Multimedia Formulas Thread (1 Viewer)

[Forbidden.]

Unlike General Mathematics or Physics where you will be given a formula sheet, you will need to memorise and apply formulas where necessary to solve problems on file sizes in IPT.

It is very likely you will be requested NOT to calculate an answer (like in Maths Ext. 1 were you may be asked NOT to prove an equation), don't, you will be wasting time if you do.

Additionally, calculators are NOT allowed in the IPT examination.

Essential Info:

1 byte = 8 bits (Divide your calculation by 8 to get a byte)

1 Kilobyte (KB) = 1024 bytes (Divide your calculation by 1024)
1 Megabyte (MB) = 1024 x 1024 bytes (Divide your calculation by 1024 x 1024)
1 Gigabyte (GB) = 1024 x 1024 x 1024 (Divide your calculation by 1024 x 1024 x 1024)


File size of image

Bit depth = No. of bits per pixel
Resolution = Horizontal x Vertical pixels
Total file size = Resolution x Bit depth

File size = Resolution x Bit Depth

e.g
Calculate the file size of an image in megabytes with a resolution of 1024 x 768 with a bit-depth of 24 bits.

File size (Megabytes) = 1024 x 768 x 24 / 8 x 1024 x 1024 MB

File size of a sound file

File size = Sample rate x Sample size x No. of sound tracks

e.g
Calculate the file size of a 2 minute stereo soundtrack with a sampling rate of 56,200 Hertz and sampling size of 32 bits in megabytes.

File size (Megabytes) = 120 x 2 x 56200 x 32 / 8 x 1024 x 1024 MB

NOTE:
Stereo uses two channels which would double the overall file size of the song hence you multiply by 2.
Additionally, 2 minutes is the equivalent of 60 x 2 seconds.

File size of a video

Total no. of frames = Frame rate x Running time
File size for each frame = Horizontal x Vertical x Bit depth
Total movie file size = Total no. of frames x Individual frame size

e.g
Calculate the file size of a video in megabytes with a frame rate of 25 frames per second, with a resolution of 1024 x 768, bit depth of 32 bits and a running time of 1 hour.

File size (Megabytes) = 25 x 1024 x 768 x 32 x 60 x 60 / 8 x 1024 x 1024 MB

NOTE:
One hour is the equivalent of 60 x 60 seconds i.e. 3600 seconds.
We use seconds because the frame rate is given in seconds.

 

[LatK7]

Thanks. That's appreciated.

One question. Do you think we'll get one of the above this year?

 

[nubix]

[Offtopic]I still can't believe this IPT course is teaching the wrong shit. A KILOBYTE = 10^3 = 1000... KIBIBYTE = 2^10 = 1024. [/Offtopic]

Thanks!

 

[Beege]

Thanks. That's appreciated.

One question. Do you think we'll get one of the above this year?

i reckon we will, last year's paper was easy so I reckon we will get a hard paper this year.

 

[Forbidden.]

[Offtopic]I still can't believe this IPT course is teaching the wrong shit. A KILOBYTE = 10^3 = 1000... KIBIBYTE = 2^10 = 1024. [/Offtopic]

Thanks!

On the other hand ... some textbooks forget to mention that there is a magnetic field to deflect electrons in a CRT monitor, otherwise there will be only a single bright dot on the centre.

i reckon we will, last year's paper was easy so I reckon we will get a hard paper this year.

Uh oh ... But it's the rank that really matters doesn't it ?

Thanks. That's appreciated.

One question. Do you think we'll get one of the above this year?

Like my Physics teacher says, don't budget your learning.

 

[Snowfreq]

Thanks for that. Had them all over the place... nice and neat.:rofl:

 

[LatK7]

Just a question regarding one of the past paper questions. 2003 multi choice, question 14

http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2003exams/pdf_doc/info_process_tech_03.pdf

The correct answer is D, now is this because the data is already considered to be in bytes?

Sorry about the noob question.

 

[nubix]

Just a question regarding one of the past paper questions. 2003 multi choice, question 14

http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2003exams/pdf_doc/info_process_tech_03.pdf

The correct answer is D, now is this because the data is already considered to be in bytes?

Sorry about the noob question.

Yes

 

[LatK7]

Thanks for that!

 

[Xenmae]

is it possible to simplify the audio algorithm to make it easier as it was in the trials of my hsc

 

[Starcraftmazter]

One question. Do you think we'll get one of the above this year?

It would be crazy if they didn't.

[Offtopic]I still can't believe this IPT course is teaching the wrong shit. A KILOBYTE = 10^3 = 1000... KIBIBYTE = 2^10 = 1024. [/Offtopic]

Couldn't agree more. Those damn nubcakes.

is it possible to simplify the audio algorithm to make it easier as it was in the trials of my hsc

Can you post the question? I (for one) am not really following.

 

[Xenmae]

more or less it said that you had 5.5 gigs of remaining hard drive space left and wants to know both the file size of a 100 minute mono sound file at 44100 frequency, 64kbps and if it would fit on the hard drive

 

[Starcraftmazter]

Yes, I remember that question. But what do you mean simplifying the audio algorithm? It's just a simple calculation to determine if it fits or not.

 

[fooguru]

Just a question regarding one of the past paper questions. 2003 multi choice, question 14

http://www.boardofstudies.nsw.edu.au/hsc_exams/hsc2003exams/pdf_doc/info_process_tech_03.pdf

The correct answer is D, now is this because the data is already considered to be in bytes?

Sorry about the noob question.

I am just wondering if it is assumed because a character is one byte?

 

[Starcraftmazter]

Yes, but I will find it very odd if they don't tell you. For example:

"A data stream consists of 7bit ASCII characters and one bit parity, like so:
10101010 10010101 11001010. Bla Bla Bla Bla Bla. Bla bla bla bla bla bla?".

 

[Xenmae]

[offtopic/]how easy was the IPT exam KEKEKEKEKEKEKE what about the mistake in 21[offtopic/]

 

[ehtefaz.hedayet]

thanks for the help 'Forbidden'

 

[Uncle]

thanks for the help 'Forbidden'

wow nice bump.
i actually did use one of these formulas in the HSC 2007 exam.
ah the memories.

even better i think they tell you to leave it as working out since you dont have the time or a calculator to evaluate it.