The Big Brother TV production team have contacted you to analyse whether their show could be broadcast using UHSatellite which is limited at 6,000,000 bits per second per TV channel. Big Brother cameramen now use HD digital cameras and only one is broadcast at a time. High Definition is used to have a closer look at the action. The resolution for each frame consists of Y = 1440 麓 1080, Cb = Cr = 720 麓 540, each pixel is quantised using 8 bits and the frame rate is 25 frames per second.
1.1 Given the resolution above, what is the size of a full uncompressed frame (in bits)?
1.2 The digital video signal is then MPEG encoded. You are told that the group of pictures (GOP) span N=12 and the prediction span M=4. With this information, use a diagram to show the frame sequence. Describe the frame types that are found in MPEG encoding.
1.3 Taking this into account, how many GOPs are streamed on average in 1 second?
The production team has given you the following table stating the average compression for each frame:
I-frame 10:1
P-frame 20:1
B-frame 60:1
1.4 Using this information, what is the size of a GOP (in bits)?
1.5 Knowing the size of the GOP, calculate the bit rate that will be generated by the encoder.
1.6 Finally, from the results above, comment on whether you would recommend UHSatellite to broadcast Big Brother. . OK, that's fairly easy. 1.1 and 1.3 aren't viable questions. Sorry.
Q. 1.4 and 1.7 don't provide enough information. sorry.
1.2 and i think 1.6 are both 7. er, or 6.5. Doesn't matter.
And of course 1.5 is the trick Q. The 'GOP' is a negative number so the 'encoder' would actually be enveloped in its own Black Hole and eventually, well, within 3.9 nanaseconds, would implode the entire universe.
Of course that's just my best guess. Am I close? ok seriosly did you come up with that yourself? or do you have no life... to bad nobody solved your problem! |
