[PARTIALLY RESOLVED] Audio quality in MeetMe with ztdummy

Asterisk Asterisk Support
1

I am having problems with MeetMe conferencing, where the audio is continuously stuttering. The prompts and recorded names are perfect, but the audio of others talking in the conference sounds like every other 20ms frame is being replaced by silence. (This is hard to describe, and the problem may not have anything to do with frames missing.)

I am using ztdummy on a Debian Linux server with kernel 2.6.8. I have tried compiling ztdummy in USE_RTC mode, but the problem is the same.

zttest reports something 99.95% accuracy, which I know is a bit on the low side, but I believe getting this wrong affects the delay between speaking and being heard rather than audio quality itself.

Best: 99.963379 – Worst: 99.938965 – Average: 99.952958

I have also tried this with a Digium card, and conferencing did work properly. Unfortunately that card stopped all the other PCI cards working so I have resorted to using analog->IP adaptors on the phone lines.

I am not aware of any other problems with the installation.

What should I be looking at next?

Thanks,

Ben

2

I am having a similar problem, I see this in my verbose CLI:

[quote=“CLI”]Jan 17 08:14:24 WARNING[13936]: channel.c:2530 ast_request: No channel type registered for 'zap’
Jan 17 08:14:24 WARNING[13936]: app_meetme.c:458 build_conf: Unable to open pseudo channel - trying device[/quote]

Even though I have compiled (make linux26) and loaded the modules:

[quote=“lsmod”]ztdummy 3848 0
zaptel 187268 3 ztdummy[/quote]

And made the changes to UDEV per the /usr/src/zaptel/README.udev:

[quote="/etc/udev/rules.d/50-udev.rules"]# Section for zaptel device
KERNEL=“zapctl”, NAME="zap/ctl"
KERNEL=“zaptimer”, NAME="zap/timer"
KERNEL=“zapchannel”, NAME="zap/channel"
KERNEL=“zappseudo”, NAME="zap/pseudo"
KERNEL=“ztdummy”, NAME="zap/ztdummy"
KERNEL=“zap[0-9]*”, NAME=“zap/%n”[/quote]

Are you seeing the same thing in your log? In my case, while I get the error it still works, but one call gets good audio and the other complete stutter.

Also, MeetMe worked fine under SuSE v9.3, and this problem has only cropped up after moving to SuSE v10.0, and v1.2.1 of Asterisk.

3

[quote=“MuppetMaster”]I am having a similar problem, I see this in my verbose CLI:

[quote=“CLI”]Jan 17 08:14:24 WARNING[13936]: channel.c:2530 ast_request: No channel type registered for ‘zap’
Jan 17 08:14:24 WARNING[13936]: app_meetme.c:458 build_conf: Unable to open pseudo channel - trying device[/quote]

Even though I have compiled (make linux26) and loaded the modules:

[quote=“lsmod”]ztdummy 3848 0
zaptel 187268 3 ztdummy[/quote]

And made the changes to UDEV per the /usr/src/zaptel/README.udev:

[quote=“/etc/udev/rules.d/50-udev.rules”]# Section for zaptel device
KERNEL=“zapctl”, NAME=“zap/ctl”
KERNEL=“zaptimer”, NAME=“zap/timer”
KERNEL=“zapchannel”, NAME=“zap/channel”
KERNEL=“zappseudo”, NAME=“zap/pseudo”
KERNEL=“ztdummy”, NAME=“zap/ztdummy”
KERNEL=“zap[0-9]*”, NAME=“zap/%n”[/quote]

Are you seeing the same thing in your log? In my case, while I get the error it still works, but one call gets good audio and the other complete stutter.[/quote]

I do not see this is my log, even after “set verbose 10”. And both the calls have bad audio.

I couldn’t get anything to work with SuSE 10, and eventually found that Debian 3.1 was the way to go. However, I am not a Linux person at all (more comfortable with *BSD) and was also trying to get an ADSL card going.

4

try this post as far as fixing the audio quality:

forums.digium.com/viewtopic.php? … highlight=

5

[quote=“gtcleaves”]try this post as far as fixing the audio quality:

forums.digium.com/viewtopic.php? … highlight=[/quote]

This would be if you are running an older version and want to patch with meetme.c that is in v1.2, correct?

6

[quote=“gtcleaves”]try this post as far as fixing the audio quality:

forums.digium.com/viewtopic.php? … highlight=[/quote]

That has done the trick, voice quality is fine now. Many thanks for your help.

7

[quote=“MuppetMaster”][quote=“gtcleaves”]try this post as far as fixing the audio quality:

forums.digium.com/viewtopic.php? … highlight=[/quote]

This would be if you are running an older version and want to patch with meetme.c that is in v1.2, correct?[/quote]

no, i think you’d do this to patch 1.2 and 1.2.1. The older versions didn’t actually have the garbled sound problem.

8

[quote=“gtcleaves”][quote=“MuppetMaster”][quote=“gtcleaves”]try this post as far as fixing the audio quality:

forums.digium.com/viewtopic.php? … highlight=[/quote]

This would be if you are running an older version and want to patch with meetme.c that is in v1.2, correct?[/quote]

no, i think you’d do this to patch 1.2 and 1.2.1. The older versions didn’t actually have the garbled sound problem.[/quote]

I see, that may explain why I did not have this problem on earlier versions of SuSE/Asterisk. I am going to give it a try and see if it does not do something about these warning messages either. Thanks!

9

With that patch my problem persists:

[quote=“CLI”]Jan 17 16:03:47 WARNING[23478]: channel.c:2530 ast_request: No channel type registered for 'zap’
Jan 17 16:03:47 WARNING[23478]: app_meetme.c:458 build_conf: Unable to open pseudo channel - trying device[/quote]

10

[quote=“MuppetMaster”]With that patch my problem persists:

[quote=“CLI”]Jan 17 16:03:47 WARNING[23478]: channel.c:2530 ast_request: No channel type registered for 'zap’
Jan 17 16:03:47 WARNING[23478]: app_meetme.c:458 build_conf: Unable to open pseudo channel - trying device[/quote][/quote]

With v1.2.2 the problem persists. Hmmm…

11

is this fixed in 1.2.3 or does a patch still need to be applied?

12

I am running 1.2.4 on a 32-bit system but am experiencing the same problem with audio choppiness. Is the version from CVS going to fix this?

13

I was able to get Asterisk 1.2.4 to run MeetMe with ztdummy so I don’t think the replacement file is necessary now that the new version is out.