Fraunhofer- Gesellschaft (A German research institute)
Overview
It is a digital Audio which compresses the tracks using the lossy format. Although, it follows the lossy format, yet, there will be no noticeable change in the quality of audio. It only discards the superfluous information that a human ear is inefficient to process or hear. With the help of the this extension, one can upload and download audio files with ease, irrespective of the internet connection speed even a dial-up connection users can access these files. There are a number of MP3 Blogs(music blogs) available on the internet where maker uploads music files and a user can download the same without any trouble. These blogs help people to get an insight into the music world. Hype Machine is an example of an audio blog.
Technical description
MP3 uses lossy data compression, which means when data is encoded it is not the full original version, it’s a substitute to original copy but in a smaller size. This compression can lead to a decrease in file size, ranging from 75% to 95%. This format is based on perceptual coding due to which this extension screens out the noise, and results in an audio file that uses a low bit rate(lowest bit rate in it is 128kbps). It provides audio of fair sound quality. As it is only an audio file, thereby, if there are any images linked to it then they need to be stored in a separate file.
This file format stores both audio and video files for playback purposes. It is used to store files that are of high quality as file compression is less in this extension. Windows OS uses this as the default format to store multimedia files but other operating systems such as Linux, Unix and Mac also support this. The data in it is encoded by various codecs such as DivX and XviD. There is a variety of software that support these files. For instance- Microsoft Movies & TV, Windows Media Player and Apple QuickTime player; etc. Due to its low compression ability, it is widely used to make short movies, promos and advertisements; etc. It should be noted that AVI format result in large files that is why it is rarely used for video streaming.
Technical description
In AVI extension, file's data is divided into blocks or chunks as it is a sub-format of RIFF(Resource Interchange file format). An identification of each chunk is done by FourCC tag. File header and metadata of video(like height, width and frame rate) are identified by ‘hdrl tag' which is sub-chunk and it is mandatory. There is one another chunk which is also obligatory that is ‘movi tag' and it has actual audio or video data. The last sub-chunk is ‘idx1 tag' and it records the offsets of the data chunks. This ‘idx1 tag' is completely optional. There is one limitation of this format that it does not contain variable bitrate data.
