C program compilation steps

 Preprocessor:

> gcc -E main.c -o main.i

Compilation:

> gcc -S main.i -o main.s

Assembler: Convert .S to obj file

>gcc -c main.s  -o main.o

>objdump -h main.o  // -> to view the .o file 

Linking:

gcc main.o -o main

> nm main.o // -> to view all the sections 

Explain with example "const int *const ptr" and its use

 This is for readonly purpose

const int *const ptr _> read as constant pointer to integer constant.

const int -> variable value must not be modified

*const ptr -> ptr should point to the same address.

This prevents

1) Accidental modification of the value

2) Accidental modification of the address.

C Interview with Sandisk.

1)Memory Organization in C.

2) Write assembly program for following C Code
Int a;
int a =10;
int *ptr = &a;

3) gave a small code with global variables, static, local, both initialized and uninitialized
Asked me where the variables are stored.

4) implement Segmentation fault/ abort. write a program.

5) Implement Heap Overflow & Corruption. Write a program

6) Implement stack overflow & corruption. Write a program

7) Questions on multi core implementation, synchronization techniques.

8) How to change the memory layout of a C program where to you configure.(RTOS)

9)How ping pong buffer work.

10) How to initialize 512 bytes from bit stream in one shot to the Structure variables

11) Write a program to create a memory leak.

12) Questions are based your answers and they go deep.

Book on C Programing for Cracking interviews

Book on C Program for Cracking interviews

Data Structures and Algorithms Made Easy : Data Structure and Algorithmic Puzzles 

Author: Narasimha Karumanchi

Language: English

Length: 429 pages

Publisher: CareerMonk Publications

http://www.careermonk.com/

C interview with HCL.

1) Write a program to Copy Nth bit of an integer into Mth bit a second integer.

2) Reverse a Single linked List (SLL) with out recursion.

3)Give a node in a SLL how do u delete it.

4) Write a program to find the Intersection node of two SLL if they are intersecting.

5) Difference between const pointer and pointer to constant.

6) Storage class in C. explain the scope of each.

7) Can u access the address of a register variable in C.

8) Can you write a algorithm for Huffman coding.

9) When u want to move a code from windows to linux what all changes do you need to
do your code to make it work in a similar way in windows.

10)How do you debug in linux. (GDB)

11)What are ways of optimizing an algorithm. what are the steps followed.

12) Write a program to find whether two binary trees are same.

Interview With Kodiak Networks for Audio & video Integration Engineer

1) How to do you find where a give architecture is Big Endian or Little Endian.

2) Who are the different bit rates  AMR -NB supports.

3) Sampling Freq Used in ARM-NB & WB.

4)How do you find the number of frames in a audio Packet.

5)What is NAL unit in H264.

6)How to find the Max No of Reference frames in  H264.

7)Difference between AMR-NB & WB.

8)If a stream is encoded for AMR-NB and has to be transmitted and at reception u have to come
that it supports on ARM-WB. How do you handle such situation.

9)What are the different Protocols used in transmitting a packet.

10) RTP Packet structure.

11) How to u determine the no of packets lost .

12)What are signals protocols u know what there purpose.

13)How do u compare two AMR-NB decoder libs from two different vendors and decide which is the best for your solution.

14)What the different factor you consider in the above comparison other that bit exactness and performance.

15)What is jitter effect in transporting packets

16) What the diff algorithms u know about handling jitter effect in transportation.

HEVC interview

1) Why HEVC?

2) How 50% reduction in bit rate is achieved at same visual quality.

3) What is the tools added to HEVC.

4)Advantages of using large block size (Coding tree Unit)  when compared to macro block.

5)What are the intra prediction modes supported.(35 modes)

6) How motion compensation is different from H264 in HEVC .

7) What are the different transforms used in HEVC( DCT, DST)

8) Why and Where DST is used

9) What are sizes of the transforms in HEVC.

10) Advantages of using large transform size in HEVC.

11) Why deblocking is done at 8x8 edge in HEVC instead of 4x4 in h264.

12) Why SAO.What type of artifacts are removed using SAO

13) Gibbs Phenomenon.

14) What is transform Skip.

15) How Tiles are different are from Slices in HEVC.

16) How do tiles support Symmetric Multi Core Processing.(SMP)

17) Whats WPP in HEVC.

18) What are the limitations on WPP when used on SMP.

