Cast an MKV from your PC to the TV, subtitles included

An MKV holds the picture, one or more soundtracks and often several subtitle tracks in one file. With AIX Player you cast it as it is: there is no copy to make first, and the soundtrack and subtitle you choose are the ones the TV gets.

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Windows 11 & 10 · Guide reviewed 28 October 2026

Cast an MKV in four steps

1. Open the MKV in AIX Player. Open it from your PC’s drive or from a USB or SD drive, the same way you would to watch it on the PC.
2. Choose the soundtrack and the subtitle. Use the audio and subtitle menus in the player. A separate subtitle file with the same name as the video, such as an SRT file, loads by itself.
3. Press cast and pick your TV. Select the cast button, or press T, and choose the TV from the list. The first time, some TVs ask once: a PIN on Fire TV and Apple TV, Allow on LG and Samsung, and on a Roku the free AIX Casting Receiver channel.
4. Watch, with the PC as the remote. Play, pause, seek, switch the subtitle or the soundtrack and disconnect from the AIX Player window.

Jellyfin, Emby and Plex videos play on your PC; casting media-server videos is not supported. These casting steps are for video files on your PC’s own drives or on a USB or SD drive. Read about media servers.

What the TV receives

Before it sends anything, AIX Player checks what the TV can play. If the TV can play the video and the sound inside the MKV directly, it gets them as they are. If it cannot, AIX Player converts the part it cannot play while the film streams. Your MKV is never changed and no converted copy is saved to disk.

• Picture. HDR stays HDR when the TV can play the file directly; otherwise the picture is converted to SDR for the TV.
• Sound. A file the TV plays directly keeps its own soundtrack. Every stream AIX Player converts carries AAC sound, which the TV can play.
• Subtitles. The subtitle you choose shows on the TV, whether it is a track inside the MKV or a separate file.

Which video each TV family plays directly

AIX Player carries a catalogue of what each TV family can decode itself, taken from the makers’ specifications and from our own measurements. Every family in it tops out at 2160p (4K) at 60 frames per second. Anything outside a TV’s list is converted while it streams.

Individual models differ, which is why AIX Player checks your own TV first. DLNA televisions vary too much to list and are checked the same way. Device guides: Chromecast, Roku, Samsung TV and the rest on the casting page.

Surround soundtracks

Many MKV files carry a surround soundtrack. When the TV can play it, the TV gets it as it is; when it cannot, the converted stream carries AAC sound instead, so you still hear the film. If you prefer, pick a stereo track before you cast.

If something goes wrong

A TV that does not appear, a cast that stutters or a picture with no sound each have a short list of causes. The casting troubleshooting guide takes them in order.

The casting allowance

Casting is part of AIX Pro: the free app includes 60 casting minutes in total, once, not per session, and Pro makes casting unlimited. Playing videos on your PC is free with no time limit.