Extract Audio from M2TS to M4A — Free Online Tool
Extract the audio track from a Blu-ray or AVCHD M2TS file and save it as an M4A file encoded in AAC — ideal for ripping lossless or high-bitrate audio from Blu-ray source material into a compact, iTunes-compatible format. M2TS files often contain multi-channel or high-quality audio streams that can be cleanly re-encoded to AAC for playback on any Apple device or modern media player.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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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
M2TS is a Blu-ray MPEG-2 Transport Stream container that typically carries video alongside one or more audio tracks encoded in formats like AC-3 (Dolby Digital), DTS, TrueHD, or PCM. Since M4A only supports audio codecs like AAC, FLAC, or Opus — and not AC-3 or DTS — FFmpeg must decode the source audio stream and re-encode it as AAC at the specified bitrate (128k by default). The video stream is discarded entirely using the -vn flag. The result is a standalone M4A audio file suitable for music libraries, podcast workflows, or iTunes sync, with no video data included.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg tool. In the browser-based version of this tool, FFmpeg runs locally via WebAssembly (FFmpeg.wasm) — your M2TS file never leaves your device. |
-i input.m2ts
|
Specifies the input file — a Blu-ray or AVCHD M2TS transport stream. FFmpeg will parse all streams inside it, including video, audio, and any subtitle tracks embedded in the MPEG-2 Transport Stream container. |
-vn
|
Disables video output entirely. This is required because M4A is an audio-only container and cannot store video streams — any H.264 or H.265 video tracks from the M2TS are discarded. |
-c:a aac
|
Sets the audio codec to AAC (Advanced Audio Coding). Since M2TS Blu-ray audio is typically in AC-3, DTS, TrueHD, or PCM — none of which are natively supported in M4A — FFmpeg must fully decode and re-encode the audio to AAC. |
-b:a 128k
|
Sets the AAC audio bitrate to 128 kilobits per second. This is a reasonable default for general listening, but given that Blu-ray source audio is often lossless or very high quality, increasing this to 192k or 256k will better preserve the original fidelity. |
-vn
|
A second instance of the video-disable flag, which is redundant in this command — one -vn is sufficient to suppress video output. It has no additional effect here but does not cause an error. |
output.m4a
|
The output filename with the .m4a extension, which tells FFmpeg to wrap the re-encoded AAC audio in an MPEG-4 audio container. This format is natively supported by iTunes, Apple Music, iOS, and most modern audio players and browsers. |
Common Use Cases
- Ripping the orchestral score or soundtrack from a concert Blu-ray into a portable M4A file for listening on an iPhone or iPad
- Extracting dialogue or commentary tracks from an AVCHD camcorder recording (M2TS) to create an audio-only archive or transcription source
- Converting high-quality Blu-ray audio content to M4A for importing into iTunes or Apple Music as a personal library track with chapter metadata support
- Pulling the audio from a Blu-ray lecture or educational disc to create a podcast-style M4A episode for offline listening
- Extracting a specific language audio track from a multi-track M2TS Blu-ray file to produce a clean, single-language M4A for distribution
- Archiving the audio portion of an AVCHD home video recording into a lightweight M4A file when the video content is no longer needed
Frequently Asked Questions
Almost certainly yes, because M2TS Blu-ray files commonly contain lossless audio formats like Dolby TrueHD, DTS-HD Master Audio, or uncompressed PCM, all of which must be decoded and re-encoded to AAC during this conversion. AAC at 128k is a lossy format, so some detail is lost compared to the original. If preserving maximum fidelity is critical, consider increasing the bitrate to 256k or 320k in the FFmpeg command, or using FLAC as the output codec instead of AAC — though note that FLAC in M4A is less universally supported.
M2TS Blu-ray files frequently carry multiple audio streams for different languages or formats. To target a specific track, add the -map flag to the FFmpeg command — for example, '-map 0:a:1' selects the second audio stream (zero-indexed). You can first run 'ffmpeg -i input.m2ts' with no output to list all detected streams and identify the index of the track you want.
You're right to notice this — in the resolved command 'ffmpeg -i input.m2ts -vn -c:a aac -b:a 128k -vn output.m4a', the -vn flag appears twice. This is a redundancy and one instance is sufficient. The flag tells FFmpeg to exclude all video streams from the output, which is essential here since M4A is an audio-only container and cannot hold video data. A single -vn before the output filename achieves the same result.
Replace the '128k' value in '-b:a 128k' with your preferred bitrate. For speech or podcasts, 96k is usually sufficient. For music from a Blu-ray source, 192k or 256k is recommended to better preserve the detail from a high-quality original. The maximum supported value is 320k. For example: 'ffmpeg -i input.m2ts -vn -c:a aac -b:a 256k output.m4a'.
Subtitle data is not preserved — M4A does not support subtitle streams, and subtitles embedded in the M2TS transport stream are discarded during conversion. Chapter markers are a different story: M4A does support chapters, but the chapter data in M2TS is stored in a Blu-ray-specific format that FFmpeg does not automatically map to M4A chapters. If chapter preservation is important, you would need to manually define them using FFmpeg's chapter metadata syntax.
Yes. On Linux or macOS, you can use a shell loop: 'for f in *.m2ts; do ffmpeg -i "$f" -vn -c:a aac -b:a 128k "${f%.m2ts}.m4a"; done'. On Windows Command Prompt, use: 'for %f in (*.m2ts) do ffmpeg -i "%f" -vn -c:a aac -b:a 128k "%~nf.m4a"'. This is especially useful for ripping audio from a folder of AVCHD recordings or Blu-ray chapter files, which are often split into multiple M2TS segments.
Technical Notes
M2TS transport streams used on Blu-ray discs often contain audio in formats that have no direct mapping to M4A-compatible codecs — specifically Dolby TrueHD, DTS-HD MA, and raw PCM. FFmpeg handles this by fully decoding the source audio to PCM internally before re-encoding it as AAC, meaning this is never a simple stream copy and always involves a full transcode. The resulting AAC stream in the M4A container uses the MPEG-4 Audio profile, which is broadly compatible with Apple devices, Android, browsers, and most modern players. One important limitation: M4A does not support multiple audio tracks, so if the M2TS source has several streams (e.g., a 5.1 surround track and a stereo commentary track), only one will be included in the output by default — FFmpeg picks the first or highest-priority audio stream unless you specify otherwise with -map. The M4A container does support chapter metadata and iTunes-style tags, but these are not automatically transferred from M2TS since the two formats use incompatible metadata systems. File size will be significantly smaller than the source M2TS, which typically ranges from several gigabytes, while a 128k AAC M4A of the same duration will be a fraction of that size.