# How many hours with 50MB cap with 24kbps stream?

Discussion in 'iPhone' started by ieko, Aug 11, 2008.

1. ### ieko macrumors member

Joined:
Oct 27, 2006
#1
I'm about to go to Russia and I'd like to use my iPhone 3G while I'm there, but I'm not sure how quick I'd burn the 50MB data cap while streaming audio at 24kbps. If anyone knows how to figure this out I'd really appreciate it, I tried to figure it out myself but I'm not sure if I'm doing it correctly. Thanks in advance!

2. ### Dmac77 macrumors 68020

Joined:
Jan 2, 2008
Location:
Michigan
#2
a 1024 kb's is one MB. so at that rate, you'll have around 35.5 minutes of audio stream.

Hope this helps!

Don

3. ### RobLikesBrunch macrumors regular

Joined:
Aug 1, 2008
#3
35.5555555555555555555555555555555555555555555555555555556 minutes

You rounded incorrectly!

It'd be 35.6 minutes!

4. ### Dmac77 macrumors 68020

Joined:
Jan 2, 2008
Location:
Michigan
#4
Damn you! Had to beat me didn't you

Don

I don't think that he'll miss the extra 29 seconds.

Don

5. ### ieko thread starter macrumors member

Joined:
Oct 27, 2006
#5
Haha okay, I came up with that number too but I wasn't sure. Thanks guys! I guess I'll be skipping that data plan!

Joined:
Jan 15, 2006
Location:
The Kop
#6
Aren't there 8 bits in a byte ?

If so then it would be quite a lot longer

Therefore the 24kbps is equal to 3KB/s

(50MB * 1024) = 51200KB cap

512000 / 3 = 17066 seconds

Which converts to 17066 / 3600 = 4 hours 45 minutes approximately

7. ### RobLikesBrunch macrumors regular

Joined:
Aug 1, 2008
#7
Music + data rates are measured in kilobits, not kilobytes.

"A kilobit per second (kbit/s or kb/s or kbps) is a unit of data transfer rate equal to 1,000 bits per second. It is sometimes mistakenly thought to mean 1,024 bits per second, using the binary meaning of the kilo- prefix, though this is incorrect."

Examples:

* 56k modem — 56,000 bit/s
* 128 kbit/s MP3 — 128,000 bit/s [1]
* 64k ISDN — 64,000 bit/s [2]
* 1536k T1 — 1,536,000 bit/s (1.536 Mbit/s)

Most digital representations of audio are measured in kbit/s:

(These values vary depending on audio data compression schemes)

* 4 kbit/s – minimum achieved for encoding recognizable speech (using special-purpose speech codecs)
* 8 kbit/s – telephone quality
* 32 kbit/s – MW quality
* 192 kbit/s – Nearly CD quality for a file compressed in the MP3 format

If your music was playing at 3kb/s it'd sound like white noise. 24kbps is already incredibly low compared to the average MP3 being around 128-192kbps.

But...it's 1,000 bits per second, so we all got it wrong, you're really going to get 34.72 minutes.

Joined:
Jan 15, 2006
Location:
The Kop
#8
That is why I converted it to bytes.

The actual conversion is to about 2.93KB/s.

9. ### Jaiden macrumors member

Joined:
Apr 6, 2008
#9
hey, a really easy way to do stuff like this is using the build in converters at google. just type in 24kbps to megabytes per hour and divide 50 by the result, and there's you're hours.

4.740740740740741 hours = 4 hours, 44 minutes, 26.6666666666676 seconds (it's always nice to have that extra .0000000000006 of a second )

I'm pretty sure google would be right, over a poster on a forum, but even so, xUKHCx still seems to be right. Here's the link if you're too lazy: http://www.google.com.au/search?q=24kbps+to+megabytes+per+hour

10. ### PoitNarf macrumors 65816

Joined:
May 28, 2007
Location:
Northern NJ
#10
I sincerely hope that none of the people that failed to do the bits to bytes conversion have a Computer Science degree

11. ### Moomba macrumors regular

Joined:
Jun 7, 2008
Location:
Charlotte, NC
#11
I know this isn't exactly what you were asking but when I was living in the Ukraine I found it ideal to simply pickup a SIM card from a local carrier. Obviously, this plan would require you to use a different phone other than your iPhone that was unlocked. I used an old Razr and Samsung Blackjack while I was there. It is also easy to buy unlocked phones there as they are the norm. Oh my point... you can do this and use the money on the pay as you go cards for data connection. Whether it be streaming audio, tethering to a computer, email, etc. It works fairly well and I found it to be the most cost effective solution overall when I was living there. Heck... I even played a couple MMORPG's via a tethered connection this way. Depending how much you use it can be a little pricey but is still far cheaper than paying data roaming charges.

12. ### ViViDboarder macrumors 68040

Joined:
Jun 25, 2008
Location:
USA
#12
Hehe, yea. Just look at your iTunes libraries!

If 24kbps would only give 34.72 minutes, then a 6.5 minute song at 128kbps would be 50MB!!!!! Well... I'll tell you that's not true

13. ### RobLikesBrunch macrumors regular

Joined:
Aug 1, 2008
#13
I understood the question as if the data was being transferred at a rate of 24kbps.

128kbps MP3s play at 128kbps, but they're compressed in the MP3 format, so they're small files. But when you play the file, you're essentially "decoding" it, so it plays at 128kbps.

14. ### ViViDboarder macrumors 68040

Joined:
Jun 25, 2008
Location:
USA
#14
Yeeeeesss... Ok. I don' tsee how that changes anything. So even if you were transfering any file at 24kbps it wouldn't matter. That's what was done. The calculation how much time at 24kbps does it take to transfer 50MB. So it's exactly as you understood the question.

How the file is decoded is irrelevant. A 128kbps MP3 is about 2x as large as a 64kbps MP3. It's kind of how it works. The compression to 128kbps limits the song to around 128kbps.