rtf

MULTIMEDIA DATA AND FILE FORMATS

MULTIMEDIA DATA AND FILE FORMATSTextGraphics ImageAudio Videoanimation.mp4.mpeg.avi.wmv.jpeg.jpg.bmp.mp3

MULTIMEDIA DATAIncludes 1. Text- Data stored char by char & it takes 1 bit/char

2. Graphics- editable unlike images, source-g tablet, keyboard, mouse

3. Images- grids of pixels can be real/virtual, Storage can be : 1 bit/pixel(B &w) 8 bit/pixel(gray scale) 24 bit/pixel(true color)

As no. of colors in an image increases, size increase, so compression tech. are used like jpeg, jpg, bmp etc.

4. Audio- continuous analog signals recorded through microphones. After recording they are digitized ,compressed and finally stored. Actually a digital audio recorder captures the audio waves at a particular interval called the sampling rate.

Quality of audio signals depends on : a) sample resolutionb)Sampling ratec)no. of audio channels sampledso better are the above parameters, better is the audio qualityBut with better audio quality, more size is required and hence storage problem arises, so different compression techs. are used :

Algos. used for compression :Lossy discards data which human ear cant hear based on psychoacoustic perceptions of human brain(uses : Music)2. Lossless do not discard any data(uses : Research)

5. Video

5. VIDEO

Like audio signals video signals are also captured in analog form and they are digitized. The conversion of video signals takes place through sampling and quantization.Sampling rate is the rate at which samples are collected, whereas quantization converts the video signal into binary value for the storage purposes.Video is displayed in series of frames(generally 30fps)For storing the video files different compression algos. are used like interframe data compression.File formats .mp4,.avi,.wmv,.mkv

6. Animation

6. ANIMATION

It lies between the motionless world of static images and the real-time world of moving images.

In animation a series of pictures are put together. Each picture contains a slightly different data and these pictures are displayed at a faster rate, proper sequence and with a proper timing and our eyes perceive as if the objects are moving, technically it is said Animation.

File formats

1. RTF(Rich Text Format)

2. TIFF(Tag Image File Format)

3.MIDI(Music Instrument File Format)

4. JPEG(Joint Photographic Experts Group)

5. MPEG (Moving Picture Expert Group)

1. RTF

Rich Text Formatcomes under the category of ---text and graphics filesprovides a method of transferring encoding formatted text and graphics between different output devices, os and applications.it allows to store text with special formatting like italics, bold, colored text with the plain textrtf files begins with control word \rtfn; where n is the version number.

2. Tiff

Tag Image File Format (TIFF) is typically used to transfer graphics from one computer system to another.TIFF is an excellent method of transporting images between file systems and software packages.It is supported by most graphics packages and has a high resolutions that is typically used when scanning images and colors of up to 48 bits.

TIFF file structure:TIFF files have a three-level hierarchy1. A file header: Of 8 bytes2. One or more IFDs (image file directories): contain codes and their data 3. Data: The data information

3. MIDI

Musical Instrument Digital Interface (MIDI)The MIDI is used as the foundation for Internet music playbackA MIDI file is a sequence of chunks.A chunk has a 4-character type, a 4-byte length code (in MSB format), and some data These chunk have the same general format as the chunks used by AIFF, IFF and WAVE; MIDI files are a lot smaller than MP3s,WMAs,WAVs.Extension is .MID

Advantages of MIDI

The music can be modified conveniently.Generally used in games as background musicGeneral MIDI specifies 175 instruments

Types of MIDI files:1. contain only one track:They are easiest to play.2. contain multiple tracks that are played simultaneously:A program to play this type of file must flatten thedata into a single event stream before playing.3. contain multiple tracks but without assuming anytiming relation among the tracks, generally used in games when a particular event happens then only the music is played

4. JPEG

Joint Photographic Expert Group (JPEG)

compression technique which provide lossy compression.It is a compression technique for gray-scale or color image uses a combination of discrete cosine transform, quantization, run-length and Huffman coding.most widely-adopted standard relating to the compression images.JPEG also forms the basis of most video compression algorithms.

5. MPEGMoving Picture Expert GroupUsed in multimedia develops standards for the coded representation ofmoving picture and associated audio information on digitalstorage media.MPEG standardization are best known for their videocompression, they also support high-quality audio compression.There are currently Five MPEG Standards in various stages ofcompletion.

MPEG codecs MPEG-1Used in digital cameras and camcorders.Also used for posting clips on the internet.bit-stream syntax allows for picture sizes of up to 4095 x 4095 pixels.MP3 audio format is part of MPEG-1 Codec

MPEG-4

MPEG-4

Used for streaming and downloading web contentThis video format is employed by a growing number of camcorders and camerasPresently the most popular format

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