Convert MTS and M2TS to MP4

AVCHD, MTS and M2TS

Sony and Panasonic launched AVCHD in 2006 for HD camcorders, and Canon and others adopted it. It records H.264 video with Dolby Digital or uncompressed PCM sound inside an MPEG transport stream, the same family as digital TV. Each press of the record button starts a new numbered file. On the card the clips end in .mts; Blu-ray discs use .m2ts for the same kind of stream.

AVCHD records at up to 28 Mbit/s, about 200 MB a minute. VLC and camcorder software play the files, but phones, many editors and web uploads often do not, which is why people turn them into MP4. Camcorders sold in Europe usually record at 50 frames or fields a second and North American ones at 60; the MP4 keeps whatever yours used.

What is copied, and the Blu-ray limit

So a typical camcorder clip, H.264 with Dolby Digital, comes out as an exact copy. Where the sound was uncompressed PCM, the AAC that replaces it takes a sixth of the room or less. M2TS files from Blu-ray discs you burned yourself convert the same way. Blu-ray films you buy are copy-protected, and Octoolo cannot read them.

Some camcorders can also record MP4 directly, such as Sony's XAVC S models; those files need no conversion at all.

Camcorder tips

• Drop the right folder. Octoolo searches three folders deep, and the clips are four folders down from the top of the card, so drop STREAM, BDMV, AVCHD or PRIVATE rather than the whole card.
• Copy before converting. Converting straight from the card works, but the MP4s are then written onto the card beside the clips, unless you choose another folder under Save in.
• Several cards? Each one starts again at 00000.MTS, so keep each card's clips in their own folder. If MP4s with the same name meet in one Save in folder, Octoolo numbers them instead of overwriting.
• Long takes may be split across several MTS files. After converting, join them in the Video Editor.
• Keep the card's folder until you have checked the MP4s. Octoolo never changes or deletes the originals.

Archive copy or sharing copy

For your archive, As it is is the choice: the MP4 holds exactly the camcorder's picture, at the same size, and plays far more widely than the MTS. For sharing, the files are heavy. A minute of AVCHD at its top setting is around 200 MB, so a ten-minute take is about 2 GB and quickly outgrows email and chat limits.

Choose Balanced or Small for those, and a Size of 720p under More settings. The picture is then re-encoded, by a graphics card with a video encoder where there is one, and the sound becomes AAC. Send the sharing copies to their own folder with Save in › A folder I choose…, so they never mix with the full-quality MP4s. More on sizes is on the video compressor page.