Tech-Guide

                                            "C" Questions Practice Set

1. What is C language ?
2. What does static variable mean?
3. What are the different storage classes in C ?
4. What is hashing ?
5. Can static variables be declared in a header file ?
6. Can a variable be both constant and volatile ?
7. Can include files be nested?
8. What is a null pointer ?
9. What is the output of printf("%d") ?
10. What is the difference between calloc() and malloc() ?
11. What is the difference between printf() and sprintf() ?
12. How to reduce a final size of executable ?
13. Can you tell me how to check whether a linked list is circular ?
14. Advantages of a macro over a function ?
15. What is the difference between strings and character arrays ?
16. Write down the equivalent pointer expression for referring the same element a[i][j][k][l] ?
17. Which bit wise operator is suitable for checking whether a particular bit is on or off ?
18. Which bit wise operator is suitable for turning off a particular bit in a number ?
19. Which bit wise operator is suitable for putting on a particular bit in a number ?
20. Does there exist any other function which can be used to convert an integer or a float to a string ?
21. Why does malloc(0) return valid memory address ? What's the use ?
22. Difference between const char* p and char const* p
23. What is the result of using Option Explicit ?
24. What is the benefit of using an enum rather than a #define constant ?
25. What is the quickest sorting method to use ?
26. When should the volatile modifier be used ?
27. When should the register modifier be used? Does it really help ?
28. How can you determine the size of an allocated portion of memory ?
29. What is page thrashing ?
30. When does the compiler not implicitly generate the address of the first element of an array ?
31. What is the benefit of using #define to declare a constant ?
32. How can I search for data in a linked list ?
33. Why should we assign NULL to the elements (pointer) after freeing them ?
34. What is a null pointer assignment error ? What are bus errors, memory faults, and core dumps ?
35. When should a type cast be used ?
36. What is the difference between a string copy (strcpy) and a memory copy (memcpy)? When should each be used?
37. How can I convert a string to a number ?
38. How can I convert a number to a string ?
39. Is it possible to execute code even after the program exits the main() function?
40. What is the stack ?
41. How do you print an address ?
42. Can a file other than a .h file be included with #include ?
43. What is Preprocessor ?
44. How can you restore a redirected standard stream ?
45. What is the purpose of realloc( ) ?
46. What is the heap ?
47. How do you use a pointer to a function ?
48. What is the purpose of main( ) function ?
49. Why n++ executes faster than n+1 ?
50. What will the preprocessor do for a program ?
51. What is the benefit of using const for declaring constants ?
52. What is the easiest sorting method to use ?
53. Is it better to use a macro or a function ?
54. What are the standard predefined macros ? 

"C++" Questions  Practice Set

1. How do you check whether a linked list is circular?
2. How do you decide which integer type to use?
3. How do you differentiate between a constructor and destructor?
4. How do you differentiate between aggregation and association?
5. How do you find out the size of a class?
6. How do you implement an itoa function?
7. How do you initialize a pointer to a function?
8. How do you link a C++ program to C functions?
9. How do you return a structure from functions?
10. How do you write a function that can reverse a linked-list?
11. What are the benefits of using exceptions in C++?
12. What are the differences between a struct and a class in C++?
13. What are the different types of Storage classes?
14. What do you mean by inline function?
15. What does extern mean in a function declaration?
16. What does extern mean in a function declaration?
17. What does it mean to declare a function or variable as static?
18. What is a conversion constructor?
19. What is a copy constructor?
20. What is a namespace?
21. What is a pure virtual function?
22. What is a scope resolution operator?
23. What is abstraction?
24. What is difference between #define and const?
25. What is difference between function overloading and overriding?
26. What is encapsulation?
27. What is function overloading?
28. What is multiple inheritance?
29. What is operator overloading?
30. What is partial specialization or template specialization?
31. What is polymorphism?
32. What is the difference between “passing by value” and “passing by reference”?
33. What is the difference between an object and a class?
34. What is the difference between declaration and definition?
35. What is the difference between declaration and definition?
36. What is the difference between delete and delete[]?
37. What is the difference between inner class and abstract class?
38. What is the difference between persistent & non-persistent objects?
39. What is the difference between structure and union?
40. What is the difference between the deep copy and shallow copy?
41. What is the difference between the private public and protected members?
42. What is the maximum size that an array can hold?
43. What is the most efficient way to reverse a linked-list?
44. What is the size of an empty class?
45. What is the use of virtual destructor?
46. What is virtual class and friend class?
47. What’s the best way to declare and define global variables?
48. Where is memory for class-object allocated?
49. Where is memory for struct allocated?
50. Why an array always starts with index zero in C++?

