M2TS

M2TS is a filename extension used for the Blu-ray Disc Audio-Video (BDAV) MPEG-2 Transport Stream (M2TS) container file format. It is used for multiplexing audio, video and other streams. It is based on the MPEG-2 transport stream container.[2][3][4][5] This container format is commonly used for high definition video on Blu-ray Disc and AVCHD. Most M2TS files can be played with ALLPlayer, MPlayer, VLC, PotPlayer and other media players, depending on used compression formats in a M2TS file.

- - Wikipedia

FLV

FLV stands for Flash Live Video. The audio and video data within FLV files are encoded in the same manner as they are within SWF files. FLV was originally developed by Macromedia. In the early 2000s, Flash Video used to be the de facto standard for web-based streaming video (over RTMP). Notable users of it include Hulu, VEVO, Yahoo! Video, metacafe, Reuters.com, and many other news providers. Flash Video FLV files usually contain material encoded with codecs following the Sorenson Spark or VP6 video compression formats.

- - Wikipedia

Step-By-Step to Convert M2TS to FLV for Mac

Interface

Step 1. Download and install the program, then double click it to run it, and then you'll see the main interface of the program.

Load Files

Step 2. Click "Add File(s)" button. Here you can select "Add Video" or "Add Folder" button to add files as you like.

Profile

Step 3. Click the drop-down arrow right beside the "Profile" column and select your desired video format from the drop-down list.

Edit

Step 4. Click "Edit" button to customize the output video like Effect, Trim, Crop, 3D Settings and Watermark.

More Reading

Close Button