1. Why the app doesn’t find my device that I want to stream to?

Please make sure that your receiving device (e.g. Samsung TV, LG TV, Chromecast, etc.) and Mac are connected to the same Wi-Fi network. If you have problems discovering your device, here are some troubleshooting tips that can help:

  1. Restart your router. Just unplug it from the power supply, wait 30 seconds, then plug it back in.

  2. Restart your device. Unplug it from the power supply for a full reboot. Please disconnect it from its power supply for at least 1 minute, then put it back in. Powering off your TV is NOT ENOUGH to do a full reboot.

  3. Make sure that your Mac and the receiving device are connected to the same Wi-Fi network, same router, and the same router channel. Some routers (dual band) have both a 2.4Ghz and a 5Ghz wireless network. So it’s important not to have your Mac on 5Ghz and the receiving device on 2.4Ghz or the other way around.

  4. If your Mac is connected to several different networks (for example, via Wi-Fi - to one network, and via Ethernet - to another), go to Preferences > DLNA tab and select the network where a search for devices should be performed.  

  5. Use an AC or N router. New routers support Wi-Fi AC & N, whereas old ones might only support Wi-Fi B and/or G. Wi-Fi B & G are not really up to modern networking tasks, so please use an AC or N router.

  6. In many cases, the firewall on your computer may prevent the devices from communicating. Apple has provided instructions for allowing applications through the firewall. Consult the information here: http://support.apple.com/kb/ht1810

  7. With antivirus products, such as Norton, you may have to follow a similar process. It’s essential as antivirus apps often have their own firewalls and network traffic blockers. It’s easier to fully disable these apps while testing for connection, then re-enable and make adjustments later.

  8. The firewall on your router may prevent communication. Check out that your router is configured properly. Most home networks don’t need any special configuration, but sometimes you may need to change a setting or two on your router to allow media streaming on your network.

Note: There is a setting “LG Connect Apps” on your WebOS based LG TV that controls whether the device can be discovered. Please set the “LG Connect Apps” option on your LG TV to “ON”, and keep it that way. On older models of LG TVs, there is a similar setting that might be called DLNA DMR (Digital Media Renderer). Please set it to “ON” and keep it that way.

2. I have multiple subnets in my home network. Would media streaming work for me?

It might not work in such circumstances. Your Mac might be able to find the devices to which you want to stream on a different subnet, but the receiving device might not be able to get the video/audio stream from your Mac. In that case, please always make sure that your Mac and the receiving device are connected to the same subnet.

3. I have a firewall on my Mac. Should I adjust specific settings for it?

Yes, in the firewall settings, you should allow for incoming connections for the app. To make this change, go to System Preferences > Security & Privacy > Firewall:

Click on the lock to make changes and select Firewall Options.

Do not select “Block all incoming connections”. If you do this, the receiving device won’t be able to reach your Mac and start media streaming. Select “Allow incoming connections” for JustStream.

4. Why the media streaming doesn’t work for me? What settings should I have on my router?

To stream media files your Mac should be able to connect to the device you want to stream to and communicate with it. The receiving device should be able to communicate with your Mac, too. Some router settings may prevent communication and lead to media streaming failure.

Check your router settings for the following points:

  1. Make sure that you have the latest firmware update for your router on the manufacturer’s website.
  2. If you have a dual-band router, use separate names for the 2.4GHz and 5Ghz networks. Check out that both the Mac and the TV are connected to the same network. E.g. if your Mac computer is on 2.4Ghz, the receiving device should also be on 2.4Ghz.
  3. In case your router has MAC address filtering, add the MAC address of the receiving device to the list of filtered devices.
  4. Disable Access Point/Client isolation on your router.
  5. Disable IGMP Proxy on your router.
  6. Disable any Virtual Private Networks (VPNs) or proxy servers on your router and/or computer.
  7. Enable UPnP/Multicast on your router.
  8. Enable IGMP on your router.

5. My TV displays the error "Format not supported". What should I do?

In most cases, this error means that your TV does not support the file format natively.

Try to uncheck the “Use native playback when supported” option on the Streaming tab in JustStream Preferences and restart the playback.

Disabling this option allows JustStream to transcode the file on the fly when streaming.

6. When is the native playback possible on my device without any need to be transcoded?

JustStream app can play your files natively on any device if they fit the device’s native player capabilities. 

Your 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 the documentation for your device to make sure that it meets these requirements.

When JustStream reproduces your video natively, it sends your file directly to the device without changing it. Native playback requires almost no CPU usage.

JustStream allows you to enable/disable the native playback on the Streaming tab in JustStream preferences. 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.

7. When is transcoding required?

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

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

8. Why is transcoding too slow?

The transcoding speed depends on the speed of the CPU of the computer that runs JustStream. The faster the CPU, the faster it can transcode. If your computer is several years old, it may simply not be powerful enough to perform the transcoding with the speed you need.

9. Why do I have frequent buffering during playback?

When you stream a video, the receiving device downloads it in small pieces and only then plays these pieces back to you. This process is called buffering. If your Mac running JustStream is not powerful enough to support a video transcoding in real-time, streaming can look choppy. That is why JustStream takes on some part of buffering. With its pre-buffering feature, JustStream gathers file segments to make streaming smooth and without interruptions. 

