WHAT’S THIS? ….. WHAT CHANGES? Uptown Funk 1 Uptown Funk 2. Uptown Funk 3
Preview:
Citation preview
- Slide 1
- Slide 2
- Slide 3
- WHATS THIS? ..
- Slide 4
- WHAT CHANGES? Uptown Funk 1 Uptown Funk 2. Uptown Funk 3
- Slide 5
- LESSON OUTCOME I understand and can explain how sound is stored
by a computer system.
- Slide 6
- WHAT DO I NEED TO KNOW AT GCSE? (a)Explain how sound can be
sampled and stored in a digital form (b)Explain how sampling
intervals and other considerations affect the size of a sound file
and the quality of its playback I understand how sound is stored by
a computer system.
- Slide 7
- THEORY NOTES Sound just like images are stored in binary format
that is then read and interpreted by a computer with the use of
metadata. Sound is often a continuously varying data (analogue) but
a computer needs this in binary format so it needs to be
transferred from analogue to digital form. To do this we sample the
sound wave at set intervals and record the values, this set of
values is saved and replayed by the computer. I understand how
sound is stored by a computer system.
- Slide 8
- BAR CHARTS - TWO SAMPLING RATES 134 245 327 410 53 625 735 83
99 1025 1116 1232 0.534 140 1.545 235 2.527 312 3.510 46 4.53 511
5.525 630 6.535 715 7.53 86 8.59 918 9.525 1021 10.516 1123 11.532
1236
- Slide 9
- SO WHAT'S THE DIFFERENCE? Uptown Funk at Normal 96000hrtz
sampling and bit rates. Uptown Funk at Half 48000hrtz sampling and
bit rates. Uptown Funk at Quarter 24000hrtz sampling and bit rates.
I understand how sound is stored by a computer system.
- Slide 10
- TASK Add a description to your graphs about what we have just
discussed. You can use the notes below to help you; The sample rate
affects the quality of the sound, a high or more frequent sample
rate improves quality as it is closer to the original but involves
a larger file size. A lower sample rate will have reduced quality
as it is less close to the original however the trade off is a
lower file size.
- Slide 11
- BIT RATE The bit rate is the amount of data that can be used to
store each sample. So as before a higher bit rate will lead to
better quality playback but will require a large file size, a lower
bit rate will reduce the file size but result in lower quality
playback. I understand how sound is stored by a computer
system.
- Slide 12
- IMPORTANT KEYWORDS Dont confuse sample rate and bit rate! They
are different. The sample rate is how frequently the data is
sampled. The bit rate is the amount of data stored at each sample
point. I understand how sound is stored by a computer system.
- Slide 13
- QUESTIONS How does the sample rate affect the quality of the
playback for an MP3 sound track? What factors affect the file size
for a sampled MP3 track? Why are there so few tracks on a typical
audio CD? Which sound file formats (MP3, WAV etc.) sample most
frequently and less frequently? I understand how sound is stored by
a computer system.