Avidemux for Mac OS X

For the conversion of MTS files to MP4 you can use the free software Avidemux.




Using this software you are able to join video files and convert to MP4 in one session.


File – Open: the first MTS-file

File – Append: the second MTS-file

and so on


For MP4 output we suggest:

  1. In the Video dropdown list on the top left: select MPEG-4 AVC
  2. Click [Configure] button, a new x264 configuration window opens up. Go to Rate Control. Move the scroll bar at the bottom to the left: 0 (High Quality). Select Average Bitrate (Two Pass) from the dropdown list and set the Average Bitrate to at least: 10000
  3. Click OK in the button of the screen to close the window
  4. In the Audio dropdown list: select MP3 (lame)
  5. Click on [Filters] button and set Resampling at 48000 then click OK
  6. In the Format dropdown list: select MP4

Now save the file by File – Save  – Save Video and type a file name with the extension *.mp4


Bear in mind that you need a powerful computer to do the encoding.

You could experiment with the Average Bitrate; a higher value means better quality