VOB is a DVD-based multimedia container video file format developed by the DVD Forum. It is based on MPEG-2. A file with the .VOB extension can have video and audio streams, audio and video data, subtitles, disc menus, and navigation content. And all this is combined into a common stream. In this case, video playback is carried out in MPEG-2 format, and audio in various audio formats. Most often, the AC-3 format is used for this, since it provides the most favorable ratio of bitrate and sound quality. The VOB format has gained popularity as files in which you can store video and sound on DVD discs. As a rule, if they have such an extension, then the files have a place in the VIDEO_TS DVD folder in the DVD root directory. Typically, .VOB format videos are opened using any video player that supports MPEG-2 compression. There are many free players that support the .VOB format. In particular, Zoom Player, Media Player Classic VLC, Media Player, Light Alloy and others. Now popular is the paid player CyberLink PowerDVD, which has rich functionality. He specializes in playing DVD videos. VOB video files, originally called DVD Video Object File, can be accompanied by .IFO and .BUP information files.
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.