The File Systems in Multimedia Operating Systems are said to have extended the File System Structure of the Unix Operating System. As characteristically notified above, the file types that are relative to the multimedia operating system require quite a number of adjustments. This basically is because of the massiveness of the files, their need for runtime instructiveness with the server, the continuity of retrieval of data and synchronization.

The handling and organization of these specific file types was a cumbersome task when the original and conventional file systems was arranged to accommodate them. With the increasing trends of graphical and media files embedded e-mail windows the handling of multimedia files has become inevitable. Their performance often comes at stake if their implementation is done using the conventional file system.

Overview

MMFS is a Multimedia File System. It extends the UNIX File System (UFS). Specifically designed for multimedia applications that may be interactive in nature, MMFS is characteristically supportive of the real-time and faster environments of the Multimedia file types. It supports single-medium editing and multiple-media playback environments. It does so by getting implemented in a file structure which is two dimensional in nature.

The optimization of performance of the multimedia files types is achieved by improved communication among the file type and the file system. The improved API does the task for the MMFS.

The interactive playback performance of the multimedia files is considerably improved as compared to those in the conventional file system. This is done by the support extended to pre-fetching that is logically supervised, disk scheduling which is real time in nature and retrieval of multi stream which is synchronized etcetera.

A movie file consisting of several files in a multimedia system.

The synchronization glitches are minimized in multi-stream retrievals due to the optimization implemented by the MMFS. The reduction in response time of multimedia file editing is also one of the major edges gained by the MMFS.

Methodology

The implementation of Multimedia File System comes in handy specifically when a conventional file system is adapted for use for Multimedia files. This implies to the everyday use desktop systems that need to incorporate multimedia files as their inevitable part. The way multimedia file systems adapt the conventional file systems is exquisite as this way the file system can efficiently handle both the multimedia and non-multimedia files. Thus a proficient single working environment is created. The Unix File System (UFS) is adapted into the Multimedia File System (MMFS) by retaining the semantics of the Unix File Access. The basis of the MMFS file system is the VFS or the Virtual File System model which had earlier been implemented on the FreeBSD which was a UNIX-Similar Operating System.

MMFS Functionalities:

Mentioning an excerpt from the Implementation and Evaluation of a Multimedia File System (Niranjan, Chiueh,Schloss, 1997 ) Sharon Shen (n.d.) quotes in her presentation that Multimedia File System (MMFS) functionalities for multimedia support are

– Synchronized multi-stream retrieval

– Editing support

– Caching and pre-fetching optimizations

– Real-time disk scheduling” (Shen, n.d.)

Design

The Multimedia File System supports two dimensional file systems. Logically linking together all the components of a single file (for example, the media streams of a single media file) the MMFS makes use of the units ‘inode’ that is used by the UFS to store the file metadata. MMFS extends the concept of ‘inode’ by overall associating the Multimedia file with a ‘mnode’ instead. Each strand of the Multimedia file is associated with a unique ‘inode’.

The multimedia specific data for each strand and the metadata of the entire Multimedia file are saved in the mnode file. The basic UFS is enhanced by the introduction of system calls. One of the introduced system calls is the mminfo which provides hints specific to the application. Thus it facilitates communication between the file system and the multimedia application, reducing overheads and synchronization flaws.

PREFETCHING is an impressive means by which the file system reads the requirement of the application ahead of the actual call for it. This prefetching reduces the actual running time of the application specially the I/O time that might be involved in gathering together the different streams of a multimedia system.