Query to convert SMS to speech in asterisk using festival

Hi experts,

I have just started working on asterisk and need to implement text-to-speech functionality through asterisk.
By studying asterisk, i got festival to do TTS in asterisk.

I have few queries, please clear them so that i could proceed further.

First, whether festival is inbuilt asterisk and if asterisk is installed properly then should i consider that festival is also installed on system or do i need to install festival separately and then attach festival with asterisk.

Second, as i studied festival that when i give festival calling in extensions.conf dial plan to convert text (that i passed as arguement into festival) into speech. I understood we can pass text string to convert into speech, like
Festival(testing festival on asterisk) : it will convert arguement text into speech.

but my question is what about text message that is coming from one client to get passed as speech to another clients via asterisk, how asterisk is going to save that message coming to it from one client, how it would be converted to speech. I read somewhere that thru

ReadFile(var=/tmp/test.txt)
Festival({$var})

it can convert text in file into speech.

So, how asterisk can save short text message into file ?

Please help, i have stuck.
Waiting for response
Thanking you.

Regards,
Tarun

Hi

Not sure about Festival, I use flite as it will do TTS on the fly and will do variables in a string for example

Flite(You have called ${EXTEN} ) and the like are all possible.

Ian