Common Video Formats (Part 2)
Previously, we learned about six video formats including AVI, WMV, RM, RMVB, and FLV. Now, let's explore some other video formats.
Versioned Object Base (VOB)
VOB files are used to store all MPEG-2 audio and video data. These data include not only the film itself but also menu and button graphics, as well as multiple subtitle sub-picture streams. IFO files control the playback of VOB files, containing information on how to play the data in the VOB files. Since IFO files are crucial for normal disc playback, a backup copy of each IFO file is saved as a BUP file with the same name. Each DVD disc contains a Video Manager (VMG), stored in the VIDEO_TS.IFO file, which holds global disc information such as the region where the disc can be played. Additionally, the disc stores menu display data in the VIDEO_TS.VOB file. When the disc is inserted into the drive, the player first displays this menu, which typically allows viewers to select scenes, language subtitles, etc.A video file with the MKV extension frequently appears online. It can integrate multiple different types of audio tracks and subtitle tracks within a single file, and its video encoding flexibility is very high, supporting common formats like DivX, XviD, 3IVX, and even streaming video formats such as RealVideo, QuickTime, and WMV. In fact, it is a new multimedia packaging format called Matroska. This advanced, open packaging format has already shown great application prospects, and some even consider it a potential replacement for AVI!
Matroska media defines three types of files: MKV is a video file that may also contain audio and subtitles; MKA is a standalone audio file that may have multiple tracks of various types; MKS is a subtitle file. Among these three, MKV is the most common.
The biggest feature of MKV is its ability to accommodate multiple different types of video, audio, and subtitle streams, even including very closed streaming media formats like RealMedia and QuickTime. This is a major颠覆 of traditional media formats, making it almost a universal media container.
Playing MKV does not require a dedicated player. Any DirectShow-based player can play it, such as Media Player Classic, BSplayer, ZoomPlayer, and even Windows Media Player, as long as the corresponding Matroska splitter plugin is installed. It is recommended to download HappyShow, an integrated codec software.
MOV is the QuickTime movie format, developed by Apple Inc. for storing common digital media types such as audio and video. When selecting QuickTime (*.mov) as the "Save as type," the animation is saved as a .mov file. QuickTime is used to store audio and video information and is now supported by all major computer platforms, including Apple Mac OS, Microsoft Windows 95/98/NT/2003/XP/VISTA, and even Windows 7.
ASF stands for Advanced Streaming Format, a streaming multimedia file format developed by Microsoft for Windows 98. ASF is the core of Microsoft's Windows Media. It is a data format that includes audio, video, images, and control command scripts. This term is currently interchangeable with WMA and WMV.
DAT (Digital Audio Tape) is a professional-quality standard media and technology for digital audio recording on tape. DAT devices are digital tape recorders with rotating heads similar to those in VCRs. Most DAT devices can record at 44.1 kHz (CD audio standard) and 48 kHz sampling rates. DAT has become the standard archiving technology in professional and semi-professional environments for mastering recordings. The digital input and output on professional DAT devices allow users to transfer audio from a DAT tape to another audio workstation for precise editing. Its compact size and low cost make DAT media an excellent way to organize recordings and produce CD-quality results.
The MPEG standard mainly includes five versions: MPEG-1, MPEG-2, MPEG-4, MPEG-7, and MPEG-21. The expert group was established in 1988, specifically responsible for creating video and audio standards for CDs, with members being technical experts in video, audio, and systems. Later, they successfully moved sound and image recording away from traditional analog methods, established the ISO/IEC 1172 compression coding standard, and developed the MPEG format, ushering the audiovisual communication field into the digital age. Therefore, the commonly referred MPEG-X versions are video, audio, and data compression standards formulated and published by ISO (International Organization for Standardization).
The video compression coding technology of the MPEG standard mainly uses inter-frame compression coding with motion compensation to reduce temporal redundancy, DCT technology to reduce spatial redundancy in images, and entropy coding to reduce statistical redundancy in information representation. The combined use of these technologies greatly enhances compression performance.
- 3GP is a video encoding format for 3G streaming media, allowing users to send large amounts of data over mobile phone networks, thereby explicitly transmitting large files such as audio, video, and data to mobile phones. 3GP is a simplified version of the MP4 format, reducing storage space and bandwidth requirements, making it usable on the limited storage space of mobile phones.