Need for a DSP processor.

Note : Comments are welcome.

1)Find whether a give number can be written as 2^n.

2)WAP to reverse characters in a string.

3)WAP to reverse a single linked list.

4)WAP to swap the bytes in a word.

5)WAP to implement sizeof() operator in C.

6)Define a MACRO to extract bits in a word between (M,N) positions.

7)How do you prove the sum of two odd numbers is even

8)you have a 4 liter jug and a 7 liter jug. how do you measure 9 liters.

9)rand() generates values between 0 to 3 with probabilities 1/6,1/3,1/6,1/3 respectively.
now write a c_rand() function which generates 0 or 1 with 1/3 and 2/3 probabilities respectively.

10)Draw the block diagram of a DSP processor.

11)Draw the block diagram of Encoder.

12)Need for deblocking filter.

13)what will the following program print.

main()
{
int i = 0;
int *ptr = NULL;
ptr = (int*) malloc(i);
if(NULL == ptr)
printf("Failed");
else
printf("Success");
}

14) What all values are stored in heap memory,data segment and stack.

15) When you allocate resource to thread the values in semaphore decremented by one.where do this value be stored.

16)How do you detect a loop in a single linked list.

17)Tell me about Cache hit, miss

18)Cache Coherency and InCoherency.

19)How does a DMA work.

20)write an assembly program to implement reconstruction.

interview questions at an MNC

1. write the DCT equations (1D & 2D)

2. What is linear and non-linear quantization?

3. Which one we would use in jpeg compression?
4. What is vector and scalar quantization? Which one we would use in jpeg compression?

5. When you apply 90 degree rotation in spatial domain, what is the change in DCT domain?
Prove with equations.

6. Mpeg4SP block diagram

C programming: interview

1. Write function for bit reversal:

Char function(char Input_Number)
{
….
….
….
Return Output_Number;

}


ARM:

1. Explain 5 stage pipeline in ARM9E processor

2. compare ARM9, ARM11, Cortex.

Psychovisual Redundancy

PsychoVisual Redundancy

It is known that the human eye does not respond to all visual information with equal sensitivity. Some information is simply of less relative importance. This information is referred to as psychovisual redundant and can be eliminated without introducing any significant difference to the human eye. The reduction of redundant visual information has some practical applications in image compression. Since the reduction of psychovisual redundancy results in quantitative loss of information, this type of reduction is referred to as quantisation. The most common technique for quantisation is the reduction of number of colours used in the image., thus colour quantisation. Since some information is lost, the colour quantisation is an irreversible process. So the compression techniques that used such process are lossy. It should be noted that even if this method of compression is lossy, in situations where such compression technique is acceptable the compression can be very effective and reduce the size of the image considerably.

Aricent Interview experience

                                                                                                         
1. Questions on the architecture of the processors(multicore).
 
2. What is emulation byte.How an emulation byte is removed in ur architecture.

3. Why is it used?(emulation byte)

4. Difference between Cavlc and Cabac.

5. Asked to give detailed explaination of each cavlc and cabac with examples.

6. What are the final values that are sent to the decoder after arthimetic coding.
  (like range 0.34-0.367).

7. Explain each and every block in the encoder and decoder

8. Why reconstruction path is used in the encoder.

9. What can the 1st macro block of a frame can be coded in I frame.(IPCM or DC).

10.Explain reordering of the residual data.

11.Deblocking filter.

12.On what all parameters the boundary strength depends.

13.Tel me a case where BS=0.

14.Questions on motion estimation and compensation.

15.why half pel and quarter pel are used instead of  integer pel.

H.264 interview experience

1. What is a video codec.

2. why we need video compression.

3. what are the different types of redundancy in an image.

4. what is temporal redundancy.

5. what is spatial redundancy.

6. what is psycho visual redundancy.

7. what is statistical redundancy.

8. Draw the block diagram of video codec .

9. why there is a reconstruction path in the encoder.

10. What are the advantages and disadvantages of reconstruction path in encoder

Introduction

Hi all

The aim of the blog is to make people have good awareness about interviews.

It mainly has questions that are asked in the interviews by various companies.

I have found many sites where you can find interview questions and stuff.

Those sites are lacking many things . I never found interview experience

of people who are pursuing a career on embeddded systems & DSP

( Video codecs).I hope this blog helps you to gather the required stuff .

All the Best ...........