Video technology includes capturing, recording, processing, storing, transmitting and reconstructing of images representing motion scenes. The images used in a video can be classified in to three- I-Frame, P-Frame and B-Frame. The I-Frame images are similar to JPEG images as it contains full images (eg: MJPEG uses only I-Frames). The P-Frame images contain only partial images comprising of only data that was changed from the last I-Frame or the previous P-Frame. B-Frames are bidirectional images which can handle the repeated portion of images by transmitting once and relocating in subsequent frames.

Let’s take a look at few of the video formats,

1. AVI (Audio Video Interleave)

AVI format combines audio and video into a single file in a standard container to allow simultaneous playback. Since it is a container format, the audio and video can be compressed with different combination of codecs. AVI format supports all video that comes through VFW (Videos For Windows) and all audio that comes through ACM (Audio Compression Manager). It contains significant overhead data which makes its file size unnecessarily large and does not support B-Frames (an image format) feature of MPEG4. It comes with .avi extension. 

2. MPEG (Moving pictures Expert Group)

The major advantage of MPEG format over other video and audio encoding formats is that they are much smaller in size, still offering the same quality. This is because the MPEG video format adopts lossy compression algorithms which removes the redundancy between subsequent images and previous images while preserving the most common parts in order to reduce redundancy of data. The MPEG video format comes with .mpg and .dat extension whereas MPEG audio formats with .mp1,.mp2 and .mp3 extensions. There are three compression standards for MPEG- MPEG-1, MPEG-2 and MPEG-4. MPEG-1 has only two audio tracks and does not support interlaced video. In Mpeg-2 the audio format was modernized to AAC and interlace support was made available.  MPEG-4 is the most recent video standard which uses the elements of both MPEG-1 and MPEG-2. It supports a lot of video formats including H.264 AVC and H.263 and audio formats including AAC,mp3 andHE-AAC. MPEG-4 gives 3D support, adds ability to define and use animated objects and also provides DRM support.

3. WMV (Windows Media Video) 

Video and audio file based on Microsofts's Advanced Systems Format (ASF). It is also a media container format and uses windows media compression technique. The common audio used in this format is Windows Media Audio (WMA) and the video used is Windows Media Video (WMV). But it supports almost all videos that comes through VFW (Video For windows) or DMO (Directx Media Objects) and all audio that comes through DMO or ACM (Audio Compression Manager). As MPEG-4, WMV also supports B-Frames making the compression very effective. The format comes with .wmv extension.

4. Flash Video (FLV or F4V)

A container file format used to display videos over the internet using Adobe Flash Player. The common flash video files are FLV and F4V. Flash video content can be embedded within swf (ShockWave Flash) which is a file format for multimedia,vector graphics and action script in Adobe flash environment. In FLV, audio and video is encoded in the same format as of swf but F4V is based on ISO Base Media File Format – a general structure for time-based multimedia files. FLV supports H.264 AVC video and audio such as mp3,AAC etc. F4V supports H.264 AVC video and mp3,AAC & HE-AAC audio. The extensions are .flv and .f4v.