Extract Audio from TS to AC3 — Free Online Tool
Extract and convert audio from a TS broadcast stream directly to AC3 (Dolby Digital) format, preserving the surround sound character of the original broadcast audio. This tool strips the video entirely and encodes the audio track using the ac3 codec at 192k bitrate, producing a .ac3 file compatible with DVD authoring, Blu-ray workflows, and home theater systems.
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FFmpeg Command
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
MPEG-2 Transport Streams used in broadcast television commonly carry audio encoded as AAC, AC3, or MP3 alongside the video. This tool discards the video stream entirely and re-encodes the audio track to AC3 (Dolby Digital) using FFmpeg's native ac3 encoder. If the source TS already contains an AC3 track, the audio is still transcoded rather than stream-copied, ensuring a clean standalone .ac3 file at the target bitrate. AC3 supports up to 5.1 surround channels, so if your TS source contains multichannel audio, the spatial information is preserved through the transcode. The output is a raw AC3 bitstream file — not wrapped in a container like MP4 or MKV — which is the standard delivery format for Dolby Digital audio in disc authoring pipelines.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser, this runs via FFmpeg.wasm compiled to WebAssembly — the same command works identically on a desktop FFmpeg installation for files over 1GB or batch processing. |
-i input.ts
|
Specifies the input MPEG-2 Transport Stream file. FFmpeg will parse all multiplexed streams inside the TS container, including video, audio, and any subtitle or data streams. |
-vn
|
Disables video output entirely — no video stream is written to the output file. This is essential here because the target format is a raw AC3 audio file, which carries no video. |
-c:a ac3
|
Encodes the audio stream using FFmpeg's native Dolby Digital (AC3) encoder. This produces a standard AC3 bitstream compatible with DVD players, Blu-ray authoring tools, and AV receivers. |
-b:a 192k
|
Sets the AC3 audio bitrate to 192 kilobits per second. This is a reasonable default for stereo content; for 5.1 surround sound extracted from broadcast TS files, consider increasing this to 384k or 448k to maintain multichannel fidelity. |
output.ac3
|
The output filename with the .ac3 extension, which signals a raw Dolby Digital bitstream file. The .ac3 extension is important — without a container like MKV or MP4, the extension is the primary way media players identify and decode this format correctly. |
Common Use Cases
- Extracting the Dolby Digital audio track from a recorded broadcast TV stream (.ts file from a DVR) for use in a DVD or Blu-ray authoring project
- Pulling the 5.1 surround sound audio from a captured live sports or concert broadcast to archive or remix separately from the video
- Preparing an AC3 audio track from a broadcast recording to import into video editing software like DaVinci Resolve or Adobe Premiere that requires a standalone audio file
- Converting the audio portion of an HLS-captured transport stream to AC3 for compatibility with AV receivers and home theater systems that require Dolby Digital input
- Stripping and re-encoding broadcast audio from a TS file to a standard AC3 bitrate for compliance with broadcast or streaming submission specifications
- Archiving the audio commentary or multi-language audio tracks from a broadcast TS recording into discrete AC3 files for long-term storage
Frequently Asked Questions
Yes, if your source TS file contains a multichannel audio track (such as 5.1 from a broadcast), FFmpeg's ac3 encoder will preserve the channel layout in the output .ac3 file. The default 192k bitrate is sufficient for stereo but on the lower end for full 5.1 — consider raising it to 384k or 448k for better fidelity across all six channels in a surround sound mix.
This tool always encodes to AC3 rather than stream-copying, which ensures a clean, self-contained .ac3 output file regardless of what the source track actually is. If you know your TS already contains AC3 and want a lossless extraction without any quality degradation, you could modify the FFmpeg command by replacing '-c:a ac3 -b:a 192k' with '-c:a copy' to perform a direct stream copy instead.
AC3 is a lossy codec, and bitrate directly affects audio fidelity. At 192k, stereo content sounds clean and is broadly acceptable for voice and music. However, for 5.1 surround content, 192k spreads across six channels, which can introduce audible compression artifacts — 384k is the more common standard for 5.1 Dolby Digital in DVD and Blu-ray authoring. The maximum AC3 bitrate is 640k, though 448k is the Blu-ray standard ceiling for AC3 tracks.
Replace the '-b:a 192k' value in the command with your desired bitrate, such as '-b:a 384k' for higher quality 5.1 surround or '-b:a 128k' for a smaller file. Valid AC3 bitrates include 96k, 128k, 192k, 256k, 320k, 384k, 448k, and 640k. For example, the full command at 384k would be: ffmpeg -i input.ts -vn -c:a ac3 -b:a 384k output.ac3
Yes. On Linux or macOS, you can use a shell loop: 'for f in *.ts; do ffmpeg -i "$f" -vn -c:a ac3 -b:a 192k "${f%.ts}.ac3"; done'. On Windows Command Prompt, use: 'for %f in (*.ts) do ffmpeg -i "%f" -vn -c:a ac3 -b:a 192k "%~nf.ac3"'. The browser-based tool processes one file at a time, so the desktop FFmpeg command is the recommended approach for batch jobs.
Raw AC3 bitstream files (.ac3) have no container metadata support — they are bare audio data without a wrapper. Any metadata present in the TS file, including language tags, program names, or track titles, will not be present in the output. If metadata preservation matters for your workflow, consider wrapping the AC3 audio in an MKV or MP4 container instead, which support metadata alongside AC3 audio streams.
Technical Notes
MPEG-2 Transport Streams are a broadcast-oriented container that can multiplex multiple audio, video, and data streams — including multiple audio tracks in different languages or formats simultaneously. When extracting audio to a raw .ac3 file, only the first detected audio stream is processed by default; if your TS contains multiple audio tracks and you need a specific one, you can use '-map 0:a:1' (for the second audio track) in the FFmpeg command. The output format is a raw Dolby Digital bitstream, not an MPEG-4 or Matroska container, so the file extension .ac3 is important for correct playback recognition. AC3 supports a maximum of 5.1 channels (six channels: front left, front center, front right, rear left, rear right, and LFE). It does not support 7.1 or Atmos configurations — for those, formats like E-AC3 (Dolby Digital Plus) or TrueHD would be required. Because AC3 is a lossy codec, each transcode generation introduces some quality loss; if the source TS audio is already AC3, stream copying (-c:a copy) is preferable when possible to avoid generational loss.