The re-buffering is also possible if the player runs out of segments, but to continue streaming enough media segments should be gathered.

By default, JustStream has automatic buffering, but you can adjust the number of seconds that the app buffers before playing your content. For this, go to Preferences > Streaming tab. Type the number of seconds you’d like the app to buffer in the “Buffer” text box. The default value is 100, but you can change that if you’d like to increase or decrease the buffering time.


  1. Increase the buffering time if you have a slow network connection and your streaming videos or music 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.

10. Why does the playback stutter?

The quality of media streaming may depend on a few main factors:

  • the quality of your home network. The wired connection is always preferable, especially for streaming HD videos. If you use a wireless network, make sure that the signal is strong, the device is located within a reasonable distance from the router, and the Wi-Fi channel you are using is being used by as few people as possible. A high-quality router is always a good investment, especially if it’s designed for high bitrate operation;
  • the power of the computer running JustStream. It concerns transcoded videos that may require considerable resources from your Mac, especially CPU, to be played smoothly;
  • the way the file has been encoded. Some top quality video files may be ‘too heavy’ for your device with its limited processing power and memory. There might be stuttering in fast moving scenes.

11. Does JustStream support subtitles when streaming to devices?

Yes, it does. JustStream uses 3 methods to stream subtitles:

1. External subtitles are stored in separate files and are streamed directly to the receiving device. It’s the most effective way to cast subtitles for a video since it does not require any processing from JustStream.

Note: Unfortunately, some devices don’t support external subtitles, e.g. Sony Bravia TVs. In this case, in order for subtitles to be shown, they need to be burned into the video (see paragraph 3 below).

2. Embedded subtitles are stored inside the video file/video container as streams. The same way video and audio streams are stored inside video files. If the file is 100% compatible with the receiving device, JustStream sends it as-is to the device.

Devices usually list all the embedded subtitles on the screen, so you can choose the proper ones by using the device’s remote control. You can also choose the preferred subtitle language.

Note: Support for displaying embedded subtitles depends on the device model. The most popular video container with embedded subtitle support is Matroska (MKV). WD, Samsung, and Panasonic devices display embedded subtitles in MKV video files.

Some devices don’t support embedded subtitles. E.g. Chromecast devices can display only subtitles out-of-the-box delivered as a text file. JustStream has to extract such text-based subtitles from the video file before streaming.

Note: It may take a long time for large files or files on remote drives.

3. Burning subtitles are drawn (or superimposed) over the video frames in the video.

JustStream burns image-based subtitles (DVD VOBSUBs, Bluray PGS) into the video during on-the-fly transcoding. In order to do the same with text subtitles, you need to turn on the option “Burn subtitles into video” that’s found in Preferences > Subtitles. This can be used in situations where the receiving device doesn’t support both external and embedded subtitles.

12. Does JustStream support multiple audio tracks when streaming to devices?

Yes, both internal and external.

Some Smart TVs support internal audio tracks and you can switch to the desired audio track in the playback settings directly on the device.

Note: Switching to another audio track in JustStream will trigger the playback restart with on-the-fly transcoding of the media.

13. Why seeking doesn’t work in some files?

Some functions may not work if there is an error in the content or container. If the Index Table has an error, the Seek (Jump) function will not work.

14. Can I stream 4K content?

4K videos are usually encoded in HEVC/h265 which is more difficult to transcode on the CPU. That’s why you will need a modern Mac and a good network to stream 4K movies.

4K content usually has a higher bitrate than the other content, so make sure that you have enough bandwidth to stream 4K files in their native resolution. If you need to transcode the video to 1080p there is no use in 4K.

Make sure that your receiving device can natively play 4K format without transcoding it. If you need to transcode the video, any quality you had will be instantly lost. Native playback of 1080p/720p will be a better solution than transcoding 4K.

15. I started streaming audio / video to TV, but the playback on TV won’t start. What to do?

  1. Check Firewall settings. In many cases, the firewall on your computer may prevent the devices from communicating. See answer to question 3.
  2. If antivirus is installed, turn off the Firewall in it or add JustStream to the exceptions. Antivirus apps often have their own firewalls and network traffic blockers. It's easier to fully disable these apps while testing for connection, then re-enable and make adjustments later.
  3. See if you have any of the following software installed, and if so, make sure it is configured to let JustStream make the connection: Radio Silence, Lulu, Little Snitch, Murus, Vallum, Hands Off, Netiquette, TCPBlock.
  4. In the Streaming settings enable the "Use native playback when supported" option and start the broadcast.
  5. If steps 1-4 did not help, turn off the "Use native playback when supported" option in the Streaming settings and start the broadcast.
  6. If step 5 did not help, reduce Quality and/or Bitrate in the Streaming settings and start the broadcasting.

16. Why is the video playing without sound?

Unfortunately, not all devices support multi-channel audio decoding. Therefore, when streaming video files with sound in AC3/E-AC3/DTS formats to such devices, playback may be without sound. In this case, enable the "Downmix audio to stereo" option in the Streaming settings and restart playback.