A M2TS file is a Sony well-qualified video file type. but it is not supported by many web sharing sites while FLV (Flash Video) is a proprietary file format used to deliver video over the Internet, If you have some M2TS files and want to upload to Youtube, Yahoo Video, Google Video or your own website and blog, it's necessary to convert M2TS to FLV(Flash Video) files, and here is an quick solution for this problem:
The tool we will need:
A M2TS to FLV Converter – Video Converter Ultimate
Video Converter Ultimate is not only a smart M2TS to FLV Converter that convert M2TS to FLV Flash Video and to other file formats in one click. plus, but also a powerful Video Converter Ultimate that can handle with almost popular Video Audio & HD Video files conversion, and it's fully compatible with Windows 7.
Free Download Video Converter and install it in your computer, then Launch the software after installation, transfer the M2TS video from your AVCHD video camera to your computer, then click "File" in menu list to load M2TS files from your computer.

Select FLV from the output formats list in "Profile" drop-down list. if you want to upload m2ts to Youtube, just choose"Youtube Video" as output format, the default settings will work great, then you can click "Output" drop-down list to specify the output directory.

Note: Video edit function such as trimming, clipping, adding effecet, etc. is available and optional in Video Converter, so that you can make personalized video clips.
Click "Convert" to begin the M2TS to FLV conversion. In several seconds, it will prompt you the conversion is completed., after encoding, you can click "Open Output" to get the converted M2TS videos directly.
Now you can feel free to upload your converted M2TS files to blog, Youtube, Google Video, etc website to share with friends, just free download Video Converter to have a try!