M2TS to AAC Converter

Extract AAC Audio from M2TS: What This Covers

M2TS is the MPEG-2 Transport Stream that AVCHD camcorders and Blu-ray authoring write, and it is a video container — so getting the sound out means decoding the audio track and re-encoding it, not copying a file out of a folder. This walk-through covers exactly that: which audio your M2TS is likely to be carrying, which of the four compression modes on this page gives you a bitrate you can predict, and how to avoid a second-generation quality hit when the source is already lossy.

How to Extract AAC from M2TS

1. Upload Your M2TS File: Drag the .m2ts clip onto the page or click "+ Add Files". Several clips can be queued and extracted with the same settings.
2. Set File Compression to Constant Bitrate: Pick a bitrate from the list — the dropdown runs from 8 kbps to 384 kbps and opens on 128 kbps, with 192–256 kbps suiting music and 5.1-sourced material. This is the control that maps one-to-one onto the encoder, so it is the one to use when you care what comes out; the Quality Preset above it is the automatic, hands-off mode and the least predictable control on the page.
3. Set Audio Channel, Audio Sample Rate and Trim (optional): Leave both on "Original" to keep exactly what the camcorder recorded, or set Audio Channel to Stereo to downmix a 5.1 track. Trim takes a Start time and a Duration if you only want a section.
4. Convert and Download: Click Convert and download the .aac file. No sign-up, no watermark. Files upload over an encrypted connection, are processed on our servers, and are deleted automatically after a few hours.

Walk-through: Which Compression Mode to Use

The File Compression group offers four modes, and they are not equally useful here. Three of them let you name the output rate yourself; the fourth is the automatic, hands-off option and the least predictable control on the page. When you care what comes back, set a rate directly.

• Constant Bitrate — a fixed list running from 8 kbps to 384 kbps and opening on 128 kbps. This is the mode to use. Pick the value that matches or exceeds the source.
• Custom Bitrate — the same idea with a free-text value (128 Kbps prefilled) if you need a rate the list does not offer.
• Specific file size — useful when a destination has a hard size cap and you would rather let quality float to hit it.
• Quality Preset — the mode the group opens on, though nothing in its dropdown is chosen for you: the list shows "Highest" as a placeholder, and leaving it alone means the server falls back to its own default rather than the value on screen. Name a bitrate instead when the output rate matters.

Bitrate choice follows the source. AVCHD's Dolby Digital track can run anywhere from 64 kbps to 640 kbps, so encoding a 384 kbps 5.1 source down to 96 kbps stereo throws away real information, while encoding a 192 kbps source up to 320 kbps just makes a bigger file without recovering anything. Match the source rate, or go slightly above it, and stop there.

What Audio Is Actually Inside Your M2TS

The AVCHD figures come from the official AVCHD format specification, which defines the format as H.264/AVC video in an MPEG-2 Transport Stream with Dolby Digital or Linear PCM audio, at a system bitrate up to 24 Mbps.

Every Control on This Page

Common Errors and How to Fix Them

• "The extracted audio sounds thinner than the original" — the bitrate was set below the source. AC-3 to AAC is a lossy-to-lossy step, so any headroom you remove is gone. Re-extract at the source's rate or higher.
• "My 5.1 track came out as two channels" — Audio Channel was set to Stereo. Put it back on Original to keep all six channels.
• "The upload takes far longer than the conversion" — that is expected. AVCHD records up to 24 Mbps, which is roughly 180 MB for every minute of footage, and the whole file has to arrive before the audio can be lifted out. Trimming here shortens the output, not the upload.
• "My editor won't import the .aac file" — some editors want AAC inside an MP4-family container rather than a bare stream. Use M2TS to M4A for the same audio in a container that carries tags.
• "The file is from a Blu-ray and nothing happens" — commercial discs are encrypted with AACS, and encrypted streams cannot be decoded. This works on footage you can already open and play.

Frequently Asked Questions

Does this keep the video as well as the audio?

No — this is an extraction, not a conversion. The H.264 video inside your M2TS is discarded and only the soundtrack is written out. If you want to keep the picture, M2TS to MP4 re-encodes video and audio together into one playable file.

Which control on this page actually sets the bitrate?

Constant Bitrate (or Custom Bitrate, if you want a value the list does not offer). The Quality Preset dropdown displays "Highest" when the page loads, but nothing is pre-selected there — if you never touch it, the server falls back to its own default rather than the value you can see. The presets are also the least predictable control here, so when the output rate matters, name it explicitly with Constant Bitrate and check the result in your player's file-info panel. Leaving the rate to the automatic mode is the single most common reason people think the extraction overlooked their settings.

What bitrate should I pick for camcorder footage?

Match the source. AVCHD's Dolby Digital audio runs between 64 and 640 kbps depending on the camera and mode, with consumer camcorders commonly recording stereo in the 192–384 kbps range. Setting Constant Bitrate to 192 or 256 kbps covers nearly all consumer footage; going higher than the source cannot recover detail Dolby Digital already discarded.

Can it downmix a 5.1 surround track to stereo?

Yes. Set Audio Channel to Stereo and the surround channels are folded down to two during extraction. Leave it on Original to keep the full channel layout — AVCHD allows up to 5.1 channels of Dolby Digital and up to 7.1 channels of Linear PCM, so there can be a lot to preserve.

Is .m2ts the same thing as .mts?

Effectively yes — same AVCHD transport stream, different filename. Camcorders write .mts on the memory card, and the file is usually renamed .m2ts when it is imported to a computer or authored to disc. If your file came straight off the card, MTS to AAC does the identical extraction.

Should I extract to AAC or to M4A?

AAC here means a bare AAC stream, which is fine for playback and for tools that read raw audio. M4A is the same AAC audio inside an MP4 container, which is what iTunes, Apple Music and most editors expect, and it has somewhere to store title, artist and cover art. If the file is going into a library or a timeline, M2TS to M4A is usually the better target.

Can I extract audio from a commercial Blu-ray disc's M2TS files?

Only if they are not copy-protected. Retail Blu-ray discs are encrypted with AACS, and an encrypted stream cannot be decoded by any conversion service. This tool works on M2TS files you can already open and play: your own camcorder footage, your own authored discs, unprotected recordings, or files you have already decrypted with separate software.

Will the extracted audio stay in sync if I put it back with the video?

It should, because the extraction starts at the beginning of the timeline unless you set a Trim start. If you do trim, note the exact start time you used — offsetting the audio by that same amount is what re-aligns it against the original clip in an editor.

Are my camcorder files kept after conversion?

No. Your M2TS is uploaded over an encrypted connection, processed on our servers, and deleted automatically after a few hours — no sign-up, no watermark, never shared or made public.