Convert MTS to WMA — Free Online Tool
Convert MTS camcorder footage (AVCHD with H.264 video and AC-3/AAC audio) to WMA by extracting and re-encoding the audio track into Microsoft's Windows Media Audio format. Ideal for pulling audio from Sony or Panasonic camcorder recordings into a Windows-native audio file for media players, archiving, or distribution.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
Drop your MTS file here
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Settings
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
MTS is an AVCHD container — a variant of the MPEG-2 Transport Stream — that carries H.264 video alongside AC-3 or AAC audio. Since WMA is a pure audio-only format, this conversion discards the video stream entirely and re-encodes only the audio. The AC-3 or AAC audio track from the MTS file is decoded and then re-encoded using the WMV2 (Windows Media Audio v2) codec at the specified bitrate. This is a full transcode of the audio, not a remux, so some minor quality loss is inherent — though at 128k bitrate, results are generally transparent for speech and acceptable for music. The output WMA file is a standalone audio container with no video, subtitles, or chapter data.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg multimedia processing tool. In the browser-based version of this tool, FFmpeg runs locally via WebAssembly (FFmpeg.wasm) — your MTS file never leaves your device. |
-i input.mts
|
Specifies the input file — an MTS file in the AVCHD format, as recorded by Sony or Panasonic camcorders. FFmpeg reads the MPEG-2 Transport Stream container and identifies the H.264 video and AC-3/AAC audio streams inside. |
-c:a wmav2
|
Sets the audio codec to WMV2 (Windows Media Audio version 2), which is Microsoft's standard lossy audio codec and the appropriate encoder for producing a WMA file. WMV2 supersedes the older wmav1 and delivers better quality at equivalent bitrates. |
-b:a 128k
|
Sets the output audio bitrate to 128 kilobits per second. This is the standard default for WMA and produces a reasonable balance between file size and audio quality for camcorder-recorded audio such as event footage, speech, or ambient sound. |
output.wma
|
Defines the output filename and tells FFmpeg to write a WMA file. The .wma extension signals FFmpeg to use the Windows Media Audio container, which will hold the wmav2-encoded audio stream with no video component. |
Common Use Cases
- Extracting spoken commentary or narration recorded on a Panasonic or Sony camcorder for use in a Windows-based audio editing project
- Pulling audio from an AVCHD wedding or event recording to create a standalone audio keepsake compatible with Windows Media Player
- Converting camcorder-recorded interviews or lectures to WMA for distribution on a Windows-centric corporate intranet or SharePoint library
- Archiving the audio track of MTS footage to a smaller, audio-only WMA file to save storage when the video is no longer needed
- Preparing camcorder audio for upload to a platform or device that accepts WMA but not MTS or raw AAC/AC-3 files
- Extracting ambient sound or field audio recorded with an AVCHD camcorder for use as background audio in a Windows Movie Maker or legacy Microsoft editing workflow
Frequently Asked Questions
Not entirely — this is a lossy-to-lossy transcode. The original MTS file contains AC-3 or AAC audio, and converting it to WMA means decoding that audio and re-encoding it with the WMV2 codec, which introduces a second generation of compression artifacts. At the default 128k bitrate, the result is generally acceptable for voice and ambient sound, but audiophiles extracting music or high-fidelity recordings may notice slight degradation compared to the source. To minimize quality loss, choose the highest bitrate option (320k) when audio fidelity matters.
WMA is a strictly audio-only container format — it has no capability to store video streams, subtitles, or chapters. The conversion intentionally extracts only the audio track and discards the H.264 video from the AVCHD source. If you need to retain the video, you would need to convert to a video container format such as MP4 or MKV instead.
By default, FFmpeg selects the first audio track in the MTS file, which is typically the primary stereo or surround mix from the camcorder. WMA does not support multiple audio tracks in a single file, so only one track can be included in the output. If your MTS file has a specific secondary audio track you need, you can modify the FFmpeg command by adding '-map 0:a:1' (for the second audio track) before the output filename to select it explicitly.
The '-b:a 128k' flag controls the output audio bitrate. You can replace '128k' with any supported WMA bitrate such as 64k (smaller file, lower quality), 192k, 256k, or 320k (larger file, better quality). For example, to get higher quality audio from your camcorder recording, use: ffmpeg -i input.mts -c:a wmav2 -b:a 256k output.wma. For spoken-word content like interviews, 96k is often sufficient and keeps file sizes small.
Yes — WMA v1 (wmav1) is an older version of the codec that offers slightly lower compression efficiency than WMV2. You can substitute it by changing the command to: ffmpeg -i input.mts -c:a wmav1 -b:a 128k output.wma. However, WMV2 is the better choice in virtually all cases — it produces better audio quality at the same bitrate and is supported by all the same Windows devices and software that support WMV1.
Yes. On Windows, you can use a simple loop in Command Prompt: 'for %f in (*.mts) do ffmpeg -i "%f" -c:a wmav2 -b:a 128k "%~nf.wma"'. On macOS or Linux, use: 'for f in *.mts; do ffmpeg -i "$f" -c:a wmav2 -b:a 128k "${f%.mts}.wma"; done'. This is particularly useful when offloading a full memory card of AVCHD footage and you want to extract audio from every clip at once. The in-browser tool processes one file at a time, so the FFmpeg command is recommended for batch jobs.
Technical Notes
MTS files from AVCHD camcorders typically carry audio as AC-3 (Dolby Digital) at 48 kHz, or occasionally AAC, with channel layouts ranging from stereo to 5.1 surround. When converting to WMA, FFmpeg decodes whichever audio codec is present and re-encodes it using WMV2. If the source is 5.1 surround AC-3, FFmpeg will by default downmix it to stereo in the WMA output, since WMA's surround support is limited and the wmav2 codec handles stereo most reliably. The WMA container supports basic metadata tags (title, artist, album, etc.), but the rich metadata embedded in the AVCHD structure — such as recording date/time stamps and GPS data written by the camcorder — will not be transferred to the WMA output, as WMA's metadata schema does not have equivalent fields. File size will be dramatically smaller than the source MTS because the H.264 video stream (which accounts for the vast majority of AVCHD file size) is completely dropped. DRM can technically be applied to WMA files, but this FFmpeg conversion produces unprotected WMA output. Note that WMA is a Microsoft-proprietary format with no native support on many non-Windows platforms, so if cross-platform compatibility matters, consider AAC or MP3 as alternative audio output targets.