Free download iCoolsoft FLV Converter for Mac.

Step 1: Install and launch iCoolsoft FLV Converter for Mac.

Step 2: Click "Add Video" button to add FLV files. You can preview them in the preview pane and take snapshot of the scenes you like by clicking the "Camera" button.

Step 3: Adjust effect, trim clips, crop displaying area, and add text/picture watermark if you like.

Step 4: Set the output format as MPEG4 from the drop-down list of "Profile". Set other parameters by clicking button "Settings".

Step 5: Set the destination and click button "Convert" to start the conversion. The software will show you the converting progress. And you may check "Open target directory after done" in that window.