blob: 62e11062ddf0b5d305003855d194aea950ea1995 (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
|
\begin{questions}
\question Lucy records using her camera. The camera saves the
audio and video parts of the recording seperately. Lucy transfers
recording to her computer. The audio file has a size of 12.8 kB.
Audio is recorded at a sample rate of 320 kB per second. The audio
resolution is 32 bits.
\begin{parts}
\part[5] In minutes, how many seconds was the recording.
\vspace{\stretch{1}}
\part[5] A video file consists of many still frames. Each
frame is a normal image. The size of a video file can
therefore be expressed as:
\begin{align*}
\mbox{Video file size} = \mbox{Number of frames} \times
\mbox{Size of each frame}
\end{align*}
If each frame is 1920 pixels wide and 1080 pixels high in
resolution, and the bit depth of 24 bits, what is the file
size of the video file.
\vspace{\stretch{1}}
\pagebreak
\part[1] Lucy combines the audio and video to form a file. She
then runs a lossy compression algorithm on the resulting file.
What is lossy compression?
\vspace{\stretch{1}}
\part[3] The file size after compression is reduced by 20\%.
What is the final file size?
\vspace{\stretch{1}}
\part[1] State an assumption made for part (d).
\vspace{\stretch{1}}
\end{parts}
\droptotalpoints
\end{questions}
|
