1
Seat No.: Enrolment
GUJARAT TECHNOLOGICAL UNIVERSITY
ME SEMESTER-1 EXAMINATION WINTER 2018
Subject Code: 3714109 Date: 04/01/2019
Subject Name: Audio Video Coding Compression
Time: 02:30 PM To 05:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.
2. Make suitable assumptions wherever necessary.
3. Figures to the right indicate full mark
Q.1

Define Multimedia Signal. Explain elements of multimedia communication system in detail.
07

Explain Delta modulation with suitable Example.
07
Q.2

A statistical encoding algorithm is being considered for transmission of a large number of long text files over a public network. Analysis of the file contents has shown that each file comprises only the six different characters E and F each of which occurs with a relative frequency of occurrence of 0.25, 0.25, 0.125, 0.125, 0.125 and 0.125 respectively.
Compute:
Huffman code for each character.
The average number of bits per codeword with the algorithm.
The entropy of the source.
The minimum no of bits required assuming fixed-length codeword.
Code efficiency, redundancy and compression ratio.
07

Apply Arithmetic Coding on message "ACEB" comprising a string of characters with the probabilities of:
A=0.30, B=0.15, C=0.25, D=0.10, E=0.20
Also decode the message using compressed code.
07
OR

Use the LZW algorithm to compress the following sequence:
1
1
1
5
5
1
1
1
1
7
7
5
5
2
2
1
1
7
7
5
5
2
2
1
1
1
1
5
5
1
1
1
Find the compression ratio
Also decode the compressed image
07
Q.3

Describe JPEG compression Algorithm.
07

List out the Motion Estimation Algorithm. Illustrate New three-step search Algorithm with its Computational complexity
07
OR
Q.3

Define wavelet functions. Discuss DWT based still image compression system
07

Describe Hybrid Video codec with appropriate Block diagram.
07
Q.4

With the aid of example frame sequence, explain the meaning of the following types of compressed frame and the reasons for their use:
1. I-frames
2. P-frames
3. B-frames
07
2

Discuss H.261 encoding following format in detail:
1. Macroblock format
2. Picture format
3. GOB structure
07
OR
Q.4

Explain MPEG Encoder and Decoder with the help of the diagram.
07

Draw and explain Perceptual coding in MPEG audio
07
Q.5

Write a short note on: Blackowski -Steinmetz four layer reference model
07

Give outline of the Box-to -Box matching and point matching .Write an algorithm for Box-to-Box approximately matching in the matching processes.
07
OR
Q.5

Wrote a short note on: Video content segmentation and indexing
07

Distinguish between layer-1 and layer-2 encoding scheme for MPEG audio compression in detail.
07