[asterisk-users] stream file outputs only silence, even with asterisk example gsm file

[Guido Sohne]

Hi all!

I am trying to hook up a text to speech system to Asterisk via AGI.
The AGI script generates a sound file and tells Asterisk to play that
file via STREAM FILE. I am creating the sound file in alaw format.

My problem is that I do not get any sound output on my softphone (IAX
soft phone)

AGI Rx << EXEC AGI tts.agi|"Hello! Welcome to Asterisk!!"
AGI Tx >> agi_request: tts.agi
AGI Tx >> agi_channel: IAX2/1234-2
AGI Tx >> agi_language: en
AGI Tx >> agi_type: IAX2
AGI Tx >> agi_uniqueid: 1154082448.87
AGI Tx >> agi_callerid: 10101
AGI Tx >> agi_calleridname: Guido Sohne
AGI Tx >> agi_callingpres: 0
AGI Tx >> agi_callingani2: 0
AGI Tx >> agi_callington: 0
AGI Tx >> agi_callingtns: 0
AGI Tx >> agi_dnid: 100
AGI Tx >> agi_rdnis: unknown
AGI Tx >> agi_context: corenett
AGI Tx >> agi_extension: 100
AGI Tx >> agi_priority: 1
AGI Tx >> agi_enhanced: 0.0
AGI Tx >> agi_accountcode:
AGI Tx >>
AGI Rx << STREAM FILE /tmp/tmp4636.92179778618 #
AGI Tx >> 200 result=0

Checking /tmp, we see that the file does exist, which ties in with the
200 response code after the script issues a STREAM FILE command to
Asterisk AGI.

ls -l /tmp
-rw-r--r--  1 asterisk root 75388 2006-07-28 10:27 tmp4636.92179778618.alaw

I've tried to copy one of the original Asterisk sound files into /tmp
and then do a STREAM FILE on it. That also does not result in any
sound being played!

AGI Rx << STREAM FILE /tmp/why-no-answer-mystery #
AGI Tx >> 200 result=0

ls -l /tmp
-rw-r--r--  1 guido    guido 10626 2006-07-28 10:31 why-no-answer-mystery.gsm

So what gives here? I can't understand what is going wrong and would
appreciate some help.

-- G.