MKV Has No Sound on Smart TV: Why It Happens and How to Fix It
Learn why modern televisions reject DTS multichannel audio tracks and how to remux MKV into universal MP4 with crystal-clear AAC stereo sound.
Samsung (since 2018) and LG (from 2020 to 2022) removed built-in hardware decoders for DTS audio in their televisions. The fastest and highest-quality solution is keeping the video stream untouched via stream copy while transcoding only the audio track to universal AAC stereo inside an MP4 container.
📑 In This Article
You download a movie or documentary on your PC, transfer it to a USB flash drive, plug it into your Samsung, LG, Philips, or TCL Smart TV, and hit play. The picture appears with striking clarity, but the TV speakers remain dead silent.
On many modern screens, an alert appears: "Audio format not supported." The issue is not caused by broken TV speakers or corrupt movie downloads, but rather by commercial licensing disputes surrounding proprietary multichannel surround codecs.
This technical guide details why major television manufacturers discontinued support for the DTS codec, why re-encoding the entire video is a slow and destructive mistake, and how to use our free convert MKV to MP4 tool to restore audio in seconds.
1. What is the MKV container and why audio fails
Matroska (.MKV) is not a standalone video format, but rather an open-standard multimedia container. It acts like an envelope capable of bundling H.264, HEVC, or AV1 video streams, multiple subtitle languages, and high-fidelity multichannel audio tracks.
High-definition films packaged in MKV containers frequently utilize cinema audio standards engineered for theatrical surround systems, such as DTS Digital Surround (at 768 kbps or 1536 kbps), DTS-HD Master Audio, or Dolby TrueHD.
When you connect a storage drive to your Smart TV, the graphics chip easily decodes the visual stream because H.264 and HEVC are standard. However, when the digital signal processor encounters a DTS audio stream for which the TV firmware lacks a paid license, it drops the track completely, causing silence.
2. Why Samsung and LG dropped DTS licensing
Until 2017, many mid-range and high-end Smart TVs included hardware decoders and paid licensing agreements for DTS audio decoding.
However, the rapid shift toward major streaming services (Netflix, Amazon Prime Video, Disney+, and Apple TV+) established Dolby Digital (AC-3), Dolby Digital Plus (E-AC-3), and AAC as the undisputed web standards. None of the major commercial streaming platforms broadcast media in DTS.
Consequently, Samsung removed DTS support across its entire television lineup starting with 2018 models (Tizen OS). LG followed suit between 2020 and 2022 on its OLED and LCD televisions running webOS. Because television manufacturers cut the licensing royalty fees, local USB playback of DTS media produces no sound.
3. Video stream copy versus audio transcoding
The most common mistake users make when attempting to fix silent MKV files is running a full transcode of the entire movie. Re-encoding a 2-hour 1080p or 4K video burns 40 to 90 minutes of processor time, generates heavy fan noise, and degrades fine visual detail.
The correct engineering solution isolates the media streams:
The visual stream is copied bit-for-bit (stream copy with -c:v copy), transferring original video packets directly into an MP4 container without re-encoding a single pixel.
Only the unsupported DTS audio track is converted into standard stereo AAC (Advanced Audio Coding) at 192 kbps or Dolby Digital AC-3. This selective conversion completes in just a few seconds and delivers full compatibility across all TV brands.
| Recurso / Critério | Conversores na Nuvem | Programas Instalados | ConversordeVideo.com |
|---|---|---|---|
| Processing Duration | 30 to 90 minutes (Full transcode) | 15 to 30 minutes (Desktop app) | A few seconds (Local in RAM) |
| Image Clarity | Visible compression artifacts | Pixel resampling loss | Identical lossless video copy |
| Audio Compatibility | Varies by encoder preset | Stereo AAC | Universal AAC Stereo 192k |
| Hardware Thermal Load | High CPU/GPU heat generation | Heavy multi-core strain | Lightweight in-memory pass |
4. Optimal FFmpeg parameters for Smart TVs
The command below demonstrates the selective stream mapping executed by our WebAssembly engine. It leaves the video stream untouched while downmixing surround audio to universal stereo AAC:
The flag -map 0:v:0 isolates the primary video track, while -c:v copy skips video re-encoding. The audio flag -c:a aac -b:a 192k produces clean, clear stereo sound at high fidelity.
The parameter -movflags +faststart shifts the container header to the front of the file, allowing TVs to start playback immediately from USB storage.
# Copies video losslessly and converts unsupported DTS audio to universal AAC
ffmpeg -i input_movie.mkv \
-map 0:v:0 -map 0:a:0 \
-c:v copy \
-c:a aac -b:a 192k -ar 48000 \
-movflags +faststart \
output_tv.mp4 6. Handling subtitles and multi-track audio
MKV files frequently contain bitmap-based subtitle streams (such as PGS or VobSub ripped from Blu-ray discs). Most television USB media players cannot render graphical subtitles from MP4 containers.
To ensure subtitles display reliably on your TV, keep an external plain text subtitle file (.srt) in the same folder as the video on your USB drive, using the exact same file name (for example, movie.mp4 and movie.srt). Smart TVs will automatically recognize and display the subtitle track.
If you also handle home recordings from AVCHD camcorders, check our guide on how to convert MTS and M2TS files to MP4 or use our audio converter.
Convert MKV to MP4
Fix silent MKV video files to play with pristine sound on any Smart TV without losing visual quality.
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