determining storage and download time (1 Viewer)

[Chickadee]

hope someone can help, i was just trying to work out the storage size for a video file for 10 sec of full screen tv quality is this right?

640x480x1=307200/1024
= 30/1024=0.29296875x30
= 8.7890625x10 = 87.89MB

then i was seeing how long it would take to download and this is where it gets confusing, i was using an online calculator and got this

87.89MB : 56k modem = 3 hrs 39 mins 25 secs

is it all correct

thanks

 

[AntiHyper]

Well it depends on the colour depth.. say for 32-bit:
640 x 480 x 32 = 9,830,400 bits
9,830,400 / 8 = 1,228,800 bytes
1,228,800 / 1024 = 1,200 kilo bytes (per frame)
Assuming that the pictures are recorded at 25 fps:
1,200 x 25 = 30,000 kbps
30,000 x 10 = 300,000 kb/10 seconds
300,000 / 1024 = 292.96875 MB/10 seconds
But you must consider that most encoders would compress it and the final result is assumed to have used all 32 bits of colour per pixels per frame

 

[Chickadee]

Well it depends on the colour depth.. say for 32-bit:
640 x 480 x 32 = 9,830,400 bits
9,830,400 / 8 = 1,228,800 bytes
1,228,800 / 1024 = 1,200 kilo bytes (per frame)
Assuming that the pictures are recorded at 25 fps:
1,200 x 25 = 30,000 kbps
30,000 x 10 = 300,000 kb/10 seconds
300,000 / 1024 = 292.96875 MB/10 seconds
But you must consider that most encoders would compress it and the final result is assumed to have used all 32 bits of colour per pixels per frame

but what i have is it correct

 

[sunny]

but what i have is it correct

No, as AntiHyper already mentioned, you didn't take into account bit depth, or frame rate.

 

[melsc]

to work out the file size of a video u need to do the following calculations.

horizontal*vertical*bit depth (bits per pixel)/ 8*1024 (this answer will be in kb)

then u need to times that by frame rate * number of frames

 

[Korn]

to work out the file size of a video u need to do the following calculations.

horizontal*vertical*bit depth (bits per pixel)/ 8*1024 (this answer will be in kb)

then u need to times that by frame rate * number of frames

U also have to equate sound into the equation

 

[melsc]

omg yes i forgot... sound is...

sample rate * sampling size * (1 for mono) or (2 for stereo)/ 8* 1024

I wouldnt bother using these equations, I only use them 4 IPT

 

[Korn]

omg yes i forgot... sound is...

sample rate * sampling size * (1 for mono) or (2 for stereo)/ 8* 1024

I wouldnt bother using these equations, I only use them 4 IPT

Do u know these equations off the top of ur head? Cause if u do u will probably go well in IPT

 

[melsc]

LOL my half yearly was 2 weeks ago so i learnt them for that...and they werent in it LOL

 

[Korn]

LOL my half yearly was 2 weeks ago so i learnt them for that...and they werent in it LOL

Yeah, i cant remember if we really need to know them, but i dont, i dont think i did either and i got Band 5, so u probably will ace

 

[melsc]

awwwww u're sweet...I hope so

 

[AntiHyper]

U don't need to remember those equations.. you just think them up as you go

 

[fatmuscle]

sorry, but does this belong into IPT section?

Mods' - ur call.