Question

Explain about different file formats in multimedia files.

Answer 1

File Formats for Multimedia:

The following is an outline of current file formats used for the production and delivery of multimedia data.

• Text Formats:

1. RTF (Rich Text Format):
   is the primary file format introduced in 1987 by Microsoft with the specification of their published products and for cross-platform documents interchange.
2. Plain text:
   Plain text files can be opened, read, and edited with most text editors. Commonly used are Notepad (Windows), Gedit or nano (Unix, Linux), TextEdit (Mac OS X) and so on. Other computer programs are also capable of reading and importing plain text. Plain text is the original and popular way of conveying an e-mail.

• Image Formats:

1. TIFF (Tagged Image File Format):
   This format is common in desktop publishing world (high-quality output), and is supported by almost all software packages. Recent versions of TIFF allows image compression, and the format is comfortable for moving large files between computers.
2. BMP (Bitmap):
   Initially this format is in use with Windows 3.1. It is quite large and uncompressed and hence BMP is used for high-resolution or large images.
3. DIB (Device Independent Bitmap):
   This format which is similar to BMP, allows the files to be displayed on a variety of devices.
4. GIF (Graphics Interchange Format):
   GIF is a compressed image format. Most of the computer color images and backgrounds are GIF files. This file format is best suitable for graphics that uses only limited colors, and it is the most popular format used for online color photos. 13-bit Color look-up table is used by the GIF format to identify its color values. This format is supported widely.
5. JPEG (Joint Photographic Experts Group):
   JPEG was designed to attain maximum image compression. It uses loss compression technique, where a compression method is referred that loses some of the data required for the image reconstruction. It works good with photographs, naturalistic artwork, and similar material but functions less on lettering, live drawings or simple cartoons.
6. TGA (Tagra):
   It is the first popular format for high-resolution images. TGA is supported by Most of the video-capture boards.
7. PNG (Portable Network Graphics):
   An extensible file format for the less-loss, portable and well-compressed storage of raster images. PNG acts as a replacement for GIF and also replaces multiple common uses of TIFF. PNG works good with online viewing applications like worldwide web. So it is fully streamable with the best display option.

• Digital Audio File Formats:

1. WAV (Waveform Audio File Format):
   It is the most popular audio file format in windows for storing uncompressed sound files. In order to attain the. reduced file size it can also be converted to other file formats like MP3.
2. MP3 (MPEG Layer-3 Format):
   MPEG Layer-3 format is the most popular format for storing and downloading music. The MP3 files are roughly compressed to one-tenth the size of an equivalent WAV file.
3. OGG:
   A free, open-source container format that is designed for obtaining better streaming and evolving at high-end quality digital multimedia. It can be compared to MP3 files in terms of quality.
4. AIFF (Audio Interchange File Format):
   A standard audio file format used by Apple which is like a WAV file for the Mac.
5. WMA (Windows Media Audio):
   It is a popular windows media audio format owned by Microsoft and designed with Digital Right Management (DRM) abilities for copyright protection.
6. RA (Real Audio Format):
   Real Audio format is designed for streaming audio over the Internet. The digital audio resources are usually stored as a computer file in computer’s hard drive or CD/DVD. Besides the variety of audio file formats available, the most common formats are wave files (.WAV) and MPEG Layer-3 files (.MP3), WMA and RA.

• Digital Video File Formats:

1. AVI (Audio/Video Interleave):
   AVI is the video file format for Windows. Here sound and picture elements are stored in alternate interleaved chunks in the file.
2. MPEG (Moving Picture Experts Group):
   MPEG is a standard for generating digital video and audio compression under the International Standards Organization (ISO) by a group of people. The group has developed MPEG-1, the standard on which Video CD and MP3 are based, MPEG-2, the standard that supports products as Digital Television set-top boxes and DVD, MPEG-4, the standard for multimedia and mobile web. MPEG-7, the standard for a search of audio and visual content. Research on MPEG-21 “Multimedia Framework” has started in 2000. Simply MPEG is the standard for digital video and audio compression.