Convert M2TS to OGA — Free Online Tool
Extract and convert the audio track from an M2TS Blu-ray or AVCHD file into an OGA container using the Vorbis codec. This tool strips the video entirely and re-encodes the audio as a high-quality, open-format Ogg Vorbis stream — ideal for archiving Blu-ray soundtracks or camcorder audio in a widely supported, patent-free format.
to
FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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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
M2TS is a Blu-ray MPEG-2 Transport Stream container that typically carries high-definition video alongside audio encoded as AC-3 (Dolby Digital), DTS, TrueHD, or AAC. OGA is an audio-only Ogg container and cannot hold video, so the conversion process fully discards the video stream. The audio track is then re-encoded from its original M2TS codec (commonly AC-3 or AAC) into Vorbis using FFmpeg's libvorbis encoder, and the result is wrapped in an Ogg container with the .oga extension. Because Vorbis uses a different compression model than AC-3 or DTS, this is a transcode — not a remux — meaning some generation loss occurs, though at quality level 4 the result is perceptually transparent for most listeners. If the M2TS file contains multiple audio tracks, only the first track is extracted by default.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg binary — the open-source multimedia processing engine that powers this conversion both in the browser (via FFmpeg.wasm) and on the desktop command line. |
-i input.m2ts
|
Specifies the input file as an M2TS Blu-ray/AVCHD Transport Stream. FFmpeg will demux the container to extract all available streams — typically one or more video tracks, audio tracks, and possibly subtitle streams. |
-c:a libvorbis
|
Instructs FFmpeg to re-encode the audio stream using the libvorbis encoder, producing Ogg Vorbis output. This is required because the audio codecs found in M2TS files (such as AC-3 or DTS) are not compatible with the OGA container. |
-q:a 4
|
Sets the Vorbis VBR quality level to 4 on a 0–10 scale, targeting approximately 128 kbps average bitrate. This provides a good balance of audio fidelity and file size, suitable for most music, dialogue, and cinematic audio extracted from Blu-ray or AVCHD sources. |
output.oga
|
Defines the output filename with the .oga extension, which signals to FFmpeg and media players that this is an audio-only Ogg container. FFmpeg automatically omits the video stream because the OGA format has no video codec support. |
Common Use Cases
- Archiving the audio commentary track from a Blu-ray rip as a standalone open-format file for listening on a media player that supports Ogg Vorbis
- Extracting concert or live performance audio from an AVCHD camcorder recording into a compact, high-quality Vorbis file for music archiving
- Pulling dialogue or narration audio from a Blu-ray documentary M2TS file to use in a video editing project where only the audio is needed
- Converting Blu-ray audio to an open, patent-free format for distribution on platforms or devices that reject proprietary codecs like AC-3 or DTS
- Stripping the audio from an M2TS broadcast capture to produce a podcast-ready or podcast-archival Ogg Vorbis file
- Generating a lightweight audio preview file from a large M2TS source without the multi-gigabyte video payload
Frequently Asked Questions
No. OGA (Ogg Audio) only supports the Vorbis, FLAC, and Opus codecs — it cannot store AC-3, DTS, TrueHD, or PCM streams natively. FFmpeg must fully decode the original M2TS audio and re-encode it as Vorbis. This means the conversion is a lossy transcode if the source is already lossy (like AC-3), so some very minor audio quality loss is introduced on top of any existing compression. If the source M2TS carries lossless audio like TrueHD or PCM, encoding it to Vorbis at quality 4 will still produce excellent perceptual quality.
By default, FFmpeg selects only the first audio stream from the M2TS file, so secondary language or commentary tracks will not appear in the output OGA. OGA also only supports a single audio track per file. To extract a specific non-default audio track, you would need to add a stream selector flag like '-map 0:a:1' to the FFmpeg command to target the second audio stream.
The size reduction will typically be dramatic. M2TS files include a full high-definition video stream alongside audio, and video accounts for the vast majority of the file size — often 95% or more. Stripping the video and encoding only Vorbis audio at quality 4 (roughly 128–160 kbps variable bitrate) from a 30-minute M2TS file that might be 15–20 GB could yield an OGA file of just 30–40 MB. The exact size depends on the length of the source file and the complexity of the audio.
The '-q:a' flag controls Vorbis VBR (variable bitrate) quality on a scale from 0 (lowest, ~64 kbps) to 10 (highest, ~500 kbps). A value of 4 targets approximately 128 kbps and is considered a good general-purpose quality level. To increase quality for archival purposes, change it to '-q:a 6' (around 192 kbps) or '-q:a 8' (around 256 kbps). To prioritize smaller file sizes, lower it to '-q:a 2' (around 96 kbps). The full modified command would be: ffmpeg -i input.m2ts -c:a libvorbis -q:a 6 output.oga
No. OGA does not support subtitle streams, so any subtitle or closed caption data embedded in the M2TS will be silently discarded. OGA does support chapter markers (chapter metadata), but FFmpeg does not automatically map M2TS chapter data to an Ogg chapter structure during this conversion, so chapters are also lost. If chapters are important, consider converting to a format like Matroska (.mka) instead, which supports both multiple audio tracks and chapter metadata.
Yes. On Linux or macOS you can use a shell loop: 'for f in *.m2ts; do ffmpeg -i "$f" -c:a libvorbis -q:a 4 "${f%.m2ts}.oga"; done'. On Windows Command Prompt the equivalent is: 'for %f in (*.m2ts) do ffmpeg -i "%f" -c:a libvorbis -q:a 4 "%~nf.oga"'. The in-browser tool processes one file at a time, so batch processing via the desktop FFmpeg command is especially useful for large collections of Blu-ray rips or AVCHD recordings.
Technical Notes
M2TS encapsulates its audio in a packetized MPEG-2 Transport Stream structure, which FFmpeg demuxes reliably. The most common audio codecs found in M2TS files are AC-3 (Dolby Digital), E-AC-3, DTS, DTS-HD Master Audio, TrueHD, and AAC — none of which are directly compatible with the Ogg container. This means a full audio decode-and-re-encode pipeline is always required for this conversion; there is no remux shortcut. The libvorbis encoder produces VBR Ogg Vorbis audio, and the quality scale is not linear: perceptual quality improves most dramatically between -q:a 0 and -q:a 5, with diminishing returns above 6. Metadata tags (title, artist, album) can be preserved if they exist in the M2TS source, as Ogg Vorbis comments support standard tag fields, but M2TS files from camcorders or Blu-ray rips rarely carry rich metadata. The .oga file extension is the IANA-registered audio-specific variant of .ogg — both are valid Ogg containers, but .oga signals audio-only content to media players. Note that while OGA supports FLAC and Opus as alternative codecs, Vorbis is the conventional default for this container. If lossless output is a priority, consider switching '-c:a libvorbis -q:a 4' to '-c:a flac' in the command to produce a lossless FLAC-in-Ogg stream, which is especially worthwhile when the M2TS source carries a lossless audio format like TrueHD or PCM.