Video formats
Video format
Defines the structure of the video file, then how the file is stored on the storage medium (CD, DVD, hard disk or communication channel). Usually different formats have different file extensions (* .avi, *. Mpg, * .mov, etc.).
Explanations of abbreviations in the descriptions of filmsDefines the structure of the video file, then how the file is stored on the storage medium (CD, DVD, hard disk or communication channel). Usually different formats have different file extensions (* .avi, *. Mpg, * .mov, etc.).
Well first of all it is necessary to say that the main requirement for formats for the Internet is compactness.
It is clear that the DVD format will not work.
But almost any video shot on a mobile or digital camera meets the requirements of the Internet.
On such formats, the creators of video hostings were oriented. Not all video formats are presented here, there are a lot more of them. But we put the main thing, that it was still a simple review, not a scientific reference.
In fact, if it's even shorter, there are 3 main formats: AVI, MPG and MOV.
MPG (Moving Pictures Experts Group) - A video file containing video encoded:
- MPEG-1 - The standard was developed in 1992, taking into account the capabilities of 2-speed CD-ROMs and 486 computers.
- MPEG-2 - the standard was adopted in 1994. It was originally developed for digital broadcasting of broadcast quality. Used in DVD, digital TV and HDTV.
- MPEG-3 - for high-definition television (HDTV), but later became part of the Mpeg2 standard and is not now separately mentioned.
- MPEG-4 (distributed short MP4 writing) - the standard is designed for very low data streams for use in videophones, multimedia e-mail, electronic information publications, etc.
And the video stream can be only one, whereas audio - a few. In particular, AVI can contain only one stream - either video or audio.
The AVI format itself does not impose absolutely any restrictions on the type of codec used, neither for video, nor for audio - they can be any. Thus, in AVI files, any video and audio codecs can be perfectly seamlessly combined. MOV - Apple Quicktime format can contain any codec, CBR or VBR. Usually they have the .QT or .MOV extension.
Note that since MPEG-4 Group chose QuickTime as the recommended format for MPEG4, their MOV files come with the extension .MPG or .MP4 (Interestingly, the video and audio streams in these files are real MPG and AAC files .You can even extract Them using options -dumpvideo and -dumpaudio.). RealVideo The format created by RealNetworks. RealVideo is used for live television broadcasting on the Internet. For example, CNN was one of the first to broadcast on the Web.
It has a small file size and the lowest quality, but you, not especially uploading your channel, will be able to watch the latest TV news release on the site of your chosen TV company. Extentions RM, RA, RAM. ASF (Active Streaming Format) - Streaming format from Microsoft.
They developed two variants of ASF, v1.0 and v2.0. V1.0 is used by their media (Windows Media Player and Windows Media Encoder) and strongly classified. V2.0 is published and patented.
Of course they differ, there is absolutely no compatibility (it's just another legal game).
MPlayer only supports v1.0, since no one has ever seen v2.0 files. Note that ASF files now appear with .WMA or .WMV extensions. WMV (Windows Media Video) - A video file recorded in Windows Media format. DivX (Digital video express) - Codec standard Mpeg4. From Version 5 it became paid (for coding). Xvid (Previously XviD) - a library of video compression standard Mpeg4.
Xvid is the main competitor to the DivX Pro codec (Xvid is DivX vice versa). Unlike the DivX codec, proprietary software developed by DivX, Inc., Xvid is a free program distributed under the GNU General Public License. MP4 is a short spelling of the Mpeg4 standard, designed for very low data streams for use in videophones, multimedia e-mail, electronic information publications, etc. *. 3GP (short for English 3 rd g eneration (mobile) p hone - (mobile) phones Third generation);
Video files for mobile phones of the 3rd generation. Some modern mobile phones (not necessarily 3G) have the functions of recording and viewing audio and video in .3GP format.
This format is a simplified version of ISO 14496-1 Media Format, which is similar to the MOV used by QuickTime.
3gp saves the video as Mpeg4 or H.263.
Audio is saved in AMR-NB or AAC-LC formats.
Ready video clips in 3gp format have a small size compared to other video formats, but unfortunately this strongly affects the quality (it is very low). FLV (Flash Video) - the file format used to transfer video over the Internet.
Used by such services as YouTube, Google Video, RuTube, Tube.BY, Muvi, Obivu and others. Although the description of the container format was opened, codecs are protected by patents, and remain proprietary.
Files in FLV format can be viewed on most operating systems, since it uses the widely used Adobe Flash and plug-ins to most browsers, and is supported by many video playback programs such as MPlayer, VLC media player, Media Player Classic) and other programs running With DirectShow. MPEG-7 is not a logical extension of Mpeg4, just the development of the same MPEG group (Moving Picture Experts Group) for the Internet.
Here is introduced a specialized language DDL (Description Definition Language - language definition definition).
The main goal of applying the new standard is to effectively search for multimedia information in a similar way to how we are currently searching for texts by keywords or phrases. As an example:
- music - after playing a few notes on the keyboard, you can get a list of music that contains such a sequence of sounds
- graphics - drawing a sketch on the screen, we will get a set of drawings containing a similar fragment
- video - by setting the appropriate object and its movement, we get a set of video or animation clips, in which this object is present.