courtsey : www.mycplus.com

"Android Multimedia StageFright/OMX/CODEC "

1. what happens when we seek?How does it work?
2. what is flush ? how does it happen?
3. what is the diff between prepare and prepareAsync execution wise?
4. what are the different states of mediaplayer?
5. what is the role of Awesomeplayer?
6. what all happens when we say start in mediaplayer?
7. what all happens as part of play in Awesomeplayer?
8. how does data gets read from extractor? how does it relate to Awesomplayer?
9. what is extractor? name different parser?what is mime-type?what is the source?
10. what does onVideoEvent function do in Awesomeplayer?
11. How does AV Sync happen in AV playback? Do we need AV Sync while Encoding too?
12. Explain frame drop and jitter issue?
13. what is OMX? tell about android Playback architecture?
14. Explain StageFright? How does it work in the playback architecture?
15. what is OMX IL Client ? OMX DL ? OMX Hardware Component?
16. how does decoder get allocated? how does it get integrated ?
17. how does buffer get allocated on ports?
18. explain the OMX calls made to component in steps for entire decoding process?
19. explain empty this buffer /fill this buffer mechanism and their callbacks?
20. how does input buffers get metadata and decoded output buffers gets rendered?
21. Explain graphics buffers , Media buffers , grapics allocator?
22. Explain the rendering path of decoded data from output buffer? what is the role of Surface flinger , hardware composer , gralloc?
23. hardware rendering and software rendering?
24. how about memcpy in these paths?How do we ensure fps?
25. what is OMX component tunneling ? how does it work?
26. If we have to include new hardware parser , how will we intgrate ?
27. what is buffer different field? what is mapping in omx?
28. how does thumbnail and playback decoding differs in the path?
29. how does stagefright implement source and sink concept?
30. what is the role of Audioplayer?
31. how does audio get decoded?
32. what if there is chopping in audio?
33. how to take PCM dump?
34. what is ALSA ? what is periodic buffers ? how many buffers get allocated and how?
35. explain the architecture for AV recording?
36. how does audio video sync happens?
37. how does timestamp encoded with each frame? fps?
38. how does camera preview works and how about if there is frame drop in preview?
39. how does frame pass to stagefright? how does it passed to encoder input? what is the format of encoder input and preview ?
40. how does audio get recorded along with video?
41. what happens with the buffers when we zoom in between or rotate the phone ?
42. what is the data sensor provide ? what are different components involved?
43. Why do we need different color formats like YUV. RGB444 RGB888 RGBA RGB565?
44. how does preview works and same buffer goes to stagefright encoder or different? how does input buffer gets data to encode?
45. how does gallery work? what does it show on album?
46. how does file manager work? what does it show for Audio video in screen?
47. what is thumbnail ? how does it work?
48. what are different frames ? how does they encoded and decoded?draw block diagram?
49. do we give entire frame for encoding or macroblock?
50. what are the size of macro block and why for H264?
51. what are the different profiles and levels of H264?
52. why H264 is better than mpeg4?
53. what is reference frame?
54. what is DPB?
55. what is display time and decoded time?
56. explain different input and ouput color formats?
57. what is DCT? why do we use DCT? why do we use 8x8 block DCT for MPEG4 and 4x4,8x8 DCT for H.264?
58. how about energy and data loss during transformation?
59. what is lossy and loss-less?                                                
60. what is POC (Picture Order Count), DON(Decoding Order Number) and Frame Number?
61. what is I, P, B, D, IDR and Reference frames?

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