know about different types of multimedia data and the file formats

1. MULTIMEDIA DATA
AND
FILE FORMATS

2. MULTIMEDIA DATA
AND
FILE FORMATS
Text
Graphics
Image
Audio
Video
animation
.mp4
.mpeg
.avi
.wmv
.jpeg
.jpg
.bmp
.mp3

3. MULTIMEDIA DATA
Includes
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)

4. 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 resolution
b)Sampling rate
c)no. of audio channels sampled
so better are the above parameters, better is the audio quality
But with better audio quality, more size is required and hence storage
problem arises, so different compression techs. are used :

5.  Algos. used for compression :
1. Lossy – discards data which human ear can’t hear
based on psychoacoustic perceptions of human
brain(uses : Music)
2. Lossless – do not discard any data(uses : Research)

6. 5. Video

7.  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

8. 6. Animation

9. 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.

10. 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)

11. 1. RTF
 Rich Text Format
 comes under the category of ---text and graphics files
 provides 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 text
 rtf files begins with control word “rtfn”; where n is the version number.

12. 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.

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

14. 3. MIDI
• Musical Instrument Digital Interface (MIDI)
• The MIDI is used as the foundation for Internet music playback
• A 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

15. Advantages of MIDI
 The music can be modified conveniently.
 Generally used in games – as background music
 General MIDI specifies 175 instruments

16. 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” the
data into a single event stream before playing.
3. contain multiple tracks but without assuming any
timing relation among the tracks, generally used in games when a
particular event happens then only the music is played

17. 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.

18. 5. MPEG
Moving Picture Expert Group
 Used in multimedia
 develops standards for the coded representation of
moving picture and associated audio information on digital
storage media.
 MPEG standardization are best known for their video
compression, they also support high-quality audio compression.
 There are currently Five MPEG Standards in various stages of
completion.

19. MPEG codecs
MPEG-1
 Used 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

20. MPEG-4

21. MPEG-4
 Used for streaming and downloading web content
 This video format is employed by a growing number of camcorders and
cameras
 Presently the most popular format

22. Thank you !