Emicsoft MP4 Converter for Mac is an MP4 converter. It can open the most popular video formats, including, DivX, XviD, MKV, MOV, H.264, 3GP, etc. and convert them into MPEG-4, H.264, MOV, ASF, WMV, 3GP, MPG, and VOB, among others. This is not a converter that will only convert to MP4 files.
The graphical user interface consists of a top menu with the options to add a file, add effects, trim your videos and crop your videos. On the right, there is a video player that can be used to preview the added video, but not the conversion effects. At the bottom of the screen, you will find conversion settings. There are quite a few different conversion profiles for devices like the AppleTV, iPod, iPhone, PSP, PS3, and more. Although there are two fields to select the audio track and the subtitle, I couldn't get subtitle hard-coding to work on an H.264 file.
In my testing, I was able to load and convert a 720p MKV file into an H.264 file with no problems. I chose a 720p AppleTV profile and the process was smooth. The resulting file played well on VLC.