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Hydrogenaudio Forum => General Audio => Topic started by: WaldoMonster on 2006-02-21 18:39:14

Title: Calculate file size from bitrate and playtime
Post by: WaldoMonster on 2006-02-21 18:39:14
Is this calculation right?
I hope I didn't fucked up with switching bits and bytes 

Thanks for the help,

Willem


Code: [Select]
Bitrate 64 kbps
Playtime 5 min

64 kbps = 64000 bps

5 min = 5 x 60 = 300 sec

            64000
64000 bps = ----- bytes/sec
              8

64000 * 300                    2400000
----------- = 2400000 bytes = ----------- = 2.29 MB
     8                        1024 * 1024
Title: Calculate file size from bitrate and playtime
Post by: Madrigal on 2006-02-21 19:51:54
Try this (http://mp3.wp.pl/p/programy/sciagnij/232.html).

Regards,
Madrigal
Title: Calculate file size from bitrate and playtime
Post by: hybridfan on 2006-02-21 20:17:57
Quote
Try this (http://mp3.wp.pl/p/programy/sciagnij/232.html).

Regards,
Madrigal
[a href="index.php?act=findpost&pid=366071"][{POST_SNAPBACK}][/a]


Wow that's really neat but does not go up to 320kbps.
Title: Calculate file size from bitrate and playtime
Post by: Alex B on 2006-02-21 20:25:47
Quote
Is this calculation right?[a href="index.php?act=findpost&pid=366054"][{POST_SNAPBACK}][/a]

It's correct.

Normally and usually a kilobit = 1,000 bits (e.g. when data transfers speeds are showed), but a kilobyte = 1,024 bytes (e.g. when file sizes are showed).

Only HD manufacturers have a bit different math. They think that 1 GB = 1,000,000,000 bytes and so on. I guess a bigger GB amount looks better. 
Title: Calculate file size from bitrate and playtime
Post by: WaldoMonster on 2006-02-21 20:29:16
Thanks for that tool 
This calculation is right for Bytes.

Mabe the tool is wrong regarding Bytes to KBytes, MBytes, etc...
It uses a factor 1000 I thought for storage they used a factor 1024,
exept for Hard Disk's because it looks better that way

<update>
Hello Alex B,

I think we typed it the same time 
</update>
Title: Calculate file size from bitrate and playtime
Post by: Alex B on 2006-02-21 20:41:41
Quote
Thanks for that tool  
This calculation is right for Bytes.

Mabe the tool is wrong regarding Bytes to KBytes, MBytes, etc...
It uses a factor 1000 I thought for storage they used a factor 1024,
exept for Hard Disk's because it looks better that way

<update>
Hello Alex B,

I think we typed it the same time  
</update>[a href="index.php?act=findpost&pid=366080"][{POST_SNAPBACK}][/a]

Yeah, and that tool indeed shows incorrect KB, MB and GB values.

Also, the real 128 kbps 2min 30s files I have are almost exactly 2.3 MB. (I don't have 64 kbps files.)
Title: Calculate file size from bitrate and playtime
Post by: kindofblue on 2006-02-22 04:54:07
Very interesting. Thanks for this. I have a lot of 64kbps files (LAME -V9 -vbr-new), and I've been wondering about how to calculate filesizes as well. According to your formula, a -V9 encoded file (~64kbps) would take up 0.46MB per 1 minute of music, so an hour's worth would be 27.47MB. I'm trying to find out the maximum number of songs I can fit in a 1GB flash player with V9, V8 and V7.