[asterisk-users] [voice mail] Estimating file size?

[Gordon Henderson]

On Sat, 26 Jun 2010, Gilles wrote:

> Hello
>
> 	To run Asterisk on an embedded appliance, ie. where RAM and
> non-volatile memory is an issue (respectively 64MB and 256MB), I need
> to check how much space voice messages take to save and play back.
>
> The appliance is connected to a landline in Europe (in case that makes
> a difference as far as codecs are concerned).
>
> Is there a document that shows the different options, with/without
> compression, so I can make an informed choice?

As far as I'm aware, voicemail just stores the files in the format 
specified in the config file without any overhead.. So if storing using 
G711, then the length of the file in seconds is the length of the file in 
bytes / 8000. GSM is 13Kb/sec, or 1625 bytes/second.

However, you can trivially test it for this and other codecs:

Dial an extension that answers and stores to voicemail, say blah blah into 
it for one minute and check the resulting file size. divide it by 60 and 
you'll get a good estimate of the number of bytes per second of recording 
for your chosen format.

Of-course the size of each voicemail is stored in the .txt file associated 
with each one, and I guess what you're probably after is how much storage 
space is left in seconds, so that's easy too, once you have the conversion 
factor - worked out as above and using whatever functions your scripting 
language has for working out how much disk space is left (e.g. 
disk_free_space() and disk_total_space() in PHP)

Gordon