M4V is a video file format that has been downloaded from the Apple iTunes store. The format contains TV shows, videos, films, music. It looks like a .MP4 file, but it sometimes has copy protection when Apple's FairPlay DRM is used (technical copyright protection). The M4V format, i.e., MPEG-4 iTunes Video File, was developed by Apple. MP4 is a container format. Like the same formats as MOV, AVI, MKV, it provides the ability to combine a variety of multimedia streams into one file. Mostly it is audio and video. In order to play the protected M4V file, the computer must be authorized using the iTunes account from which the videos were purchased. In this case, it can be used in order to buy video. Unprotected M4V files can be played by other video players if the extension is changed from .M4v to .Mp4. Files with the M4V extension contain both sound and video data. You can convert M4V files to MP4 format. In this case, it will be possible to play them on other computers, since the M4V files are protected by DRM. MP4 files, compared to the M4V format, do not allow you to specify partition information.
MMF is the Yamaha SMAF sound file format developed for mobile devices. The MMF format is linked to SMAF (Synthetic Music Mobile Application Format) files. Many people know this format because they very often use it as ringtones in cell phones. Yamaha’s SMAF tools were developed primarily by Yamaha to provide audio files that users could use as unique ringtones for their mobile phones. However, then the format was slightly improved. Now such files are capable of storing information, graphic, as well as text. You can create an SMAF file using Yamaha SMAF Tools. It can also be saved in WAV or MID format. It’s not uncommon to confuse MMF and SMAF formats. The fact is that MMF are called file extensions. SMAF is called the file itself. The MMF file is identical to MIDI files. It is capable of supporting music playback and showing graphics. Due to the implementation of the image display function, SMAF files now have considerable potential in the mobile application market. This is because they can store high quality images when the file size is limited at the same time. Typically, the size of SMAF files is much smaller than files of other formats that can perform the same functions.