MP3 hard drive space / time calculator

4 replies [Last post]
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Joined: 01/12/2004

Hi there,

Any chance you've come up with a calculator that can convert a gigabyte of MP3's (stereo @ 128kps) to time?

Thanks in advance,

Dave K

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Joined: 02/12/2009

The hard drive space calculator I built only works for uncompressed audio. It's harder for MP3s. There are many mp3 encoding settings and variables to consider beside just the bit rate. So, it's not a straight calculation. But here's two easy solutions...

For Mac users, just install the MP3-Info Contextual Menu:
http://www.cdfinder.de/mp3info/index.html

For PCs or Macs, another easy method is to download iTunes:
http://www.apple.com/itunes/download/

Install and launch it, then turn off
Preferences--> Advanced--> "Copy files to iTunes Music folder"

Then drag your folder of mp3s into the iTunes library window. It will build a list of all the tracks. Look at the bottom of the window for the total time or you can browse by genre, artist etc to get subtotals. If you click on the time it will toggle between hours/minutes/seconds and hours in decimal form.

I did a quick check in my collection, and 1GB of 128k MP3s is about 18 hours, 22 minutes. (An iTunes Smart Playlist of 128k files limited to 1GB.) Your mileage will vary depending on album cover art, sample rate, VBR vs CBR etc.

(I like to turn off "Keep itunes Music folder organized" too because I organize my files by genre folders. More on that here.)

n/a
Offline
Joined: 01/12/2004

Thanks, Tony

We're in a slightly different situation here at a university archive where we have thousands of soundfiles on a remote server and just need to calculate the total time available, so the iTunes-solution isn't really workable for us (though I LOVE the program for encoding!).

Check out this chart from a pro-audio manufacturer that shows comparitive MP3 storage times:
http://www.d-mpro.com/Products/docs/PMD670_media_times.pdf

Would you mind looking it over to see if it seems accurate? (Their figure of 17:44 / GB seems pretty close to your calculation...)

Thanks for all of us struggling to manage these systems,

Dave

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Joined: 02/12/2009

Ah, there we go. Yeah, that chart is pretty good but slightly off. I checked it against various bitrates and drive space. The time on the chart seems to be consistently lower than my times by about 2-3% for the same rate/space. But that's pretty close!

Plus, my files are mostly full stereo (not joint stereo), and they have embedded album art. So they are larger files than your typical mp3 of the same bitrate. Which means that my collection should reflect _less_ time for the same hard drive space. So maybe that chart is actually high by 5% or more for the typical mp3 collection?

Like I said before, there are many parameters beside bitrate to consider.

Since that chart is based on the files recorded by the Marantz PD670, that chart reflects times for the particular variety of 128k mps that it records. Is it joint stereo? Variable bitrate?
http://www.d-mpro.com/Products/PMD670.html

Also note that 128k mono is the same time per space as 128k stereo, which has always seemed counter-intuitive to me. Basically, 128k mono is (1) 256k track. I've always felt that it should be (1) 128k track. But I guess it's reasonable to assume stereo (ie 2 tracks) as the assumed track count.

n/a
Offline
Joined: 01/12/2004

All good points and questions; for our purposes just knowing that a
gigabyte equals roughly 17:44 is close enough - we just need a constant
multiplier to tracks trends and plan storage. Thanks much for your
help & interest, Tony.

Sonic regards,

Dave

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