Free online M2V to FLV converter

Source format overview

M2V is a MPEG-2 video elementary stream file. It contains video only, with no audio, subtitles, or container metadata. M2V files are commonly used in DVD authoring, broadcast workflows, and video editing pipelines where the video stream is stored separately from audio. Because it is an elementary stream, it is often paired with another file for audio, such as .wav or .ac3.

Target format overview

FLV is the Flash Video container format. It was widely used for web video delivery, especially in older Flash-based players and websites. FLV can carry video and audio in a single file, and it is often associated with H.263, Sorenson Spark, or H.264 video, depending on the encoder and playback environment. Its main advantage is broad compatibility with legacy Flash workflows, though it is now largely obsolete for modern web use.

How to perform the conversion

The most reliable method is to use FFmpeg, which can read MPEG-2 video and encode it into an FLV-compatible stream. If your M2V file has no separate audio, the output FLV will contain video only unless you add an audio source.

Basic conversion command:

ffmpeg -i input.m2v -c:v flv -c:a aac output.flv

If the source has no audio, use:

ffmpeg -i input.m2v -an -c:v flv output.flv

If you have a separate audio file, you can combine them:

ffmpeg -i input.m2v -i audio.wav -c:v flv -c:a aac output.flv

Step by step:

1. Install FFmpeg on your computer.
2. Place the .m2v file, and optionally the matching audio file, in the same folder.
3. Open a terminal or command prompt in that folder.
4. Run the appropriate ffmpeg command.
5. Check the resulting .flv file in a media player that supports FLV playback.

If you prefer a graphical workflow, some desktop video tools can import MPEG-2 streams and export FLV, but support for FLV export is less common in modern software. For a quick no-install option, you can convert the file on 101convert.com for free.

Notes on quality and compatibility

M2V to FLV is a lossy conversion if the video is re-encoded, so some quality loss is expected. To preserve quality, use a high enough bitrate or a suitable quality setting during encoding. Because M2V is video-only, you must supply separate audio if you want sound in the FLV output.

Compatibility is another important limitation: FLV is a legacy format and is not ideal for modern streaming or playback. Many current players and platforms prefer MP4 with H.264 or H.265. If your goal is long-term usability, FLV is usually chosen only when a specific older system requires it.