Free online MTS to M1V converter

Some older video applications and hardware accept only MPEG-1 elementary video streams, while camcorders commonly produce MTS files in AVCHD format. Converting creates an M1V video stream, but it does not retain the original audio because M1V carries video only.

What the MTS format is

MTS is an MPEG-2 Transport Stream file commonly used by AVCHD camcorders and Blu-ray-compatible recording systems. It usually contains H.264/AVC video with AC-3 or LPCM audio, plus transport-stream metadata. Sony, Panasonic, Canon, and other HD camcorders may save recordings with the .mts extension; editing applications can also export or ingest this format.

What the M1V format is

M1V is an MPEG-1 video elementary stream, normally identified by the .m1v extension. It contains compressed video without an audio track or general-purpose container metadata, so it suits older MPEG-1 decoders, authoring workflows, and software that specifically requests a raw MPEG-1 video stream.

M1V is much less efficient than H.264. The conversion can therefore produce a larger file at a comparable visual quality, or noticeably lower quality at a similar size.

How to convert MTS to M1V

FFmpeg is the most direct desktop method because it can decode AVCHD and write an MPEG-1 video elementary stream.

1. Install FFmpeg and place the source file in a convenient folder.
2. Open a terminal or Command Prompt in that folder.
3. Run:

ffmpeg -i input.mts -map 0:v:0 -an -c:v mpeg1video -q:v 2 -f mpeg1video output.m1v

Replace input.mts and output.m1v with the actual filenames. The -map 0:v:0 option selects the first video stream, -an removes audio because M1V cannot store it, -c:v mpeg1video selects MPEG-1 video, and -q:v 2 requests high quality using FFmpeg's quality scale. Use a larger value such as 4 or 6 to reduce the output size and quality.

For a legacy system that expects standard-definition MPEG-1 dimensions, add scaling and an explicit frame rate, for example:

ffmpeg -i input.mts -map 0:v:0 -an -vf "scale=720:480" -r 29.97 -c:v mpeg1video -q:v 3 -f mpeg1video output.m1v

Use dimensions and frame rates required by the target device; do not force NTSC settings onto PAL footage. On Linux, macOS, or Windows, you can also use a graphical FFmpeg front end, but its output must be configured as MPEG-1 video with no audio and an .m1v filename.

For conversion without installing software, upload the file to the free converter on 101convert.com, choose M1V as the output format, and download the result after processing.

Quality and compatibility limitations

This is a codec conversion, not a file-extension change: copying or renaming an MTS file to .m1v will not work. Audio is discarded unless it is extracted separately to a compatible audio file and combined later in a container that supports both streams; it cannot be embedded in a pure M1V stream.

Interlaced camcorder footage may show combing artifacts after conversion. If the target is progressive, add a deinterlacing filter such as -vf "yadif,scale=720:480". Test the resulting stream with the destination application because some older MPEG-1 decoders impose limits on resolution, frame rate, bitrate, or sequence headers.