtitles tab is disabled.


Search for devices on: If your Mac is connected to several different networks (for example, via Wi-Fi to one network, and via Ethernet to another), you need to choose the network where a search for devices should be performed.

Send “stop” before playing: Some TV sets require a STOP command before playing files, otherwise, they won’t work. It's better to uncheck this box if your TV works properly.


Enable subtitles

If checked, subtitles that are stored in external files or embedded in videos will be included in playback.

Enable extraction of embedded text-based subtitles

A video file of a certain format (e.g. MKV) may have one or several embedded subtitle tracks. If checked, JustStream will try to extract text-based subtitles from the video file into subtitle files and deliver them to the receiving device.

This may take a long time for large files or files on remote drives.

Tip: Disable this option if your Smart TV supports embedded subtitles.

Encoding: JustStream identifies the encoding of subtitles automatically. If encoding is not autodetected, the indicated encoding will be used.

Burn subtitles into video: if enabled, subtitles are drawn over the video frames during on-the-fly transcoding. Burning subtitles into videos lets you watch subtitles on devices that are not capable of displaying external or embedded subtitles.

When overlaying subtitles on a video, you can select the font and size of the subtitles, the color of the text, outline, and background of the subtitles, as well as change the style of ASS subtitles.

Apply these settings to ASS files: if checked, the predefined subtitles formatting and style of .ass files will be ignored so that JustStream style could be applied to subtitles.