How to convert MTS and  M2TS files shot by AVCHD camcorder to MP4?
For the high quality performance, AVCHD camcorders have  established their authority in high definition camera market. However, this  kind of camcorder record footages in the format of MTS and M2TS, which get no  native supports from virtually all media players or video editors. In that case,  it’s necessary for AVCHD camera owners to transfer these files into other video  formats, so as to enjoy them on local computer or portable devices, or do further  editing via various video editors. To solve this problem to some extent, my  thread here will concentrate on how to convert MTS and M2TS files shot by AVCHD  camcorder to the format of MP4 in  detail, if you are looking for such a solution by chance, please feel free to  follow it, and sincerely hope this helps.
The application I will use in my post is Pavtube MTS/M2TS Converter. You can  download it via clicking on the link attached on it. As long as you have  installed it, just launch it, and next we will begin with its step-by-step  instruction together in the following passages.
Step 1: Run Pavtube MTS/M2TS Converter
After that, a wine red interface will pop up as below,  please click on “Add” button to load your MTS and M2TS files into this  software.
 
Step 2: Select MP4 as  output format and specify save path
Once MTS and M2TS files are loaded, then you can click on  the drop-down list of “Format” to select MP4 as output format. Notice that,  there are different kinds of MP4 formats, some are for iPod, some are for  iPhone, some are for PSP/PS3, and some are for others, please choose a proper  one according to your end use of the output MP4 files. Here I choose “H.264 Video  (*.mp4)” for instance.
 
Meanwhile, if you dislike using the save path set by  default to store the output MP4 files, you can hit the folder icon at the  opposite side of “Output” to specify a destination folder by yourselves. By the  way, imagine you have the need of combine multiple MTS and M2TS files into a  single file, you can tick checkbox “Merge into one file” to realize this goal.
Step 3: Set advanced  settings
Pavtube MTS/M2TS  Converter allows users adjusting video and audio parameters including  codec, bit rate, aspect ratio, frame rate, sample rate, etc. to take charge of  the output file size and image quality. Generally speaking, the larger input  values, the better image quality, but the larger file size as well; on the contrary,  the smaller inserted figures, the more inferior image quality, but the smaller  file size. That is to say, you are able to balance the output file size and  quality by your own.
 
Step 4: Convert
As soon as all the above three steps are set well, what  you should do next is just hitting “Convert” button to start conversion. When  it finished, click on “Open” button, and then you can get the generated MP4  files there.