Summary:ASTERISK-06533: Audio file playback distorts on EM64T machine
Reporter:Shawn Lawrence (radar)Labels:
Date Opened:2006-03-13 01:36:54.000-0600Date Closed:2006-05-26 09:55:25
Versions:Frequency of
Description:Both GSM and S-Linear audio files have poor audio quality when played back running a server with an EMT64 processor.  I used demo-congrats.gsm (standard audio file) as a basis for comparison.  The server is running the 1.2 SVN branch code on CentOS 4.


I have a Dell 850 server containing an Intel 2.8GHz EMT64 chip running the SVN 1.2 release branch on CentOS 4.  I got a complaint from a customer noting their recorded audio files had a lot of ticks and distortions in them (sounded like they were in a fish tank).  I thought it was their audio files so I playing some of the standard audio files included with asterisk and got the same result.  To rule out the possibility it was the version of asterisk, I loaded the same asterisk code onto a Dell 750 server (Pentium 4 3 GHz hyperthreading, but not EMT64 chip) running CentOS 4 and tried listening to the same audio files.  The audio files played cleanly on this server.

To ensure it wasn't a hardware problem, I tried it on another identical Dell 850 server.  Both 850 servers produced the same results.  On either server, you can hear pops in the background on either self recorded or standard asterisk sound files.  
Comments:By: Clod Patry (junky) 2006-04-23 14:18:37

Still an issue here?


By: Shawn Lawrence (radar) 2006-04-24 11:08:41

Far as I know, it still is.  I will get the latest stable branch code and retest to be sure.

By: Matt O'Gorman (mogorman) 2006-04-24 11:30:08

radar this problem does not sound like a bug, as many people are running succesfully with your setup and it sounds very odd.  Anyways can you please provide more information, like how you are playing this audio back from what channels etc so that we can try to solve your problem.


By: Jared Smith (jsmith) 2006-04-24 11:32:06

Can you please give us more details, such as:

How are the prompts being played?
Are these VoIP calls, PSTN calls, etc?
Are there any relevant errors or warnings in the log files or on the Asterisk console?
If you have any Digium cards installed, are they sharing interrupts with any other hardware on the machine?

By: Shawn Lawrence (radar) 2006-05-10 21:37:19

Answers to questions:

1. The calls come in from a Quintum CMS gateway over SIP to Asterisk.
2. The calls are professionally recorded wav files by Allison (the infamous voice of Asterisk) converted to GSM format using community suggested conversion options.
3. There are no warnings/errors on the console and no indication of problems in the SIP debug messages (when turned on)

By: Joshua C. Colp (jcolp) 2006-05-19 09:15:32

The question about having zaptel hardware is still valid though - do you have a timing source (be it hardware OR ztdummy?)

By: Serge Vecher (serge-v) 2006-05-26 09:55:24

Radar: if this is still an issue in and you have some answers regarding your hardware setup as requested by joshnet, please feel free to reopen the bug.